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Diphenyl

Diphenyl is a chemical compound consisting of two benzene rings joined by a single carbon-carbon bond.
It is a colorless, crystalline solid with a characteristic aromatic odor.
Diphenyl is used in various industrial applications, such as the production of polychlorinated biphenyls (PCBs), heat transfer fluids, and as a chemical intermediate.
The compound has been studied for its potential biological and pharmacological properties, including its effects on the central nervous system and possible antioxidant activities.
Researchers can utilize PubCompare.ai's AI-powered platform to effortelessly locate and compare diphenyl research protocols from literature, pre-prints, and patents, ensuring they find the most accurate and reproducible methods to unlock their research potential.

Most cited protocols related to «Diphenyl»

1
Comprehensive Antioxidant and Enzyme Inhibitory Assays
Cited 78 times
Antioxidant (DPPH and ABTS radical scavenging, reducing power (CUPRAC and FRAP), phosphomolybdenum, and metal chelating (ferrozine method)) and enzyme inhibitory activities [cholinesterase (ChE) Elmann’s method], tyrosinase (dopachrome method), α-amylase (iodine/potassium iodide method), and α -glucosidase (chromogenic PNPG method)) were determined using the methods previously described by Zengin et al. (2014) (link) and Dezsi et al. (2015) (link).
For the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging assay: Sample solution (1 mg/mL; 1 mL) was added to 4 mL of a 0.004% methanol solution of DPPH. The sample absorbance was read at 517 nm after a 30 min incubation at room temperature in the dark. DPPH radical scavenging activity was expressed as millimoles of trolox equivalents (mg TE/g extract).
For ABTS (2,2′-azino-bis(3-ethylbenzothiazoline) 6-sulfonic acid) radical scavenging assay: Briefly, ABTS+ was produced directly by reacting 7 mM ABTS solution with 2.45 mM potassium persulfate and allowing the mixture to stand for 12–16 in the dark at room temperature. Prior to beginning the assay, ABTS solution was diluted with methanol to an absorbance of 0.700 ± 0.02 at 734 nm. Sample solution (1 mg/mL; 1 mL) was added to ABTS solution (2 mL) and mixed. The sample absorbance was read at 734 nm after a 30 min incubation at room temperature. The ABTS radical scavenging activity was expressed as millimoles of trolox equivalents (mmol TE/g extract) (Mocan et al., 2016a (link)).
For CUPRAC (cupric ion reducing activity) activity assay: Sample solution (1 mg/mL; 0.5 mL) was added to premixed reaction mixture containing CuCl2 (1 mL, 10 mM), neocuproine (1 mL, 7.5 mM) and NH4Ac buffer (1 mL, 1 M, pH 7.0). Similarly, a blank was prepared by adding sample solution (0.5 mL) to premixed reaction mixture (3 mL) without CuCl2. Then, the sample and blank absorbances were read at 450 nm after a 30 min incubation at room temperature. The absorbance of the blank was subtracted from that of the sample. CUPRAC activity was expressed as milligrams of trolox equivalents (mg TE/g extract).
For FRAP (ferric reducing antioxidant power) activity assay: Sample solution (1 mg/mL; 0.1 mL) was added to premixed FRAP reagent (2 mL) containing acetate buffer (0.3 M, pH 3.6), 2,4,6-tris(2-pyridyl)-S-triazine (TPTZ) (10 mM) in 40 mM HCl and ferric chloride (20 mM) in a ratio of 10:1:1 (v/v/v). Then, the sample absorbance was read at 593 nm after a 30 min incubation at room temperature. FRAP activity was expressed as milligrams of trolox equivalents (mg TE/g extract).
For phosphomolybdenum method: Sample solution (1 mg/mL; 0.3 mL) was combined with 3 mL of reagent solution (0.6 M sulfuric acid, 28 mM sodium phosphate and 4 mM ammonium molybdate). The sample absorbance was read at 695 nm after a 90 min incubation at 95°C. The total antioxidant capacity was expressed as millimoles of trolox equivalents (mmol TE/g extract) (Mocan et al., 2016c (link)).
For metal chelating activity assay: Briefly, sample solution (1 mg/mL; 2 mL) was added to FeCl2 solution (0.05 mL, 2 mM). The reaction was initiated by the addition of 5 mM ferrozine (0.2 mL). Similarly, a blank was prepared by adding sample solution (2 mL) to FeCl2 solution (0.05 mL, 2 mM) and water (0.2 mL) without ferrozine. Then, the sample and blank absorbances were read at 562 nm after 10 min incubation at room temperature. The absorbance of the blank was sub-tracted from that of the sample. The metal chelating activity was expressed as milligrams of EDTA (disodium edetate) equivalents (mg EDTAE/g extract).
For ChE inhibitory activity assay: Sample solution (1 mg/mL; 50 μL) was mixed with DTNB (5,5-dithio-bis(2-nitrobenzoic) acid, Sigma, St. Louis, MO, United States) (125 μL) and AChE [acetylcholines-terase (Electric ell AChE, Type-VI-S, EC 3.1.1.7, Sigma)], or BChE [BChE (horse serum BChE, EC 3.1.1.8, Sigma)] solution (25 μL) in Tris–HCl buffer (pH 8.0) in a 96-well microplate and incubated for 15 min at 25°C. The reaction was then initiated with the addition of acetylthiocholine iodide (ATCI, Sigma) or butyrylthiocholine chloride (BTCl, Sigma) (25 μL). Similarly, a blank was prepared by adding sample solution to all reaction reagents without enzyme (AChE or BChE) solution. The sample and blank absorbances were read at 405 nm after 10 min incubation at 25°C. The absorbance of the blank was subtracted from that of the sample and the cholinesterase inhibitory activity was expressed as galanthamine equivalents (mgGALAE/g extract) (Mocan et al., 2016b (link)).
