Mukund M. Mehrotra

Water induced dismutation of superoxide anion generates singlet molecular oxygen

Direct spectroscopic measurement of 1268 nm singlet oxygen emission from KO2 suspensions at room temperature in three non-protonic solvents--CCl4, Cl2FCCClF2, and C6F14 by the action of water is reported. The results clearly show that the singlet oxygen generation is due to a water induced reaction, and suggest that one role of the enzyme superoxide dismutase may be the protection of biological structures, for example, lipid membranes, from degradation by singlet oxygen.

A simple and enantioselective synthesis of (+)-biotin

Abstract An enantioselective and stereospecific synthesis of the important vitamin (+)-biotin in 12 steps from L-cystine dimethyl ester is recorded.

A stereoselective and practical synthesis of 5,6(S,S)-epoxy-15(S)-hydroxy-7(E),9(E),11(Z),13(E)-eicosatetraenoic acid (4), possible precursor of the lipoxins

Abstract A stereoselective synthesis of 4 , a possible biosynthetic precursor of lipoxins, is reported. A pathway is suggested by which 4 can give rise to the biologically active lipoxins 1 and 2 .

On the synthesis and structure of lipoxin B

Abstract A synthesis of lipoxin B, a recently discovered biologically active eicosanoid, and the assignment of stereoformula 2 is reported.

Stereochemistry of the lipoxygenase-catalyzed allylic hydroperoxide→oxiranylcarbinol rearrangements

Abstract The anaerobic rearrangement of 15-( S )-HPETE ( 1 ) which is effected by the enzyme soybean lipoxygenase - type I leads stereospecifically to the hydroxy epoxide 2 by a cis addition of two oxygens to the 13,14-double bond.

SPECTRAL OBSERVATION OF SINGLET MOLECULAR OXYGEN FROM AROMATIC ENDOPEROXIDES IN SOLUTION

Abstract— The characteristic near‐infrared emission band of O2 (1Δg) at 1.28 μm has been recorded from carbon tetrachloride solutions of the 1, 4‐endoperoxides of 1,4‐dimethyInaphthalene and 1, 4‐dimethoxy‐9.10‐diphenylanthracene undergoing thermal decomposition.

An efficient and simple method for the conversion of 15-HPETE to 14,15-EPETE (lipotriene A) and 5-HPETE to leukotriene a as the methyl esters

Abstract Simple new methodology is described for the synthesis from arachidonic acid of the important eicosanoids lipotriene A methyl ester (5) and leukotriene A methyl ester (10), a key feature being the use of a novel chemical method for effecting the allylic hydroperoxide → oxiranyl carbinol rearrangement.

A new method for the 1, 4-oxygenation of 1-alkylated cyclopentadienes

Abstract The diene 1 was efficiently transformed into the ketol 2 by a three-step process which includes a novel oxygenation by a chlorochromate reagent.

New synthetic routes to leukotrienes and other arachidonate derived epoxy eicosatetraenoic acids (epete's). Exclusion of the hydroxy epoxide pathway for leukotriene biosynthesis

Abstract Synthetic hydroxy epoxides 3 and 5 have been utilized for the synthesis of the methyl esters of leukotriene A ( 4 ) and 14,15-EPETE ( 6 ) and for the demonstration that the acid corresponding to 3 is not an intermediate in leukotriene biosynthesis.

Practical, stable standards for the reversed phase HPLC analysis of peptidic leukotrienes

Abstract The stable glutathione derivatives 1 , R = n -C 6 H 13 and R = n -C 8 H 17 , are useful as reference compounds for the identification and quantitation of leukotrienes C 4 , D 4 and E 4 by reversed phase HPLC analysis.