Reusser F
Antimicrob Agents Chemother. 1976 Oct;10(4):618-22. doi: 10.1128/AAC.10.4.618.
The antibiotic tirandamycin (a 3-acyltetramic acid structurally related to streptolydigin) specifically inhibits transcription by interfering with the function of bacterial ribonucleic acid polymerase. Ribonucleic acid polymerases from rat liver nuclei are not subject to tirandamycin inhibition. Qualitatively, the mode of action of the antibiotic is identical to that of streptolydigin in inhibiting chain initiation as well as chain elongation during the transcriptional process. However, tirandamycin is approximately 40 times less potent than streptolydigin. The structures of the 3-acyl groups of the two acyltetramic acid antibiotics tirandamycin and streptolydigin differ only slightly in the degree of oxidation of the terminal dioxabicyclo (3.1)nonane system and possess the same stereochemistry (D. J. Duchamp, A. R. Branfman, A. C. Button, and K. L. Rinehart, 1973). More significantly, major differences occur at the 1 and 5 positions of the tetramic acids. Tirandamycin contains no substituents; streptolydigin contains a substituted acetamide function at position 5 and a sugar moiety at position 1. The lack of substituents at the 1 and 5 positions of the tetramic acid portion in tirandamycin is probably responsible for the reduced biopotency of tirandamycin as compared with streptolydigin.
抗生素替兰霉素（一种与链霉溶菌素结构相关的3-酰基四胺酸）通过干扰细菌核糖核酸聚合酶的功能来特异性抑制转录。大鼠肝细胞核中的核糖核酸聚合酶不受替兰霉素抑制。从定性上讲，该抗生素的作用模式与链霉溶菌素在转录过程中抑制链起始和链延伸的作用模式相同。然而，替兰霉素的效力约为链霉溶菌素的40分之一。两种酰基四胺酸抗生素替兰霉素和链霉溶菌素的3-酰基结构仅在末端二氧杂双环（3.1）壬烷系统的氧化程度上略有不同，并且具有相同的立体化学结构（D. J. 杜尚普、A. R. 布兰夫曼、A. C. 巴顿和K. L. 莱因哈特，1973年）。更显著的是，在四胺酸的1位和5位出现了主要差异。替兰霉素没有取代基；链霉溶菌素在5位含有一个取代的乙酰胺官能团，在1位含有一个糖部分。替兰霉素四胺酸部分的1位和5位缺乏取代基，这可能是其与链霉溶菌素相比生物活性降低的原因。
