1260 infinity liquid chromatography system

The phytochemical compositions of the extracts were analyzed quantitatively. Quantitative analyzes were carried out by using LC–ESI–MS/MS technique (Agilent Technologies 1260 Infinity liquid chromatography system, Santa Clara, CA, USA) [70 (link)]. Information on the details of the performed analyzes are included in the Supplementary File (Tables S1 and S2). All tests were carried out in triplicate. In order to determine the degree of statistical difference, Tukey’s test was used.

An Agilent Technologies 1260 Infinity liquid chromatography system coupled to a 6420 Triple Quadrupole mass spectrometer was used for the qualitative and quantitative analyses. The separation was achieved by means of a Poroshell 120 EC-C18 (100 mm × 4.6 mm I.D., 2.7 μm) column, and using 0.1% formic acid (A)/methanol (B) as mobile (selected based on the sufficient chromatographic resolution of isomeric compounds). This configuration also allows for improvements in the method sensitivity. The gradient elution profile herein adopted was set as follows: 0.00 min 2% B eluent, 3.00 min 2% B eluent, 6.00 min 25% B eluent, 10.00 min 50% B eluent, 14.00 min 95% B eluent, 17.00 min 95% B, and 17.50 min 2% B eluent. The column temperature was maintained at 25 °C. The flow rate was 0.4 mL/min, and the injection volume was 2.0 μL. The MS instrumentation was directly coupled with the LC system via an ESI source, operating both in negative and positive multiple reaction monitoring (MRM) mode. The ESI parameters were: capillary voltage −3.5 kV, gas temperature 300 °C, gas flow 11 mL/min, nebulizer pressure 40 psi.
The different analytes were identified by means of their retention times, mass spectra, and tandem mass spectra. Specifically, quantitative analyses were performed using a specific MRM transition for each analyte.

Photoelectrochemical biocatalysis was coupled with the photoelectrochemical regeneration of NADH using the FeOOH/BiVO₄/perovskite solar cell tandem configuration with the two-electrode configuration. The reaction medium for the enzymatic reaction consisted of NAD⁺ (2 mM), M (0.5 mM), α-ketoglutaric acid disodium salt dihydrate (50 mM), (NH₄)₂SO₄ (250 mM), and GDH (40 U) in 3 ml of phosphate buffer (0.1 M, pH 7.5). The l-glutamate production was analyzed by using a 1260 Infinity liquid chromatography system (Agilent Technologies, U.S.A.). TTN_GDH, TOF_GDH were calculated according to Eqs. (2) and (3), respectively: $${\mathrm{TTN}}_{\mathrm{GDH}}=\frac{\mathrm{Maximum}\mathrm{concentration}\mathrm{of}\mathrm{L}-\mathrm{glutamate}}{\mathrm{Concentration}\mathrm{of}\mathrm{GDH}},$$ $${\mathrm{TOF}}_{\mathrm{GDH}}\left({\mathrm{h}}^{-1}\right)\mathrm{=}\frac{\mathrm{Concentration}\mathrm{of}\mathrm{L}-\mathrm{glutamate}\mathrm{after}\mathrm{reaction}\mathrm{for}\mathrm{the}\mathrm{first}\mathrm{hour}}{\mathrm{Concentration}\mathrm{of}\mathrm{GDH}\times \mathrm{time}}.$$

An exponentially growing culture of M. fujisawaense DSM5686 was used to inoculate one L modified AMS + 50 mM MeOH to a starting optical density of 0.02. A total of 6 1 L cultures were grown at a time. These cultures were incubated at 30°C and shaken at 200 rpm to stationary phase (approximately 72 hours). The culture was centrifuged at 4,700 rpm for 10 min followed by extraction of the clarified supernatant with an equal volume of ethyl acetate acidified with 0.01% (vol/vol) acetic acid. The organic phase was then dried by rotary evaporation. Dried crude supernatant extracts were resuspended in 1 mL of 1:3 water:acetonitrile (ACN) and applied onto a preequilibrated Discovery C₁₈ solid-phase extraction (SPE) column (3 mL, 500 mg) then washed and eluted sequentially with 6 mL of 25%, 50%, 75%, and 100% ACN in water. The acyl-HSL was found in the 75% ACN fraction by LC-MS. This fraction was dried and resuspended in 500 µL of 25% ACN in water and separated using an Agilent 1260 Infinity liquid chromatography system. A Waters SunFire C18 column (3.5 µm particle size, 46 mm × 100 mm) was used for reverse phase separation with a flow rate of 1 mL min⁻¹. Solvent A: Water + 0.1% trifluoroacetic acid; Solvent B: ACN + 0.1% trifluoroacetic acid. Gradient: 0–1 min, 10–35% B. 1–21 min, 35–55% B. 21–22 min, 55–100% B. 22–30 min, 100% B. 30–31 min, 100–10% B. 31–36 min, 10% B.