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...

Incubation of phenobarbital-induced rat liver microsomes with 2,2',5,5'-tetrachlorobiphenyl (TCB) yielded about 30% of the substrate as 3-hydroxy-TCB, 3,4-dihydroxy-TCB, 3,3'-dihydroxy-TCB (tentative identification), and 3,4-dihydro-3,4-dihydroxy-TCB in relative amounts of about 1:1:0.05:0.05. Under identical conditions, 2,2',5,5'-tetrachlorobiphenyl 3,4-oxide (TCBO) yielded about 45% of the su...

Male Fischer rats which had been implanted with a heterotopic bladder were randomly divided into five groups and their heterotopic bladders were instilled once a week for 20 weeks with 0.5 ml phosphate-buffered saline:dimethyl sulfoxide solution (4:1) or this solution containing 1 mumol benzidine (BZ), N'-hydroxy-N-acetylbenzidine, the N'-glucuronide of N'-hydroxy-N-acetylbenzidine, or the N-gl...