For Tyrosinase inhibitory activity assay: Sample solution (1 mg/mL; 25 μL) was mixed with tyrosinase solution (40 μL, Sigma) and phosphate buffer (100 μL, pH 6.8) in a 96-well microplate and incubated for 15 min at 25°C. The reaction was then initiated with the addition of L-DOPA (40 μL, Sigma). Similarly, a blank was prepared by adding sample solution to all reaction reagents without enzyme (tyrosinase) solution. The sample and blank absorbances were read at 492 nm after a 10 min incubation at 25°C. The absorbance of the blank was subtracted from that of the sample and the tyrosinase inhibitory activity was expressed as kojic acid equivalents (mgKAE/g extract) (Mocan et al., 2017 (link)).
For α-amylase inhibitory activity assay: Sample solution (1 mg/mL; 25 μL) was mixed with α-amylase solution (ex-porcine pancreas, EC 3.2.1.1, Sigma) (50 μL) in phosphate buffer (pH 6.9 with 6 mM sodium chloride) in a 96-well microplate and incubated for 10 min at 37°C. After pre-incubation, the reaction was initiated with the addition of starch solution (50 μL, 0.05%). Similarly, a blank was prepared by adding sample solution to all reaction reagents without enzyme (α-amylase) solution. The reaction mixture was incubated 10 min at 37°C. The reaction was then stopped with the addition of HCl (25 μL, 1 M). This was followed by addition of the iodine-potassium iodide solution (100 μL). The sample and blank absorbances were read at 630 nm. The absorbance of the blank was subtracted from that of the sample and the α-amylase inhibitory activity was expressed as acarbose equivalents (mmol ACE/g extract) (Savran et al., 2016 (link)).
For α-glucosidase inhibitory activity assay: Sample solution (1 mg/mL; 50 μL) was mixed with glutathione (50 μL), α-glucosidase solution (from Saccharomyces cerevisiae, EC 3.2.1.20, Sigma) (50 μL) in phosphate buffer (pH 6.8) and PNPG (4-N-trophenyl-α-D-glucopyranoside, Sigma) (50 μL) in a 96-well microplate and incubated for 15 min at 37°C. Similarly, a blank was prepared by adding sample solution to all reaction reagents without enzyme (α-glucosidase) solution. The reaction was then stopped with the addition of sodium carbonate (50 μL, 0.2 M). The sample and blank absorbances were read at 400 nm. The absorbance of the blank was subtracted from that of the sample and the α-glucosidase inhibitory activity was expressed as acarbose equivalents (mmol ACE/g extract) (Llorent-Martínez et al., 2016 (link)).
All the assays were carried out in triplicate. The results are expressed as mean values and standard deviation (SD). The differences between the different extracts were analyzed using one-way analysis of variance (ANOVA) followed by Tukey’s honestly significant difference post hoc test with α = 0.05. This treatment was carried out using SPSS v. 14.0 program.
Uysal S., Zengin G., Locatelli M., Bahadori M.B., Mocan A., Bellagamba G., De Luca E., Mollica A, & Aktumsek A. (2017). Cytotoxic and Enzyme Inhibitory Potential of Two Potentilla species (P. speciosa L. and P. reptans Willd.) and Their Chemical Composition. Frontiers in Pharmacology, 8, 290.
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Publication 2017
2
Collection and Characterization of Nanoparticulate Matter
Cited 36 times
nPM collection and transfer into aqueous suspension. We collected nPM with a high-volume ultrafine particle (HVUP) sampler (Misra et al. 2002 ) at 400 L/min flow in Los Angeles City near the CA-110 Freeway. These aerosols represent a mix of fresh ambient PM mostly from vehicular traffic nearby this freeway (Ning et al. 2007 (link)). The HVUP sampler consists of an ultrafine particle slit impactor, followed by an after-filter holder. The nPM (diameter < 200 nm) was collected on pretreated Teflon filters (20 × 25.4 cm, polytetrafluoroethylene, 2 μm pore; Pall Life Sciences, Covina, CA). We transferred the collected nPM into aqueous suspension by 30 min soaking of nPM-loaded filters in Milli-Q deionized water (resistivity, 18.2 MW; total organic compounds < 10 ppb; particle free; bacteria levels < 1 endotoxin units/mL; endotoxin-free glass vials), followed by vortexing (5 min) and sonication (30 min). As a control for in vitro experiments with resuspended nPM, fresh sterile filters were sham extracted. Aqueous nPM suspensions were pooled and frozen as a stock at –20°C, which retains chemical stability for ≥ 3 months (Li N et al. 2003; Li R et al. 2009). For in vitro experiments, nPM suspensions were diluted in culture medium, vortexed, and added directly to cultures.
