4 coumaric acid

Gallic acid, quercetin, formic acid, tryptophan, catechin, epigallocatechin, chlorogenic acid, vanillin, epicatechin, cyanidin-3-O-glucoside, 4-coumaric acid, isoquercitrin, myricetin, quercitrin, and naringenin, Folin-Ciocalteu reagent, DPPH (2,2-diphenyl-1-picrylhydrazyl), methanol analytical grade, aluminum chloride, sodium acetate, and sodium carbonate were purchased from Sigma Aldrich (Merck; Darmstadt, Germany).

The bacterial strains and plasmids used in this study are listed in Table 1. Antibiotics were added to the medium at the following concentrations: kanamycin, 50 mg/L; ampicillin, 100 mg/L. Ferulic acid, cinnamic acid, 4-coumaric acid, and caffeic acid were purchased from Sigma-Aldrich (United States) and used as substrates for in vitro and/or in vivo reactions and standard for product identification by high-performance liquid chromatography (HPLC). Coenzyme A (CoA), adenosine triphosphate (ATP), and malonyl-CoA were purchased from Sigma-Aldrich for enzyme activity assays. The restriction enzymes (NEB, United States; Takara, Japan), AccuPower Ligation kit (Bioneer, Korea), and KOD-plus-DNA polymerase (TOYOBO, Japan) were used according to the manufacturer’s instructions.

E. coli DH5α and E. coli C41 (DE3) [30 (link)] were used in the general DNA manipulation and expression of biosynthetic genes, respectively. T-blunt vector (Solgent, Korea) was used in the polymerase chain reaction (PCR) cloning. pET-22b(+) and pET-28a(+) were purchased from Novagen (USA). 4-coumaric acid, resveratrol, pterostilbene, and 3,5,4’-trimethoxystilbene were purchased from Sigma-Aldrich (USA). Pinostilbene was purchased from Tokyo Chemical Industry, Co (Japan). IPTG was purchased from A.G. Scientific, Inc (USA). NMR solvent was purchased from Cambridge Isotope Laboratories, Inc. (USA). Hypergrade solvent for LC-MS was purchased from Merck KGaA (Germany).

Persimmon (Diospyros kaki L. cv. Mopan) was collected from Baoding City, Hebei Province of China in October 2018. The fruits were treated with CO₂ to remove astringency and stored at −20°C until use. Active wine dry yeast (Saccharomyces cerevisiae) was purchased from Angel Yeast Co., Ltd. (Yichang, China).
The standard compounds of gallic acid, protocatechuic acid, catechin, vanillic acid, syringic acid, 4‐coumaric acid, syringaldehyde, ferulic acid, guaiacol, benzoic acid, salicylic acid, quercetin, 3‐octanol and methanol, ethanol, acetonitrile (HPLC grade), acetic acid, rutin, and ethyl acetate were purchased from Sigma‐Aldrich (St. Louis). Folin–Ciocalteu, Na₂CO₃, Al (NO)₃, Na OH, HCl, Fehling reagent, glucose, pectinase (pectinase > 3.5 × 10⁴ U g⁻¹, cellulase > 9 × 10⁴ U g^{− 1}), and other chemicals were of analytical grade and purchased from Fluka (Buchs, Switzerland).

Sodium hydroxide, citric acid, trans-ferulic acid, trans-isoferulic acid, sinapic acid, caffeic acid, 4-hydroxybenzoic acid, 3’-coumaric acid, 4’-coumaric acid, vanillic acid (3-methoxy-4-hydroxybenzoic acid), protocatechuic acid (3,4-dihydroxybenzoic acid), 3’,4’-dihydroxyphenylacetic acid, 3-(3’-hydroxyphenyl)propionic acid, 3-(4’-hydroxyphenyl)propionic acid, 3-(3’,4’-dihydroxyphenyl)propionic acid (aka dihydrocaffeic acid), 3-(3’,5’-dihydroxyphenyl)propionic acid, 3-(3’-methoxy-4’-hydroxyphenyl)propionic acid (aka dihydroferulic acid), and hippuric acid were purchased from Sigma-Aldrich (St. Louis, MO, USA) as were secoisolariciresinol, enterolactone and enterodiol. Homovanillic acid (3’-methoxy-4’-hydroxyphenylacetic acid) was purchased from Extrasynthese (Genay Cedex, France). Ferulic acid-4’-O-sulphate disodium salt, isoferulic acid-3’-O-β-D-glucuronide, and dihydrocaffeic acid-3’-O-sulphate sodium salt were purchased from Toronto Research Chemical, (Toronto, Canada). Daidzein was purchased in part from AASC. Ltd (Southampton, UK) and in part provided by Prof. Alan Crozier (Department of Nutrition, University of California, Davis, CA, USA).