Rudinger,J. et al., Collection of Czechoslovak Chemical Communications, 1960, vol. 25, p. 2022 - 2028
作者:Rudinger,J. et al.
DOI:——
日期:——
N-Carbamoylation of 2,4-Diaminobutyrate Reroutes the Outcome in Padanamide Biosynthesis
作者:Yi-Ling Du、Doralyn S. Dalisay、Raymond J. Andersen、Katherine S. Ryan
DOI:10.1016/j.chembiol.2013.06.013
日期:2013.8
Padanamides are linear tetrapeptides notable for the absence of proteinogenic amino acids in their structures. In particular, two unusual heterocycles, (S)-3-amino-2,-oxopyrrolidine-1-carboxamide (S-Aopc) and (S)-3-aminopiperidine-2,6-dione (S-Apd), are found at the C-termini of padanamides A and B, respectively. Here we identify the padanamide biosynthetic gene cluster and carry out systematic gene inactivation studies. Our results show that padanamides are synthesized by highly dissociated hybrid nonribosomal peptide synthetase/polyketide synthase machinery. We further demonstrate that carbamoyltransferase gene padQ is critical to the formation of padanamide A but dispensable for biosynthesis of padanamide B. Biochemical investigations show that PadQ carbamoylates the rare biosynthetic precursor L-2,4-diaminobutyrate, generating L-2-amino-4-ureidobutyrate, the presumed precursor to the C-terminal residue of padanamide A. By contrast, the C-terminal residue of padanamide B may derive from glutamine. An unusual thioesterase-catalyzed cyclization is proposed to generate the S-Aopc/S-Apd heterocycles.
Kurtz, Journal of Biological Chemistry, 1949, vol. 180, p. 1253,1258
作者:Kurtz
DOI:——
日期:——
A Simple Synthesis of Isotopic Citrulline and Two of Its Homologs
作者:Lloyd H. Smith
DOI:10.1021/ja01629a114
日期:1955.12
Syntheses and evaluation as antifolates of MTX analogs derived from 2,.omega.-diaminoalkanoic acids
作者:J. R. Piper、G. S. McCaleb、J. A. Montgomery、F. A. Schmid、F. M. Sirotnak
DOI:10.1021/jm00146a008
日期:1985.8
(MTX) analogues 27a-c bearing 2, omega-diaminoalkanoic acids (ornithine and its two lower homologues) in place of glutamic acid were synthesized by routes proceeding through N2-[4-(methylamino)benzoyl]-N omega-[(1,1-dimethylethoxy)carbonyl]-2, omega-diaminoalkanoic acid ethyl esters and N2-[4-(methylamino)benzoyl]-N5-[(1,1-dimethylethoxy)carbonyl]-2, 5-diaminopentanoic acid followed by alkylation with