New flavonoid glycosides and other chemical constituents from Clerodendrum phlomidis leaves: isolation and characterisation

Abstract

Phytochemical investigation of the plant Clerodendrum phlomidis Linn. F. (Lamiaceae) has now led to the isolation of two new flavonoid glycosides (1, 2) together with six known compounds identified as pectolinaringenin (3), pectolinaringenin-7-O-β-d-glucopyranoside (4), 24β-ethylcholesta-5,22E,25-triene-3β-ol (5), 24β-ethylcholesta-5,22E,25-triene-3β-O-β-D-glucopyranoside (6), (2S,3S,4R,10E)-2-[(2′R)-2′-hydroxytetracosanoylamino]-10-octadecene-1,3,4-triol (7) and andrographolide (8) mainly by spectroscopic analysis. Compounds 4 and 6–8 are reported for the first time from C. phlomidis.

Keywords::

• Clerodendrum phlomidis
• flavonoid glycosides
• 2D NMR (HSQC
• HMBC
• COSY
• NOESY)

Acknowledgements

The authors express their gratitude to the Director, IICB, for laboratory facilities. This work received financial assistance from the Council of Scientific and Industrial Research (CSIR) Government of India. B.Y., A.H., S.S., S.S. and A.K.M. are recipients of Research Fellowships and N.B.M. of an Emeritus Scientist grant from CSIR, India. Thanks are due to Dr B. Achari (Ex-Emeritus Scientist, CSIR), Dr Sukdeb Banerjee (Ex-Senior Principal Scientist, CSIR) for helpful suggestions and Mr E. Padmanaban for NMR spectra.