Taxinine derivatives

Hosoyama, H. Shigemori, H. Tomida, A. Tsumo, T Kobayashi, J. Modulation of multidmg resistance in tumor cells by taxinine derivatives. Bioorg. Med. Chem. Lett., 1999, 9 389-392. 

Taxanes.—The cage-like structure (117) of the taxinines possessing an 1 l-en-13-one system allows the formation of a transannular C-3—C-11 bond on irradiation. However, the C-13 carbonyl is held away from C-3 so that the oxygen atom cannot participate in an intramolecular hydrogen-abstraction process. Thus irradiation of the diacetate (118) afforded (119), which was related by acetylation to taxinine L, a minor constituent of T. cuspidata. When the C-9 and C-10 hydroxy-groups were converted into their isopropylidene derivative, the central ring was sufficiently deformed to increase the separation between C-3 and C-11. A different photochemical reaction then occurred and a cyclopropyl ketone (120) was obtained. 

A true taxoid dimer was prepared by Cheng and coworkers by Diels-Alder cyclization of taxinine B and taxacin I derivatives. Thus oxidation of 20-hydroxy-4,5-ene-7-oxotaxinine derived from natural taxinine B... 

Cheng Q, Oritani T, Horiguchi T, Yamada T, Hassner A (2000) Novel Dimeric Taxoids via Highly Regio- and Stereospecific Diels-Alder Cycloadditions of Taxinine B and Taxicine I Derivatives. Tetrahedron 56 1181... 

Horiguchi T, Nagura M, Cheng Q, Oritani T, Kudo T (2000) Chemical Oxidation of Taxoids with m-CPBA and Dimethyl Dioxirane Regioselective Epoxidation of Taxinine J Derivatives. Heterocycles 53 2629... 

Bonafonsine, K"3.3 C35H42O6S4 Allose deriv., C"l.ll C35H42O9 Taxinine, T40.1 C35H43N5O... 

Other naturally occurring molecules which have been studied include taxol (171), taxinine (172), a 2,3-dioxabicyclo[4,4,0]decyl derivative (173),the beyer-15(16)-en-12-one system (174), cochlioquinone B (175), and the chromophore from the fluorescent peptide produced by... 

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