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Biosynthesis of a Flavonol from a Flavanone by Establishing a One-pot Bienzymatic Cascade
Published on: August 14, 2019
Two new flavonol glycosides from Otostegia limbata BENTH.
Afsar Khan1, Viqar Uddin Ahmad, Umar Farooq
1H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan.
Chemical & Pharmaceutical Bulletin
|March 3, 2009
Summary
Two novel, complex flavonol glycosides were isolated from Otostegia limbata roots. These compounds represent the largest flavonoid derivatives discovered in the Otostegia genus to date.
Area of Science:
- Phytochemistry
- Natural Product Chemistry
- Organic Chemistry
Background:
- The genus Otostegia is known for its diverse secondary metabolites.
- Flavonol glycosides are a class of compounds with potential biological activities.
- Exploring the chemical constituents of medicinal plants is crucial for discovering new therapeutic agents.
Purpose of the Study:
- To isolate and characterize new compounds from Otostegia limbata.
- To investigate the chemical diversity of flavonoids within the Otostegia genus.
Main Methods:
- Extraction of plant material using methanol and subsequent partitioning with BuOH.
- Isolation of compounds using chromatographic techniques.
- Structure elucidation using spectroscopic methods (NMR, MS) and chemical analysis.
Main Results:
- Two new flavonol glycosides were identified: kaempferol 3-O-[beta-D-glucopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->3)]-[beta-D-glucopyranosyl-(1-->4)]-alpha-L-rhamnopyranoside]-7-O-[alpha-L-rhamnopyranoside] and kaempferol 3-O-[beta-D-glucopyranosyl-(1-->4)-beta-D-6'''''[4-hydroxy (E)-cinnamoyl]glucopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-rhamnopyranoside]-7-O-[alpha-L-rhamnopyranoside].
- These compounds are characterized by their large and complex glycosidic structures.
- To the best of the authors' knowledge, these are the largest flavonoid derivatives reported from the Otostegia genus.
Conclusions:
- The study successfully identified two novel and structurally complex flavonol glycosides from Otostegia limbata.
- The findings expand the known chemical diversity of flavonoids in the genus Otostegia.
- These complex natural products warrant further investigation for their potential biological activities.
