新霉素是从链霉菌分离的大环抗生素。新抗霉素的作用机理尚未在文献中描述。事实证明，一种被称为氧化型新抗霉素的紧密相关的化合物，苦味素A，可以下调grp78的转录并抑制GRP 78分子伴侣的表达。这种抑制作用会影响GRP 78在促进内质网（ER）蛋白质折叠中的作用，并抑制化疗耐药性肿瘤对ER应激反应的耐药性增强。苦味素A和新抗霉素之间的紧密结构亲缘关系表明新抗霉素毒性具有相似的作用机理。 Neoantimycin is a macrocyclic antibiotic isolated from|Streptomyces|bacteria. The mechanism of action of Neoantimycin is undescribed in the literature. A closely related compound described as an oxidized-type neoantimycin, prunustatin A, is demonstrated to downregulate grp78 transcription and suppress the expression of the GRP 78 molecular chaperone. This suppression affects the role of GRP 78 in promoting protein folding at the endoplasmic reticulum (ER), and suppresses the pro-resistance enhancement of ER stress response by chemotherapy-resistant tumors. The close structural kinship between prunustatin A and Neoantimycin suggests a similar mechanism of action for Neoantimycin toxicity.