Project description:Ten new dolabrane-type diterpenoids, notolutesins A-J (1-10), were isolated from the Chinese liverwort Notoscyphus lutescens, along with four known compounds. The structures of the new compounds were established on the basis of extensive spectroscopic data, and that of 1 was confirmed by single-crystal X-ray crystallography. The absolute configuration of 1 was determined by comparing its experimental and calculated electronic circular dichroism spectra. All of the isolates were evaluated for their cytotoxicity against a small panel of human cancer cell lines, and compound 1 exhibited an IC50 value of 6.2 ?M against the PC3 human prostate cancer cell line.
Project description:Epiphytic dwarf males on the females present a possible solution to the problem of short fertilization distances in mosses. However, leptokurtic spore dispersal makes dwarf males likely to be closely related to their host shoot, with an accompanying risk of inbreeding. The capacity of a female to harbour a high number of different dwarf males suggests that there may be mechanisms in place that counteract inbreeding, such as polyandry and post-fertilization selection. We have genotyped sporophytes, female host shoots and dwarf males in four populations of the moss Homalothecium lutescens. We found no evidence of selective sporophyte abortion based on level of heterozygosity. The occurrence of entirely homozygous sporophytes together with significantly positive inbreeding coefficients in three of the populations (mean FIS between 0.48 and 0.64) suggest frequent mother-son mating events. However, 23% of all sampled sporophytes had a higher level of heterozygosity compared with the mean expected heterozygosity at the population level. Polyandry was frequent, on average 59% of the sporophytes on a female shoot were sired by distinct fathers. In conclusion, sporadic fertilizations by dwarf males originating from nonhost female shoots appear to counteract strong inbreeding.
