Quantitative and Qualitative Analysis for Phenolic Compounds and Phytochemical Screening and Targeting of Leaves and Fruits of Lotus tetragonolobus L.

Abstract

Lotus tetragonolobus L. is a Mediterranean annual legume for which phytochemical information remains scarce. This paper made a qualitative comparative study on the phytochemical composition of aqueous and alcoholic extracts of leaves and fruits and investigated the distribution of 11 phenolic analytes of interest in both organs. Tannins and flavonoids always appeared in both tissues and both extraction media, but carbohydrates and/or glycosides appeared with lower qualitative strength. Saponins were observed in the alcoholic fruit extract only, sterols in the alcoholic leaf extract only, and triterpenoids in the aqueous leaf extract and the two fruit extracts. Under these conditions, alkaloids, anthraquinones, and cardiac glycosides were not detected. The cumulative response of the targeted phenolic panel was 8.029 in the leaves and 37.913 in the fruits, which means that the cumulative response in the fruits was about 4.72-fold higher. The highest values were 2-chlorophenol (8.219ppm), 4-nitrophenol(7.002ppm) and phenol (6.569ppm) in fruits; 2,4-dinitrophenol (3.495) and 4-nitrophenol (1.883) were the greatest in leaves. These results show that the chemical profile measured exhibits evident organ-dependent differences. Due to the presence of many reported analytes that are halogenated or nitrated phenols, as opposed to more conventional endogenous phenolics of plants, definitive biological interpretation requires confirmation of compound identity, quality-control performance, and possible environmental or procedural sources. The dataset is a useful preliminary basis for chromatogram validation and bioactivity-directed exploration of L. tetragonolobus.