Chemical constituents from the fruits of Withania coagulans (Stocks) Dunal

Abstract

Withania coagulans (Stocks) Dunal (family: Solanaceae) is a rigid undershrub found in Iran, Afghani stan, Pakistan, northern India and Nepal. Its fruits are used to treat asthma, biliousness, flatulent colic, cough, diabetes, dyspepsia, liver complaints, intestinal infections, skin rashes, stomachache, strangury and wounds. The air-dried fruits of W. coagulans were exhaustively extracted with methanol in a Soxhlet apparatus. The concentrated methanol extract was adsorbed on silica gel to be chromatographed on a silica gel column. The column was eluted with dichloromethane, ethyl acetate and methanol suc cessively to isolate ten new phytoconstituents characterized as (3R,4R)-dihydroxyadipic-γ,γ’-dilactone (n-hexa-1(3),4(5)-diolide, 2), (20S,22R)-1-oxo-witha-2,24-dienolide (withacoagulanide A, 3), (20S,22R)- 1-oxo-witha-24-enolide (withacoagulanide B, 4), (20S,22R)-1-oxo-witha-6β-ol-2,24-dienolide (witha coagulanide C, 5), (20S,22R)-1-oxo-witha-3β,5β-diol-24-enolide (withacoagulanide D, 6), (20S,22R)-1- oxo-witha-6β-ol-2,24-dienolide-6β-D-arabinopyranosyl-2′-(2′′-methoxy)-benzoate (withacoagunalide C 6-arabinosyl 2′-O-anisate, 7), (20S,22R)-1-oxo-witha-3β-ol-24-enolide-3β-O-D-galactoyranosyl- (2′→1′′)-β-O-D-galactopyranoside (3-O-digalactosyl withacoagulanide B, 8), 1-oxo-3-seco-witha-21, 27, 28-trioic acid-24-ene-6β-ol-19(8), 18(11)-diolide-6β-O-D-galacuronopyranoside (3-secowithacoag ulanolide 6β-olyl galactourinoside, 10), (20S,22R)-1-oxo-witha-6β-ol-2,24-enolide-6β-O-D-(4′-acetoxy arabinopyranosyl-(2′→1′′)-(3′′,4′′-diacetoxy arabinopyranosyl)-2′′-(2′′′-methoxy)-benzoate (withacoag ulanide C 6β-olyl diarabinosyl 2′′-(O)-anisate, 11) and n-hexanoyl-β-O-D-xylopyranosyl-(2′→1′′)-β-O-D-xylopyranosyl-(2′′→1′′′)-β-O-D-xylopyrano- side (caproyl trixyloside, 12) along with the known rare chemical compounds identified as cetyl palmitate (hexadecyl hexadecanoate, 1) and glyceryl-1,2-di hexadecanoate-3-phosphate (glyceryl-1,2-dipalmityl 3-phosphate, 9). The structures of isolated phyto constituents were established on the basis of analysis of spectral data and chemical means.