Impact hd microtof q 3 mass spectrometer

The seed cultures were made in trypticase soy broth (TSB) and incubated at 30°C on a 200-rpm shaker. Then, seed cultures were diluted at the ratio of 1:50 into 50 mL of R5MS broth in 250 mL flasks. The 2% resin XAD-16 was added into the fermentation broth after 4-day cultivation and cultivated at 30°C, 200 rpm for another day. The resin XAD-16 was collected and extracted with methanol. The MeOH crude extract was separated by silica gel column chromatography (CH₂Cl₂-MeOH, 20:1 to 1:1) to yield five fractions (Frs. 1-5). Fr. 4 was further purified by semi-preparative HPLC (B: ACN and A:H₂O with 0.1% TFA (trifluoroacetic acid), 0–4 min 25% B, 4–29 min 50% B, 29–40 min 100% B, 40–45 min 25% B, 2 mL/min) to give 1 (5 mg, t_R = 28 min) and 2 (8 mg, t_R = 29 min) (Supplementary File).
1D NMR spectrum for compound 1 or 2 was obtained using TMS as an internal standard on a Bruker AVNEO 600 MHz. HRESIMS spectra were obtained using the standard ESI source on a Bruker Impact HD microTOF Q III mass spectrometer (Bruker Daltonics, Bremen, Germany). Semi-preparative HPLC was performed using an ODS column (Agilent ZORBAX SB-C18, 9.4 mm × 250 mm, 5 μm, 2 mL/min).

Optical rotations were obtained on a JASCO P-1020 digital polarimeter (JASCO Corporation, Tokyo, Japan). UV spectra were recorded on a Thermo Scientific Dionex Ultimate 3000 DAD detector, and IR spectra were taken on a Nicolet NEXUS 470 spectrophotometer as KBr disks (Thermo Fisher Scientific, Waltham, MA, USA). ¹H and ¹³C NMR, DEPT, and 2D NMR spectra were recorded on an Agilent 500 MHz DD2 (Agilent Technologies Inc., Santa Clara, CA, USA) using TMS as an internal standard. HRESIMS spectra were measured on a Bruker Impact HD microTOF Q III mass spectrometer (Bruker, Rheinstetten, Germany) using the standard ESI source. UHPLC-MS was operated using a Thermo Scientific Dionex Ultimate 3000 system coupled with the Bruker amazon SL Ion Trap mass spectrometry, controlled by Hystar v3.2 and Chromeleon Xpress software. A Thermo Scientific™ Acclaim™ C₁₈ column (2.1 × 100 mm, 2.2 μm) was used. The mobile phase consisted of H₂O and acetonitrile (ACN), both containing 0.1% formic acid. Semipreparative HPLC (Agilent Technologies Inc., Santa Clara, CA, USA) was performed using an ODS column (Bruker ZORBAX SB-C₁₈, 9.4 × 250 mm, 5 μm, 3 mL min⁻¹). Vacuum-liquid chromatography (VLC) was carried out over silica gel H (Qingdao Marine Chemical Factory, Qingdao, China).