25346-33-2Relevant articles and documents
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Meriwether,L.S. et al.
, p. 5163 - 5169 (1961)
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Synthesis and mass spectra of rearrangement bio-signature metabolites of anaerobic alkane degradation via fumarate addition
Chen, Jing,Zhou, Lei,Liu, Yi-Fan,Hou, Zhao-Wei,Li, Wei,Mbadinga, Serge Maurice,Zhou, Jing,Yang, Tao,Liu, Jin-Feng,Yang, Shi-Zhong,Wu, Xiao-Lin,Gu, Ji-Dong,Mu, Bo-Zhong
, (2020/05/01)
Metabolite profiling in anaerobic alkane biodegradation plays an important role in revealing activation mechanisms. Apart from alkylsuccinates, which are considered to be the usual biomarkers via fumarate addition, the downstream metabolites of C-skeleton rearrangement can also be regarded as biomarkers. However, it is difficult to detect intermediate metabolites in both environmental samples and enrichment cultures, resulting in lacking direct evidence to prove the occurrence of fumarate addition pathway. In this work, a synthetic method of rearrangement metabolites was established. Four compounds, namely, propylmalonic acid, 2-(2-methylbutyl)malonic acid, 2-(2-methylpentyl)malonic acid and 2-(2-methyloctyl)malonic acid, were synthesized and determined by four derivatization approaches. Besides, their mass spectra were obtained. Four characteristic ions were observed at m/z 133 + 14n, 160 + 28n, 173 + 28n and [M - (45 + 14n)]+ (n = 0 and 2 for ethyl and n-butyl esters, respectively). For methyl esterification, mass spectral features were m/z 132, 145 and [M - 31]+, while for silylation, fragments were m/z 73, 147, 217, 248, 261 and [M - 15]+. These data provide basis on identification of potential rearrangement metabolites in anaerobic alkane biodegradation via fumarate addition.
Novel fatty acid methyl esters from the actinomycete Micromonospora aurantiaca
Dickschat, Jeroen S.,Bruns, Hilke,Riclea, Ramona
supporting information; experimental part, p. 1697 - 1712 (2012/02/04)
The volatiles released by Micromonospora aurantiaca were 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 from S-adenosyl methionine (SAM).
Histamine H3 and H4 receptor affinity of branched 3-(1H-imidazol-4-yl)propyl N-alkylcarbamates
?azewska, Dorota,Wiecek, Ma?gorzata,Ligneau, Xavier,Kottke, Tim,Weizel, Lilia,Seifert, Roland,Schunack, Walter,Stark, Holger,Kie?-Kononowicz, Katarzyna
scheme or table, p. 6682 - 6685 (2010/06/16)
A series of imidazole-containing (non-)chiral carbamates were tested at human histamine H3 receptor (H3R). All compounds displayed Ki values below 100 nM. A trend for a stereoselectivity at human H3R was observed for the chiral α-branched ligands. Selected compounds were also tested at human histamine H4 receptor and showed moderate to weak affinities (118-1460 nM).
