作者:John W. Huffman、Julia A.H. Lainton、W. Kenneth Banner、Sammy G. Duncan、Robert D. Jordan、Shu Yu、Dong Dai、Billy R. Martin、Jenny L. Wiley、David R. Compton
DOI:10.1016/s0040-4020(96)01134-9
日期:1997.2
The synthesis of both sidechain epimers of 1′-(4), 2′-(5), 3′-methyl-(6) and 4′-methyl-Δ8-tetrahydrocannabinol (7) has been carried out. The synthetic approach entailed the acid catalyzed condensation of the appropriate substituted resorcinol with menthadienol to provide the Δ8-THC analogue. Both isomers of 1′-(4) and 2t́-Δ8-THC (5) were more potent than Δ8-THC, both in vitro and in vivo. The 3′-methyl
New Nodularins: A General Method for Structure Assignment
作者:Michio Namikoshi、Byoung Wook Choi、Ryuichi Sakai、Furong Sun、Kenneth L. Rinehart、Wayne W. Carmichael、William R. Evans、Phillip Cruz、Murray H. G. Munro、John W. Blunt
DOI:10.1021/jo00088a014
日期:1994.5
A general method has been developed for assigning the structures of nodularin, a potent hepatotoxin, tumor promoter, and protein phosphatase inhibitor, and minor components isolated from a cultured and a bloom sample of the cyanobacterium Nodularia spumigena. It consists of (1) FABMS analysis (determination of molecular weight and molecular formula), (2) H-1 NMR spectroscopy on the parent compound and chiral GC analysis of an acid hydrolyzate (identification and stereochemistry of amino acid components), (3) ozonolysis followed by NaBH4 reduction (conversion to a linear peptide), and (4) FABMS/CID/MS analyses of the linear peptide and the parent compound (sequence analysis). The method has been employed in assigning structures to three new nodularins (2-4) and can be applied to other cyclic peptides containing alpha,beta-dehydroamino acid unit(s), especially the related microcystins, cyclic heptapeptide hepatotoxins. Two nodularins, [DMAdda(3)]nodularin (2) and [(6Z)-Adda(3)] nodularin (3), were obtained from a bloom sample collected from Lake Ellesmere (New Zealand), and [D-Asp(1)] nodularin (4) was isolated from cultured cells (strain L-575). The LD50s of 2 and 4 were 150 and 75 mu g/kg (ip, mice), respectively, but 3 did not show apparent toxicity at 2.0 mg/kg.
Enantioselective synthesis of C3-C10 fragment (northeastern zone) of maytansinoids with 4-chiral centers (4S,5S,6R,7S)
作者:A.I. Meyers、James P. Hudspeth
DOI:10.1016/s0040-4039(01)82028-1
日期:1981.1
Total synthesis of (-)-maysine
作者:A. I. Meyers、K. A. Babiak、Arthur L. Campbell、Daniel L. Comins、Michael P. Fleming、Rainer Henning、Manfred Heuschmann、James P. Hudspeth、John M. Kane
DOI:10.1021/ja00353a027
日期:1983.7
Tius, M. A.; Gu, X.; Truesdell, J. W., Molecular Crystals and Liquid Crystals (1969-1991), 1987, vol. 150, p. 247 - 256
作者:Tius, M. A.、Gu, X.、Truesdell, J. W.、Savariar, S.、Yang, D. K.、Crooker, P. P.