Biological evaluation of secondary metabolites from the roots of Myrica adenophora.
Bioassay-guided fractionation of the roots of Myrica adenophora led to isolation of 24 known compounds and hitherto unknown compounds, including three A-type proanthocyanidins [adenodimerins A-C], two esters of sucrose [myricadenins A and B ], and the phenolic glycoside 6'-O-galloyl orbicularin. Spectroscopic analyses were used to determine their structures. Adenodimerin A, myricananin C, and myricetin showed strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities, with SC50 values of 7.9, 16.3, and 15.9 μM, respectively. Adenodimerin A, myricanone, myricananin C, (-)-myricanol, myricanol 11-O-β-D-glucopyranoside, and myricetin showed stronger 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging activities than the positive control, with SC50 values of 7.5, 19.6, 12.0, 22.3, 19.6, and 15.6 μM, respectively. 5-Deoxymyricanone, porson, 12-hydroxymyricanone (-)-myricanol, and (+)-galeon exhibited anti-tubercular activity against Mycobacterium tuberculosis H37Rv in vitro and MICs values of 25.8, 40.0, 35.8, 30.0, and 15.0 μg/mL, respectively. Myricadenin A, myricanone, myricananin C, and (-)-myricanol exhibited anti-inflammatory activities in the iNOS assay with EC50 values of 18.1, 1.00, 13.0, and 7.5 μM, respectively.
Constituents of Eugenia sandwicensis with potential cancer chemopreventive activity.
A triterpenoid, 3beta-cis-p-coumaroyloxy-2alpha,23-dihydroxyolean-12-en-28-oic acid (1), and two natural products, 3beta-trans-p-coumaroyloxy-2alpha,23-dihydroxyolean-12-en-28-oic acid (2) and 23-trans-p-coumaroyloxy-2alpha,3beta-dihydroxyolean-12-en-28-oic acid (3), were isolated from a chloroform-soluble extract of the stems of Eugenia sandwicensis, along with 10 known compounds. Of these compounds, 2 showed significant inhibitory activity (79.2% at 4 microg/ml) in a 7,12-dimethylbenz[a]anthracene-induced mouse mammary organ culture assay system of relevance to cancer chemoprevention. Gallic acid was isolated as an antioxidative constituent of an ethyl acetate-soluble extract of E. sandwicensis stems. Isolates 1-3 were characterized on the basis of spectral and chemical evidence.
Pterocarine, a New Diarylheptanoid from Pterocarya tonkinesis, Its Cell Cycle Inhibition at G0/G1 Phase and Induction of Apoptosis in HCT-15 and K562 Cells
Pterocarine (1), a new diarylheptanoidal compound, was isolated from Pterocarya tonkinesis (Franch.) Dode. together with a known diarylheptanoid, myricatomentogenin (2), through a bioassay-guided fractionation procedure. The structure of 1 was elucidated as (+)-3',4”-epoxy-1-(4'-hydroxyphenyl)-7-(3”-hydroxyphenyl)-heptane-3-one by the spectroscopic methods. Pterocarine (1) inhibited the proliferation of tsFT210, HCT-15 and K562 cells with the inhibition rates of 20.2±2.4, 23.8±2.4 and 50.5±1.2% at 100μg/mL, respectively. Flow cytometric analysis indicated that 1 could inhibit the cell cycle of tsFT210, HCT-15 and K562 cells at the G0/G1 phase and could also induce apoptosis in HCT-15 (19%) and K562 (11%) cells.