Evaluation of trigonelline content in some Trigonella species

Trigonelline (TG) which is derived from the methylation of the nitrogen atom from nicotinic acid, is thoroughly known for hypoglycemic, hypolipidemic properties. This study was taken to analyze genetic diversity in respect to evaluation and fluctuation of trigonelline content between five species of genus Trigonella L., comprised of T.uncata, T.monanta, T. arcuate, T. persica, and T.coerulescens. Hence the seeds of mentioned species were collected from different cultivation areas of Iran. By HPLC method, mobile phase composition was SLS (pH adjusted to 3 with HCl): acetonitrile (50.0:50.0 v/v) and the detection wavelength was at λ=265 nm. The result showed significant variation in alkaloid TG ingredient among different mentioned species. Majority of them were rich in TG and its recorded value was higher than standard pharmaceutical levels. Seeds of T. coerulescens, local selected clone from Azarbayjan-e Gharbi-Makoo with the amount of 92.78 μg/ml, presented a higher level in comparison with other species, and the lowest one (18.22μg/ml) belonged to T.monanta, which was cultured in Kermanshah- Javanrood. In addition, the highest amount of trigonelline obtained between T. uncata ecotypes belonged to Tu1 that was cultivated in Hormozgan-Hajiabad. Generally, TG content can be influenced by genotypic characteristic rather than environmental factors, however totally the resultant interaction between genotype and ecological factors impresses the content of alkaloid as a secondary metabolite. Our research confirmed that trigonelline was distinctive among the species and it can be considered as a taxonomic character for discrimination the taxonomic relationships between the different taxa at the inter- and intra-specific levels.

Keywords:

T. coerulescens , T. persica , Trigonelline , HPLC