cyclize การใช้

• ?-Epoxy carbonyls have been known to cyclize to furans.
• Naringenin chalcone can spontaneously cyclize to naringenin ( a flavanone ).
• This brings them into close proximity and encourages them to cyclize.
• The remaining carbons on the side chain cyclize to form a furan ring and the molecule is oxidized further to form azadirone and azadiradione.
• In the biosynthesis of cocaine, however, only the ( S )-enantiomer can cyclize to form the tropane ring system of cocaine.
• Butelase 1 has been shown to cyclize the linear precursor of kalata B1 with > 95 % yield at a remarkable rate of 5.42?0 5 M & minus; 1 s & minus; 1.
• Carothers surmised that the problem with the polyamides that had been made from ?-aminocaproic acid was due to cyclization reactions, so he replaced ?-aminocaproic acid with 9-aminononoic acid which would not cyclize.
• These divergent enzymes differ from CHS in their preference for starter molecules, the number of acetyl additions ( often through malonyl-CoA ) and even in the mechanism of ring formation used to cyclize identical polyketide intermediates.
• In the commonly accepted mechanism, these diones would go through a common enol intermediate, meaning that the meso and " d, l "-racemic isomers would cyclize at the same rate as they form from a common intermediate.
• In very rare cases, a DTT adduct may be formed, i . e ., the two sulfur atoms of DTT may form disulfide bonds to different sulfur atoms; in such cases, DTT cannot cyclize since it has no such remaining free thiols.
• Other reasons have been offered to explain why certain specific non-proteinogenic amino acids are not generally incorporated into proteins; for example, ornithine and homoserine cyclize against the peptide backbone and fragment the protein with relatively short half-lives, while others are toxic because they can be mistakenly incorporated into proteins, such as the arginine analog canavanine.
• Putrescine is then converted into " N "-methyl putrescine via methylation by SAM catalyzed by putrescine " N "-methyltransferase ( PMT ) . " N "-methylputrescine then undergoes deamination into 4-methylaminobutanal by the " N "-methylputrescine oxidase ( MPO ) enzyme, 4-methylaminobutanal then spontaneously cyclize into " N "-methyl-? 1-pyrrollidium cation.