Nasunin from eggplant consists of cis-trans isomers of delphinidin 3-[4-(p-coumaroyl)-L-rhamnosyl (1-->6)glucopyranoside]-5-glucopyranoside.
Two major anthocyanins were isolated from the acidified methanolic extract of eggplant (Solanum melongena L.) by column chromatography and preparative high-performance liquid chromatography. These anthocyanins were interconvertible under room light illumination condition. By means of tandem time-of-flight mass spectrometry and nuclear magnetic resonance spectroscopy, their structures were identified and elucidated as delphinidin 3-[4-(cis-p-coumaroyl)-l-rhamnosyl(1-->6)glucopyranoside]-5-glucopyranoside (compound 1) and delphinidin 3-[4-(trans-p-coumaroyl)-l-rhamnosyl-(1-->6)glucopyranoside]-5-glucopyranoside (compound 2), respectively. The results indicated that nasunin comprised cis and trans isomers of the p-coumaric acid moiety in its structure.
Ichiyanagi
Takashi
T
Faculty of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, 265-1 Higashijima, Niigata 956-8603, Japan. kouji@niigata-pharm.ac.jp
Kashiwada
Yoshiki
Y
Shida
Yasuo
Y
Ikeshiro
Yasumasa
Y
Kaneyuki
Takao
T
Konishi
Tetsuya
T
D000872:Anthocyanins / Q000032:analysis* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D003373:Coumaric Acids / Q000032:analysis / Q000737:chemistry; D005638:Fruit / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D011422:Propionates; D032323:Solanum melongena / Q000737:chemistry*
D000872:Anthocyanins; D003373:Coumaric Acids; D011422:Propionates; C118727:nasunin; C017185:delphinidin; C495469:p-coumaric acid