Methanol hplc grade

Sesamol (98% purity), 2-Amino-2-norbornanecarboxylic acid (BCH) (98% purity), L-dopa (98% purity), L-tyrosine (99% purity), and melphalan (95% purity) were purchased from Sigma-Aldrich (St. Louis, MO, USA). L-Leucine (99% purity) and L-alanine (99% purity) were purchased from TCI Chemicals (Tokyo, Japan). Methanol HPLC grade was purchased from RCI Labscan (Bangkok, Thailand). Dimethyl sulfoxide (DMSO) biological grade was purchased from PenReac AppliChem (Barcelona, Spain). The reagents and culture media including Dulbecco’s modified Eagle’s medium of high glucose (DMEM), Hank’s balanced salt solution (HBSS) without Ca²⁺ and Mg²⁺ supplemented, and penicillin and streptomycin were purchased from GIBCO^®, Invitrogen (Grand Island, NY, USA). Fetal bovine serum (FBS) was purchased from GE Life Sciences (Parramatta, Australia). Sodium hydroxide (NaOH) and hydrochloric acid (HCl) were from RCI Labscan (Bangkok, Thailand).

Ethanol (95%, AR grade), acetonitrile (HPLC grade), and methanol (HPLC grade) were purchased from RCI Labscan, Bangkok, Thailand. Methanol (AR grade) was purchased from Honeywell, Charlotte, NC, USA. Deionized water was obtained using a water purification system from Thermo Scientific Co. (Waltham, MA, USA). Gallic acid, quercetin, and kaempferol were purchased from the TOKYO chemical industry Co., Ltd., Tokyo, Japan. Sodium carbonate, embelin, and doxorubicin hydrochloride were purchased from Sigma-Aldrich, St. Louis, MO, USA. Folin–Ciocalteu, orthophosphoric acid, and dimethylsulfoxide were obtained from Merck, Darmstadt, Germany. McCoy’s 5A medium, Eagle’s Minimum Essential Medium, and Dulbecco’s phosphate-buffered saline were purchased from Lonza, Walkersville, MD, USA. Penicillin, streptomycin, Dulbecco’s Modified Eagle Medium, fetal bovine serum, and 0.25% Trypsin-EDTA (Ethylenediaminetetraacetic acid) were purchased from Gibco, Waltham, MA, USA.

Thirty-three LAB strains isolated from Thai fermented vegetables were used throughout this study. These strains, twenty-seven Lactobacillus spp., two Pediococcus spp., two Enterococcus spp. and two Weissella strains, were obtained from the Culture Collection of the National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Thailand. All strains were stored at −80 °C in 20% glycerol.
De Man Rogosa and Sharpe (MRS) medium (Merck, Darmstadt, Germany) was used to culture the 33 strains of plant-derived LAB. Chemical reagents including sodium chloride (NaCl), potassium chloride (KCl), sodium phosphate (Na₂HPO₄), and potassium phosphate monobasic (KH₂PO₄) were purchased from Carlo Erba Reagents (Bangkok, Thailand). Methanol (HPLC grade) was purchased from RCI Labscan (Bangkok, Thailand). Sodium dodecyl sulfate was purchased from Bio-Rad (Bangkok, Thailand). All enzymes and other chemical reagents were purchased from Sigma-Aldrich (St. Louis, MO, USA).
A solid standard of ZEA (5 mg) was purchased from Romer Labs (Singapore). It was dissolved in absolute methanol. A working solution was prepared to 2 µg/mL and stored in the dark at −20 °C in screw cap bottles until use.

Sesamol (98% purity) was purchased from Sigma-Aldrich (St. Louis, MO, USA). Methanol (HPLC grade (99.9% purity)) and acetonitrile (HPLC grade (99.9% purity)) were purchased from RCI Labscan (Bangkok, Thailand). Dimethyl sulfoxide (DMSO) (biological grade (purity 99.9%)) was purchased from PenReac AppliChem (Barcelona, Spain). Reagent and culture media, including Dulbecco’s Modified Eagle’s Medium (DMEM) (high glucose), penicillin, streptomycin, and 0.25% trypsin-ethylenediamine tetraacetic acid (EDTA) (1X) were bought from GIBCO^®, Invitrogen (Grand Island, NY, USA). Fetal bovine serum (FBS) was purchased from GE Life Sciences (Parramatta, Australia). The reagents used in the cell-based assay were of molecular biological grade.

The rhizomes were separated from KP plants (Rom-Kloa variety) cultivated in Chat Trakan district, Phitsanulok province, Thailand. The voucher specimen (No. VS001) was deposited in the Faculty of Pharmacy, Silpakorn University, Thailand. KP rhizomes were sun-dried, ground, and separated by sieves with size between 177 and 250 μm before being stored at 25 °C.
PMF, DMF and TMF standards were acquired from Indofine Chemical Company (Hillsborough, NJ, USA). Ethanol (AR grade) and methanol (HPLC grade) were purchased from RCI Labscan (Bangkok, Thailand) and Fisher scientific (Seoul, Korea), respectively. Acetic acid (AR grade) was bought from Merck KGaA (Darmstadt, Germany). Ultrapure water was processed by a TKA Pacific-UP/UPW water purification system (Niederelbert, Germany).

Standards formononetin and isoformononetin were secured from Changzhou Guiding Bio-Tech. Co., Ltd. (Changzhou, China). Tetracycline (Sigma-Aldrich Co.^®, St. Louis, MO, USA) and vancomycin hydrochloride (United States Pharmacopeia Reference Standard) were used as a positive control for antibacterial assays. Acetone, methanol, ethanol, and hexane used for extraction and solvent partitioning were obtained from Sigma-Aldrich Co.^® (St. Louis, MO, USA), while ethyl acetate was purchased from RCI Labscan^® Limited (Bangkok, Thailand). Dichloromethane used in the flash column purification was purchased from Thermo Fisher Scientific^® Co. (Waltham, MA, USA). Water and methanol (HPLC-grade) from RCI Labscan^® Limited (Bangkok, Thailand) were used as mobile phase for HPLC purification. Water, acetonitrile, and formic acid (MS-grade) were purchased from Sigma-Aldrich Co. ^® (St. Louis, MO, USA).