Agilent 6530 accurate mass spectrometer

Diclofenac, carrageenan, and solvents such as n-hexane, chloroform, acetone, ethyl acetate, and methanol were obtained from Sigma-Aldrich (St Louis, MO, USA). Mueller-Hinton Broth was purchased from Thermo Fisher Scientific (Massachusetts, USA). silica gel (60 N, spherical, neutral, 40-50 μm) was obtained from Kanto Chemical Co., Inc. (Tokyo, Japan). Plethysmometer was purchased from Panlab, Havard Apparatus. Infrared spectra were recorded on an IR Prestige-21 spectrometer (Shimadzu, Kyoto, Japan). NMR spectra were recorded using a Bruker Avance 500 spectrometer (Bruker, MA, USA), with TMS as an internal reference. HRESIMS data were measured on an Agilent 6530 Accurate-Mass spectrometer (Agilent, CA, USA). Analytical TLC was performed on precoated silica gel 60F₂₅₄ and RP-18 F₂₅₄ plates (0.25 or 0.50 mm thickness, Merck KGaA, Darmstadt, Germany). Spots were detected under UV radiation (254 nm and 365 nm) and by spraying the plates with 10% sulfuric acid followed by heating with a heat gun.
D. benenica Q.B.Nguyen & Škorničk was collected in January 2020 at Quang Nam province and identified by Hue University of Agriculture and Forestry. A voucher specimen (DB1) was deposited in the Faculty of Chemistry at the Hue University of Education.

A JASCO P-2000 polarimeter (Hachioji, Tokyo, Japan) was used to record optical rotation. UV spectra were measured using a Shimadzu UV-1800 spectrophotometer (Shimadzu, Kyoto, Japan). Circular dichroism spectra were studied with a Chirascan CD spectrometer (Applied Photophysics Ltd., Surrey, United Kingdom). A Bruker Avance 500 spectrometer (Bruker, MA, USA) was exploited for investigating NMR spectra and TMS as an internal reference. HRESIMS data were performed using an Agilent 6530 Accurate-Mass spectrometer (Agilent, CA, USA). The column chromatography studies were conducted with YMC RP-18 (Fuji Silysia Chemical Ltd, Kasugai, Aichi, Japan), Cosmosil 75C18-OPN (Nacalai Tesque Inc., Kyoto, Japan), silica gel (40–50 µm, Kanto Chemical Co., Tokyo, Japan), Diaion HP-20 (Mitsubishi Chem. Co., Tokyo, Japan) and Sephadex LH-20 (Dowex 50WX2-100, Sigma–Aldrich, USA). Pre-coated silica gel 60F₂₅₄ and RP-18 F₂₅₄ plates (0.25 or 0.50 mm thickness, Merck, Germany) were exploited to investigate analytical TLC. Preparative HPLC with a DAD detector applied was Agilent 1260 Infinity II system (Agilent, CA, USA) and using a Zorbax SB–C₁₈ column (5 µm particle size, 9.4 × 250 mm).