Antioxidant, Antifungal and Aphicidal Activity of Triterpenoids Spinasterol, 22,23-Dihydrospinasterol From Colocynthis (Citrullus Colocynthis L.) Leaves

Abstract Terpenoids from natural plants resources are valuable for diverse biological activities which exhibited important part in medical and agrochemicals industry. This study aimed to assess the antioxidant, antifungal and aphicidal activity of a mixture of Spinasterol, 22,23-dihydrospinasterol from Citrullus colocynthis leaves. 1, 1-diphenyl-2-picrylhydrazyl (DPPH) was used to assess the antioxidant activity whereas, antifungal activity was tested by mycelium growth inhibition assay on three pathogenic fungi Magnaporthe grisea, Rhizoctonia solani and Phytophthora infestans. Aphicidal activity against adults of Myzus persicae was also determined via In-vitro and In-vivo assays. The outcome of the study exposed that Spinasterol, 22, 23-dihydrospinasterol afforded moderate antioxidant activity even at lower concentrations i.e. 19.98, 31.52, 36.61 and 49.76% at 0.78, 3.0, 12.5 and 50µgmL− 1 respectively. However, reasonable fungicidal activity of Spinasterol, 22; 23-dihydrospinasterol was recorded as being EC50 values 129.5 and 206.1µgmL− 1 against R. solani and M. grisea respectively. On the other hand, Boscalid and Carbendazim being a positive control proved highly effective against all fungi except for M. grisea and P. infestans with EC50 values 868 and 272109µgmL− 1 respectively. The significant insecticidal activity was afforded via residual as well as greenhouse assay being LC50 values as 42.46, 54.86, 180.9 µgmL− 1 and 32.71, 42.46 and 173.8µgmL− 1 at 72, 48 and 24 h respectively. Moreover, antioxidant activity of Spinasterol, 22,23-dihydrospinasterol presented strong positive correlation versus antifungal and insecticidal activity. Spinasterol, 22,23-dihydrospinasterol possess good antioxidant and aphicidal activity with moderate fungicidal activity which could be a suitable candidate as an alternative to synthetic pesticidal agents.