Cysteinoyl- and Cysteine-containing Dipeptidoylbenzotriazoles with Free Sulfhydryl Groups: Easy Access to N-terminal and Internal Cysteine Peptides
作者:Tarek S. Ibrahim、Srinivasa R. Tala、Said A. El-Feky、Zakaria K. Abdel-Samii、Alan R. Katritzky
DOI:10.1111/j.1747-0285.2011.01303.x
日期:2012.8
N‐protected, free sulfhydryl cysteinoylbenzotriazoles 7a–c (70–85%), which on treatment with diverse amino acids and dipeptides afforded the corresponding N‐protected, free sulfhydryl N‐terminal cysteine dipeptides 8a–e and tripeptides 8f–h in 73–80% yields. N‐Protected, free sulfhydryl cysteine‐containing dipeptides 9a,b were converted into the corresponding N‐protected, free sulfhydryl dipeptidoylbenzotriazoles
通过用1-(苄氧羰基)苯并三唑(Cbz-Bt)1a,N-(叔丁氧羰基)处理l-半胱氨酸,可以制备70-75%产率的N-保护半胱氨酸的每个带有一个巯基的半胱氨酸。苯并三唑(Boc-Bt)1b和1-(9-芴基甲氧基-羰基)苯并三唑(Fmoc-Bt)1c。N-保护的,游离的巯半胱氨酸4a-c中然后转化成相应的N-保护的,游离的巯cysteinoylbenzotriazoles 7A-C(70-85%),其上具有不同氨基酸的二肽和治疗得到相应的N -保护的游离巯基N端半胱氨酸二肽8a-e和三肽8f-h,产率为73-80%。将N保护的含游离巯基半胱氨酸的二肽9a,b转化为相应的N保护的游离巯基二肽基苯并三唑10a,b(69-81%),将其用氨基酸,二肽和三肽处理后得到内部半胱氨酸三肽11A-C ,四肽11D,è和五肽11F,每个都包含A N -受保护的游离巯基在温和条件下的收率为70-90%。用