Five new terpenoids, including two vibsane-type diterpenoids (1, 2) and three iridoid allosides (3-5), together with eight known ones, were isolated from the leaves and twigs of Viburnum odoratissimum var.sessiliflorum. Their planar structures and relative configurations were determined by spectroscopic methods, especially 2D NMR techniques. The sugar moieties of the iridoids were confirmed as β-D-allose by GC analysis after acid hydrolysis and acetylation. The absolute configurations of neovibsanin Q (1) and dehydrovibsanol B (2) were determined by quantum chemical calculation of their theoretical electronic circular dichroism (ECD) spectra and Rh₂(OCOCF₃)₄-induced ECD analysis. The anti-inflammatory activities of compounds 1, 3, 4, and 5 were evaluated using an LPS-induced RAW264.7 cell model. Compounds 3suppressed the release of NO in a dose-dependent manner, with an IC₅₀ value of 55.64 μmol·L^-1. The cytotoxicities of compounds 1-5 on HCT-116 cells were assessed and the results showed that compounds 2 and 3 exhibited moderate inhibitory activities with IC₅₀ values of 13.8 and 12.3 μmol·L^-1, respectively.
Terpenes/pharmacology* ; Viburnum/chemistry* ; Molecular Structure ; Diterpenes/chemistry* ; Plant Leaves/chemistry*

OBJECTIVETo study the antiproliferation effect on HepG2 cells and its underlying mechanism of the active chemical composition of the Viburnum Odoratissimum.

METHODS3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction assay and trypan blue dye exclusion assay were used to assess the effect of vibsane-type diterpenoids on the proliferation of various tumor cells. Alterations in cell cycle and apoptosis were determined by flowcytometry. The enzymatic activity of caspase-3/7 was measured by Apo-ONE homogeneous Caspase-3/7 Assay kit.

RESULTSCompound 1 #, a vibsane-type diterpenoid, was found to significantly inhibit the growth of HepG2 cells by anticancer proliferation activity screening. It was demonstrated that the modified groups on side chain coupled to C11 site affected the cell growth-inhibition activity of compounds by structure-activity analysis. In addition, HepG2 cell line was most sensitive to compound 1 #, which induced growth arrest of HepG2 cells in a dose- and time-dependent manner. Study on the mechanisms underlying these effects indicated that compound 1 # induced significant G0/G1 phase arrest of HepG2 cells in a time- and concentration-dependent manner. Meanwhile, It was found that higher concentrations of compound (5-10 micromol/L) caused evident increase in the unmber of apoptotic cells and dose-dependent activation of caspase-3/7.

CONCLUSIONVibsane-type diterpenoids could significantly inhibit the growth of HCC HepG2 cells. Induction of cell cycle arrest and apoptosis may play important roles in their anticancer effects.

Apoptosis ; drug effects ; Cell Cycle Checkpoints ; drug effects ; Cell Proliferation ; drug effects ; Diterpenes ; pharmacology ; Hep G2 Cells ; Humans ; Viburnum ; chemistry

Viburnum odoratissimum is a folk medicinal plant, it can dredge the meridian passage and contains mainly diterpenes, triterpenes, flavonoids, sesquiterpenes, lignans, coumarin glycosides, etc. Vibsanin-type diterpenoids are the characteristic compounds of V. odoratissimum, and are divided into eleven-membered ring, seven-membered ring, and rearrangement-type. Vibsanin B, vibsanin C and neovibsanin A are the representative compounds of the three subtypes of vibsanin-type diterpenoids respectively. V. odoratissimum has cytotoxic activity, antibacterial activity, fish piscicidal activity and activity of inhibiting the growth of plants, Cytotoxic activity is the main biological activity.
Animals ; Antineoplastic Agents, Phytogenic ; chemistry ; isolation & purification ; pharmacology ; Cell Line, Tumor ; Cytotoxins ; chemistry ; isolation & purification ; pharmacology ; Diterpenes ; chemistry ; isolation & purification ; pharmacology ; Flavonoids ; chemistry ; isolation & purification ; Humans ; Lignans ; chemistry ; isolation & purification ; Molecular Structure ; Plant Leaves ; chemistry ; Plants, Medicinal ; chemistry ; Triterpenes ; chemistry ; isolation & purification ; pharmacology ; Viburnum ; chemistry