Comparative phytochemical screening through high-performance thin layer chromatography technique and free radical scavenging ability of five species of genus Clerodendrum

Species of Clerodendrum are a well-known medicinal plant in the Indian traditional system of medicines for its multi-purpose use in the management of various diseases or disorders. For scientific validation of the traditional claims, this study aimed to delineate the antioxidant properties and phenolic contents of methanolic leaf extracts of five species under the genus Clerodendrum viz . , Clerodendrum viscosum Vent . (CV), Clerodendrum indicum (L.) Kuntze (CIN) , Clerodendrum inerme (L.) Gaertn. (CI) , Clerodendrum chinense (Osbeck) Mabb. (CC) and Clerodendrum japonicum (Thunb.) Sweet (CJ). The antioxidant activities of the extracts were evaluated by the ABTS, DPPH, ferric reducing antioxidant power (FRAP) and total antioxidant capacity (PMD) assays. Chromatographic and spectrophotometric techniques were used to determine the total phenolic and flavonoid contents of the extracts. Out of the five plants, CC showed the most prominent antioxidant activity in comparison with standard antioxidant compound (Ascorbic acid) with IC 50 values of 58.22 ± 1.23 μg/mL (for DPPH), 122.11 ± 4.00 μg/mL (for ABTS), 105.33 ± 5.14 μg/mL (for FRAP) and 166.11 ± 3.52 μg/mL (for PMD) assay. HPTLC fingerprint indicated significant variations in the phytoconstituents of the five species. The gallic acid and vanillic acid were the two prominent phenolic compounds present in three species viz., CV, CI , and CC. Moreover, CC showed a significant correlation between antioxidant capacities and their total phenolic contents, which corroborate s the traditional claims of local people . Thus, promising antioxidant ability and distinctive presence of polyphenolic compounds suggest that CC plant may be helpful in the future development of herbal formulations and natural sources of antioxidants in the food and pharmaceutical industries.