Results 151 to 160 of about 1,359 (207)

Photoactive C16-C21 fragmentation of catharanthine

Tetrahedron Letters, 1991
Photolysis of catharanthine in the presence of several potential electron acceptors and cyanide ion leads to either addition of cyanide at C3 and C5 or to C16-C21 fragmentation and addition of cyanide at C21.
Richard J. Sundberg, Patrice Desos, Kumar G. Gadamasetti, Michal Sabat   +3 more
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Catharanthine: A novel stimulator of pancreatic enzyme release

Cell and Tissue Research, 1978
The plant alkaloid, catharanthine, was shown to stimulate release of amylase from pancreatic fragments and to cause extensive degranulation of pancreatic acinar cells with accumulation of membrane material in the Golgi region. The extent and time course of maximal catharanthine stimulation was comparable to that induced by the cholinergic analog ...
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SOME ASPECTS OF THE CHEMISTRY OF CATHARANTHINE AND CLEAVAMINE

Canadian Journal of Chemistry, 1965
Chemical and spectroscopic evidence is presented for an interesting acid-catalyzed rearrangement of the alkaloid catharanthine. Four reaction products (descarbomethoxycatharanthine and cleavamine and its two dihydro derivatives) were isolated, and their formation is rationalized by a mechanism involving ring-opened intermediates. Evidence is presented
James P. Kutney, Richard T. Brown, Edward Piers   +2 more
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Catharanthine tartrate ameliorates osteoclastogenesis by destabilizing HIF-1α

Cellular Signalling
With the aging population, postmenopausal osteoporosis (PMOP), clinically manifested by reduced bone density, weakened skeletal strength, and compromised skeletal microstructure, has become the most prevalent type. The decline in estrogen levels fosters oxidative stress and osteoclastogenesis, which significantly enhance the activity of osteoclasts ...
Luqiong, Cai, Chenxin, Yu, Binli, Zhao, Qihang, Wu, Haibo, Liang, Meng, Zhou, Jiansen, Miao, Jiangtao, Luo, Jiake, Xu, Haiming, Jin, Youjin, Pan   +10 more
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On the rearrangement of catharanthine, stemmadenine and tabersonine in acetic acid

Tetrahedron, 1971
Abstract Experimental details of the reaction of tabersonine (VII) and stemmadenine (XII) in refluxing acetic acid are presented: the main product in the latter reaction is O-acetylstemmadenine (XIII). The formation of partially racemic pseudocatharanthine (III) both in the treatment of catharanthine (I) with hot acetic acid and in Kutney's ...
R.T. Brown, J.S. Hill, G.F. Smith, K.S.J. Stapleford   +3 more
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Rearrangement du squelette de la catharanthine

Tetrahedron, 1976
Resume Catharanthine N -oxide 1 leads through a [2,3]-sigmatropic rearrangement to 2 whose structure is established by chemical studies and confirmed by X-ray analysis.
Y. Langlois, F. Guéritte, R.Z. Andriamialisoa, N. Langlois, P. Potier, A. Chiaroni, C. Riche   +6 more
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Réarrangement du squelette de la catharanthine. IV. Nor-5 catharanthine et couplage avec la vindoline.

Canadian Journal of Chemistry, 1979
5-Norcatharanthine 3 was prepared from catharanthine 5. The coupling of the corresponding Nb-oxide 10 with vindoline 4, under modified Polonovski reaction conditions, led to two dimers without breaking the structural framework.The isolation of 5-nor-16-demethoxycarbonylcatharanthine 20 by cleavage of one of the coupling products (18) of vindoline 4 ...
Ratremaniaina Zo Andriamialisoa, Nicole Langlois, Yves Langlois, Pierre Potier, Peter Bladon   +4 more
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The acyclic dienamine–indoloacrylate addition route to catharanthine

Tetrahedron, 2008
Abstract Condensation of methyl 3-benzyl-1,2,3,4,5,6-hexahydroazepino[4,5-b]indole-5-carboxylate (3) with methyl Z-4-formylhex-3-enoate (6) gave cis-fused dimethyl 5-benzyl-4-ethyl-2,4a,5,6,7,12-hexahydro-1H-benzo[2,3]azepino[4,5-b]indole-2,12b-dicarboxylate and its trans-fused diastereomer.
Nan Huang, Tao Jiang, Tiansheng Wang, Mustapha Soukri, Rakesh Ganorkar, Bruce Deker, Jean-Michel Léger, Jose Madalengoitia, Martin E. Kuehne   +8 more
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Catharanthine oxidation in flavin mononucleotide-mediated catharanthine-vindoline coupling reaction for synthesis of dimeric indole alkaloids under near-ultraviolet light

Journal of Bioscience and Bioengineering, 1999
A reaction model for the flavin mononucleotide-mediated coupling of catharanthine (C) and vindoline (V) under near-ultraviolet light was established based on the results of experiments on the effects of various physical and chemical factors on the disappearance of C and V, and the synthesis of the product, a dihydropyridinium intermediate (IM).
K, Hirata, T, Akagi, S, Duangteraprecha, M, Honda, Y, Sakamoto, H, Nagase, K, Miyamoto   +6 more
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Enhancement of producing catharanthine by suspension growth ofCatharanthus roseus

Biotechnology Letters, 1990
Increased production of catharanthine (about 200 μg/mL) was obtained at low light intensity under chemostat cultivation as compared with batch and fed-batch processes. Photo-inhibition was observed at high light intensity. Cells after being frozen with 5% DMSO produced more catharanthine (up to 350 μg/L) in batch culture than those from conventional ...
Hyung H. Park, Suk K. Choi, Jae K. Kang, Hyeon Y. Lee   +3 more
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