• Archives of Pharmacal Research
• /
• v.27 no.10
• /
• pp.1020-1022
• /
• 2004

A new ceramide alomacrorrhiza A was isolated from the ethanolic extract of the plant Alocasia macrorrhiza (L.) Schott. Its chemical structure was elucidated as (2S,3S,4R)-2N-[(2'R)-2'- hydroxy-hexacosanoyl]-tetradecane-1,3,4-triol based on extensive 1D, 2D NMR, EI-MS, FABMS, HR-FAB-MS spectroscopic data and chemical degradation studies.

• Journal of Microbiology and Biotechnology
• /
• v.21 no.9
• /
• pp.930-936
• /
• 2011

Two new cyclic depsipeptides wewakamide A (1) and guineamide G (2) have been isolated from the marine cyanobacterium Lyngbya semiplena and Lyngbya majuscula, respectively, collected from Papua New Guinea. The amino and hydroxy acid partial structures of wewakamide A and guineamide G were elucidated through extensive spectroscopic techniques, including HR-FABMS, 1D $^1H$ and $^{13}C$ NMR, as well as 2D COSY, HSQC, HSQC-TOCSY, and HMBC spectra. The sequence of the residues of wewakamide A was determined through a combination of ESI-MS/MS, HMBC, and ROESY. Wewakamide A possesses a ${\beta}$-amino acid, 3-amino-2-methylbutanoic acid (Maba) residue, which has only been previously identified in two natural products, guineamide B (3) and dolastatin D (4). Although both new compounds (1,2) showed potent brine shrimp toxicity, only guineamide G displayed significant cytotoxicity to a mouse neuroblastoma cell line with $LC_{50}$ values of 2.7 ${\mu}M$.

• Natural Product Sciences
• /
• v.14 no.4
• /
• pp.233-238
• /
• 2008

The aerial parts of Epimedium koreanum Nakai have been used to stimulate hormone secretion in treating impotence. Ten flavonol glycosides, 3,4,5-trihydroxy-8-prenylflavone 7-O-[${\beta}$-D-glucopyranosyl($1{\rightarrow}2$)-${\beta}$-D-glucopyranoside] (1), hyperoside (2), icarisid II (3), 2"-O-Rhamnosylicarisid II (4), epimedin A (5), epimedin B (6), epimedin C (7), icariin (8), hexandraside E (9), and epimedoside A (10) were isolated from the an ethylacetate soluble extracts of the aerial parts of Epimedium koreanum Nakai through activity-monitord fractionation and isolation method. The structures of compounds 1 - 10 were elucidated by high resolution fast atom bombardment mass spectrometry and two dimentional nuclear magnetic resonance spectroscopy analysis. Compounds 1 and 4 showed potent antioxidant activity, with $IC_{50}$ values of 19.7 and 11.5 ${\mu}g$/mL and 88.2 and 90.5 ${\mu}M$, respectively.

• Korean Journal of Environmental Agriculture
• /
• v.15 no.2
• /
• pp.167-178
• /
• 1996

In order to identify PCP glucose conjugates transformed from PCP in soybean and rice cell suspension cultures, the purified metabolites were acetylated, purified twice by HPLC using a normal and a reversed phase column, and then subjected to fast atom bombardment(FAB) mass spectrometric analysis. As were the conjugates, their acetylated derivatives of the glucose conjugates formed at the early stage(48 hr) of metabolism were separated by HPLC into three fractions. FABMS analysis of each fraction revealed that, at least in two fractions, the locations of the spectral peaks were practically coincident with those deducible from the structures of pentachlorophenyl and tetrachlorophenyl ${\beta}-D-glucopyranosides$. Based on information obtained from mass spectral and chromatographic analysis of not only the water-soluble metabolites but also aglycones and glycone, it is concluded that PCP is primarily metabolized to glucose conjugates, which account for more than 50% recovery of the PCP-conveyed radioactivity from the water soluble metabolites : The conjugates are mainly made up of pentachlorophenyl ${\beta}-D-glucopyranoside$, tetrachlorophenyl ${\beta}-D-glucopyranosides$( probably 2 or more isomers), and 2-hydroxy-3,4,5,6-tetrachlorophenyl ${\beta}-D-glucopyranoside$.