A new dimeric carbazole alkaloid from Murraya koenigii (L.) leaves with α-amylase and α-glucosidase inhibitory activities

Abstract

A new dimeric carbazole alkaloid, 3,3′,5,5′,8-pentamethyl-3,3′-bis(4-methylpent-3-en-1-yl)-3,3′,11,11′-tetrahydro-10,10′-bipyrano[3,2- a ]carbazole, was isolated from the hexane extract of leaves of Murraya koenigii (L.) Sprengel. (Family: Rutaceae). The structure was elucidated based on 13 C and 1 H NMR, High-Resolution Mass Spectrometry (HRMS), and 2D NMR data. The in vitro antidiabetic activity of the new dimer was investigated in terms of α-amylase and α-glucosidase enzyme inhibition assays. The dimer exhibited significant α-amylase inhibitory activity (IC 50 = 30.32 ± 0.34 ppm) and α-glucosidase inhibitory activity (IC 50 = 30.91 ± 0.36 ppm). • New dimeric asymmetric carbazole alkaloid was identified from fresh leaves of Murraya koenigii . • The new dimer has two different monomeric units connected at C-10 and C-10′. • The new compound exhibits significant α-amylase and α-glucosidase inhibitory activity. • And thus could be a potential lead compound for treatment of diabetes.