Animals and exposure conditions. The nPM suspensions were reaerosolized by a VORTRAN nebulizer (Vortran Medical Technology 1 Inc., Sacramento, CA) using compressed particle-free filtered air [see Supplemental Material, Figure S1 (doi:10.​1289/ehp.1002973)]. Particles were diffusion dried by passing through silica gel; static charges were removed by passing over polonium-210 neutralizers. Particle sizes and concentrations were continuously monitored during exposure at 0.3 L/min by a scanning mobility particle sizer (SMPS model 3080; TSI Inc., Shoreview, MN). The nPM mass concentration was determined by pre- and postweighing the filters under controlled temperature and relative humidity. Inorganic ions [ammonium (NH4+), nitrate (NO3–), sulfate (SO42–)] were analyzed by ion chromatography. PM-bound metals and trace elements were assayed by magnetic-sector inductively coupled plasma mass spectroscopy. Water-soluble organic carbon was assayed by a GE-Sievers liquid analyzer (GE-Sievers, Boulder, CO). Analytic details for nPM-bound species are given by Li R et al. (2009). Samples of the reaerosolized nPM were collected on parallel Teflon filters for electron paramagnetic resonance (EPR) analysis.
Mice (C57BL/6J males, 3 months of age) were maintained under standard conditions with ad libitum Purina Lab Chow (Newco Purina, Rancho Cucamonga, CA) and sterile water. Just before nPM exposure, mice were transferred from home cages to exposure chambers that allowed free movement. Temperature and airflow were controlled for adequate ventilation and to minimize buildup of animal-generated contaminants [skin dander, carbon dioxide (CO2), ammonia]. Reaerosolized nPM or ambient air (control) was delivered to the sealed exposure chambers for 5 hr/day, 3 days/week, for 10 weeks. Mice did not lose weight or show signs of respiratory distress. Mice were euthanized after isoflurane anesthesia, and tissue was collected and stored at –80°C. All rodents were treated humanely and with regard for alleviation of suffering; all procedures were approved by the University of Southern California Institutional Animal Care and Use Committee.
EPR spectroscopy of nPM. The reaerosolized nPM was collected on filters (described above), which were inserted directly in the EPR quartz tube (Bruker EPR spectrometer; Bruker, Rheinstetten, Germany); spectra were measured at 22°C. The g-value was determined following calibration of the EPR instrument using DPPH (2,2-diphenyl-1-picrylhydrazyl) as a standard. The EPR signal for DPPH was measured and the corresponding g-value was calculated. The difference from the known g-value of 2.0036 for DPPH was then used to adjust the observed g-value for the sample.
Cell culture and nPM exposure. Hippocampal slices from postnatal day 10–12 rats were cultured 2 weeks in a humidified incubator (35°C/5% CO2) (Jourdi et al. 2005 (link)) with nPM suspensions added for 24–72 hr of exposure. Primary neurons from embryonic day 18 rat cerebral cortex were plated at 20,000 neurons/cm2 on cover slips coated with poly-d-lysine/laminin and cultured in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with B27, at 37°C in 5% CO2 atmosphere (Rozovsky et al. 2005 (link)). Primary glial cultures from cerebral cortex of neonatal day 3 rats (F344) were plated at 200,000 cells/cm2 in DMEM/F12 medium supplemented with 10% fetal bovine serum and 1% l-glutamine and incubated as described above (Rozovsky et al. 1998 (link)). For conditioned medium experiments, glial cultures were treated with 10 mg nPM/mL; after 24 hr, media were transferred by pipette to neuron cultures.
Neurite outgrowth and toxicity assays. After treatments, neurons were fixed in 4% paraformaldehyde and immunostained with anti–β-III-tubulin (1:1,000, rabbit; Sigma Chemical Co., St. Louis, MO); F-actin was stained by rhodamine phalloidin (1:40; Molecular Probes, Carlsbad, CA). A neurite was defined as a process extending from the cell soma of the neuron that was immunopositive for both β-III-tubulin (green) and F-actin (red). The length of neurites was measured using NeuronJ software (Meijering et al. 2004 (link)). Growth cones were defined by the presence of actin-rich filopodia and lamellipodia (Kapfhammer et al. 2007 ). Collapsed growth cones were defined as actin-rich neuritic endings in which filopodia and lamellipodia were indistinguishable. In neurite outgrowth and growth cone collapse assays, individual neurons were selected from two cover slips per condition; n is the total number of neurons analyzed per treatment. Cytotoxicity in slice cultures was assayed by lactate dehydrogenase (LDH) release to media and by cellular uptake of propidium iodide (PI) (Jourdi et al. 2005 (link)). Neuronal viability was assayed by Live/Dead Cytotoxicity Kit (Invitrogen, Carlsbad, CA) by computer-assisted image analysis of fluorescent images. Mitochondrial reductase was assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) at 585 nm in undifferentiated PC12 cells (Mosmann 1983 (link)). For viability assays, n is the total number of hippocampal slices analyzed (LDH release and PI uptake) or the total number of cell culture wells analyzed per condition.
