Chain length and activity

Chain Length and Activation Energy in Chain Reactions... 

Nonionic Microemulsions Dependence of Oil Chain Length and Active Component (Lidocaine)... 

Table 3. Effect of the acylating agent chain length and activation on its reactivity ...

OS 41a] ]R 19] ]P 30] Ten different substrates (C4-C8 alcohols) were reacted with rhodium(I)-tris(fn-sulfophenyl)phosphane [110]. The variance in conversions (ranging from about 1-62%) determined was explained by differences in the solubility of the alcohols in the aqueous catalytic layer and by their different intrinsic activities. Chain length and steric/electronic effects of the different alcohols affected their reactivity in a well-known pattern (Figure 4.63). The results obtained correspond to the conversions achieved in a well-mixed traditional batch reactor (40 cm ). They further agreed with data from mono-phasic processing. 

Notably, natural variation in the type III PKS active site cavity, like that observed in Ipomoea and Petunia, does not result in functionally impaired enzymes, but in fact, generates catalytically active enzymes that display both altered substrate and product specificities. Sequential increases in the side chain volume of position 256 in alfalfa CHS2 result in decreases in polyketide chain length and predictable shifts in the ratio of tetraketide to triketide reaction products.32 These results functionally link the volume of the elongation/cyclization lobe in type III PKS to chain length determination. 

Volatiles and cuticular extracts of the wheat stem sawfly, Cephus cinc-tus Norton (Hymenoptera Cephidae), were analyzed. The bifunctional 9-acetyloxynonanal gave the strongest EAD response. Additional EAD-active compounds included 13-acetyloxytridecanal, aldehydes with 9—16 carbon chain lengths, acids with 8—10 carbon chain lengths, and pheny-lacetic acid. The odor of phenylacetic acid was detected instantly by human... 

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