Tetracenomycin (Tcm) F2 cyclase, which catalyzes the cyclization of the anthrone Tcm F2 to the naphthacenone Tcm F1 in the biosynthesis of the anthracycline antibiotic Tcm C in Streptomyces glaucescens, has been purified to homogeneity and characterized. The N-terminal sequence of the enzyme establishes that it is encoded by the tcml gene, whose deduced product has a molecular weight of 12 728....

Reductive Claisen rearrangement of 1-allyloxy-8-methoxy-9, 10-anthraquinone followed by demethylation and reduction, and of 1,8-bisallyloxy-9,lO-anthraquinone followed by reduction provides regiospecific syntheses of 2-propyl- and 2,7-dipropyl anthralin

Reaksi penataan ulang Claisen merupakan salah satu reaksi penting untuk pembentukan ikatan baru karbon-karbon dalam sintesis organik. Secara umum, hanya dapat berlangsung kondisi yang cukup ekstrim yaitu suhu tinggi 180-225oC dengan waktu lama. Dalam penelitian ini dilakukan alil 1-naftil eter terlebih dahulu melalui substitusi gugus pada senyawa 1-naftol pemanasan 58oC selama 8 jam. Produk ali...

The use of a non-coordinating solvent for the aza-Claisen rearrangement of delta,epsilon-disubstituted acetimidates switches on a substrate directing effect that gives excellent stereoselectivity.

Unsaturated eight-membered lactones undergo decarboxylative and non-decarboxylative transannular Ireland-Claisen rearrangement reactions, to give substituted vinylcyclobutanes. A formal synthesis of (±)-grandisol is described.

Enzymes within the biosynthetic pathway of mycolic acid (C(60)-C(90) a-alkyl,b-hydroxyl fatty acid) in Mycobacterium tuberculosis are attractive targets for developing new anti-tuberculosis drugs. We have turned to the simple model system of Corynebacterium matruchotii to study the terminal steps in the anabolic pathway of a C32 mycolic acid called corynomycolic acid. By transposon-5 mutagenesi...

‎for any group $g$‎, ‎we define an equivalence relation $thicksim$ as below‎: ‎[forall g‎, ‎h in g gthicksim h longleftrightarrow |g|=|h|]‎ ‎the set of sizes of equivalence classes with respect to this relation is called the same-order type of $g$ and denote by $alpha{(g)}$‎. ‎in this paper‎, ‎we give a partial answer to a conjecture raised by shen‎. ‎in fact‎, ‎we show that if $g$ is a nilpote...