1260 infinity

Gel permeation chromatography (GPC) was performed to evaluated molecular weight (Mw) and molecular number (Mn) of PLA:PCL SMPNs after gamma irradiation.
Analyses were performed using Agilent Technologies 1260 Infinity GPC apparatus, a chromatographic system composed by a precolumn (Agilent GPC/SEC Guard Columns) and three Ultrastyragel columns connected in series (7.7 × 250 mm each with different pore diameters of 104 Å, 103 Å, and 500 Å), a pump (Agilent Technologies 1260 Infinity), an IR detector (Agilent Technologies 1260 Infinity), and a data handling software (OpenLab and Cirrus).
PLA:PCL pristine powder and non-irradiated and gamma-irradiated PLA:PCL electrospun nanofibrous scaffolds were solubilized in THF and the solutions obtained (1 mg/mL) were filtered with a Fluoropore 0.45-μm (Millipore) filter before being injected in GPC; THF was the mobile phase and constant flow rate was set at 1 mL/min.

Crude extracts of co- and mono-cultures (5.0 mg/mL in methanol) were initially screened by HPLC-UV analysis (Agilent Technologies 1260 Infinity) with spectral scanning from 230−320 nm and a linear gradient from 0–100% methanol.
The co-culture crude was then fractionated by vacuum liquid chromatography on silica gel 60 (Acros Organics™ ultra-pure 60A 40-63u), eluting with a gradient of n-hexane−ethyl acetate−MeOH to give 10 subfractions (CC1-CC10). HPLC-UV-HRESIMS analysis revealed that most metabolites that were not observed in the monocultures were in CC2; hence, further purification of this fraction was carried out by reversed-phase HPLC (Agilent Technologies 1260 Infinity) (ACE C18-HL 10 µM 10 × 250 mm) equipped with a diode array detector (DAD). HPLC separation was performed using solvent A (95% H₂O, 5% methanol, and 0.1% trifluoroacetic acid) and solvent B (100% methanol) as eluents, with a linear gradient from 20%−100% MeOH over 40 min and a solvent flow rate of 1.5 mL min⁻¹. All of the employed chemicals were HPLC-grade. The separation afforded 4.0 mg of an indolocarbazole alkaloid, BE-13793C 1.
BE-13793C: yellow solid. UV (PDA) λmax: 245, 305, 330, 395nm; IR (neat) ν_max (cm⁻¹): 3427, 1740, 1590, 1422, 1343, 1205, 857 nm; ¹H, ¹³C-NMR data, see Table 1; HR ESIMS (positive mode) m/z calculated [M + H]⁺ = 358.0822; observed [M + H]⁺ = 358.0826; ∆ = 1.0576 ppm.

Molecular weight distributions were assessed using a DMF GPC instrument operating at 60 °C. The set-up comprised two Polymer Laboratories PL gel 5 μm Mixed-C columns and one PL polar gel 5 μm guard column connected in series to an Agilent Technologies 1260 Infinity multidetector suite and an Agilent Technologies 1260 Infinity pump injection module. The GPC eluent was HPLC-grade DMF containing 10 mM LiBr and was filtered prior to use. The flow rate was 1.0 ml min^–1 and DMSO was used as a flow-rate marker. Calibration was conducted using a series of ten near-monodisperse poly(methyl methacrylate) standards ranging from 625 to 618 000 g mol^–1. Chromatograms were analyzed using Varian Cirrus GPC software (version 3.3).

After treatment with 8-OaS for 3 days, GABA and glutamate were detected using high-performance liquid chromatography (HPLC; Agilent Technologies 1260 Infinity, Agilent Technologies, Wilmington, DE), according to previously described methods (Wang et al. 2017 (link)). Before derivatization, the samples were dissolved with boracic acid buffer (pH 9.0) and centrifuged for 15 min at 3000 r/min at 4 °C. Samples were mixed with 2,4-dinitrofluorobenzene (DNFB) and 0.5 mol/L NaHPO₃ buffer for 1 h at 60 °C; then, a phosphate buffer solution (pH 7) was added to stop the reaction. Samples were analyzed using a UV detector (360 nm, Agilent Technologies 1260 Infinity). The mobile phase was KH₂PO₄ buffer (pH 6.0), acetonitrile, and ddH₂O (84:8:8, v/v/v) at a flow rate of 1.0 mL/min. A Themo TC-C18 column (250 × 4.6 mm²; particle size 5 mm) was used. The concentrations were obtained using the LC solution software (Shimadzu) based on standard substances.