Development of novel synthetic methodologies and their application to synthesis of natural products are described. The first topic is about an extension of the scope of our indole synthesis by radical cyclization of o-alkenylphenyl isocyanides. By utilizing this methodology and nitrogenzenesulfonamide chemistry, an efficient total synthesis of hexacyclic aspidosperma indole alkaloid, aspidophyt...

Putrescine N-methyltransferase (PMT) is the first alkaloid-specific enzyme for nicotine and tropane alkaloid formation. The pmt gene from Nicotiana tabacum was fused to the CaMV 35S promoter and integrated into the Atropa belladonna genome. Transgenic plants and derived root cultures were analysed for gene expression and for levels of alkaloids and their precursors. Scopolamine, hyoscyamine, tr...

The subcellular localization of enzymes involved in indole alkaloid biosynthesis in leaves of Catharanthus roseus has been investigated. Tryptophan decarboxylase and strictosidine synthase which together produce strictosidine, the first indole alkaloid of this pathway, are both cytoplasmic enzymes. S-Adenosyl-l-methionine: 16-methoxy-2,3-dihydro-3-hydroxytabersonine-N-methyltransferase which ca...

The complexation behavior of palmatine (P) and dehydrocorydaline (DHC) alkaloid guest molecules by cucurbit[7]uril (CB7) host have been investigated by means of fluorescence spectra in aqueous phosphate buffer solution (pH 7.2). It is found that each alkaloid exhibits dramatic fluorescence enhancement upon complexation with CB7, and the intensity of the emittance is strong enough to be readily ...

Based on MS and NMR data and bioassay-guided tracing, three insecticidal alkaloids I, II and III from Cynanchum mongolicum were identified to be antofine N-oxide, antofine and tylophorine. Alkaloid I was more toxic than alkaloids II and III, but they were less active against Spodoptera litura than total alkaloids. The contact toxicity from these alkaloids against the aphid Lipaphis erysimi was ...

Induced mutagenesis is best approach for creation of genetic variability but most of interest is paid towards crop plants with only a few exceptions. But even widely used medicinal plants could receive a little attention in this direction. Catharanthus roseus is an important plant medicinal plant yielding antihypertensive alkaloid ajmalcine and anticancerous alkaloid vincristine and vinblastine...

Hatomamicin, a new alkaloid antibiotic, was isolated from the culture filtrate of a strain of Saccharopolyspora. The antibiotic was extracted with EtOAc and purified by silica gel column chromatography. The free alkaloid was obtained as pale yellowish prisms from CH3CN solution. It exhibits antimicrobial activity against Gram-positive organisms. The apparent molecular formula of hatomamicin was...

Baliospermum montanum leaves yielded 3-hydroxy-2,4-dimethoxy-10-methyl-9-acridanone (1), an alkaloid from the CHCl₃ fraction. Spectroscopic analysis was performed to assign the structure of the new compound (1) and its absolute configuration. The compound was evaluated for its effect in anaphylaxis by estimation of the release of histamine in systemic anaphylaxis model. The acridanone alkaloid ...

areas by La] et al. (1937) and Chopra et al. (1939). There is little to doubt that adulterated mustard oil is primarily responsible for the large outbreaks of epidemic dropsy. More recently S. N. Sarkar (1948) has isolated the toxic alkaloid, sanguinerine, from argemone oil and shown its capillary dilating and other deleterious properties in animals. Bailey, Robinson and Staunton (1950) have la...

Using appropriate precursors, the two unnatural alkaloids 4(5)-[N-isocaproylaminomethyl]imidazole and 3-[2-N-isovalerylaminoethyl]pyrazole were produced by Dolichothele sphaerica. The former compound represents an unnatural alkaloid formed by the simultaneous introduction of two unnatural precursors, namely isocaproic acid and 4(5)-aminomethylimidazole. The latter compound represents an aberran...