Abstract
•Naphthoquinones (1-9) were isolated from chloroform soluble fraction of Diospyros lotus.•Compound (1-9) was studied for in vitro antiglycation potential; among tested compound; compound 4 and 5 was found most active.•It is concluded that naphthoquinones (1-8) exhibited good antiglycation and lipoxygenase inhibitory potential.
Medicinal plants are a key source of important natural products, which are used for discovery of new drugs. The aim of this work was to explore the natural compounds having in vitro antiglycation and lipoxygenase inhibition potential. Consequently, compounds such as di-naphthodiospyrols A (1), di-naphthodiospyrols B (2), di-naphthodiospyrols C (3), di-naphthodiospyrols D (4), di-naphthodiospyrols E (5), di-naphthodiospyrols F (6), di-naphthodiospyrols g (7), 8-hydroxyisodiospyrin (8), and diospyrin (9) were isolated for the first time from Diospyros lotus Linn. In vitro antiglycation and lipoxygenase inhibitory activity results indicated that compound 4 exhibits the highest antiglycation activity with inhibition IC50 = 287.45 ± 1.60 μM), followed by compound 5 with an IC50 value of 248.72 ± 2.09 μM respectively. Similarly, compounds 7 and 8 showed moderate activity with IC50 values of 234.87 ± 2.00 , and 228.98 ± 1.98 μM, respectively, when compared with rutin (IC50 = 295.22 ± 1.55 μM). . The isolated compounds (1‒9) were also subjected to lipoxygenase inhibitory activity. Results revealed that secondary metabolites (1‒7) exhibit an excellent inhibitory effect against lipoxygenase, with IC50 values of 90.35 ± 0.96, 87.09 ± 1.00, 84.01 ± 1.01, 40.49 ± 0.49, 44.70 ± 0.49, 79.04 ± 0.86, and 62.09 ± 0.18 μM, for compounds 1, 2, 3, 4, 5, 6, and 7, respectively. The standard drugs Baicalein and Tenidap sodium exhibited inhibitory effect with IC50 values of 40.98 ± 0.08 μM and 23.00 ± 0.05 µM, respectively. Within this context, compounds with high inhibition potential against lioxygenase can be regarded as lead compounds in drug discovery. Furthermore, these compounds can be further studied as antiglycating agents to increase the chemical space for new chemical entities having drug-like properties.