5 mm cptci cryoprobe

Optical rotations were measured using a Jasco P-1010 Polarimeter with sodium light (589 nm). UV spectra were recorded with a Waters 2998 Photodiode Array Detector. ¹H and ¹³C NMR spectra were recorded on a Bruker AV-600 spectrometer with a 5 mm CPTCI cryoprobe. ¹H chemical shifts are referenced to the residual DMSO-d₆ (δ 2.49 ppm) and ¹³C chemical shifts are referenced to the DMSO-d₆ solvent peak (δ 39.5 ppm). Low and high-resolution ESI-QIT-MS were recorded on a Bruker-Hewlett Packard 1100 Esquire–LC system mass spectrometer. Merck Type 5554 silica gel plates and Whatman MKC18F plates were used for analytical thin-layer chromatography. Reversed-phase HPLC purifications were performed on a Waters 1525 Binary HPLC Pump attached to a Waters 2998 Photodiode Array Detector. All solvents used for HPLC were Fisher HPLC grade.

The structure determination of the isolated compounds 1 and 2 was performed using mass and NMR spectral data. Low-resolution electrospray ionization quadrupole ion trap MS were recorded on a Bruker-Hewlett Packard 1100 Esquire–LC system mass spectrometer while ¹H, ¹³C and 2D NMR spectral data sets in DMSO-d₆ were obtained using a Bruker AV-600 spectrometer with a 5 mm CPTCI cryoprobe.

Optical rotations were determined using a JASCO P-2000 polarimeter (JASCO International Co., Ltd., Tokyo, Japan). IR spectra were measured with a Nicolet 6700 FT-IR spectrometer (Thermo Electron Corp., Waltham, MA, USA). NMR data analysis was performed with a JNM-ECA 600 MHz spectrometer (Jeol Ltd., Tokyo, Japan) coupled with a 5 mm CPTCI cryoprobe (Bruker, Germany). For column chromatography, silica gel (Merck KGaA, Darmstadt, Germany, particle size 63–200 μm) and RP-18 (Merck KGaA, particle size 75 μm) were used. Sephadex LH-20 from Sigma-Aldrich (St. Louis, MO, USA) was also used. Thin-layer chromatography (TLC) was conducted using silica gel 60 F₂₅₄ and RP-18 F₂₅₄ plates from Merck KGaA, Darmstadt, Germany. High-performance liquid chromatography (HPLC) was carried out using a Gilson system with a UV detector (at 201 and 254 nm) and an Optima Pak C₁₈ column (10 × 250 mm, particle size 5 μm, RS TECH Co., Ltd., Chungcheongbuk-do, Korea).