Isolation, characterization, HPLC quantification, in-vitro and in-silico evaluations of coumarins and coumarolignans from Blighia unijugata stem with their chemotaxonomic significance

Abstract

Blighia unijugata Baker (Bu) is an ethno-medicinal plant reputed for its antioxidant, anti-diabetic, anti-inflammatory, and anticancer properties. However, these claims lack scientific validation regarding the isolation and characterization of its bioactive compounds. This study aimed to isolate, characterize, and evaluate the biological potential of compounds from Bu stem, complemented with in-silico analysis.

Ten known compounds, including umbelliferone, scopoletin, cleomiscosin A-D, linustam A, fraxin, lupeol, and stigmasterol, were isolated and characterized for the first time from Bu, with cleomiscosin A-D, and linustam A being reported for the first time from the genus, highlighting their taxonomic importance. HPLC quantification of major coumarin derivatives from the stem was also achieved. Cleomiscosin A-D, linusam A, and scopoletin demonstrated significant antioxidant activity with IC₅₀ values ranging from 43.2 to 58.4 μg/mL (DPPH) and 12.8–44.3 μg/mL (ABTS•). Cytotoxicity assays showed that Bu isolates had minimal toxicity on RAW 264.7 macrophage cells. The α-amylase inhibition IC₅₀ values ranged from 70.7 to 273.1 μg/mL, with scopoletin (70.7 μg/mL) showing activity comparable to acarbose (62.6 μg/mL). In-silico molecular docking revealed that Cleomiscosin C, Cleomiscosin D, and Fraxin exhibited strong interactions and affinity against Poly (ADP-ribose) polymerase 1 (PARP1), with binding energies of −8.67, −8.91, and −9.59 kcal/mol, respectively.

This study highlights the therapeutic potential of Bu, particularly in cancer treatment, suggesting PARP1 inhibitory potential underscoring the significance of in-silico analyses in understanding their biological activities, warranting further investigation into their mechanisms of action and therapeutic applications.