Variability of flavonoids contents in young flowers of Siamese neem tree

• Published in: Planta Medica
• Main Authors: Chaisawangwong, W, Gritsanapan, W
• Format: Conference Proceeding
• Language: English
• Published: 21.07.2009
• ISSN: 0032-0943; 1439-0221
• DOI: 10.1055/s-0029-1234670

Siamese neem tree ( Azadirachta indica A. Juss. var. siamensis Valeton) of the family Meliaceae is a medicinal plant found in every part of Thailand. Young leaves and flowers of this plant are commonly consumed as a bitter tonic vegetable [1]. The flower extract has been reported to exhibit in vitro free radical scavenging activity and can inhibit lipid peroxidation of bronchogenic cancer cell line [2]. Active compounds in the flowers are flavonoids such as rutin and quercetin [3]. Decoction extract of the flowers of Siamese neem tree gave the most effective DPPH scavenging activity [4]. In this experiment, the decoction extracts of the young flowers collected from 14 different locations in Thailand were quantitative analyzed for the contents of active components rutin and quercetin. By validated HPLC, the aqueous flower extracts contained rutin, and quercetin in the ranges from 429.81±0.18 to 1081.77±0.68mg %w/w (average 757.74±251.60mg %w/w), and 3.12±0.02 to 19.62±1.06mg %w/w (average 9.84±6.27mg % w/w), respectively. HPLC chromatograms of all extracts showed similar pattern which rutin is a major active constituent. The ranges of flavonoids contents will be useful as a guidance for standardization of the flower extracts of this plant for pharmaceutical purposes. Acknowledgements: This project was granted by The Thailand Research Fund (TRF) with Office of Small and Medium Enterprises Promotion (OSMEP). References: [1] Clayton, T. et al. (1996) Medicinal plants in Thailand, Amarin Printing, Bangkok, Thailand. [2] Sithisarn, P., Gritsanapan, W. (2005) Mahidol J. Pharm. Sci. 32:31–35. [3] Sithisarn, P. et al. (2005)J. Ethnopharmacol. 99:109–112. [4] Chaisawangwong, W., Gritsanapan, W. (2007) Proceedings of Pharma Indochina V, Bangkok, Thailand.