[Show abstract][Hide abstract] ABSTRACT: Seven ellagitannins, lagerstroemin (1), flosin B (2), stachyurin (3), casuarinin (4), casuariin (5), epipunicacortein A (6), and 2, 3-(S)-hexahydroxydiphenoyl-alpha/beta-D-glucose (7), together with one ellagic acid sulfate, 3-O-methyl-ellagic acid 4'-sulfate (8), ellagic acid (9), and four methyl ellagic acid derivatives, 3-O-methylellagic acid (10), 3,3'-di-O-methylellagic acid (11), 3,4,3'-tri-O-methylellagic acid (12), and 3,4,8,9,10-pentahydroxydibenzo[b,d]pyran-6-one (13), were identified by the bioassay-directed isolation from the leaves of Lagerstroemia speciosa (L.) Pers. The chemical structures of these components were established on the basis of one- and two-dimensional NMR and high-resolution mass spectroscopic analyses. Other known compounds, including corosolic acid, gallic acid, 4-hydroxybenzoic acid, 3-O-methylprotocatechuic acid, caffeic acid, p-coumaric acid, kaempferol, quercetin, and isoquercitrin, were also isolated from the same plant. The obtained ellagitannins exhibited strong activities in both stimulating insulin-like glucose uptake (1-5 and 7) and inhibiting adipocyte differentiation (1 and 4) in 3T3-L1 cells. Meanwhile, ellagic acid derivatives (10-13) showed an inhibitory effect on glucose transport assay. This study is the first to report an inhibitory effect for methyl ellagic acid derivatives.
Full-text · Article · Dec 2008 · Journal of Agricultural and Food Chemistry
[Show abstract][Hide abstract] ABSTRACT: Black cohosh has become one of the most important herbal products in the US dietary supplements market. It is manufactured from roots and rhizomes of Cimicifuga racemosa (Ranunculaceae). Botanical identification of the raw starting material is a key step in the quality control of black cohosh preparations. The present report summarizes a fingerprinting approach based on high performance liquid chromatography-photodiode array/mass spectrometric/evaporative light scattering detection (HPLC-PDA/MS/ELSD) that has been developed and validated using a total of 10 Cimicifuga species. These include three North American species, Cimicifuga racemosa, Cimicifuga americana, Cimicifuga rubifolia, and seven Asian species, Cimicifuga acerina, Cimicifuga biternat, Cimicifuga dahurica, Cimicifuga heracleifolia, Cimicifuga japonica, Cimicifuga foetida, and Cimicifuga simplex. The chemotaxonomic distinctiveness of the HPLC fingerprints allows identification of all 10 Cimicifuga species. The triterpene glycoside cimigenol-3-O-arabinoside (3), cimifugin (12), and cimifugin-3-O-glucoside (18) were determined to be suitable species-specific markers for the distinction of C. racemosa from the other Cimicifuga species. In addition to identification, the fingerprint method provided insight into chemical interconversion processes occurring between the diverse triterpene glycosides contained in black cohosh. The reported method has proven its usefulness in the botanical standardization and quality control of black cohosh products.
Full-text · Article · May 2006 · Journal of Chromatography A