COMPREHENSIVE PHARMACOGNOSTIC AND PHYTOCHEMICAL PROFILING OF TABERNAEMONTANA ALTERNIFOLIA LEAVES: QUANTIFICATION OF PHENOLICS, ALKALOIDS, FLAVONOIDS, AND EVALUATION OF AFLATOXIN AND HEAVY METAL CONTAMINATION

Objectives: The study aimed to establish pharmacognostic standards and quantify major bioactive constituents, phenolics, alkaloids, and flavonoids in the leaves of Tabernaemontana alternifolia (Apocynaceae). Methods: Leaves were collected from the Ratnagiri region of Maharashtra, India, authenticated, and subjected to detailed macroscopic, microscopic, physicochemical, and phytochemical evaluations. Microscopy was used to identify diagnostic anatomical features, whereas physicochemical parameters such as ash values and extractive values were determined using standard procedures. Qualitative and quantitative phytochemical analyses were performed to assess the presence and levels of key metabolites. Heavy metal content was analyzed using atomic absorption spectroscopy, and aflatoxins were assessed using liquid chromatography-tandem mass spectrometry (MS)/MS. Results: Microscopic examination revealed a dorsiventral leaf with bicollateral vascular bundles and abundant microsphenoidal calcium oxalate crystals. Physicochemical parameters included total ash (5.67±0.76% w/w), acid-insoluble ash (0.54±0.01% w/w), and water-soluble ash (3.21±0.04% w/w), confirming minimal inorganic contamination. Soxhlet extraction produced the highest extractive value (17.93±1.37% w/w). Phytochemical screening confirmed the presence of alkaloids, phenolics, flavonoids, tannins, saponins, proteins, and reducing sugars. Quantitative analysis showed notable levels of total phenolics (11.82 mg gallic acid equivalents/g), flavonoids (7.53 mg rutin equivalents/g), and alkaloids (4.0 mg atropine equivalents/g). Heavy metals (Cd, Pb, As, and Hg) were below detectable limits, and aflatoxins (B1, B2, G1, and G2) were absent. Conclusion: This study establishes key pharmacognostic and phytochemical benchmarks for T. alternifolia leaves. Soxhlet extraction yielded the highest extractive value, whereas quantitative analyses revealed appreciable levels of phenolics, flavonoids, and alkaloids, indicating notable bioactive potential. The absence of heavy metals and aflatoxins confirms material safety, supporting its standardization, quality control, and further pharmacological development.