| 138994-84-0

• 分子结构分类: 有机化合物 - 木脂素、新木脂素和相关化合物
• CAS: 138994-84-0
• 化学式: C₄₃H₅₄N₆O₁₀
• 分子量: 814.936
• InChiKey: WXPUMXVQBTYYFG-MJAXMUKPSA-N

反应信息

• 作为产物：
  描述：

  (1S,4R,7R,10R,13S,16S)-7-(hydroxymethyl)-24-methoxy-10-[(4-methoxyphenyl)methyl]-4,9,13,15,29-pentamethyl-22-oxa-3,6,9,12,15,29-hexazatetracyclo[14.12.2.218,21.123,27]tritriaconta-18,20,23,25,27(31),32-hexaene-2,5,8,11,14,30-hexone 、 碘甲烷 在 aluminum oxide 、 potassium fluoride 作用下， 以 乙二醇二甲醚 为溶剂， 反应 24.0h， 以100%的产率得到
  参考文献：
  名称：

  New antitumor bicyclic hexapeptides, RA-VI and -VIII from rubia cordifolia ; Conformation-activity relationship II

  摘要：

  The structures of new antitumor bicyclic hexapeptides, RA-VI and -VIII from Rubia cordifolia were elucidated by the spectroscopic and chemical methods. A combination of two-dimentional NMR techniques and NOE relationships showed that the amino acids constituting the beta-turn of RA-VI are Ser-2 and D-Tyr-3 and those of RA-VIII, Thr-2 and Tyr-3. By the conformational analysis of RA-VI in its crystalline state using the X-ray diffractometric technique, RA-VI was shown to have, in its solid state, a type V beta-turn structure at the residues Ser-2 and D-Tyr-3, while other RAs have type II beta-turns. Further, by 2D-NMR techniques, temperature effects on NH protons and NOE experiments, in solution of CDCl3, RA-VI was shown to exist only as conformer A and RA-VIII as conformers A, B and C. The difference between the solid state and solution state conformations of RA-VI was also shown by the refinement of the restrained molecular dynamics calculations using AMBER program. RA-VIII, having a smaller population of conformer A with type II beta-turn than other RAs, showed a reduced biological activity, and the N-methyl derivative of RA-VIII, whose conformer A content is further reduced, gave a further reduced activity, suggesting that conformer A contributes to the activity. However, RA-VI, existing in solution 100% as conformer A, showed a very low activity and N-methylation increased the activity. This shows that the stereochemistry and molecular mobility of the aromatic side chain of Tyr-3 over this turn, as elucidated by the C-13 spin lattice relaxation times, plays a more important role in the antitumor activity of the compounds of this series in addition to the type II beta-turn structures.

  DOI：

  10.1016/s0040-4020(01)96155-1