Architecture and life forms of Thymus jenisseensis (Lamiaceae)

Thymus jenisseensis is endemic to Southern Siberia. The structure of Thymus jenisseensis were studied with the use of an architectural approach. The architectural unit consist of branched compound skeletal axis of the 1st and 2nd order, and is repeated many times in the structure of adults. As a result of studying the architectural units of individuals growing in different sites of a coenopopulation, in the upper border of the forest belt (Tsagan-Shibetu, Republic of Tuva), differences were identified. An architectural unit consisting of branched orthotropic or ascending basisympodially accreting compound skeletal axes develops on a site of a dry riverbed; an architectural unit consisting of branched orthotropic or ascending acrosympodially accreting compound skeletal axes develops on a site of high-altitude steppe on a plain. The diversity of compound skeletal axes in the structure of architectural units contributes to the formation of two biomorphs (dwarf subshrub and dwarf shrub), changes in the vitality and duration of development of T. jenisseensis individuals. The identified features of architecture are morphological mechanisms of adaptation of the species to living conditions.

Novel fatty acid methyl esters from the actinomyceteMicromonospora aurantiaca

The volatiles released byMicromonospora aurantiacawere collected by means of a closed-loop stripping apparatus (CLSA) and analysed by GC–MS. The headspace extracts contained more than 90 compounds from different classes. Fatty acid methyl esters (FAMEs) comprised the major compound class including saturated unbranched, monomethyl and dimethyl branched FAMEs in diverse structural variants: Unbranched, α-branched, γ-branched, (ω−1)-branched, (ω−2)-branched, α- and (ω−1)-branched, γ- and (ω−1)-branched, γ- and (ω−2)-branched, and γ- and (ω−3)-branched FAMEs. FAMEs of the last three types have not been described from natural sources before. The structures for all FAMEs have been suggested based on their mass spectra and on a retention index increment system and verified by the synthesis of key reference compounds. In addition, the structures of two FAMEs, methyl 4,8-dimethyldodecanoate and the ethyl-branched compound methyl 8-ethyl-4-methyldodecanoate were deduced from their mass spectra. Feeding experiments with isotopically labelled [2H10]leucine, [2H10]isoleucine, [2H8]valine, [2H5]sodium propionate, and [methyl-2H3]methionine demonstrated that the responsible fatty acid synthase (FAS) can use different branched and unbranched starter units and is able to incorporate methylmalonyl-CoA elongation units for internal methyl branches in various chain positions, while the methyl ester function is derived fromS-adenosyl methionine (SAM).

Synthese und absolute Konfiguration kettenverzweigter, Cimetidin-analoger Thioether / Synthesis and Absolute Configuration of Chain Branched Cimetidine Analogous Thioethers

Chain branched Cimetidine analogous thioethers, promising building blocks for the preparation of H2-histaminergic compounds, were synthetized from chiral aminoalkanethiols. Enantiomerically pure amino acids or aminoalcohols were used as starting materials. In one case, a resolution via neutral and acid di-O-(4-toluoyl)tartrates was achieved in good yields and satisfying enantiomeric excess. The absolute configuration of an ethyl branched compound was determined using X-ray diffraction and anomalous dispersion