Quercetin

The C. elegans N2 Bristol (wild type), daf-2(e1370), age-1 (hx546), daf-16 (mgDf50), sek-1 (ag1), hsf-1 (sy441) (Caenorhabditis Genetics Center (CGC), University of Minnesota, Minneapolis, MN, USA), nsy-1 (tm850), pmk-1 (tm676), and skn-1 (tm4241) (National BioResource Project (NBRP), Tokyo Women’s Medical University, Japan) nematode strains were cultured (20°C) on nematode growth medium (NGM) plates that were spread with Escherichia coli (OP50) (Table 1) [22 (link),23 (link)]. Quercetin (Cayman chemical company, Michigan, USA) was dissolved in dimethyl sulfoxide (DMSO; Kanto Chemical Co., Inc., Tokyo, Japan) to a concentration of 0.01 M, before being diluted to 50- and 500 μM in OP50, and spread onto NGM plates for each Quercetin-feeding assay. We defined the plates spread onto NGM plates with OP50 as OP plate and with Quercetin, containing OP50 as Q plate. 200 μl of OP50 and Quercetin were spread onto NGM plates and dried.

Standard compounds including gallic acid, protocatechuic acid, catechol, chlorogenic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, sinapic acid, syringic acid, vanillin, ferulic acid, p-coumaric acid, benzoic acid, ellagic acid, cinnamic acid, apigenin, (+)-catechin, esculetin, fisetin, galangin, isohamnetin, isoquercitrin, kaempferol, luteolin, myricetin, quercetin, rhamnetin, and rutin, were purchased from Kanto Chemical Co., Inc., Tokyo, Japan.
Reagents including 1,1-diphenyl-2-picrylhydrazyl (DPPH), dibutyl hydroxytoluene (BHT), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), potassium persulfate (K₂S₂O₈), Folin-Ciocalteu’s reagent, aluminium (III) chloride hexahydrate (AlCl₃·6H₂O), β-carotene, linoleic acid, polyoxyethylen esorbitan monopalmitate (Tween-40), trichloroacetic acid (CCl₃COOH), iron (III) chloride (FeCl₃), sodium carbonate (Na₂CO₃), disodium hydrogenphosphate (Na₂HPO₄), sodium dihydrogenphosphate (NaH₂PO₄), sodium hydroxide (NaOH), and hydrochloric acid (HCl), were obtained from Kanto Chemical Co., Inc., Tokyo, Japan. All chemicals used were of analytical grade.

Folin-Ciocalteu’s phenol, potassium phosphate monobasic and dibasic, xanthine, xanthine oxidase, allopurinol, and hydrochloric acid were obtained from Sigma-Aldrich Japan K.K., Tokyo, Japan. Aluminium (III) chloride hexahydrate, 1,1-diphenyl-2-picrylhydrazyl (DPPH), sodium acetate, acetic acid, dibutyl hydroxuytoluene (BHT), gallic acid, and quercetin were purchased from Kanto Chemical Co. Inc., Tokyo, Japan. Acetone, potassium peroxodisulfate, 2,2’-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) were obtained from Nacalai Tesque, Inc., Kyoto, Japan. Methanol (MeOH), ethyl acetate (EtOAc), ethanol, and methanol plus were obtained from Junsei Chemical Co., Ltd., Tokyo, Japan. All of the bacteria strains, including Escherichia coli, Proteus mirabilis, Staphylococcus aureus, and Bacillus subtilis, were purchased from Sigma-Aldrich (Tokyo, Japan).