1. X-ray study on homo-oligopeptides t-Boc(L-Nva)6OMe and HCl.H(L-Nva)6OMe
P Spadon, A Del Pra Int J Pept Protein Res. 1980 Jan;15(1):54-8. doi: 10.1111/j.1399-3011.1980.tb02549.x.
Observations of extended peptide chains, whose direction is perpendicular to the fiber axis (cross-beta-structure) have hitherto been confined to fibrous proteins and to some synthetic polydisperse polypeptides of rather low molecular weight. This structure has now been found in some monodisperse linear homo-oligopeptides with aliphatic hydrocarbon side chains. X-ray fiber diagrams of t-Boc(L-Nva)6OMe and HCl.H(L-Nva)6OMe show the characteristic reflections of this form. In addition, the good orientation of suitably prepared specimens has enabled a fairly complete determination of the hexapeptides unit cell to be made. Both molecules are packed in a pseudomonoclinic lattice whose dimensions are: a = 4.80, b = 59.0, c = 14.86 A, beta = 85 degrees and a = 4.80, b = 58.50, c = 14.84 and beta = 86 degrees for t-Boc(L-Nva)6-OMe and HCl.H(L-Nva)6OMe respectively. It has not been possible from the available experimental data to establish whether the arrangement of the chains within the sheets is parallel or antiparallel.
2. X-ray study on homo-oligopeptides t-BOC-(D-Ala)7-OMe and HCl.H(D-Ala)7-OMe
D R Rueda, P Spadon, G M Bonora, G Zanotti Int J Pept Protein Res. 1979 Apr;13(4):374-8. doi: 10.1111/j.1399-3011.1979.tb01895.x.
Observations of extended peptide chains, whose direction is perpendicular to the fiber axis (cross-beta-structures) have hitherto been confined to fibrous proteins and to some synthetic polydisperse polypeptides of rather low molecular weight. This structure has now been found in some monodisperse linear homo-oligopeptides with aliphatic hydrocarbon side chains. X-ray diffraction photographs of t-Boc-(D-Ala)7-OMe and HCl.H(D-Ala)7-OMe show characteristic reflections for this form. In addition, the good orientation of suitably prepared specimens has enabled a fairly complete determination of the unit cell of the heptapeptides to be made. t-Boc-(D-Ala)7-OMe and HCl.H(D-Ala)7-OMe molecules are packed in a monoclinic lattice with a = 4.80, b = 34.5, c = 5.82 A, beta = 65.6 degrees and a = 4.80, b = 29.5, c = 5.82 A, beta = 65.6 degrees, respectively. It has not been possible to establish whether the arrangement of the chains within the sheets is parallel or antiparallel.
3. The synthesis, distribution, and anti-hepatic cancer activity of YSL
Wenfeng Ding, Jiali Zhang, Zhi Yao, Rong Lu, Dezhu Wu, Ginfu Li, Zilong Shen, Yingji Sun, Gang Lin, Chao Wang, Ming Zhao, Shiqi Peng Bioorg Med Chem. 2004 Sep 15;12(18):4989-94. doi: 10.1016/j.bmc.2004.06.030.
YSL was prepared stepwise from C terminal to N terminal with the side chain un-protective amino acids, Boc-Leu-OMe, Boc-Ser-OH, and Boc-Tyr-OH, as the starting materials in 39.5% total yield (31.2g/per batch). With the side chain un-protective Boc-(3,5-dibromo)-Tyr-OH and HCl.Ser-Leu-OMe as the starting materials (3,5-(3)H-Tyr)-Ser-Leu-OH was obtained in 29% yield. The determination of radioactive quantity in the urine and feces indicated that even after the administration for 130 h only 8.4% (5.35% in urine and 3.05% in feces) of total radioactive quantity from the metabolite of [3,5-(3)H-Tyr]-Ser-Leu-OH were monitored. The distribution study revealed the relative accumulation level of the individual tissue was arranged in the sequence of spleen>liver>kidney>lung>heart>muscle>brain. Selecting hepatic cancer as the target YSL significantly increased the survival time of H22 tumor cells implanted mice.
