Jing-Rong Cui

NO inhibitory guaianolide-derived terpenoids from Artemisia argyi

An unusual dimeric guaianolide, artemilinin A (1) and a sesquiterpene-monoterpene lactone, isoartemisolide (2), were isolated from the leaves of Artemisia argyi. Their structures were elucidated on the basis of extensive spectroscopic analysis (IR, HR-ESIMS, 1D- and 2D-NMR), and the absolute configurations were determined by CD spectra and quantum chemical ECD calculation. Furthermore, in in vitro assay, compound 2 exhibited pronounced inhibition on the lipopolysaccharide (LPS)-induced nitric oxide (NO) production in BV-2 microglial cells with an IC50 value of 4.00μM.

Cytotoxic activity of some Asarum plants.

The cytotoxic activity against some tumor cell lines of 16 commonly used species of Asarum was evaluated in this study. All of these plants were widely used in Asian countries as traditional medicines or folk medicines. Their inhibitory activities against four tumor cell lines (HL-60, BGC-823, KB and Bel-7402) were compared. It was observed that 10 of the tested extracts (eight ethanol extracts and two water extracts) among 32 extracts of these plants showed cytotoxic activity. Those 95% ethanol extractions from A. caudigerellum, A. forbesii, A. inflatum and A. maximum exhibited the highest cytotoxic activity, and 95% ethanol extracts or water extracts of A. sieboldii var. seoulense, A. himalaicum, A. splendens and A. crispulatum showed selective activity against one or two cells among the tested tumor cells. This is the first report of Asarum plants possessing cytotoxic activity against tumor cell lines.

SYNTHESIS, SPECTROSCOPIC CHARACTERIZATION, AND IN VITRO ANTITUMOR ACTIVITY OF TETRAPHENYLANTIMONY DERIVATIVES OF ANALOGUES OF DEMETHYLCANTHARIDIN AND DEMETHYLDEHYDROGEN-CANTHARIDIN

ABSTRACT A series of novel tetraphenylantimony(V) derivatives of the analogues of demethylcantharidin and demethyldehydrogencantharidin, exo-7-oxa-bicyclo[2,2,1]-heptane-3-arylamide-2-carboxylic acid and exo-7-oxa-bicyclo[2,2,1]-heptene-3-arylamide-2-carboxylic acid, of the general formulas , , , and have been synthesized and characterized by elemental analyses, IR, 1H NMR and mass spectroscopy. Preliminary antitumor activity tests show that these compounds have significant antitumor activity in vitro against five human neoplastic cell lines.

Cytotoxic oleanane triterpenoid saponins from Albizia julibrissin

Bioassay-guided fractionation of the ethanolic extract of the stem bark of Albizia julibrissin led to the isolation of ten new oleanane-type triterpenoid saponins, julibrosides J37-J46 (1-10), along with six known analogues (11-16). In addition, 11 prosapogenins (17-27) were prepared by mild or strong alkaline hydrolysis of the total saponin. The structures of 1-27 were determined by spectroscopic and chemical means, and their cytotoxicities against four human cancer cell lines, BGC-823, A549, HCT-116, and HepG2 were evaluated. Compounds 5-16 exhibited significant inhibitory activity with IC50 values ranging from 2.59 to 9.30μM, and 8 turned out to be the most active compound with all IC50 values <5μM. A preliminary structure-activity relationship of these saponins clearly indicated that the outer monoterpenoid moiety (MT) is a crucial substituent for cytotoxicity, and the linkage sites of the MT unit greatly influenced the activity. It could also be inferred that the existence of 16-OH of the aglycone almost has no effect on cytotoxicity and the N-acetyl-glucosamine moiety at C-3 seems to enhance activity.