Immunoblotting. Mouse hippocampi were homogenized using a glass homogenizer in cold lysis buffer as described by Jourdi et al. (2005) (link). After sample preparation, 20 μg protein was electrophoresed on 10% sodium dodecyl sulfate polyacrylamide gels, followed by transfer to polyvinylidene fluoride (PVDF) membranes. The PVDF membranes were blocked with 5% bovine serum albumin for 1 hr and probed with primary antibodies overnight at 4°C: anti-GluA1 (glutamate receptor subunit 1; 1:3,000, rabbit; Abcam, Cambridge, MA), anti-GluA2 (1:2,000, rabbit; Millipore, Billerica, MA), anti-PSD95 (1:1,000, mouse; Abcam), anti-synaptophysin (1:5,000, mouse; Stressgene; Enzo, Plymouth Meeting, PA), and anti-β-III tubulin (loading control; 1:15,000, rabbit; Sigma), followed by incubation with secondary antibodies (1:10,000) conjugated with IRDye 680 (rabbit, LI-COR Biosciences, Lincoln, NE) and IRDye 800 (mouse, LI-COR). Immunofluorescence was detected by infrared imaging (Odyssey, LI-COR).
Quantitative polymerase chain reaction (qPCR). Total cellular RNA was extracted from cerebral cortex of nPM-exposed mice and rat primary glia (Tri Reagent; Sigma), and cDNA (2 μg RNA; Superscript III kit; Invitrogen) was analyzed by qPCR, with primers appropriate for mouse (in vivo) or rat (in vitro). Genes examined by qPCR were CD14, CD68, CD11b, CD11c, GFAP (glial fibrillary acidic protein), IFN-γ (interferon-γ), IL-1α, IL-1, IL-6, and TNFα. Data were normalized to β-actin.
Statistical analysis. Data are expressed as mean ± SE. The numbers of individual measurements (n) are described above and listed in the figure legends. Single and multiple comparisons used Student’s t-test (unpaired) and one-way analysis of variance (ANOVA)/Tukey’s honestly significant difference, with statistical significance defined as p < 0.05.
Morgan T.E., Davis D.A., Iwata N., Tanner J.A., Snyder D., Ning Z., Kam W., Hsu Y.T., Winkler J.W., Chen J.C., Petasis N.A., Baudry M., Sioutas C, & Finch C.E. (2011). Glutamatergic Neurons in Rodent Models Respond to Nanoscale Particulate Urban Air Pollutants in Vivo and in Vitro. Environmental Health Perspectives, 119(7), 1003-1009.
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Publication 2011
3
Antioxidant Activity of F. religiosa Leaf Extract
Cited 26 times
The free RSA of the dilute leaf extract of F. religiosa was tested using a 1,1-diphenyl-2-picryl hydrazyl (DPPH) technique. A total of 24 milligrams of DPPH were dissolved in 100 mL of methanol for making the stock solution. Filtration of DPPH stock solution using methanol yielded a usable mixture with an absorbance of around 0.973 at 517 nm. In a test tube, 3 mL DPPH workable solutions were combined with 100 µL of leaf extract. Three milliliters of solution containing DPPH in 100 µL of methanol is often given as a standard. After that, the tubes were kept in complete darkness for 30 min. The absorbance was therefore determined at 517 nm. The following formula was used to compute the percentage of antioxidants or RSA [19 (link)]:
where: Ac—Control reaction absorbance; As—Testing specimen absorbance.
Baliyan S., Mukherjee R., Priyadarshini A., Vibhuti A., Gupta A., Pandey R.P, & Chang C.M. (2022). Determination of Antioxidants by DPPH Radical Scavenging Activity and Quantitative Phytochemical Analysis of Ficus religiosa. Molecules, 27(4), 1326.
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Publication 2022
Antioxidants Darkness diphenyl Filtration Methanol Plant Leaves Technique, Dilution
4
Prenatal and Postnatal Pesticide Exposure and Children's Cognitive Development
Cited 26 times
Study setting and design. The CHAMACOS study is a community/university partnership. We conducted this longitudinal birth cohort study of predominantly Mexican-American low-income families living in the Salinas Valley, California. This agricultural region is located southeast of the San Francisco Bay Area. Common crops include lettuce, strawberries, artichokes, broccoli, and grapes. About 235,000 kg of OP pesticides were used in this region in 1999–2000, when study participants were pregnant (CDPR 2001). Current data show that use of OP pesticides in California is decreasing overall; however, use of OP pesticides in Monterey County remained steady between 2001 and 2008 but declined 18% from 2008 to 2009 (CDPR 2010).
Detailed methods for the CHAMACOS study have been described elsewhere (Eskenazi et al. 2004 (link), 2006 (link)). Briefly, pregnant women were recruited in six community clinics, serving primarily farmworker families, between October 1999 and 2000. Eligible women were ≥ 18 years old, < 20 weeks of gestation, Spanish or English speaking, eligible for low-income health insurance, and planning to deliver at the local public hospital. All study activities were approved by the University of California–Berkeley Committee for the Protection of Human Subjects. Written, informed consent was obtained from the mothers, and child assent was obtained at 7 years of age.
The initial cohort included 601 women who delivered 526 live-born surviving singletons. For the present study, we excluded two children with missing prenatal DAP concentration measurements, four children with a medical condition that would affect assessment (autism, Down syndrome, hydrocephalus, deafness), children who were lost to follow-up and/or did not participate at the 7-year study visit (n = 72 moved, n = 59 refused, n = 24 unable to trace, n = 21 unable to schedule, n = 2 deceased), and children missing the cognitive assessment at the 7-year visit (n = 13). Families included in this analysis (n = 329) did not differ significantly from the original full cohort on most attributes, including urinary DAP concentrations during pregnancy, maternal measures of cognitive ability, maternal education, marital status, poverty category, and child’s birth weight. However, mothers of children included in the present study were slightly older (mean age, 26.7 vs. 26.0 years, p = 0.07) and breast-fed longer (8.7 months vs. 7.2, p = 0.01) than those from the initial cohort.
