89760-63-4Relevant articles and documents
Total Synthesis of TAN-1057 A/B, a New Dipeptide Antibiotic from Flexibacter sp. PK-74
Sokolov, Viktor V.,Kozhushkov, Sergei I.,Nikolskaya, Sofia,Belov, Vladimir N.,Es-Sayed, Mazen,De Meijere, Armin
, p. 777 - 783 (2007/10/03)
TAN-1057 (1a, b) - a new natural dipeptide antibiotic active against methicillin resistant strains of Staphylococcus aureus - was synthesized starting from Na,Nδ,Nω-tri-Z-L-arginine 20b via the corresponding diazoketone 21b. This upon photolysis rearranged to the ketene which was trapped by (±)-2,4,5,6-tetrahydro-5-methylamino-2-ureidopyrimidin-4-one (3) to yield the fully protected dipeptide 23 (30%). The latter was deprotected by hydrogenolysis to give the final compound as a mixture of two epimers - TAN-1057A, B - isolated previously from a strain of Flexibacter sp. PK-74. The intermediate 3 was prepared from 3-amino-2-(N-Z-N-methylamino)propionic acid methyl ester hydrochloride (16) and 2-methyl-2-thiopseudobiuret hydroiodide (18) in one step in 35% yield.
Stabilized analogs of thymopentin. 2. 1,2- and 3,4-ketomethylene pseudopeptides
DeGraw, Joseph I.,Almquist, Ronald G.,Hiebert, Charles K.,Judd, Amrit K.,Dousman, Linda,Smith, R. Lane,Waud, William R.,Uchida, Itsuo
, p. 2398 - 2406 (2007/10/03)
In this second paper in a series of three studies of stable analogs of thymopentin (Arg1-Lys2-Asp3-Val4-Tyr5), the synthesis of analogs stablized at peptide bonds 1,2 and 3,4 via insertion of ketomethylene units is described. A tris(carbobenzyloxy)arginyl(k)norleucine pseudopeptide was synthesized and coupled to Asp-Val-Phe-resin units followed by HF cleavage to prepare Arg(k)Nle-Asp-Val-Phe analogs. Preparation of N-BOC Asp(k)Val and N- BOC Asp(k)Ala units followed by coupling to Phe- or Tyr-resin units provided resin-bound pseudotripeptide substrates for attachment of various arginyl dipeptides. Cleavage from the resin afforded 3,4-ketomethylene-stabilized pseudopeptide analogs of thymopentin. The Arg-Lys-Asp(k)Val-Phe and ArgLys- Asp(k)Val-Tyr analogs were more strongly bound to CEM cells than thymopentin itself. There was significant enhancement of stability in serum for the analogs, especially those containing Arg(k)Nle or Arg-NMeLys moieties at the 1,2-peptide bond.