The enzymatic kinetic resolution of tert-butyl 2-(1-hydroxyethyl) phenylcarbamate via lipase-catalyzed transesterification reaction was studied. We investigated several reaction conditions and the carbamate was resolved by Candida antarctica lipase B (CAL-B), leading to the optically pure (R)- and (S)-enantiomers. The enzymatic process showed excellent enantioselectivity (E > 200). (R)- and (S)...

Full-length de novo sequencing from tandem mass (MS/MS) spectra of unknown proteins such as antibodies or proteins from organisms with unsequenced genomes remains a challenging open problem. Conventional algorithms designed to individually sequence each MS/MS spectrum are limited by incomplete peptide fragmentation or low signal to noise ratios and tend to result in short de novo sequences at l...

Both chlorozotocin and 1-(2-chloroethyl)-3-cyclohexyl-1nitrosourea (CCNU) bind specifically to the extended euchromatin fraction of the HeLa cell genome. After a 2-hr incubation of log-phase cells with each radiolabeled drug at 30 /(M, both alkylation (chlorozotocin and CCNU) and carbamoylation (CCNU) of nuclear chromatin were shown to be confined to late-eluting fractions from an ECTHAMcellulo...

The development of genetically altered murine animals has generated a need for in vitro systems in the mouse. We have now characterized a novel isolated bile duct unit (IBDU) preparation from the mouse to facilitate such studies. The mouse IBDU is isolated by portal perfusion of collagenase, blunt dissection, further enzymatic digestions, filtering through sized mesh, and culturing on Matrigel ...

Most surgeons seem to favour the former method. Even when the erisophake is used instead of forceps, the technique of zonulolotomy and delivery of the lens remains essentially the same. Since the introduction of A.C.T., however, mechanical zonulolotomy has been replaced by enzymatic zonulolysis and the extraction of the lens by seizing it at the 12 o'clock position is being increasingly practis...

background: in patients with non-obstructive azoospermia (noa), vital spermatozoa from the tissue is obtained from testes by enzymatic treatment besides the mechanical treatment. objective: to increase the sperm recovery success of testicular sperm extraction (tese), with enzymatic digestion if no sperm is obtained from testis tissue by mechanical method. materials and methods: tissue samples w...