Totalsynthesis of modified pentapeptide, caldoramide, a cytotoxic linear pentapeptide from the marine cyanobacterium Caldora penicillate is described. Notable features of the route include the efficient preparation of three key fragments and final assembly to the natural product via sequential amide couplings. The spectral data of the synthetic compound was found to be in comparison with that of the
Trungapeptin A, a novel cyclodepsipeptide isolated from a marine cyanobacterium (Lyngbya majuscula), has been synthesised and its structure unambiguously confirmed.
从海洋蓝藻(Lyngbya majuscula)中分离出的新型环表肽 Trungapeptin A 已被合成,其结构也已得到明确证实。
A Flexible Asymmetric Approach to Methyl 5-Alkyltetramates and Its Application in the Synthesis of Cytotoxic Marine Natural Product Belamide A
By using a methyl tetramate derivative (R)‐ or (S)‐9 as a novel chiral building block, a direct, flexible, and highly enantioselective approach to methyl (R)‐ or (S)‐5‐alkyltetramates (2) is disclosed. Among the synthesized methyl 5‐alkyltetramates 2, methyl 5‐methyltetramate (2 a) is found in cytotoxic mirabimide E (4) and dysideapyrrolidone (5), and methyl 5‐benzyltetramate (2 g) is a substructure
通过使用四甲基甲酸酯衍生物(R)‐或(S)‐9作为新型手性结构单元,可以直接,灵活且高度对映选择性地合成四甲基(R)‐或(S)‐5‐烷基四酸酯(2)。披露。在合成的5-烷基四酸甲酯2中,在细胞毒性的mirabimide E(4)和dysideapyrrolidone(5)中发现了5-甲基四酸甲酯(2 a),而5-苄基四酸甲酯(2 g)是有效的抗肿瘤药物dolastatin 15中的子结构。 (3)。在此方法的基础上,从(S)-9的七个步骤完成了抗有丝分裂四肽belamide A(7)的首次不对称合成,总收率为23.8%。不仅确认了(+)-belamide A(7)的结构和绝对构型,还确认了用于记录13 C NMR光谱,13 C NMR光谱数据相关性和天然belamide A的旋光度数据的溶剂。 (7)已被修改。