Cumambrins A and B fromTanacetum santolina
To isolate the lactones, this plant (1350 g), collected in the flowering stage in June, 1975, on the Ustyurt plateau (Karakalpakia) was extracted five times with chloroform, and the solvent was distilled off to dryness. The concentrated residue was treated with aqueous ethanol (i:I), and the precipitate that deposited was filtered off. The neutral substances were extracted from the filtrate with hexane and chloroform. In the chloroform-extracted material two substances were detected with Rf 0.38 and 0.24 [TLC, benzene--methanol (9:1), Silufol UV-254]. This resin (22 g) was chromatographed on silica gel. When the column was eluted with henzene--hexane (7:3) and with benzene, two substances were isolated.
The guaianolides of ambrosia cumanensis HBK : The structures of cumambrins A and B☆
Abstract Cumambrins A and B isolated from Ambrosia cumanensis HBK were shown to be guaianolides with structures Ia and Ib.
Genetics of the phenotypic evolution in sheep: a molecular look at diversity-driving genes
Background After domestication, the evolution of phenotypically-varied sheep breeds has generated rich biodiversity. This wide phenotypic variation arises as a result of hidden genomic changes that range from a single nucleotide to several thousands of nucleotides. Thus, it is of interest and significance to reveal and understand the genomic changes underlying the phenotypic variation of sheep breeds in order to drive selection towards economically important traits. Review Various traits contribute to the emergence of variation in sheep phenotypic characteristics, including coat color, horns, tail, wool, ears, udder, vertebrae, among others. The genes that determine most of these phenotypic traits have been investigated, which has generated knowledge regarding the genetic determinism of several agriculturally-relevant traits in sheep. In this review, we discuss the genomic knowledge that has emerged in the past few decades regarding the phenotypic traits in sheep, and our ultimate aim is to encourage its practical application in sheep breeding. In addition, in order to expand the current understanding of the sheep genome, we shed light on research gaps that require further investigation. Conclusions Although significant research efforts have been conducted in the past few decades, several aspects of the sheep genome remain unexplored. For the full utilization of the current knowledge of the sheep genome, a wide practical application is still required in order to boost sheep productive performance and contribute to the generation of improved sheep breeds. The accumulated knowledge on the sheep genome will help advance and strengthen sheep breeding programs to face future challenges in the sector, such as climate change, global human population growth, and the increasing demand for products of animal origin.