中华医学超声杂志

应用化学 ›› 1990, Vol. 0 ›› Issue (1): 1-9.

• 综述 •    下一篇

二肽和三肽甜味剂的结构性能关系

曾广植   

  1. 中国科学院上海有机化学研究所 上海 200032
  • 收稿日期:1989-04-07 修回日期:1989-06-24 出版日期:1990-02-10 发布日期:1990-02-10

STRUCTURE-ACTIVITY RELATIONSHIPS OF DI-AND TRIPEPTIDE SWEETENERS

Zeng Guangzhi(Tseng Kuang-chih)   

  1. Shanghai Institute of Organic Chemistry, Academia Sinica, Shanghai 200032
  • Received:1989-04-07 Revised:1989-06-24 Published:1990-02-10 Online:1990-02-10

PDF

295

被引次数

4 | 2

摘要：

本文用作者(1980)提出的多点接触U-型诱导适应甜苦味受体模型说明与Asparta-me类似的二肽三肽甜味剂中结构与性能相互关系。其中生甜基(Glucophore)G=-O2C(CH2)0-1·CHNH2R+,R=H;助味基(Auxogluc)AN=R,R为N-端酰胺基;C-端助味基AC=CONHC·R1R2R3,此处R3>R2>R1。AN和AC的主干链均以其能达到味受体膜的外层中部C-9位时化合物最甜。G的定味位置和方向不同,AN和AC主干链可到达的膜层深浅也将不同,然而总以能到达受体膜的C-9位时才能产生最强微扰。故最有利的助味基常以其约相当于一脂肪酸酰基C9的链长为最好,且过犹不及。若以不对称碳原子上取代基R1R2R3的体积大小(而不是以原子序数大小)作我们称之为“拓朴”构型的准则,则并联三肽AN-G-AC2的三个氨基酸都必需是“拓朴”-D-型才能产生高甜度。而串联三肽G-AC1-AC2中仅需AC2是“拓朴”-L-型。二肽G-AC中AC的主干链宽度R1-C-R2以≤(CH2)4为度;三肽G-AC1-AC2中AC2宽度以≤(CH2)5为度。除其他指标外,R,R2和R3本身或其取代基所具有极性效应、空间效应,疏水效应对这些甜味剂所产生的甜强度及稳定性的影响都是容易理解的。

关键词: 生甜基, 助甜基, C-9律, “拓朴”构型

Abstract:

A U-shaped induced-fitting model of sweet-bitter receptor with multiple point attach-ment was proposed by the author in 1980. In this paper it is employed to illustrate thestructure-activity relationships of di- and tripeptide sweeteners analogous to Aspartame.The glucophore is taken to be G=-O2C(CH-2)0-1 CHNH-2+R when R=H, the auxogluc onthe N-end to be AN=R when R=any acyl group and that on the C-end to be Ac=CONH-CR1R2R3 where R3>R2>R1 in size. The main chains of both AN and Ac will attain amaximal sweetness, if either or both can reach the C-9 position of the top layer of thereceptor membrane. However, the depth where the main chain of AN or Ac can reach de-pends on the orientation and position where G is ancholed on the sulface. Nevertheless, itwill cause the highest perturbation shuold it reach this C-9 position. Thus the optimalchainlength of an auxogluc is often equivalent to no more or less than that of a C8 to C10acyl group. If one supposes that the size instead of the atomic number of substituentsR1R2R3 on the dissymmetric a-carbon atom be adopted as the standard for what we call"topo" configuration, then the three amino acids in paralle connection AN-G-Ac must allbe of a "topo"-D-configuration to have a high sweetness intensity whiie only an A2c ofthem in series connection G-A1c-A2c must be of a "topo"-L enantiomer. For a dipeptideG-Ac, the width R1-C-R2 of Ac must be≤(CH2)4;for a tripeptide G-A1c-A2c, that ofA2c must be≤(CH2)5. The polar, steric and hydrophobic effects of substituents on R, R2and R3 have understandable influences, inter alia, on the stability as well as sweetnessintensity of these concerned sweetencrs.

Key words: glucophore, auxogluc, C-9 rule, "topo"configuration

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