Structural implication in cytotoxic effects of sterols from Sellaginella tamariscina.

A bioassay-guided fractionation of the CH(2)Cl(2) extract of Selaginella tamariscina yielded six sterols 1-6 such as (4α, 5α)-4, 14-dimethylcholest-8-en-3-one (1), ergosta-4, 6, 8(14), 22-tetraene-3-one (2), ergosterol endoperoxide (3), 7β-hydroxycholesterol (4), 7β-hydroxysitosterol (5), and 7α-hydroxysitosterol (6). The structures of isolated compounds were determined using spectroscopic methods. Among these isolates, compounds 2-5 showed potent cytotoxicity against five human tumor cells, while compounds 1 and 6 did not.

A new furofuran lignan from Geranium thunbergii Sieb. et Zucc.

A new furofuran lignan, 4-hydroxykobusin (3), together with known lignans, kobusin (1), and 7,7'-dihydroxybursherenin (2), were isolated from the whole plant of Geranium thunbergii Sieb. et Zucc (Geraniaceae). The structures were determined based on the spectral data and a comparison with the published data.

Effects of phenylethanoid glycosides from Digitalis purpurea L. on the expression of inducible nitric oxide synthase.

We have isolated four different phenylethanoid glycosides (purpureaside A, desrhamnosyl acteoside, calceolarioside B and plantainoside D) from the leaves of Digitalis purpurea (foxglove). The effects of these glycosides on activator protein-1 (AP-1)-mediated inducible nitric oxide synthase (iNOS) gene expression in the Raw264.7 macrophage cell line have been studied.

Matrix metalloproteinase-1 inhibitor from the stem bark of Styrax japonica S. et Z.

A bioassay-guided fractionation of the ethyl acetate soluble fraction from the stem bark of Styrax japonica S. et Z. (Styracaceae) yielded two new lignan compounds, styraxjaponoside A (1) and styraxjaponoside B (2), along with three known compounds, matairesinoside (3), egonol glucoside (4), and dihydrodehydrodiconiferyl alcohol 9'-O-glucoside (5).

Structure-antiviral activity relationships of cecropin A-magainin 2 hybrid peptide and its analogues.

In order to elucidate the structure-antiviral activity relationship of cecropin A (1-8)-magainin 2 (1-12) (termed CA-MA) hybrid peptide, several analogues with amino acid substitutions were synthesized. In a previous study, it was shown that serine at position 16 in CA-MA hybrid peptide was very important for antimicrobial activity. Analogues were designed to increase the hydrophobic property by substituting a hydrophobic amino acid residue (S --> A, V, F or W, position 16) in the CA-MA hybrid peptide.

Pentacyclic triterpenoids and their cytotoxicity from the stem bark of Styrax japonica S. et Z.

The methylene chloride soluble fraction of MeOH extract from the stem bark of Styrax japonica S. et Z. (Styracaceae) showed significant cytotoxicity by SRB method against five human tumor cell lines.

Antioxidative constituents from Buddleia officinalis.

Four flavonoids (1-4), a phenylethyl glycoside (5), and a phenylpropanoid glycoside (6) were isolated from the flowers of Buddleia officinalis (Loganiaceae). Their structures were determined by chemical and spectral analysis. Among the isolated compounds, luteolin (1) and acteoside (6) exhibited the most potent antioxidative activity on the NBT superoxide scavenging assay.

A new phenolic amide from Lycium chinense Miller.

A new phenolic amide, dihydro-N-caffeoyltyramine (1) was isolated from the root bark of Lycium chinense Miller, along with known compounds, trans-N-caffeoyltyramine (2), cis-N-caffeoyltyramine (3), and lyoniresinol 3alpha-O-beta-D-glucopyranoside (4). Their structures were determined by spectroscopic analysis. A NBT superoxide scavenging assay revealed that three phenolic amides showed potent antioxidative activity.