Procedures for preparing 4,4-dimethyloxazoline (DMOX) and pyrrolidine derivatives from fatty acid methyl esters (FAMEs) were modified to provide milder simpler conditions the derivatization reactions widely used in mass spectrometric analysis of acids. DMOX obtained overnight at room temperature presence sodium borohydride. The proposed method, involving a low-temperature condensation-cyclizati...

From the treatment of 5-hydroxy-1,4-naphthoquinone (juglone) with acetic anhydride and H2SO4 followed subsequently by treatment with methanolic HCl, 5-hydroxy-3-methoxy-1,4-naphthoquinone (3-methoxy juglone) and 8-hydroxy-4-methoxy-1,2-naphthoquinone were obtained as products rather than the anticipated product 2,5-dihydroxy-1,4-naphthoquinone (2-hydroxy juglone). The reaction and the identific...

Two new xanthones, 6-hydroxy-3,7-dimethoxy-8-(3-methylbut-2-enyl)-6',6'-dimethyl-5'-hydroxy-4',5'-dihydropyrano(2',3':1,2)xanthone (1) and 6-hydroxy-3,7-dimethoxy-8-(2-oxo-3-methylbut-3-enyl)-6',6'-dimethyl-5'-hydroxy-4',5'-dihydropyrano(2',3':1,2)xanthone (2), have been isolated from the stems of Cratoxylum cochinchinense (Lour.) Blume. Their structures were established on the basis of spectro...

The proton-ligand and metal-ligand stability constants of the complexes of Cu(II), Ni(II),Co(II) with 1-Benzothiazol2-yl-3-(2-hydroxy phenyl)-5-(4-methoxy phenyl) pyrazoline (L), 1-Benzothiazol-2-yl-3-(2-hydroxy phenyl)-5-phenyl pyrazoline (L), 1-Benzothiazol-2-yl-3-(2-hydroxy phenyl)-5-(4-chloro phenyl) pyrazoline(L), 1-Benzothiazol-2-yl3-(2-hydroxy-5-methyl phenyl)-5-(4-methoxy phenyl) pyrazo...

In this article we describe a new methodology for the total synthesis of 3,4-unsubstituted coumarins from commercially available starting materials. Six examples were prepared, including five naturally occurring coumarins--7-hydroxy-6,8-dimethoxy-coumarin (isofraxidin), 7-hydroxy-6-methoxycoumarin (scopoletin), 6,7,8-trimethoxy-coumarin, 6,7-dimethoxycoumarin (scoparone), and 7,8-dihydroxycouma...

The methanol extract from the leaves of Spathelia excelsa yielded six alkaloids: 2-(12-oxo-tridecanyl)-3-methoxy-4-quinolone, 2-(10-hydroxy-10-methyldodecanyl)-3-methoxy-4-quinolone, 2-(11-hydroxy-11-methyldodecanyl)-3-methoxy-4-quinolone, 2-(12-hydroxytridecanyl)-3-methoxy-4-quinolone, 7-hydroxy-2-(3-hydroxy-3-methylbutyl)-4-quinolone and 6-hydroxy-2-(3-hydroxy-3-methylbutyl)-4-quinolone, in a...

Male Spraque-Dawley rats were 6 or 7 times more susceptible than females to the acute toxic effects of a single i.p. injection of N-hydroxy-2-acetylaminofluorene. The N-hydroxy compound were equally toxic in male and female Fischer rats and about twice as toxic to male as to female Wistar rats. A negative correlation between the 50% lethal dose of N-hydroxy-2-acetylaminofluorene and hepatic N-h...

A new bio-based dimethacrylate (EMHO) consisting of three isomers, that is (ethane-1,2-diyl-bis(9-methacryloyloxy-10-hydroxy octadecanoate) [EMHO-i1], ethane-1,2-diyl-9-hydroxy-10-methacryloyloxy-9′-methacryloyloxy-10′-hydroxy octadecanoate [EMHO-i2], and ethane-1,2-diyl-bis(9-hydroxy-10-methacryloyloxy [EMHO-i3]), was made by a three-step reaction starting from esterification oleic acid with e...