Cognitive assessment. We used the Wechsler Intelligence Scale for Children, 4th edition (WISC-IV), to assess cognitive abilities at the 7-year study visit (Wechsler 2003 ). All assessments were completed by a single experienced bilingual psychometrician, who was trained and supervised by a pediatric neuropsychologist. Quality assurance measures included review of videotaped assessments. For subtests in which a ceiling was not achieved (< 10%), missing values were imputed based on scores obtained by other children with similar score patterns. Scores for four domains were calculated based on the following subtests: Verbal Comprehension (composed of the Vocabulary and Similarities subtests), Perceptual Reasoning (Block Design and Matrix Reasoning subtests), Working Memory (Digit Span and Letter-Number Sequencing subtests), and Processing Speed (Coding and Symbol Search subtests). All subtests were administered in the dominant language of the child, which was determined through administration of the oral vocabulary subtest of the Woodcock–Johnson/Woodcock–Muñoz Tests of Cognitive Ability in both English and Spanish (Woodcock and Johnson 1990 ). Ultimately, 67% of children were tested in Spanish and 33% in English. WISC-IV scores are standardized against U.S. population–based norms for English- and Spanish-speaking children.
The numbers of children with available scores were 329 for Perceptual Reasoning and Verbal Comprehension and 298 for Processing Speed and Working Memory (because we did not administer letter-number sequencing and symbol search for the first 3 months of assessments). A Full-Scale intelligence quotient (IQ) was available for 297 children.
Maternal interviews and assessments. Women were interviewed twice during pregnancy (median gestation, 13 and 26 weeks), after delivery, and when children were 6 months and 1, 2, 3.5, 5, and 7 years of age. Interviews were conducted in Spanish or English by bilingual, bicultural interviewers. At the 6-month visit, mothers were administered the Peabody Picture Vocabulary Test (PPVT) to assess verbal intelligence (Dunn and Dunn 1981 ). The Infant-Toddler HOME (Home Observation for Measurement of the Environment) inventory was completed at 6 months and 1 and 2 years of age, and a short version was completed at 3.5 and 5 years (Caldwell and Bradley 1984 ). Additional information was obtained from prenatal and delivery medical records, which was abstracted by a registered nurse.
Urinary OP metabolite measurements. Urine was collected at two time points during pregnancy. The first urine sample was collected at enrollment into the study, between 5 and 27 weeks of gestation (median, 13 weeks). The second urine sample was collected between 18 and 39 weeks (median, 26 weeks). Urine was collected from the children at 6 months and 1, 2, 3.5, and 5 years of age; no urine was collected at the 7-year visit.
Urine specimens were aliquoted and stored at −80°C until shipment on dry ice to the Centers for Disease Control and Prevention (CDC; Atlanta, GA) for analysis. Six nonspecific OP DAP metabolites were measured in maternal and child urine: three dimethyl (DM) phosphate metabolites (dimethylphosphate, dimethylthiophosphate, dimethyldithiophosphate) and three diethyl (DE) phosphate metabolites (diethylphosphate, diethylthiophosphate, and diethyldithiophosphate). These six metabolites cannot be traced back to individual pesticides but together represent the breakdown products of about 80% of the total OP pesticides used in the Salinas Valley (CDC 2009 ). The most commonly used OP pesticides in the Salinas Valley are chlorpyrifos and diazinon (which devolve to DE), as well as malathion and oxydemeton-methyl (which devolve to DM). DAP metabolite concentrations were measured using gas chromatography/tandem mass spectrometry and quantified using isotope dilution calibration (Bravo et al. 2002 (link)). Details of urine collection, analysis, detection frequencies, and quality control procedures are described elsewhere (Bradman et al. 2005 (link)). Concentrations below the limit of detection (LOD) were randomly imputed based on a log-normal probability distribution whose parameters were estimated using maximum likelihood estimation. This method has been shown to perform better than simple substitution methods such as LOD/2 or LOD/√–2 (Lubin et al. 2004 (link)). The DAP metabolite concentrations were expressed on a molar basis and summed to yield total DE, DM, and DAP concentrations.
Other environmental contaminants. We also considered the potential confounding effects of other known or suspected neurotoxicants: polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), p,p´-dichlorodiphenyltrichloroethane (DDT), p,p´-dichlorodiphenyldichloroethylene (DDE), and lead. Lead was measured in maternal blood at 26 weeks of gestation, in cord blood for a subset of the participants by the California Department of Public Health (Richmond, CA, USA), and in children’s blood at 2 years of age by the Monterey County Public Health Laboratory (Salinas, CA, USA), using graphite furnace atomic absorption spectrophotometry. PBDEs, PCBs, DDT, and DDE were measured by the CDC (Atlanta, GA) in maternal serum samples collected at 26 weeks of gestation, on average, using gas chromatography/isotope-dilution high-resolution mass spectrometry and were expressed on a serum lipid basis. Total lipids were determined based on the measurement of triglyceride and total cholesterol in serum using standard enzymatic methods (Roche Chemicals, Indianapolis, IN) (Phillips et al. 1989 (link)).
