Chemical investigation of the CH(2)Cl(2)/CH(3)OH extracts from aerial parts of the Australian plant Goniothalamus australis has resulted in the isolation of two pyridocoumarin alkaloids, goniothalines A (1) and B (2) as well as eight known natural products, aristolactam AII (3), enterocarpam II (4), caldensine (5), sauristolactam (6), (-)-anonaine (7), asimilobine (8), altholactone (9) and (+)-...

1. Tritiation of arecoline hydrochloride by catalytic exchange in aqueous media (done by The Radiochemical Centre) gave arecaidine hydrochloride of high specific radioactivity; this on treatment with diazomethane gave [(3)H]arecoline, which was oxidized with peroxyacetic acid to [(3)H]arecoline 1-oxide. 2. Arecoline 1-oxide gave arecaidine 1-oxide on acid hydrolysis and 1,2-dihydro-1-methylnico...

The stereochemical course of the reaction catalyzed by the soluble form of bovine lung guanylate cyclase has been investigated using [alpha-18O]guanosine 5'-triphosphate (Rp diastereomer) and guanosine 5'-O-(1-thiotriphosphate) (Sp diastereomer) as substrates. The product from the 3-thiomorpholino-1',1'-dioxide sydnonimine-stimulated enzymatic cyclization of [alpha-18O] guanosine 5'-triphosphat...

The dirhodium carbene derived from bis(4-methoxyphenyl)diazomethane and [Rh(tpa)4 ]⋅CH2 Cl2 (tpa=triphenylacetate) was characterized by UV, IR, and NMR spectroscopy, HRMS, as well as by X-ray diffraction. The isolated complex exhibits prototypical rhodium carbene reactivity in that it cyclopropanates 4-methoxystyrene at low temperature. Experimental structural information on this important type...

A 2,3-dihydroxybiphenyl 1,2-dioxygenase from the naphthalenesulfonate-degrading bacterium Sphingomonas sp. strain BN6 oxidized 3-chlorocatechol to a yellow product with a strongly pH-dependent absorption maximum at 378 nm. A titration curve suggested (de)protonation of an ionizable group with a pKa of 4.4. The product was isolated, purified, and converted, by treatment with diazomethane, to a d...

A novel synthesis of trimethylsilyldiazomethane (TMSCHN2 ) by diazotization of trimethylsilylmethylamine (TMSCH2 NH2 ) is reported using batch and continuous flow synthesis. The latter affords a daily production of 275 g (2.4 mol) of TMSCHN2 . Other silylated methylamines were also successfully reacted under the developed reaction conditions to furnish various silicon-bearing diazomethane reage...

Abstract Herein, we describe the construction of a reduction-responsive oligonucleotide by post-modification an with diazo compound bearing 4-nitrobenzyl group as cleavable moiety. High-performance liquid chromatography and mass spectrometry were used to reveal introduction 5?-phosphate oligonucleotide, subsequent reduction-triggered recovery original oligonucleotide. The protocol for preparati...