The structure and stereochemistry of phlogantholide-A, a diterpene from Phlogacanthus thyrsiflorus
TL;DR: The structure and stereochemistry of phlogantholide-A, a new diterpene lactone isolated from the leaves of Phlogacanthus thyrsiflorus has been determined as 2β,15,18-trihydroxy- ent -labd-8(17),13dien-16-oic lactone by chemical and spectroscopic means as mentioned in this paper.
About: This article is published in Phytochemistry.The article was published on 1985-01-01. It has received 17 citations till now. The article focuses on the topics: Diterpene.
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TL;DR: The role of labdane diterpenes is underlined not only as tools for the study of the biochemistry and regulation of biochemical and metabolic pathways of mammalian cellular systems, but also as potential pharmacological agents in the fight against diseases such as cancer and heart disorders.
Abstract: The terpenoids are a class of natural products with biological activity. The number of isoprene units from which they are biogenetically composed is used for their classification. The diterpenes are another group from which several compounds with high biological activity have been produced. The most studied plant families are Asteraceae and Labiatae, as well as Conifers, which are the main sources of diterpenes. The lack of, or insufficient, chromatographic data (RI, Rt) as well as of reference compounds for most labdanes is the main reason for their absence from the chemical fingerprints of plantextracts. Also their use as chemotaxonomic markers within the species in which they occur is limited. The configuration at the C-13 carbon atom has been investigated, especially in the case of manoyl oxide, as well as the various isomers, the ratio of which determines antimicrobial activity. A variety of biological activities have been encountered in labdane diterpenes such as antibacterial, antifungal, antiprotozoal, enzyme inducing, anti-inflammatory activities and modulation of immune cell functions. More recent studies have shown that labdane exhibits significant cytotoxic and cytostatic effects against leukemic cell lines of human origin and interferes with the biochemical pathways of apoptosis and the cell cycle phases, as well as with the expression of several protooncogenes such as c-myc and bcl-2 . This report underlines the role of these compounds, not only as toolsfor the study of the biochemistry and regulation of biochemical and metabolic pathways of mammalian cellular systems, but also as potential pharmacological agents in the fight against diseases such as cancer and heart disorders.
87 citations
TL;DR: The structure, including the relative configuration of phlogacantholide B (1), was confirmed by X-ray crystallographic analysis of its diacetate (6) and the structure was elucidated by chemical and spectroscopic evidence.
Abstract: Two new diterpene lactones, phlogacantholides B (1) and C (2), and three new diterpene lactone glucosides, phlogacanthosides A (3), B (4), and C (5), together with lupeol, beta-sitosterol, betulin, P-daucosterol, (+)syringaresinol, and (+)-syringaresinol-4-O-beta-D-glucopyranoside, were isolated from the roots of Phlogacanthus curviflorus. Their structures were elucidated by chemical and spectroscopic evidence. The structure, including the relative configuration of phlogacantholide B (1), was confirmed by X-ray crystallographic analysis of its diacetate (6).
18 citations
TL;DR: In this article, the inhibitory effects of neoandrographolide compounds on nitric oxide production in lipopolysaccharide-activated macrophages were evaluated and their preliminary structure-activity relationships (SAR) were discussed.
Abstract: Microbial transformation of neoandrographolide ( 1 ), was performed by Mucor spinosus (AS 3.2450). Ten metabolites were obtained and identified as 14-deoxyandrographolide ( 2 ), 17,19-dihydroxy-8,13- ent -labdadien-16,15-olide ( 3 ), 3,14-dideoxyandrographolide ( 4 ), 7β-hydroxy-3,14-dideoxyandrographolide ( 5 ), 17,19-dihydroxy-7,13- ent -labdadien-16,15-olide ( 6 ), 8(17),13- ent -labdadien-16,15-olid-19-oic acid ( 7 ), 8α,17β-epoxy-3,14-dideoxyandrographolide ( 8 ), 8β,17,19-trihydroxy- ent -labd-13-en-16, 15-olide ( 9 ), phlogantholide-A ( 10 ), 19-[(β- d -glucopyranosyl)oxy]-19-oxo- ent -labda-8(17),13-dien-16,15-olide ( 11 ) by spectroscopic and chemical means. Among them, products 3 , 5 , 6 , 8 and 9 were characterized as new compounds. The inhibitory effects of compounds 1 – 11 on nitric oxide production in lipopolysaccharide-activated macrophages were evaluated and their preliminary structure–activity relationships (SAR) were discussed.
16 citations
TL;DR: In this article, a new diterpene glucoside, phloganthoside has been isolated from Phlogacanthus thyrsiflorus and its structure has been established as Phlogantholide-A-19- O -β- d -glucopyranoside.
13 citations
TL;DR: In this article, entlabdane diterpenoid glucosides, andropaniosides A and B, along with five known analogs, andrographiside, neoandrographolide and andropanoside, 14-deoxy-11,12-didehydroandrograpiside and 19-O-β-D-glucopyranosyl-entlabda-8(17),13-dien-15,16,19-triol were isolated from a methanol extract of the
10 citations
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TL;DR: Neoandrographolide (2) is shown to be the β-glucoside of ent -19-hydroxy-8(17), 13-labdadien-16,15-olide as mentioned in this paper.
44 citations
TL;DR: In this paper, a number of new transformation products of andrographolide and of its acid transformation product, isoandrograpolide, have been prepared; the structure of the iso-andrographylide has been elucidated; and the chemical results described afford proof of the stereochemistry at C-3 and C-9 of the bicyclic nucleus of androgramolide; the assigned configuration of the substituents at C -4 is supported by NMR study.
40 citations
37 citations
TL;DR: The remaining uncertainty in the structure of iresin (I) has now been settled rigorously by comparing the course of tribromination-dehydrobromination experiments of its derived nor-ketone XI with steroid models.
18 citations
TL;DR: In this article, the C-6 and C-11 resonance assignments of isovirescenol-B, made earlier, should be interchanged, and the corresponding C-12 resonance assignments for 14-deoxy-and-rographolide and isodeoxyandrograpolide should be replaced.
Abstract: Carbon-13 NMR signal assignments of the labdane diterpenoids andrographolide and 14-deoxyandrographolide, along with their acetates, and isodeoxyandrographolide have been made. This study indicates that the C-6 and C-11 resonance assignments of isovirescenol-B, made earlier, should be interchanged.
13 citations