Data analysis. Nonspecific total DAP, DE, and DM metabolites (nanomoles per liter) were transformed to the log10 scale. All analyses were conducted on non-creatinine-adjusted values; models were rerun with creatinine-adjusted values (nanomoles per gram of creatinine) in sensitivity analyses. We examined the association between urinary DAP concentrations and cognitive scores using multiple linear regression, with point estimates representing the change in cognitive scores for each 10-fold increase in DAP concentrations. For prenatal exposure, we examined associations with the DAP concentrations measured separately for urine collected during the first and second half of pregnancy (≤ 20 vs. > 20 weeks of gestation). Because we found similar relations between cognitive scores and DAPs measured earlier or later than 20 weeks of gestation, we averaged the two DAP measures for further analyses; for 20 children (6%) only one prenatal measure was available for the analyses. Because DM and DE metabolites might have different relationships to the outcomes, they were examined separately.
For postnatal exposure, we examined the cross-sectional association of cognitive scores with DAP concentrations measured in children’s urine collected at different ages in separate models. We also calculated the cumulative DAP level between 6 and 60 months using the area under the curve (AUC), calculated using the trapezoidal method. For 46 children with one missing DAP measurement at 1, 2, or 3.5 years, we imputed the mean of the two measures closest in time for the AUC calculation. Forty-nine children who were missing DAP measures at either the 6-month or 5-year visit, or missing more than one DAP measure from the three other time points, were excluded from the AUC analysis. For comparison with prenatal exposure, we calculated the mean urinary DAP concentrations measured during childhood for children with at least three of five measures (taken at 6 months and 1, 2, 3.5, and 5 years); this excluded 20 children.
To explore possible synergistic effects between pre- and postnatal DAP concentrations, we included an interaction term for mean prenatal DAP concentrations × AUC. However, this term was not statistically significant (p > 0.15) and thus was not included in the final models.
We retained the following variables as covariates for all analyses: maternal intellectual abilities (PPVT score, continuous), maternal education (three categories), and continuous HOME score at 6 months. Maternal intellectual abilities and HOME score were included in models because they were associated with both DAP concentrations and IQ scores in univariate analyses (p < 0.2), and maternal education was included because it is an important determinant of children’s cognitive development. Language of testing was also included in models for Verbal Comprehension and Full-Scale IQ because of observed language-related differences in scores for these scales. We conducted additional analyses to evaluate the confounding effect of other factors associated with neurodevelopment in the literature: breast-feeding duration (in weeks, continuous), maternal age (continuous), birth order (continuous), HOME score at 1, 2, 3.5, and 5 years (continuous), poverty category (coded as in Table 1), marital status (married or living as married/not married), children’s age at WISC-IV testing (in months, continuous), and maternal levels of PBDEs, PCBs, DDE, DDT, and lead during pregnancy. Each of these variables was added individually to the final model, but none was retained because none changed the magnitude of the coefficient for urinary DAP concentrations by > 10%. In separate analyses, we also investigated potential confounding and effect modification by variables possibly on the causal pathway (i.e., birth weight and gestational age, assessed continuously). Because most children (67%) were tested in Spanish, we reran the analyses restricted to this subset. Finally, we examined the interaction between sex and DAP concentrations, based on previous findings in this cohort (Marks et al. 2010 (link)).
We compared effect estimates for urinary DAPs measured in early versus late pregnancy and in the prenatal versus postnatal periods using seemingly unrelated estimation (Weesie 1999 ); we used the mean postnatal DAP concentrations (as opposed to AUC) for these analyses in order to compare metrics with similar units. We used generalized additive models with 3-degree-of-freedom cubic splines to evaluate the shape of dose–response curves, test the linearity assumption, and investigate potential thresholds while controlling for covariates. We did not observe evidence of departure from linearity or threshold for effect, so we retained the simpler models based on linear regression. For illustration, we grouped DAP concentrations into quintiles, entered this categorical variable in the multiple regression model with the same covariables described above, and obtained the mean IQ score for each quintile.
Univariate and multiple linear regression analyses were conducted with SPSS (version 19.0; IBM Corp., Somers, NY), and generalized additive model and seemingly unrelated estimation (“suest” command) were performed with STATA (version 10.1; StataCorp, College Station, TX).
Bouchard M.F., Chevrier J., Harley K.G., Kogut K., Vedar M., Calderon N., Trujillo C., Johnson C., Bradman A., Barr D.B, & Eskenazi B. (2011). Prenatal Exposure to Organophosphate Pesticides and IQ in 7-Year-Old Children. Environmental Health Perspectives, 119(8), 1189-1195.
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Publication 2011
5
Cytotoxicity Evaluation of Arrabidaea chica
Cited 23 times
Cytotoxicity was measured by MTT colorimetric assay, in accordance with [23 (link)]. Briefly, 100 μL of peritoneal macrophages (5 × 105 cells/well) were added to 96-well plates and incubated for 2 h, at 37 °C with 5 % CO2. After that, 100 μL of the crude ethanolic extracts or fractions of A. chica were added to the wells in serial concentrations (600 to 0.97 μL/mL). For each concentration a negative control was maintained. Dimethyl sulfoxide (DMSO) was used as a control drug in serial dilutions starting at 20 %. After 24 h of incubation, 5 μL of MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] was added to each well, then the plates were incubated again for 2–4 h under the same conditions. Later, they were centrifuged at 1500 xg and 200 μL of each well supernatant was discarded, before 100 μL of DMSO was added. Absorbance was measured in a spectrophotometer, at a wavelength of 540 nm. 50 % cellular cytotoxicity (CC50) was calculated using GraphPad Prism 5.
