1. Synthesis and characterization of new galanthamine derivatives comprising peptide moiety
Lyubomir T Vezenkov, Maria G Georgieva, Dantcho L Danalev, Tchavdar B Ivanov, Galya I Ivanova Protein Pept Lett. 2009;16(9):1024-8. doi: 10.2174/092986609789055412. Epub 2009 Sep 1.
New analogues of galanthamine containing peptide fragments either at 6 or 11 position, were synthesized by reaction between galanthamine molecule and dipeptides and tripeptide, derivatives of N-(3,4-dichlorophenyl)-D,L-Ala-OH. The best results according to yields, easily purification of the target products, and simplicity of the scheme realisation was achieved by using of cyanomethyl ester of Boc-Gly-OH as activated compound.
2. Bovine prothrombin fragment 1, segment 1-10. Synthesis and immunological investigation
P B Ten Kortenaar, W W Wilkerson, N T Boggs 3rd, D A Madar, K A Koehler, R G Hiskey Int J Pept Protein Res. 1980 Nov;16(5):440-9. doi: 10.1111/j.1399-3011.1980.tb02968.x.
The N-terminal decapeptide methyl ester, H-Ala-Asn-Lys-Gly-Phe-Leu-Gla-Gla-Val-Arg-OCH3 (16) of bovine prothrombin fragment 1 has been prepared by standard solution techniques, via a fragment coupling strategy. Hexapeptide Boc-Ala-Asn-Lys epsilon (Boc)-Gly-Phe-Leu-OBzl (9) was obtained by coupling Boc-Ala-Asn-Lys epsilon (Boc)Gly-OH (6) to the trifluoroacetate salt of H-Phe-Leu-OBzl (8). Hydrogenolysis of (9) followed by coupling to HCl. H-Gla gamma (OtBu)2-Gla gamma (OtBu)2-Val-Arg(HCl)-OCH3 (14) gave the fully protected decapeptide (15). Treatment of 15 with 90% trifluoroacetic acid followed by ion exchange chromatography of 15 yielded the methyl ester (16). The decapeptide 16 labeled with 125I using the Bolton-Hunter reagent, did not bind to antibodies specific for the calcium ion-induced conformation of bovine fragment 1.
3. N-urethane-protected amino alkyl isothiocyanates: synthesis, isolation, characterization, and application to the synthesis of thioureidopeptides
Vommina V Sureshbabu, Shankar A Naik, H P Hemantha, N Narendra, Ushati Das, Tayur N Guru Row J Org Chem. 2009 Aug 7;74(15):5260-6. doi: 10.1021/jo900675s.
Synthetically useful N-Fmoc amino-alkyl isothiocyanates have been described, starting from protected amino acids. These compounds have been synthesized in excellent yields by thiocarbonylation of the monoprotected 1,2-diamines with CS2/TEA/p-TsCl, isolated as stable solids, and completely characterized. The procedure has been extended to the synthesis of amino alkyl isothiocyanates from Boc- and Z-protected amino acids as well. The utility of these isothiocyanates for peptidomimetics synthesis has been demonstrated by employing them in the preparation of a series of dithioureidopeptide esters. Boc-Gly-OH and Boc-Phe-OH derived isothiocyanates 9a and 9c have been obtained as single crystals and their structures solved through X-ray diffraction. They belong to the orthorhombic crystal system, and have a single molecule in the asymmetric unit (Z' = 1). 9a crystallizes in the centrosymmetric space group Pbca, while 9c crystallizes in the noncentrosymmetric space group P2(1)2(1)2(1).
