Gemini

Manufactured by Agilent Technologies

Sourced in United States

The Gemini is a high-performance liquid chromatography (HPLC) system designed for analytical and preparative applications. It provides reliable and precise separation and purification of complex samples. The Gemini features advanced automation, intuitive software, and robust hardware to deliver consistent and reproducible results.

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Lab products found in correlation

15 protocols using gemini

Synthesis and Characterization of 2(3H)-Furanone Derivative

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Melting points were measured in open capillary tubes on an electrothermal melting point apparatus and were uncorrected. The infrared spectra (ν, cm⁻¹) were recorded using the KBr wafer technique on a Fourier transform infrared Thermo Electron Nicolet iS10 spectrometer (Thermo Fisher Scientific Inc., Waltham, MA) at the Faculty of Science, Ain Shams University. The ¹H and ¹³C NMR spectra (δ, ppm) were measured on a Varian GEMINI (GEMINI, Manufacturing & Engineering Inc., Anaheim, CA, USA) at the Faculty of Science, Cairo University, with tetramethyl silane (TMS) as an internal standard in DMSO-d₆ as a solvent. The mass spectra were recorded on a direct probe controller inlet part to single quadrupole mass analyzer (Thermo Scientific GCMS MODEL (ISQ LT)) using the Thermo X-CALIBUR software at the Regional Center for Mycology and Biotechnology (RCMB), Al-Azhar University, Cairo, Egypt. Elemental analyses were performed on a PerkinElmer 2400 CHN elemental analyzer (PerkinElmer, Waltham, MA) at the Faculty of Science, Ain Shams University. Thin-layer chromatography (TLC) was run using TLC aluminum sheets silica gel F254 (Merck, Whitehouse Station, NJ). The 2(3H)-furanone derivative 1 and its corresponding acid hydrazide 2 were synthesized as previously reported.⁴³

Ramadan S.K., Abdel Haleem D.R., Abd-Rabboh H.S., Gad N.M., Abou-Elmagd W.S, & Haneen D.S. (2022). Synthesis, SAR studies, and insecticidal activities of certain N-heterocycles derived from 3-((2-chloroquinolin-3-yl)methylene)-5-phenylfuran-2(3H)-one against Culex pipiens L. larvae. RSC Advances, 12(22), 13628-13638.

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Characterization of Novel Organic Compounds

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Reagents were obtained from commercial suppliers and were used without further purifification. Melting points were determined in a Fischer Johns apparatus (Pittsburgh, PA, USA) and are uncorrected. NMR spectra were recorded on Varian System instrument (Palo Alto, CA, USA) at 400 MHz for ¹H- and 100 MHz for ¹³C- and a Varian Gemini at 200 MHz for ¹H- and 50 MHz for ¹³C-. The spectra were obtained in CDCl₃ solutions using TMS as an internal reference. ³¹P chemical shifts are reported relative to H₃PO₄ as an internal reference. High-resolution CI⁺ and FAB⁺ mass experiments were performed on a JEOL HRMStation JHRMS-700 (Akishima, Tokyo, Japan). The purifification of all compounds was carried out by column chromatography using (silica gel 230–400 mesh). The dichloromethane and acetonitrile were reflfluxed on phosphorous pentoxide and hexane with sodium and benzophenone. Formaldehyde (30%) was used for the reactions.

Salgado-Escobar O., Hernández-Guadarrama A., Romero-Estudillo I, & Linzaga-Elizalde I. (2019). Direct Synthesis of Phosphonates and α-Amino-phosphonates from 1,3-Benzoxazines. Molecules, 24(2), 294.

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Synthesis of Acyl Meldrum's Acids and Enaminones

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Commercially available reagents were purchased from Sigma Aldrich or Acros and used without further purification. Acyl Meldrum’s acids 9a–f and enaminones 10a–d were prepared according to literature procedures; 9a, 9b, 9c, 9f^{44 (link)}, 9d, 9e^{45 (link)}, 10a–d^{46 (link)}. Analytical thin layer chromatography was performed on aluminum sheets of UV 254 Merck silica gel, and flash chromatography using SilicaFlash P60 silica gel (40–63 µm). ¹H and ¹³C NMR spectra were recorded with Bruker Avance III HD 400 MHz or Varian Gemini 500 MHz and NMR chemic al shifts were reported in δ (ppm) using residual solvent peaks as standards, with the coupling constant J measured in Hz. High resolution mass spectra were recorded with an Agilent 6540 Q TOF system High resolution (HRMS) was recorded on Agilent 6540 QTOF.

Ryczkowska M., Trocka A., Hromova A, & Makowiec S. (2024). Meldrum’s acid assisted formation of tetrahydroquinolin-2-one derivatives a short synthetic pathway to the biologically useful scaffold. Scientific Reports, 14, 487.