Cortez de Sá J., Almeida-Souza F., Mondêgo-Oliveira R., Oliveira I.D., Lamarck L., Magalhães I.D., Ataídes-Lima A.F., Ferreira H.D, & Abreu-Silva A.L. (2016). Leishmanicidal, cytotoxicity and wound healing potential of Arrabidaea chica Verlot. BMC Complementary and Alternative Medicine, 16, 1.
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Publication 2016
Biological Assay Bromides Cells Colorimetry Complex Extracts Cytotoxin diphenyl Ethanol Macrophages, Peritoneal prisma Sulfoxide, Dimethyl Technique, Dilution Tetrazolium Salts

Most recents protocols related to «Diphenyl»

1
DPPH Assay for Antioxidant Activity
Not available on PMC !
The 1,1-diphenyl-2-picryl hydrazyl (DPPH) assay was carried out to evaluate the free radical scavenging activity of the plant extract as described by Mishra et al. (2012) . This is based on the reduction of the stable DPPH free radical, which is deep violet in colour, to the yellowcoloured diphenyl-picryl hydrazine by antioxidants. Briefly, 1 ml the extract (0.2 -1mg/ml) in methanol was added to 4ml (0.004% w/v) methanol solution of DPPH. After 30mins the absorbance of the solution was measured at 517nm using a UV spectrophotometer which was compared with the corresponding percentage inhibition of standard ascorbic acid. The free radical scavenging activity (FRSA) was calculated using the formular: % scavenging = [Abs (control) -Abs (sample) /
Abs control] x 100.
Jada M.S., Stephen H., Zailani H.A., & Wurochekke A.U. (2024). Effect of Methanolic Extract of <i>Ficus trigonata</i> Leaves on Lipid Profile and Liver Function Indices in <i>Plasmodium berghei</i> Infected Mice. Caliphate Journal of Science and Technology, 6(1), 45-53.
Publication 2024
2
DPPH Scavenging Activity Assay
Free-radical-scavenging activity was determined in microplates through the diphenyl-1-picrylhydrazyl (DPPH) test (29). Samples (15.15 μL) were mixed with 303 μL of a methanol solution of DPPH (153 mM). The absorbance was measured at λ = 517 nm (Cary Varian). The absorbance of the DPPH radical, without the sample, constituted the basis. The amount of samples required to inhibit the activity of 1 mL of DPPH at 50% specified the IC50 (mg). The tests were performed in triplicate, and the results were expressed as the mean ± SD.
Fratianni F., Amato G., Ombra M.N., De Feo V., Nazzaro F, & De Giulio B. (2024). Chemical Characterization and Biological Properties of Leguminous Honey. Antioxidants, 13(4), 482.
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Publication 2024
3
Antioxidant Capacity Evaluation by DPPH Assay
The radical-scavenging activity was evaluated by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay. Each extract (50 µL) was diluted to 200 µL of DPPH methanol solution (100 mM) in a 96-well plate. The mixture was shaken vigorously and left in a dark place after 30 min. The absorbance was read at 515 nm using a UV-Vis spectrophotometer (SPECTROstarNano, BMG Labtech, Ortenberg, Germany). Trolox was used as a reference antioxidant standard and the results were expressed as mg Trolox Equivalent/100 g of fresh weight (mg TE/100 g FW). DPPH for all extracts was carried out in triplicate [8 (link)].
De Rosa T., Ponticelli M., Teta R., Carlucci V., Milella L., Esposito G, & Costantino V. (2024). Harnessing Cyanobacteria’s Bioactive Potential: A Sustainable Strategy for Antioxidant Production. Microorganisms, 12(1), 175.
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Publication 2024
4
Toxicological and Physicochemical Properties of 1,3-Diphenyl-1H-Pyrazole-4-Carbaldehydes and 4,5-Dihydrooxazoles
The toxicological and physicochemical properties of 1,3-diphenyl-1H-pyrazole-4-carbaldehydes 4a-j and (4S*, 5S*)-5-(1,3-diphenyl-1H-pyrazol-4-yl)-4-tosyl-4,5-dihydrooxazoles 6a-j were evaluated on the OSIRIS DataWarrior V.4.7.2 program (http://www.organicchemistry.org/prog/peo/ accessed on 2 February 2024) [39 (link)]. The drug-like and pharmacokinetic properties were assessed with the SwissADME server platform [40 (link)]. The physicochemical properties were analyzed based on Lipinski’s rules, considering Log P value, molecular weight, hydrogen bond donors, and hydrogen bond acceptors [65 (link)].
Tlapale-Lara N., López J., Gómez E., Villa-Tanaca L., Barrera E., Escalante C.H., Tamariz J., Delgado F., Andrade-Pavón D, & Gómez-García O. (2024). Synthesis, In Silico Study, and In Vitro Antifungal Activity of New 5-(1,3-Diphenyl-1H-Pyrazol-4-yl)-4-Tosyl-4,5-Dihydrooxazoles. International Journal of Molecular Sciences, 25(10), 5091.
