The Active Centres of Agelastatin A, a Strongly Cytotoxic Alkaloid of the Coral Sea Axinellid SpongeAgelas dendromorpha, as Determined by Comparative Bioassays with Semisynthetic Derivatives
作者:Michele D'Ambrosio、Antonio Guerriero、Francesco Pietra、Marina Ripamonti、C�cile Debitus、Jean Waikedre
DOI:10.1002/hlca.19960790315
日期:1996.5.8
Agelastatin A (1), an unusual alkaloid of the axinellid sponge Agelas dendromorpha from the Coral Sea, can be selectively acetylated (7) or methylated at OHC(8a) (4), peracetylated (8) or permethylated at OHC(8a), NH(5), and NH(6) (5), or, finally, subjected to C(9)C(8a) (14) or C(5b)C(8a) β-elimination (11–13), in a regiospecific manner or not, depending on the reaction conditions. Under acidic conditions
Agelastatin A(1),一种来自珊瑚海的无心轴海绵海绵Agelas dendromorpha的不常见生物碱,可以在OHC(8a)上选择性乙酰化(7)或甲基化(4),在OHC(8a)上过乙酰化(8)或全甲基化, NH(5)和NH(6)(5),或者最后经过C(9)C(8a)(14)或C(5b)C(8a)β消除(11-13),视反应条件而定是否为区域特异性方式。在酸性条件下,化合物12区域选择性地(虽然不是内/外立体选择性地)添加H 2 O或MeOH ,从而产生了类固醇/类固醇混合物1/18或4/19。类似地,11或13添加MeOH,分别得到混合物(-)- 2/20或15/16。化合物13还加入AcOH,得到混合物8/17。中间cisoid治疗的形式得到21用H 3 ö +经受N(5)N(6),得到桥接五环22,其构成用于一个证明cisoid配置。从构象研究中,设计了规则,以允许从NM