5α-Acetyl Isogoniothalamin Oxide: A Novel Styrl Lactone From Goniothalamus sesquipedalis (Annonaceae)

Author

CM. Hasan1, M.Y. Mia1, M.A. Rashid1 and J.D. 2, 1Department of Pharmacy, University of Dhaka, Dhaka-1000, Bangladesh 2Department of Chemistry. University of Glasgow, G12 8QQ, U.K.

Proceeding

Trends in Traditional Medicine Research, Proceedings of the International Conference on the Use of Traditional Medicine & Other Natural Products in Health Care

Date

8/6/1993

Keyword

Goniothalamus sesquipedalis, Thomas, styryl lactone, antibacterial property.

Abstract

Goniothalamus sesquipedalis Hook, f and Thomas is a small shrub that grows in hilly areas of Bangladesh. Plants of this genus are reported to exhibit potential antitumour, cytotoxic and pesticidal activities. The petroleum ether extract of stem bark of Goniothalamus sesquipedalis afforded a new styryl lactone, the structure of which was established as 6-(7,8-trans-epoxystyryl-5, 6-dihydro-5-acetyl)-2-pyrone (5α-acetyl isogoniothalamin oxide) on the basis of comparison of its 1H and 13C spectral data with those of related compounds goniothalamin oxide, synthetic isogoniothalamin oxide and 5α -acetyl goniothalamin. Further, the stereochemistry of the protons at C-5 and C-6 as well as the acetyl moiety was confirmed by NOE experiments. In vitro antibacterial screening of the styryl lactone against 10 pathogenic organisms showed promising results. The minimum inhibitory concentration (MIC) of 5α -acetyl isogoniothalamin oxide was also determined and was found to be 4 µg/ml  against Vibrio cholerae.