Indian Journal of Natural Products and Resources Vol. 3(1), March 2012, pp. 131-134 A simple and improved method for isolation of karanjin from Pongamia pinnata Linn. seed oil S D Katekhaye*, M S Kale and K S Laddha 1 Department of Pharmaceutical Sciences and Technology 1 Medicinal Natural Products Research Laboratory Institute of Chemical Technology, Matunga Mumbai-400 019, Maharashtra, India Received 14 February 2011; Accepted 16 November 2011 Study was undertaken with the objective to develop a simple method for isolation of karanjin from Karanja (Pongamia pinnata Linn.) seed oil. The seed oil was subjected to liquid–liquid extraction with methanol. The extract was further subjected to solvent partitioning followed by crystallization to get karanjin, purity of which was ascertained by HPLC. The purity of isolated karanjin was found to be 98%. Mass spectrum for the compound in ESI + mode showed signals at 293 [M+H] + , which confirmed the molecular weight to be 292. From IR, 1 H and 13 C NMR spectral data, structure elucidation was done and the structure was conformed as karanjin. Keywords: Pongamia pinnata, Karanjin, Karanja oil, Medicinal oil, HPLC. IPC code; Int. cl. (2011.01)—A61K 36/00 Introduction Pongamia pinnata (Linn.) Pierre syn. P. glabra Vent., belonging to family Fabaceae, is a medium sized glabrous tree, found throughout India up to an altitude of 1200 m. The plant, known as Karanj or Karanja, grows in forest from which many tonnes of seeds are collected every year in India 1 . Different parts of this plant have been used as a source of traditional medicine. P. pinnata seeds contain 33-36% oil which is mainly used in tanning industry for the dressing of leathers and to some extent it is used in soap industry. Oil is employed in scabies, herpes, leucoderma, sometime as stomachic and cholagogue in dyspepsia and sluggish liver 2 . Karanjin is an active principle responsible for the curative effects of the oil in skin diseases 1 . Seed extract inhibits growth of herpes simplex virus and also possesses hypoglycaemic, antioxidative, anti-ulcerogenic, anti-inflammatory and analgesic properties 3 . The seed oil contains 5-6 % flavonoids 1,4 in which the main constituent is karanjin, a furano- flavonoid (Figure 1). During the course of exploration of new compounds from P. pinnata seed oil several workers 5-11 have identified some new components of its seed oil apart from karanjin. Karanjin possess pesticidal 12 and insecticidal 13 activity, promising anti-hyperglycemic, anti-ulcer activity in experimental animals 14 and also anti-inflammatory activity 15 . Considering the role of karanjin in different areas and from reported work on the extraction, isolation and purification of karanjin gives an impression that there is a need to develop simple method for the isolation of karanjin in large quantities. Present study was aimed to develop the simple procedure for the isolation of karanjin from seed oil which will assist in evaluation, formulation development and can be employed to develop the natural pesticide for food and agricultural use. Materials and Methods Seed oil HPLC-grade methanol and AR grade petroleum ether (40-60°C) were sourced from Merck (India) and P. pinnata seed oil was procured from local market, Mumbai, India. Distilled water was filtered through 0.45 μm filter. Extraction and isolation In the present study, method for isolation of karanjin has been attempted (Flow Chart) with a view to minimizing the processing steps and to avoid tedious processes. Purification of karanjin by silica gel chromatography involves greater losses of karanjin resulting in poor yield 11,16 . Though the steps ——————— *Correspondent author: E-mail: shankar.katekhaye@gmail.com Figure 1—Chemical structure of karanjin