The hetero-Diels-Alder reaction between a nitroso dienophile and a conjugated diene to give the 3,6-dihydro-2H-1,2-oxazine scaffold is useful for the synthesis of many biologically interesting molecules due to the diverse opportunities created by subsequent transformations of the resulting 1,2-oxazine ring. This review discusses the rationale for the observed regio- and stereoselectivity and th...

A facile and highly regioselective Pd-catalyzed oxidative coupling of N-tosylhydrazones providing efficient access to 2,3-disubstituted-1,3-butadienes has been developed. This process features readily available starting materials and mild reaction conditions. Further transformations of the obtained dibranched 1,3-dienes, through Diels-Alder reactions and indene synthesis, are also demonstrated,...

Nitric Oxide (NO) is a bioactive signaling molecule that mediates a variety of biotic and abiotic stresses. The present study investigated the role of NO (as SNP [sodium nitroprusside]) in ameliorating lead (Pb)-toxicity in Triticum aestivum (wheat) roots. Pb (50 and 250 μM) alone and in combination with SNP (100 μM) was given to hydroponically grown wheat roots for a period of 0-8 h. NO supple...

Electrophilic nitro-fatty acids (NO2-FAs) are endogenously formed by redox reactions of nitric oxide ((.)NO)- and nitrite ((.)NO2)- derived nitrogen dioxide with unsaturated fatty acids. Nitration preferentially occurs on polyunsaturated fatty acids with conjugated dienes under physiological or pathophysiological conditions such as during digestion, metabolism and as adaptive inflammatory proce...

Immature stages of Ceratitis capitata were tested as a model for hematoporphyrin IX (HP IX) phototoxicity. The lethal concentration 50 (LC(50)) of HP IX in the food was determined during postembryonic development until adult emergence as 0.173 mm (95% CI: 0.138-0.209). The corresponding HP IX LC(50) during the dispersal period alone was 0.536 mm (95% CI: 0.450-0.633). HP IX toxicity was compare...

Methyl linoleate hydroperoxide produced by autoxidation was refluxed with 10(-4) M Cu-naphthenate in benzene. Two new geometrical isomers of oxooctadecadienoate (compounds I and II) were found in addition to the four known isomers. They were isolated by a Sephadex LH-20 column chromatography with chloroform-hexane (2:1) and purified by HPLC on Nucleosil ®100-5 and Zorbax ODS columns. UV, IR, MS...

Two homologous cDNAs, CoFad2 and CoFac2, were isolated from a Calendula officinalis developing seed by a polymerase chain reaction-based cloning strategy. Both sequences share similarity to FAD2 desaturases and FAD2-related enzymes. In C. officinalis plants CoFad2 was expressed in all tissues tested, whereas CoFac2 expression was specific to developing seeds. Expression of CoFad2 cDNA in yeast ...