PubMed · 2699016
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
R D Murray. 1989. Coumarins.. https://doi.org/10.1039/np9890600591
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Coumarins are structurally diverse phenylpropanoid derivatives with ecological and pharmacological significance, yet the biosynthetic logic underlying their diversification remains incompletely understood in non-model medicinal plants. Angelica pubescens (Apiaceae), widely used in traditional Chinese medicine, accumulates a rich repertoire of furanocoumarins and dihydrofuranocoumarins, making it an ideal system to investigate this metabolic complexity. Here, we combined chromosome-level genome assembly, transcriptome and metabolite profiling, phylogenetics, and heterologous expression assays to dissect coumarin biosynthesis in A. pubescens. We identified two functionally specialized O-methyltransferases, ApOMT1 and ApOMT2, which catalyze regioselective methylation of xanthotoxol and bergaptol to yield the furanocoumarins xanthotoxin and bergapten. We also characterized ApCYP736A121, a cytochrome P450 enzyme that converts osthenol to the dihydrofuranocoumarin columbianetin via a previously unknown mechanism. Gene expression and metabolite accumulation patterns across tissues and developmental stages revealed functional partitioning among pathway branches. Phylogenetic and syntenic analyses indicated that ApOMT1 and ApOMT2 arose through subfunctionalization following gene duplication, whereas ApCYP736A121 evolved via neofunctionalization from a distantly related CYP736 ancestor. Together, our findings uncover dual biosynthetic routes to structurally distinct coumarins in A. pubescens and provide insights into the evolutionary mechanisms contributing to metabolic innovation in Apiaceae. This work lays a foundation for future efforts to engineer coumarin pathways and understand their ecological functions in medicinal plants.
Two new sesquiterpene coumarins, named szowitsiacoumarin A (1) and szowitsiacoumarin B (2), and a phenylpropanoid derivative, 2-epihelmanticine (3), together with nine known compounds, auraptene (4), umbelliprenin (5), galbanic acid (6), methyl galbanate (7), farnesiferol B (8), farnesiferol C (9), persicasulfide A (10), beta-sitosterol and stigmasterol were isolated from the roots of Ferula szowitsiana. The structures of these compounds were elucidated by extensive spectroscopic methods including 1D-((1)H and (13)C) and 2D-NMR experiments (DQF-COSY, HSQC, HMBC, and ROESY) as well as HR-MALDI-MS analysis. Since the configuration of 2-epihelmanticine was previously only partly determined, a relative configurational analysis of its four stereocenters was carried out on the basis of the recently reported J-based method. The inhibiting activity of prenylated coumarins, auraptene (4) and umbelliprenin (5), in addition to galbanic acid (6), as major component, and of the Me(2)CO extract of Ferula szowitsiana (Apiaceae) roots has been evaluated against promastigotes of Leishmania major. Umbelliprenin and auraptene showed significant activity with IC(50) values of 4.9microg/ml (13.3microM) and 5.1microg/ml (17.1microM) after 48h incubation, respectively.
The metabolic pools of Pelargonium sidoides DC and Pelargonium reniforme CURT, associated with the origin of the herbal medicine Umckaloabo, exhibit remarkable diversity and complexity. They comprise a variety of phenolic and polyphenolic compounds, a notable wealth of highly oxygenated simple coumarins and a number of miscellaneous uncommon metabolites. Noteworthy, the roots of both species express conspicuously distinct coumarin variations that facilitate their identification. Of the range of coumarins identified the titled species shared the ubiquitous scopoletin and the unique members 6,7,8-trihydroxycoumarin and 8-hydroxy-5,6,7-trimethoxycoumarin merely. Furthermore, the current data on the coumarin profiles suggest the occurrence of coumarin sulphates and coumarin glycosides to be apparently confined to P. sidoides, while the occurrence of conventional proanthocyanidins was a common chemical feature. An unprecedented diterpene, designated as reniformin, was encountered in the roots of P. reniforme, possessing a novel diterpene skeleton linked to a unique p-oxyphenethansulfonic moiety. Coumarins were less abundant in the aerial parts of both species. These were rich in flavonoids and hydrolysable tannins including a unique series of O-galloyl-C-glucosylflavones (P. sidoides and P. reniforme) and novel ellagitannins with a (1)C(4) glucopyranose core in P. reniforme, trivially named pelargoniins, accompanied by the new 4-allyl-2,5-dimethoxyphenol-1-beta-D-glucoside. These Pelargoniums have thus represented an attractive source of fascinating secondary metabolites. A proprietary extract of the roots of P. sidoides, EPs 7630, has been developed from this traditional herbal medicine and introduced into modern phytotherapy in Europe. Structural examination of EPs 7630 constituents showed excellent agreement of the profile with that of P. sidoides.