Available online www.jocpr.com Journal of Chemical and Pharmaceutical Research, 2016, 8(1):389-393 Research Article ISSN : 0975-7384 CODEN(USA) : JCPRC5 389 Isolation of flavonoids from Indigofera heterantha seeds Taj Ur Rehman 1,2* , Ghias Uddin 1 and Khanzadi Fatima Khattak 1 and Wajiha Liaqat 2 1 Department of chemistry, Abdul Wali Khan University, Mardan, KPK, Mardan, Pakistan 2 Institute of Chemical Sciences, University of Peshawar, Peshawar, K.P.K, Pakistan _____________________________________________________________________________________________ ABSTRACT The seeds of Indigofera heterantha yielded a flavonoid characterized as quercetin 3-O-α-L-rhamnoside along with known 3,5,7-trihydroxy-6,4´-dimethoxyflavone and 3,5,4´-trihydroxy-6,7-dimethoxyflavone. The isolated compounds were characterized by using modern spectroscopic techniques such as UV, IR, NMR and mass. Key words: Indigofera heterantha seeds, Leguminosae, flavonoids _____________________________________________________________________________________________ INTRODUCTION Indigofera heterantha Wall, commonly known as Himalayan Indigo is a deciduous shrub. It is widely distributed in tropical region of the world. In Pakistan, genus Indigofera is represented by about 24 species [1]. A number of phytochemicals such as lignins, triterpenes, steroids, alkaloids, flavonoids, acylphloroglucinols, saponins, tannins, quinines, rutin, cafffeic acid, gallic acid, myricetin, galangin and quercetin have been reported from the genus [2-4]. Some species of this genus contains nitro group containing chemical compounds including 3-nitropropionate and other toxic substances which act as suicide in-activators of succinate dehydrogenase [2]. The current phytochemical investigation on the seed constituents of Indigofera heterantha, led to the isolation of three flavonids. Out of these three compounds, one is new source and the remaining are known. EXPERIMENTAL SECTION General procedure The ultraviolet (UV) spectral analysis was carried out in methanol by using Hitachi U-3200 spectrophotometer. Similarly, JASCO 302-A infrared spectrometer was used for carrying out infrared (IR) spectral analysis. The 1 H and 13 C NMR spectra were obtained at (400, 500, 100 and 125 MHz on Bruker AM-400 and AMX-500) nuclear magnetic resonance spectrometers using tetramethylsilane (TMS) as internal reference. The Heteronuclear 2D 1 H- 13 C chemical shift experiments were done at 500 MHz. The NOE difference measurements were carried out on Bruker A M-600. The electron impact (EI) mass spectra were conceded via Finnegan MAT 311 and 312 spectrometers, joined with PDP 11/34 computer system. Both the high resolution mass measurements (HR-MS) and fast atomic bombardment (FAB) mass measurements were recorded on Joel JMS HX 110 mass spectrometer using glycerol or thioglycerol as the matrix and cesium iodide (CsI) as internal standard for exact mass measurements. Column chromatography was conceded on silica gel (Si 60, 70-230 mesh, Merck) and the vacuum liquid chromatography (VLC) was done on (Si 60, GF 254 , E. Merck) silica gel. The Flash column chromatography was carried out via (Si 60, 230-400 mesh, E. Merck) silica gel as adsorbent using Eyela Flash Chromatograph model known as EF-10, by the process of purification. In addition to it, (20×20, 0.5 mm thick; E. Merck) precoated silica