Propyl 3 4 5 trihydroxybenzoate

All standard chemicals (toluhydroquinone, orcinol, epoxysuccinic acid, phenoxyacetic acid, 2,5-dihydroxybenzoic acid (gentisic acid), fusaric acid, 3-(3,4-dihydroxyphenyl)-2-propenoic acid (caffeic acid), propyl-3,4,5-trihydroxybenzoate, jasmonic acid, sterigmatocystin, penicillin G, physcion and riboflavin) and chromatographic solvents were of highest analytical grade and purchased from either Sigma Aldrich or Fisher Scientific, except ethyl acetate (Acros Organics), orsellinic acid (Alfa Aesar) and chrysophanol (Acros Organics). Water was obtained from a Milli-Q system (Millipore). Cholinium chloride (>98 %, Sigma Aldrich), hereafter referred to solely as choline, and 1-ethyl-3-methylimidazolium chloride ([C₂mim]Cl, >98 %, Iolitec) were dried in vacuo (40–70 °C, 24–48 h, ca. 0.01 mbar) prior to use. Monodictyphenone was kindly provided by Prof. Thomas J. Simpson (University of Bristol, UK) [33 (link)].

C. gabunensis stem bark was collected in September 2012 from the woods of Imo state, Nigeria and authenticated by H. Donyeachusim, a taxonomist in the University of Port Harcourt, Nigeria. A voucher specimen is deposited in the University of Port Harcourt, Nigeria (UPH1028). All the solvents used in this study supplied by Fischer Scientific, UK are of high analytical grade and HPLC grade when used for chromatography. 3,4,5-trihydroxybenzoic acid (gallic acid, 1); 3,4-dihydroxybenzoic acid (protocatechuic acid, 2); 4-hydroxy-3-methoxybenzoic acid (vanillic acid, 3); 4-hydroxy-3,5-dimethoxybenzoic acid (syringic acid, 4); 3,4,5-trimethoxybenzoic acid (5); ethyl 3,4,5-trihydroxybenzoate (ethyl gallate, 6); propyl 3,4,5-trihydroxybenzoate (propyl gallate, 7); and dodecyl 3,4,5-trihydroxybenzoate (lauryl gallate, 13) were purchased from Sigma Aldrich UK.