Norlignans from Pouzolzia zeylanica var. microphylla and their nitric oxide inhibitory activity

Identification of lignans as ATP citrate lyase (ACLY) inhibitors from the roots of Pouzolzia zeylanica

A new lignan, named pouzolignan P (1), together with 14 known ones (2 - 15) were isolated from the roots of Pouzolzia zeylanica (L.) Benn. Their structures were deduced based on the detailed spectroscopic analysis. All the isolates were evaluated for their inhibitory activities toward the ATP citrate lyase (ACLY). Among them, four lignans, isopouzolignan K (3), gnemontanins E (5), gnetuhainin I (6), and styraxlignolide D (15) showed excellent ACLY inhibitory effect with IC50 values of 9.06, 0.59, 2.63, and 7.62 μM, respectively. These compounds were further evaluated for their cholesterol-lowing effects on ox-LDL-induced high-cholesterol HepG2 cells. Compound 15 emerges as the most potent ACLY inhibitor, which significantly decreased the TC level in a dose-dependent manner. In addition, molecular docking simulations elucidated that 15 formed a strong hydrogen-bond interaction with Glu599 of ACLY, which was an important site responsible for the enzyme catalytic activity.

New Neolignan and Dihydrostilbene Derivatives from Pouzolzia sanguinea Inhibit NO Production in LPS-Activated BV2 Cells

Three dihydrostilbene derivatives (1-3) and 5 neolignans (4-8) were isolated from the ethyl acetate-soluble fraction of Pouzolzia sanguinea. Two new compounds (1 and 4) were obtained. Their structures, as well as their absolute configuration, were elucidated by means of high-resolution electrospray ionization mass spectrometry, nuclear magnetic resonance, and circular dichroism spectral data. Compounds 1-8 inhibited NO production in lipopolysaccharide-activated BV2 cells with half-maximal inhibitory concentration (IC50) values ranging from 22.7 ± 1.5 to 61.2 ± 3.1 µM. Of these, compounds 1 and 2 exhibited the most NO inhibitory activity with IC50 values of 22.7 ± 1.5 and 25.1 ± 2.1 µM, respectively, in comparison with the positive control, NG-monomethyl-L-arginine, IC50 value 22.1 ± 1.2 µM.

Two new norlignans from the aerial parts of Pouzolzia sanguinea (Blume) Merr

Two new norlignans, pouzolignan N (1) and pouzolignan O (2), together with five known norlignans, pouzolignan F (3), pouzolignan G (4), pouzolignan H (5), pouzolignan L (6), and gnetifolin F (7) were isolated from the aerial parts of Pouzolzia sanguinea (Blume) Merr. Their chemical structures were elucidated via HR-ESI-MS and NMR spectroscopic methods. Absolute configurations at stereocenters were confirmed by comparisons of CD spectra with those of TD-DFT calculations. Compounds 1-6 exhibited chemical structures unique to Pouzolzia species. At a concentration of 30 µM, compounds 1-7 exhibited weak cytotoxic activity toward CAL27 and MDA-MB-231 cell lines (cell viability from 65.3 ± 0.86 to 98.8 ± 1.23%). They also inhibited anoctamin-1 activity with inhibitory rates from 8.1 ± 0.87 to 24.3 ± 1.41%.