5973-11-5Relevant articles and documents
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.
Photochromic glassy liquid crystals comprising mesogenic pendants to dithienylethene cores
Kim, Chunki,Marshall, Kenneth L.,Wallace, Jason U.,Chen, Shaw H.
supporting information; experimental part, p. 5592 - 5598 (2010/03/03)
Photochromic glassy liquid crystals were synthesized using dithienylethenes as the volume-excluding cores to which liquid crystalline mesogens were chemically bonded through alkyl spacers. Nematic, smectic, and cholesteric glassy liquid crystals were demonstrated with glass transition temperatures above 90 °C and clearing points up to 220 °C without traces of crystallization on cooling or crystalline melting on heating. A monodomain cholesteric glassy liquid crystalline film containing an enantiomeric 2-methylpropylene chiral spacer was characterized as a left-handed helical stack, exhibiting a selective reflection band centered at 686 nm, an orientational order parameter of 0.65 for the quasi-nematic layers, and a combination of reflective coloration with photoswitchable absorptive coloration.
Synthesis and biological activity of methyl 2,6,10-trimethyldodecanoate and methyl 2,6,10-trimethyltridecanoate: Male-produced sexual pheromones of stink bugs Euschistus heros and Piezodorus guildinii
Zarbin, Paulo H. G.,Reckziegel, Aurelia,Plass, Ernst,Borges, Miguel,Francke, Wittko
, p. 2737 - 2746 (2007/10/03)
Methyl 2,6,10-trimethyltridecanoate (1) and methyl 2,6,10-trimethyldodecanoate (2) have been identified as male-produced sex pheromones of the Brazilian soybean stink bugs Euschistus heros (F.) and Piezodorus guildinii (Westwood). In order to establish a defined attractive blend for both species, compounds 1 and 2 were synthesized as mixtures of stereoisomers to be employed in behavior bioassays. (±)-Citronellol (3) was utilized as starting material, and the syntheses was carried out in six steps with good overall yield. When tested alone, synthetic compounds 1 and 2 proved to be active in a two-choice olfactometer; however, a 20: 1 mixture of 1 and 2 was much more attractive to E. heros females. A similar blend had been found among the headspace volatiles of males.
