Dependence of the hydrolysis rate a series N-methoxy-2-phenyl-1,3-oxazinanes on Hammett substituent constant phenyl ring was determined, yielding reaction ρ=−1.40±0.05. Based this information, 4-(benzoyloxy)benzaldehyde selected as protecting group for new (2R,3S)-4-(methoxyamino)butane-1,2,3-triol phosphoramidite building block. The yield preparation block well its coupling in automated oligon...

Two new furanonaphthoquinones, (3R)-7-methoxy-α-dunnione (5) and (3R)-6-hydroxy-7-methoxy-α-dunnione (6), along with the known (3R)-dunnione (1), (3R)-α-dunnione (2), (3R)-7-hydroxy-α-dunnione (3), and 1-hydroxy-2-methylanthraquinone (4), were isolated from in vitro cultures of Streptocarpus dunnii. The structures of compounds 5 and 6 were established by spectroscopic means. This is the first r...

Three new butanolides, 2-(1-methoxy-11-dodecenyl)-penta-2,4-dien-4-olide (1), (2Z,3S,4S)-2-(11-dodecenylidene)-3-hydroxy-4-methylbutano lide (2) and (2E,3R,4R)-2-(11-dodecenylidene)-3-hydroxy-4-methoxy-4-methylbu tanolide (3), were isolated from the stems of Lindera obtusiloba BLUME. Their chemical structures were assigned by spectroscopic evidence. They exhibited cytotoxicity against cultured ...

Leguminosae, Erythrina, Pterocarpans, Isoflavans, Phytoalexins Two new phytoalexins isolated from the fungus-inoculated leaflets of Erythrina sandwicensis have been identified as (—)-6aS; 11 aS-3,6 a,9-trihydroxy-10-isopentenylpterocarpan (sandwicarpin) and (—)-6a/?; 11 a^-3-hydroxy-9-methoxy-10-isopentenylpterocaipan (sandwicensin). These compounds co-occur with several known pterocarpan (deme...

Felbamate is an anti-epileptic drug associated with hepatotoxicity and aplastic anemia. These toxicities are believed to be mediated by the formation of the reactive species 2-phenylpropenal. 4-Hydroxy-5-phenyl-[1,3]oxazinan-2-one is a metabolic precursor for 2-phenylpropenal. 4-Hydroxy-5-phenyl-[1,3]oxazinan-2-one exists in equilibrium with 3-oxo-2-phenylpropyl carbamate, which can undergo bet...

Five new: 21,23-dihydro-21-hydroxy-23-oxonomilin (1), 21,23-dihydro-23-methoxy-21-oxonomilin (2), 21,23-dihydro-21-hydroxy-23-oxonomilinic acid methyl ester (3), 21,23-dihydro-23-methoxy-21-oxolimonin (4), and 21,23-dihydro-21-oxolimonin (5), and seven known limonoids were isolated from peels of satsuma orange (Citrus reticulata). The isolated compounds were evaluated for their inhibitory effec...

A carpin (3-hydroxy-9-methoxypterocarpan) (Medicarpin) (1) and four isoflavones, 7-hydroxy-4'-methoxy-isoflavone (Formononetin) (2); 7,4'-dimethoxyisoflavone (3); 5,4'-dihydroxy-7-methoxy-isoflavone (Prunetin) (4) and 7-hydroxy-6,4'-dimethoxyisoflavone (5) were isolated from the tuber roots of Butea superba Roxb. Compounds 2 and 4 showed moderate cytotoxic activity on KB cell lines with IC(50) ...

Photoresponsive molecular devices can be a valuable tool to promote chemical changes in response multiple signals, such as photons and pH, deliver drugs or detect physiological conditions vivo. For example, trans-chalcones (Ct) from 4′-hydroxyflavylium (F1) 7-hydroxyflavylium (F2) undergo cis-trans isomerization by photoreaction into many different structures. The takes place at slow rate pH ch...

A simple method for design of some novel 1,2-benzoxaphosphinines 2–9, was achieved. The methodology depended on cyclization 1-(2-hydroxy-phenyl)-3-phenylpropane-1,3-dione (1) as starting material with phosphorus halides in dry solvent the presence a base. Reaction substrate 1 halides, such P,P-dichlorophenylphosphine, phenyl phosphonic dichloride, phosphorodichloridate, and oxychloride toluene ...