A-non-substituted

The first STS structure solved was that of a pinosylvin-forming STS from Pinus sylvestris. Pine trees can by-pass the C4H reaction and directly produce the CoA thioester of cinnamate that allows this STS to utilize a non-substituted cinnamoyl-CoA starter in vz vo.11 However, when presented in vitro with p-coumaroyl-CoA, the enzyme proves to be comparable in activity to STS enzymes from organisms that utilize the para-substituted cinnamoyl starter. 

The asymmetric hydroxylation of A-non-substituted ethyl 2-carbamoyl-2-phenylacetate in THF was mediated by Davis oxaziridine, 2-(benzenesulfonyl)-3-phenyl-oxaziridine as oxidant in the presence of a combination of rare-earth metal alkoxide Pr(OPr )3 and the ligand A-((S)-l-(2-hydroxyphenylcarbamoyl)-2-methylpropyl)-2-hydroxybenzamide as catalyst afforded enantioenriched (68-92% ee) (R)-ethyl 2-carbamoyl-2-hydroxy-2-phenylacetate (yield 39-96%) with a densely... 

Very recently, crystal structure analysis was conducted on a non-substituted compound of sexithio-phene (hexamer) by Horowitz et al. [107(b)] and Siegrist et al. [107(c)] independently. Although different crystal structures are proposed, the presence of the stretched S-trans conformation (see Figure 8.2) is evident. This conformation can be seen in common for the non-substituted a,a -linked compounds up to the hexamer along with the methyl-substituted ones [22,104]. On the other hand, the oligothiophenes substituted with long or bulky side/end-groups on various positions [105-107(a)] assume the conforma-... 

Other well-known G-nerve agents contain fluor (i.e., sarin, soman, and cyclosarin), whereas tabun contains —CN as a leaving group (Table 57.2, Figure 57.3). However, sarin and soman have one substitution by a P—O—bond, and another has a P=C bond, so they are usually named phosphonates. Phosphoroamidate compoimds have also been synthesized with a non-substituted amido group (P-NH2/ i e., methamidophos)... 

In comparison with oxygen, ammonium is absolutely required for growth if no other nitrogen source is available. In fact it is a non-substitutable nutrient for biosynthesis whereas oxygen is an electron acceptor that can be substituted by glucose (reduced to ethanol). If glucose conversion is not complete due to ammonium limitation, the restriction of ammonium supply compared to glucose uptake is expressed as ... 

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