Polycitone A and Polycitrins A and B: New Alkaloids from the Marine Ascidian Polycitor sp
摘要:
Three novel compounds polycitone A (1a) and polycitrins A and B (2 and 3) were isolated from the marine ascidian Polycitor sp. The structures of compounds 1a, 2, and 3 were established mainly on the basis of NMR spectroscopic data and, in the case of 1a, also by single-crystal X-ray diffraction analysis. The crystallographic analysis was performed on 1b, the penta-O-methyl derivative of 1a, both compounds yielding poorly diffracting crystals of highly anisotropic shape. It required, in view of the dominating heavy-atom content of 1b; diffraction measurements with an intense rotating-anode X-ray source. Polycitone A and polycitrins A and B represent the first examples of two new classes of marine products which might biogenetically be close to the lamellarins. The penta-O-methyl derivative 1b, was found to inhibit the growth of SV40 transformed fibroblast cells in a concentration of 10 mu g/mL.
Total Syntheses of the Marine Pyrrole Alkaloids Polycitone A and B
摘要:
Polycitone B (2) was obtained in four steps from pyrrole dicarboxylic acid 3, including Friedel-Crafts reaction of the corresponding acid chloride with anisole. The conversion of 2 into polycitone A(1) was achieved in two steps via Mitsunobu alkylation of the pyrrolic NH groups. The synthesis of polycitone A proceeds in 18% overall yield and offers the possibility of varying the subsituents on the pyrrole ring.
Compounds of general formula (I) wherein the nature of the group R is not particularly critical and typically takes various forms, include the natural compound halitulin of formula (1) have antitumor activity.
Total Syntheses of the Marine Pyrrole Alkaloids Polycitone A and B
作者:Andreas T. Kreipl、Caroline Reid、Wolfgang Steglich
DOI:10.1021/ol026555b
日期:2002.9.1
Polycitone B (2) was obtained in four steps from pyrrole dicarboxylic acid 3, including Friedel-Crafts reaction of the corresponding acid chloride with anisole. The conversion of 2 into polycitone A(1) was achieved in two steps via Mitsunobu alkylation of the pyrrolic NH groups. The synthesis of polycitone A proceeds in 18% overall yield and offers the possibility of varying the subsituents on the pyrrole ring.
Polycitone A and Polycitrins A and B: New Alkaloids from the Marine Ascidian Polycitor sp
Three novel compounds polycitone A (1a) and polycitrins A and B (2 and 3) were isolated from the marine ascidian Polycitor sp. The structures of compounds 1a, 2, and 3 were established mainly on the basis of NMR spectroscopic data and, in the case of 1a, also by single-crystal X-ray diffraction analysis. The crystallographic analysis was performed on 1b, the penta-O-methyl derivative of 1a, both compounds yielding poorly diffracting crystals of highly anisotropic shape. It required, in view of the dominating heavy-atom content of 1b; diffraction measurements with an intense rotating-anode X-ray source. Polycitone A and polycitrins A and B represent the first examples of two new classes of marine products which might biogenetically be close to the lamellarins. The penta-O-methyl derivative 1b, was found to inhibit the growth of SV40 transformed fibroblast cells in a concentration of 10 mu g/mL.