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Publication 2024
5
Antioxidant Potential Evaluation via DPPH Assay
The 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity assay
followed the method of Lim et al. (2023) with slight modifications.31 (link) The positive control used is ascorbic acid (AA)
with a concentration ranging from 0 to 25 μg. In 1.5 mL microcentrifuge
tubes, 50 μL of the positive control or the extracts was allowed
to react with 1 mL of 0.1 mM DPPH in the dark for 30 min. The blank
set (negative control) is prepared by adding 1 mL of methanol instead
of DPPH into the 50 μL extract samples and positive control.
Absorbance of the reaction and blank sets was measured at 518 nm using
a UV–vis spectrophotometer microplate reader (TECAN, infinite
M200 PRO). The half-maximal effective concentration (EC50) is calculated from the linear regression equation of the DPPH scavenging
activity scatter plot against the sample concentration.
Lim M.W., Quan Tang Y., Aroua M.K, & Gew L.T. (2024). Glycerol Extraction of Bioactive Compounds from Thanaka (Hesperethusa crenulata) Bark through LCMS Profiling and Their Antioxidant Properties. ACS Omega, 9(12), 14388-14405.
Publication 2024

Top products related to «Diphenyl»

1
2 2 diphenyl 1 picrylhydrazyl (dpph) by Merck Group
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DPPH is a chemical compound used as a free radical scavenger in various analytical techniques. It is commonly used to assess the antioxidant activity of substances. The core function of DPPH is to serve as a stable free radical that can be reduced, resulting in a color change that can be measured spectrophotometrically.
2
Methyl thiazolyl tetrazolium (mtt) by Merck Group
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MTT is a colorimetric assay used to measure cell metabolic activity. It is a lab equipment product developed by Merck Group. MTT is a tetrazolium dye that is reduced by metabolically active cells, producing a colored formazan product that can be quantified spectrophotometrically.
3
Gallic acid by Merck Group
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Gallic acid is a naturally occurring organic compound that can be used as a laboratory reagent. It is a white to light tan crystalline solid with the chemical formula C6H2(OH)3COOH. Gallic acid is commonly used in various analytical and research applications.
4
Dimethyl sulfoxide (dmso) by Merck Group
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DMSO is a versatile organic solvent commonly used in laboratory settings. It has a high boiling point, low viscosity, and the ability to dissolve a wide range of polar and non-polar compounds. DMSO's core function is as a solvent, allowing for the effective dissolution and handling of various chemical substances during research and experimentation.
5
Quercetin by Merck Group
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Quercetin is a natural compound found in various plants, including fruits and vegetables. It is a type of flavonoid with antioxidant properties. Quercetin is often used as a reference standard in analytical procedures and research applications.
6
Fetal bovine serum (fbs) by Thermo Fisher Scientific
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Fetal Bovine Serum (FBS) is a cell culture supplement derived from the blood of bovine fetuses. FBS provides a source of proteins, growth factors, and other components that support the growth and maintenance of various cell types in in vitro cell culture applications.
7
Folin ciocalteu reagent by Merck Group
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The Folin-Ciocalteu reagent is a colorimetric reagent used for the quantitative determination of phenolic compounds. It is a mixture of phosphomolybdic and phosphotungstic acid complexes that undergo a color change when reduced by phenolic compounds.
8
Methanol by Merck Group
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Methanol is a clear, colorless, and flammable liquid that is widely used in various industrial and laboratory applications. It serves as a solvent, fuel, and chemical intermediate. Methanol has a simple chemical formula of CH3OH and a boiling point of 64.7°C. It is a versatile compound that is widely used in the production of other chemicals, as well as in the fuel industry.
9
Ascorbic acid by Merck Group
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Ascorbic acid is a chemical compound commonly known as Vitamin C. It is a water-soluble vitamin that plays a role in various physiological processes. As a laboratory product, ascorbic acid is used as a reducing agent, antioxidant, and pH regulator in various applications.
10
Trolox by Merck Group
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Trolox is a water-soluble vitamin E analog that functions as an antioxidant. It is commonly used in research applications as a reference standard for measuring antioxidant capacity.

More about "Diphenyl"

Diphenyl, also known as Biphenyl, is a versatile organic compound consisting of two benzene rings connected by a single carbon-carbon bond.
This colorless, crystalline solid has a distinctive aromatic odor and finds various industrial applications.
In the production of polychlorinated biphenyls (PCBs), diphenyl serves as a key chemical intermediate.
Additionally, it is utilized in heat transfer fluids and other industrial processes.
Researchers have explored the potential biological and pharmacological properties of diphenyl, including its effects on the central nervous system and possible antioxidant activities.
Techniques like DPPH (2,2-diphenyl-1-picrylhydrazyl) assays, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays, and Folin-Ciocalteu reagent tests have been employed to investigate the compound's antioxidant and free radical scavenging capabilities.
Solvents such as DMSO (Dimethyl sulfoxide) and methanol have been utilized in diphenyl research, while compounds like gallic acid, quercetin, and ascorbic acid (vitamin C) have been used as reference standards.
The FBS (Fetal Bovine Serum) is a common cell culture supplement that may be incorporated in diphenyl-related studies.
PubCompare.ai's AI-powered platform can assist researchers in effortlessly locating and comparing diphenyl research protocols from literature, preprints, and patents.
This ensures that they can find the most accurate and reproducible methods to unlock their research potential and advance the understanding of this versatile compound.