International Journal of Phytomedicine 8 (2016) 80-94 http://www.arjournals.org/index.php/ijpm/index Original Research Article Antimicrobial Activity of Some Trigonella Species Rakhee Dangi 1, 3* , Dasharath Oulkar 2 , Prashant Dhakephalkar 1 , Sanjay Kumar Singh 1 , Kaushik Banerjee 2 , Dattatray Naik 1 , Shubhada Tamhankar 1 , Suryaprakasa Rao 1, 4 *Corresponding author: Rakhee Dangi 1 Agharkar Research Institute, GG Agarkar Road, Pune 411004, Maharashtra, India. 2 National Research Centre for Grapes, Solapur Road, Pune 412307, Maharashtra, India. 3 Present Address: Bharati Vidyapeeth’s Rajiv Gandhi Institute of Information Technology and Biotechnology, Katraj-Dhankavdi, Pune 411043, Maharashtra India. 4 Present Address: Indian Institute of Science Education and Research (IISER) 900, NCL Innovation Park, Dr Homi Bhabha Road ,Pune 411008, Maharashtra India. Abstract The genus Trigonella includes many medicinal and aromatic plant species used in traditional as well as veterinary medicines for different diseases, alone or in combination with other remedies. The crude methanol extracts of 15 Trigonella species were assayed for antimicrobial activity against four medicinally important multidrug resistant clinical isolates, five plant pathogenic bacteria and five fungi. Three species showed a broad spectrum of antibacterial activity inhibiting all the test bacteria. Acidified ethanolic extract of the most promising species, T. suavissima was purified by column chromatography. Characterization of a partially purified ethyl acetate fraction by LC/ESI/MS showed the presence of 7’4’ dihydroxy flavone and (2E)-3-{5-[4-(Ethoxycarbonyl)phenyl]furan-2-yl}prop-2- enoate) Three species showed strong antifungal activity against Aspergillus niger and Fusarium solani. The saponin extract of T. spicata showed a selective activity against A. niger and the sapogenin extract against F. solani. A polyhydroxylated alkaloid was isolated from the sapogenin extract of T. spicata using chromatographic techniques with structural characterization done by LC/ESI/MS, 13 C and 1 H NMR. The study reveals that Trigonella species are potential sources of natural compounds that may act as antimicrobial agents. It represents the most extensive survey of antimicrobial activity in Trigonella done to date.. Keywords: Antimicrobial activity; Trigonella suavissima Lindl; T. spicata Sm; Saponins; Sapogenin Introduction Plants are rich source of a variety of bioactive secondary metabolites reported to have in vitro antimicrobial properties. The revival of interest in plant derived antimicrobial compounds is mainly due to the current wide spread belief that “green medicine” is more safe than costly synthetic drugs, many of which have adverse side effects. Active agents from plants are not only non- toxic but also easily biodegradable. Many of the earliest drugs and pesticides were plant extracts and several plants have been exploited for their antimicrobial activity [1]. The genus Trigonella includes medicinal and aromatic plant species at a risk of genetic erosion [2]. Fenugreek (T. foenum- graecum) has been referred to as a medicinal herb both in Indian “Ayurvedic” and traditional Chinese medicines. Medicinal uses vary from wound healing to promotion of lactation in weaning mothers and a sex stimulant. Fenugreek seeds in human diet can reduce blood sugar, blood cholesterol and sickness due to air pollution [3]. Some sources of fenugreek seeds have been reported to possess antimicrobial activity against both gram-positive and gram-negative bacteria [4] while extracts from fenugreek seeds examined by De et al. [5] were unable to prevent the growth of either bacteria or yeast. Fatty oil from fenugreek seeds (T. foenum-graecum) has been reported to be useful for developing plant derived antifungal drugs [6]. Though much attention has been paid to T. foenum- graecum, nevertheless there are a number of other species of this genus, known to occur as weeds but need more studies [7]. Wild and weedy legume species of Trigonella are used in traditional as well as veterinary medicines for different diseases, alone or in combination with other remedies. Normally, these plants are picked up by the poorer class and used as vegetable with some species used since centuries in traditional “ayurvedic” or ethnomedical practices as alternative source of medicine [7, 8]. Many are included in Indian herbals along with T. foenum-graecum [9]. Since Trigonella species have received little assessment for their medicinal potential, the present paper describes the results of screening organic extracts of Trigonella against a wide range of ISSN: 0975-0185 This work is licensed under a Creative Commons Attribution 3.0 License.