In the course of study on Psiadia dentata (CASS.) DC, an endemic species of the Reunion Islands used in traditional medicine to treat abscesses, 2) two methoxylated flavonoids, 3,4Ј-dimethylkaempferol (ermanin) and 3-methylkaempferol (isokaempferide), have been isolated as a result of a bioassay guided fractionation of the antipoliovirus compounds.3) Further investigations of non-flavonoid compounds resulted in the isolation of another active product in minute amounts corresponding to a new 7-prenyloxycoumarin. We report here the isolation and identification of this compound along with the first investigation of its antiviral and cytotoxic activity.Partition of a CHCl 3 extract from dried leaves between hexane and 90% aqueous MeOH, followed by various chromatographic steps, resulted in the isolation of a crystalline solid. This compound (1) showed a strong yellow fluorescence under UV light (366 nm), and was thought to be a coumarin as it was positive to KOH/EtOH and ammonia vapour.The IR spectrum of 1 showed absorption bands at 3296, 3086, 1702 (wide band), 1622, 1566 and 1030 cm Ϫ1 indicating the presence of a hydroxyl group (probably a phenolic one), a diethylenic CH, a conjugated OCO moiety, ethylenic and aromatic CϭC, and a C-O moiety, respectively.High resolution liquid secondary ion mass spectrometry (HR-LSI-MS) revealed [MϩH] ϩ at m/z 277.1076, which corresponds to the molecular formula C 15 H 16 O 5 ; the 68 unit difference between [MϩH] ϩ (m/z 277) and the base peak (m/z 209) corresponded to loss of a C 5 H 8 fragment, which could be due to a Mac-Lafferty 6-center translation mechanism.
A biologically guided fractionation from Lepista inversa (Scop.: Fr.) led to the isolation of clitocine, an exocyclic amino nucleoside. This compound and two mixtures of beta/alpha anomers (mixture A, 40:60 and mixture B, 80:20) were synthesized or isolated depending on the purification procedure. The beta anomer and clitocine mixtures A and B showed similar cytotoxic activities with IC50 values ranging from 20.5 to 42 nM in murine cancer cell lines (3LL and L1210) and from 185 to 578 nM in human cancer cell lines (DU145, K-562, MCF7, and U251). An in vivo study of mixture B was carried out on 3LL- and L1210-tumor-bearing mice. Clitocine solubilized in beta-hydroxypropylcyclodextrin and injected at concentrations of 0.5, 3, and 5 mg kg-1 did not significantly increase the survival rate and lifespan of 3LL-tumor-bearing mice. In contrast, clitocine showed antitumor activity on L1210-tumor-bearing mice with a significant increase in lifespan and a decrease in the development of ascites observed at 3 mg kg-1. The induction of apoptosis may be the basis of the antitumor activity of clitocine against L1210 as suggested by flow-cytometry analysis of cells treated in vitro.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.