INTRODUCTION: Various species of the genus Rheum (Polygonaceae) are known for their high content of medicinally important hydroxyanthraquinones. However, little information is available concerning the polyphenolic composition of garden or dietary rhubarb Rheum rhaponticum L. (R. rhaponticum). OBJECTIVE: Determination of further polyphenols in the roots and petioles of R. rhaponticum. METHODOLOGY: The dried plant material was extracted with 10-fold excess (v/w) of methanol and subsequently diluted five times with methanol-water (1:1) and analysed by reversed-phase liquid chromatography using tandem UV-photodiode array and mass selective detection (RP-HPLC-UV-ESI/MS(2)). Polyphenols were identified using either HPLC-ESI/MS(2) data obtained for respective commercial standards or by comparison of a parent ion fragmentation picture with the respective MS(2 )spectrum from the literature. RESULTS: The roots of R. rhaponticum were very rich in various hydroxystilbenes and contained four main substance groups--derivatives of trans-piceatannol, trans-resveratrol, trans-rhapontigenin and trans-deoxyrhapontigenin. Additionally, pterostilbene acetylglucosides and a number of hydroxyanthraquinones and their glycosides were identified in the root samples. The profile of polyphenols in the petioles of R. rhaponticum was similar to that of the roots but the content of individual substances was remarkably lower. The petioles of the R. rhaponticum additionally contained significant amounts of derivatives of flavonol quercetin, which is a good antioxidant. CONCLUSION: The study has shown that roots of R. rhaponticum contain a wide variety of hydroxystilbenes and deserve further consideration as a source of medicinally interesting compounds. Copyright (c) 2008 John Wiley & Sons, Ltd.
INTRODUCTION: Various species of the genus Rheum (Polygonaceae) are known for their high content of medicinally important hydroxyanthraquinones. However, little information is available concerning the polyphenolic composition of garden or dietary rhubarbRheum rhaponticum L. (R. rhaponticum). OBJECTIVE: Determination of further polyphenols in the roots and petioles of R. rhaponticum. METHODOLOGY: The dried plant material was extracted with 10-fold excess (v/w) of methanol and subsequently diluted five times with methanol-water (1:1) and analysed by reversed-phase liquid chromatography using tandem UV-photodiode array and mass selective detection (RP-HPLC-UV-ESI/MS(2)). Polyphenols were identified using either HPLC-ESI/MS(2) data obtained for respective commercial standards or by comparison of a parent ion fragmentation picture with the respective MS(2 )spectrum from the literature. RESULTS: The roots of R. rhaponticum were very rich in various hydroxystilbenes and contained four main substance groups--derivatives of trans-piceatannol, trans-resveratrol, trans-rhapontigenin and trans-deoxyrhapontigenin. Additionally, pterostilbene acetylglucosides and a number of hydroxyanthraquinones and their glycosides were identified in the root samples. The profile of polyphenols in the petioles of R. rhaponticum was similar to that of the roots but the content of individual substances was remarkably lower. The petioles of the R. rhaponticum additionally contained significant amounts of derivatives of flavonol quercetin, which is a good antioxidant. CONCLUSION: The study has shown that roots of R. rhaponticum contain a wide variety of hydroxystilbenes and deserve further consideration as a source of medicinally interesting compounds. Copyright (c) 2008 John Wiley & Sons, Ltd.
Authors: Almuth Hammerbacher; Steven G Ralph; Joerg Bohlmann; Trevor M Fenning; Jonathan Gershenzon; Axel Schmidt Journal: Plant Physiol Date: 2011-08-24 Impact factor: 8.340
Authors: Yun Sun Lee; Hyun Kyoung Ju; Yeon Jeong Kim; Tae-Gyu Lim; Md Romij Uddin; Yeon Bok Kim; Jin Hong Baek; Sung Won Kwon; Ki Won Lee; Hak Soo Seo; Sang Un Park; Tae-Jin Yang Journal: PLoS One Date: 2013-12-16 Impact factor: 3.240