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Pentacyclic Triterpenes
About: Pentacyclic Triterpenes is a research topic. Over the lifetime, 416 publications have been published within this topic receiving 10931 citations.
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TL;DR: Two new triterpene glucosides have been isolated from the stems of a specimen of Combretum laxum growing in the “Pantanal” of the central-western region of Brazil and their in vitro antifungal activities against standard strains of Candida albicans, C. krusei and Cryptococcus neoformans are evaluated.
Abstract: Two new triterpene glucosides, beta-D-glucopyranosyl 2alpha,3beta,24-trihydroxyolean- 12-en-28-oate and beta-D-glucopyranosyl 2alpha,3beta,23,24-tetrahydroxyurs-12-en-28-oate, in addition to nine known compounds belonging to three different triterpene classes (oleanane-, ursane- and lupane-type) have been isolated from the stems of a specimen of Combretum laxum growing in the "Pantanal" of the central-western region of Brazil. Among the known triterpenes, beta-D-glucopyranosyl 2alpha,3beta,6beta-trihydroxyolean-12-en-28-oate is reported for the first time in the Combretaceae, while bellericoside and asiatic acid are described for the first time in the genus Combretum. The structures of the isolated compounds have been established on the basis of spectral techniques (1D-, 2D-NMR and MS). Their in vitro antifungal activities against standard strains of Candida albicans, C. krusei and Cryptococcus neoformans were also evaluated in this work.
89 citations
TL;DR: In this paper, transcriptional changes in sweet basil after methyl jasmonate (MeJA) treatment, which is considered an elicitor of secondary metabolites, and identified 388 candidate MeJA-responsive unique transcripts.
Abstract: Sweet basil (Ocimum basilicum) is well known for its diverse pharmacological properties and has been widely used in traditional medicine for the treatment of various ailments. Although a variety of secondary metabolites with potent biological activities are identified, our understanding of the biosynthetic pathways that produce them has remained largely incomplete. We studied transcriptional changes in sweet basil after methyl jasmonate (MeJA) treatment, which is considered an elicitor of secondary metabolites, and identified 388 candidate MeJA-responsive unique transcripts. Transcript analysis suggests that in addition to controlling its own biosynthesis and stress responses, MeJA up-regulates transcripts of the various secondary metabolic pathways, including terpenoids and phenylpropanoids/flavonoids. Furthermore, combined transcript and metabolite analysis revealed MeJA-induced biosynthesis of the medicinally important ursane-type and oleanane-type pentacyclic triterpenes. Two MeJA-responsive oxidosqualene cyclases (ObAS1 and ObAS2) that encode for 761- and 765-amino acid proteins, respectively, were identified and characterized. Functional expressions of ObAS1 and ObAS2 in Saccharomyces cerevisiae led to the production of β-amyrin and α-amyrin, the direct precursors of oleanane-type and ursane-type pentacyclic triterpenes, respectively. ObAS1 was identified as a β-amyrin synthase, whereas ObAS2 was a mixed amyrin synthase that produced both α-amyrin and β-amyrin but had a product preference for α-amyrin. Moreover, transcript and metabolite analysis shed light on the spatiotemporal regulation of pentacyclic triterpene biosynthesis in sweet basil. Taken together, these results will be helpful in elucidating the secondary metabolic pathways of sweet basil and developing metabolic engineering strategies for enhanced production of pentacyclic triterpenes.
89 citations
TL;DR: Kinetic studies revealed that corosolic acid and oleanolic acid showed non-competitive inhibition and acarbose showed mixed-type inhibition against α-amylase, which provides valuable implications for the triterpenes alone or in combination with acarbOSE as a therapeutic agent for the treatment of diabetes mellitus.
88 citations
TL;DR: Oleanolic acid and its synthetic derivatives have been identified as novel inhibitors of glycogen phosphorylase and 4 (IC50 = 3.3 microM) is the most potent GPa inhibitor.
88 citations