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Synthesis and Characterization of Novel Compounds

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The starting chemicals for syntheses were purchased from Sigma-Aldrich (St. Louis, MO, USA). Other chemicals and solvents were purchased from local commercial sources and were of analytical grade quality. The melting point was measured by a digital melting point apparatus Barnstead Electrothermal IA9200 and is uncorrected. ¹H- and ¹³C-NMR spectra were recorded on a Varian Gemini (600 and 150 MHz, respectively); chemical shifts are given in parts per million (ppm); tetramethylsilane was used as an internal standard; and DMSO-d₆ was used as the solvent. Infrared (IR) spectra were acquired by Fourier transform infrared spectroscopy (FT-IR) attenuated total reflectance REACT IR 1000 (ASI Applied Systems) with a diamond probe and MTS detector. Mass spectra were performed on a liquid chromatography mass spectrometer LC-MS using an Agilent Technologies 1200 Series equipped with mass spectrometer Agilent Technologies 6100 Quadrupole LC-MS. The course of the reactions was followed by thin-layer chromatography (TLC) (Merck Silica gel 60 F254), and a UV lamp (254 nm), and iodine vapors were used for visualization of the TLC spots.

Zlacká J., Murár M., Addová G., Moravčík R., Boháč A, & Zeman M. (2022). Synthesis of Glycolysis Inhibitor PFK15 and Its Synergistic Action with an Approved Multikinase Antiangiogenic Drug on Human Endothelial Cell Migration and Proliferation. International Journal of Molecular Sciences, 23(22), 14295.

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NMR Spectroscopic Characterization of Organic Compounds

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All other chemicals were provided by Aldrich or ACROS and were of the highest quality. ¹H and ¹³C NMR spectra were determined with a 300 MHz Varian Gemini apparatus with tetramethylsilane as internal standard for the ¹H NMR spectra (s = singlet, d = doublet, dd = double doublet, t = triplet, br. s = broad signal, br. d = broad doublet, m = multiplet) and the solvent signal – DMSO-d6 (δ = 39.6 ppm) or CDCl3 (δ = 76.9 ppm) – for the ¹³C NMR spectra. Exact mass measurements were performed with a quadrupole/orthogonal acceleration time-of-flight tandem mass spectrometer (qTOF2, Micromass, Manchester, UK) fitted with a standard electrospray ionization (ESI) interface. All solvents were carefully dried or bought as such.

Saudi M., Zmurko J., Kaptein S., Rozenski J., Neyts J, & Van Aerschot A. (2014). Synthesis and evaluation of imidazole-4,5- and pyrazine-2,3-dicarboxamides targeting dengue and yellow fever virus. European Journal of Medicinal Chemistry, 87, 529-539.

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Spectroscopic Characterization of Organic Compounds

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IR spectra were recorded using a NICOLET iS50 instrument equipped with a liquid N₂-cooled mercury-cadmium-telluride (MCT-A) detector. A flat crystal plate Zn-Se ATR unit (crystal thickness 4 mm) was used. The incidence angle was 45°. The ATR accessory was obtained from Pike Technologies.
¹H NMR, ¹³C NMR, and ³¹P{H}NMR spectra were recorded on BRUKER Ultra Shield 400 Plus (400 MHz), BRUKER Avance III (600 MHz), and Varian Gemini (200 MHz) spectrometers, unless otherwise noted. Measurements were made in CDCl₃ or DMSO-d₆ solutions. Coupling constants were expressed in Hertz (Hz). ³¹P NMR spectra were obtained with the use of broadband ¹H decoupling. Copies of IR and NMR spectra are presented at Supplementary Materials Figures S1–S54. Electrospray ionization mass spectra were performed on a Varian 500-MS LC ion trap (University of Lodz). Elemental analysis was performed on a Micro Vario Cube elemental analyzer (Elementar).

Kosińska A., Virieux D., Pirat J.L., Czarnecka K., Girek M., Szymański P., Wojtulewski S., Vasudevan S., Chworos A, & Rudolf B. (2022). Synthesis and Biological Studies of Novel Aminophosphonates and Their Metal Carbonyl Complexes (Fe, Ru). International Journal of Molecular Sciences, 23(15), 8091.

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Comprehensive Characterization of Reaction Products

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NMR spectra of products as well as the proportions of each product in the reaction mixture were recorded on Varian Gemini at 200 MHz and Varian Mercury 400 MHz (¹H-NMR), and 50 and 100 MHz (¹³C-NMR) spectrometers, using CDCl₃ as a solvent and tretramethylsilane (TMS) as an internal standard. A mass spectrometric analysis was performed using an Agilent 6530 quadrupole time-of-flight (QTOF) LCMS with an electrospray ionization (ESI) source (Agilent Technologies, Santa Clara, CA, USA). A mass spectrometry analysis was conducted in positive ion mode, set for a detection of mass-to-charge ratio (m/z) of 100–1000. The X-ray structures were obtained using an APEX-Bruker apparatus.

