ABSTRACT
Scopolamine is a pharmaceutically important tropane alkaloid which is used therapeutically in the form of an anesthetic and antispasmodic drug. The present study demonstrates enhanced scopolamine production from transgenic hairy root clones of Duboisia leichhardtii wherein the expression of quinolinate phosphoribosyl transferase (QPT) gene was silenced using the QPT-RNAi construct under the control of CaMV 35 S promoter. The RNAi hairy roots clones viz. P4, P7, P8, and P12 showed the enhanced synthesis of scopolamine with significant inhibition of nicotine biosynthesis. Optimization of culture duration in combination with methyl jasmonate elicitor in different concentrations (50 µM-200 µM) was carried out. Maximum synthesis of scopolamine had obtained from HR clones P7 (8.84 ± 0.117 mg/gm) on the 30th day of cultivation. Conspicuously, elicitation with wound-associated hormone methyl jasmonate enhanced the yield of scopolamine 2.2 fold (19.344 ± 0.275 mg/gm) compared to the culture lacking the elicitor. The transgenic hairy roots cultures established with RNAi mediated silencing of quinolinate phosphoribosyl transferase gene provides an alternative approach to increase the yield of scopolamine in fulfilling the demand of this secondary metabolite.
Subject(s)
Duboisia/metabolism , Gene Silencing/physiology , Genes, Plant/genetics , Plant Roots/metabolism , Quinolinic Acids/metabolism , Scopolamine/metabolism , Acetates/metabolism , Alkaloids/metabolism , Cyclopentanes/metabolism , Duboisia/genetics , Oxylipins/metabolism , Plant Roots/genetics , Plants, Genetically Modified/genetics , Plants, Genetically Modified/metabolism , Tropanes/metabolismABSTRACT
Saraca asoca (Roxb.) de Wilde, a common tree of India, is popularly used in the Ayurvedic and modern herbal systems of medicine for genito-urinary problems of women. Considering the reported antimicrobial or anti-inflammatory effect of S. asoca bark against such infections, we studied the anti-inflammatory activity-guided isolation of active compounds from methanol extract. The methanol extract of bark has yielded 10 compounds out of which 3'-deoxyepicatechin-3-O-ß-D-glucopyranoside (6) and 3'-deoxycatechin-3-O-α-L-rhamnopyranoside (8) have been found to be in vitro and in vivo active. 3',5-Dimethoxy epicatechin (3), 3'-deoxyepicatechin-3-O-ß-D-glucopyranoside (6), 3'-deoxycatechin-3-O-α-L-rhamnopyranoside (8) and epigallocatechin (9) are being reported for the first time from S. asoca.