Méndez A., Valdez-Camacho J.R, & Escalante J. (2020). Photooxidation of 2-(tert-Butyl)-3-Methyl-2,3,5,6,7,8-Hexahydroquinazolin-4(1H)-one, an Example of Singlet Oxygen ene Reaction. Molecules, 25(21), 5008.

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Synthesis and Characterization of Bakuchiol Salicylate

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Bakuchiol salicylate was synthesized with salicylic acid (Sigma-Aldrich, St Louis, MO, USA) and bakuchiol (Sytheon, Boonton, NJ, USA and Abcam, Cambridge, MA, USA; two different suppliers were used to ensure reproducibility) by the modified Steglich esterification method using dichloromethane as solvent, with dicyclohexylcarbodiimide as condensing agent and 4-N,N-dimethylaminopyridine as catalyst. After solvent evaporation and removal of dicyclourea by filtration, the obtained residue was loaded onto a silicon dioxide (high-purity Fluka silica gel, pore size 60 Å, 70–230 mesh) column, and eluted with toluene/cyclohexane (1/1 v/v). The solvent was evaporated under vacuum, and the oily residue was analysed by infrared detection (Satellite FT-IR spectrophotometer; Mattson Instruments, Madison, WI, USA), nuclear magnetic resonance (200 MHz; Gemini; Varian, Palo Alto, CA, USA), diode array spectrophotometry (HP-8452A; Agilent Technologies, Palo Alto, CA, USA) and high-performance liquid chromatography (HPLC) (series 1100; Agilent Technologies) equipped with an injector (Rheodyne^® 7725), binary pump, diode array–ultraviolet detection modules, C18 column (Xterra MS Waters; Milford, MA, USA) and ChemStation software. Samples dissolved in ethanol (10 μL) were eluted with 0.1% formic acid/acetonitrile gradient at 0.3 mL/min.

Ma S., Gobis K., Swindell W.R., Chaudhuri R., Bojanowski R, & Bojanowski K. (2017). Synthesis and activity of the salicylic acid ester of bakuchiol in psoriasis-surrogate keratinocytes and skin substitutes. Clinical and experimental dermatology, 42(3), 251-260.

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Ruthenium-based Catalytic Complexes Synthesis

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All solvents and substrates were purchased from Sigma. The melting points (mp) were determined on a Mel-Temp apparatus and are uncorrected. The IR spectra were recorded by a Perkin–Elmer Spectrum One FT-IR spectrometer on a KBr pellet. NMR spectra of ligands and complexes were performed in DMSO‑d₆, with TMS as internal standard on a Varian Gemini 200 MHz NMR spectrometer (¹H at 200 and ¹³C at 50 MHz). NMR spectra of ligands 4a-e and their ruthenium complexes 5a-e are presented in Supplementary Material.

Janković N., Milović E., Jovanović J.Đ., Marković Z., Vraneš M., Stanojković T., Matić I., Crnogorac M.Đ., Klisurić O., Cvetinov M, & Abbas Bukhari S.N. (2022). A new class of half-sandwich ruthenium complexes containing Biginelli hybrids: anticancer and anti-SARS-CoV-2 activities. Chemico-Biological Interactions, 363, 110025.

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Analytical Characterization of Organic Compounds

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All materials and solvents were of analytical reagent grade (Sigma-Aldrich-Merck KgaA, Darmstadt, Germany). Thin-layer chromatography was performed on Merck silica gel 60F₂₅₄ plates and visualized with UV light. The results of elemental analyses (%C, H, N) for all of the obtained compounds were in agreement with the calculated values that were within the ±0.4 % range. The ¹H and ¹³C NMR spectra in CDCl₃ or DMSO-d₆ were recorded on Varian Unity Plus (500 MHz) and Varian Gemini (200 MHz) instruments (Varian Medical Systems, Palo Alto, CA, USA). IR Spectra (KBr) were determined as KBr pellets of the solids on a Satellite FT-IR spectrophotometer (Bruker, Madison, WI, USA). Melting points were determined using a Stuart SMP30 apparatus (Stone, Staffordshire, UK) and were retained without any corrections.

Gobis K., Szczesio M., Olczak A., Korona-Głowniak I., Augustynowicz-Kopeć E., Mazernt-Politowicz I., Ziembicka D, & Główka M.L. (2022). Differences in the Structure and Antimicrobial Activity of Hydrazones Derived from Methyl 4-Phenylpicolinimidate. Materials, 15(9), 3085.

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