mic 18

Stearyl glycyrrhetinate 是甘草提取物中的主要成分之一，具有抗菌作用，对金黄色葡萄球菌菌株的 MIC 大于 256 mg L。

Pachybasin 是一种蒽醌真菌代谢物。 Pachybasin 对大肠杆菌、枯草芽孢杆菌、M. luteus、S. cerevisiae、C. albicans、A. niger 和 A. flavus 具有抗菌活性，MIC 值为 64.0 μg mL，对金黄色葡萄球菌具有抗菌活性 和尖孢镰刀菌，MIC 值分别为 32.0 和 16.0 μg mL。

Nocardamine is a ferrioxamine siderophore that has been found inStreptomycesand has diverse biological activities.1,2,3,4It chelates iron in a chrome azurol S assay (IC50= 9.9 μM).1Nocardamine inhibitsM. smegmatisandM. bovisbiofilm formation (MIC = 10 μM for both), an effect that can be reversed by iron.2It is cytotoxic to T47D, SK-MEL-5, SK-MEL-28, and RPMI-7951 cancer cells (IC50s = 6, 18, 12, and 14 μM, respectively).3Nocardamine also induces morphological changes in BM-N4 insect cells.4 1.Lopez, J.A.V., Nogawa, T., Futamura, Y., et al.Nocardamin glucuronide, a new member of the ferrioxamine siderophores isolated from the ascamycin-producing strain Streptomyces sp. 80H647J. Antibiot. (Tokyo)72(12)991-995(2019) 2.Ishida, S., Arai, M., Niikawa, H., et al.Inhibitory effect of cyclic trihydroxamate siderophore, desferrioxamine E, on the biofilm formation of Mycobacterium speciesBiol. Pharm. Bull.34(6)917-920(2011) 3.Kalinovskaya, N.I., Romaneko, L.A., Irisawa, T., et al.Marine isolate Citricoccus sp. KMM 3890 as a source of a cyclic siderophore nocardamine with antitumor activityMicrobiol. Res.166(8)654-661(2011) 4.Matsubara, K., Sakuda, S., Tanaka, M., et al.Morphological changes in insect BM-N4 cells induced by nocardamineBiosci. Biotechnol. Biochem.62(10)2049-2051(1998)

Anti-MRSA agent 18 (E17)，MRSA和S. aureus的MIC值分别是4 μg mL与2 μg mL，它抑制MRSA的机制主要是与细菌细胞膜中的磷脂酰甘油和心磷脂发生相互作用。这种作用引起细胞膜的通透性及极化状态发生改变，导致细胞内的ROS水平升高，以及DNA与蛋白质的渗漏，从而促进细菌的快速死亡。

Benastatin A is a polyketide synthase-derived benastatin that has been found inStreptomycesand has diverse biological activities.1,2,3It inhibits glutathione S-transferase (GST; Ki= 5 μM for the rat liver enzyme).2Benastatin A is active against several bacteria, including methicillin-resistantS. aureus(MRSA; MIC = 3.12 μg ml). It induces apoptosis and cell cycle arrest at the G1 G0phase in Colon 26 mouse colon cancer cells when used at concentrations of 20 and 16 μM, respectively.3 1.Xu, Z., Schenk, A., and Hertweck, C.Molecular analysis of the benastatin biosynthetic pathway and genetic engineering of altered fatty acid-polyketide hybridsJ. Am. Chem. Soc.129(18)6022-6030(2007) 2.Aoyagi, T., Aoyama, T., Kojima, F., et al.Benastatins A and B, new inhibitors of glutathione S-transferase, produced by Streptomyces sp. MI384-DF12. I. Taxonomy, production, isolation, physico-chemical properties and biological activitiesJ. Antibiot. (Tokyo)45(9)1385-1390(1992) 3.Kakizaki, I., Ookawa, K., Ishikawa, T., et al.Induction of apoptosis and cell cycle arrest in mouse colon 26 cells by benastatin AJpn. J. Cancer Res.91(11)1161-1168(2000)

Antitubercular agent-18 (Compound 9a) 为抗结核剂，对M. tuberculosisH37Rv、Spec. 192、Spec 210 及 Spec. 800 的最小抑制浓度(MIC)值依次为2、2、2 及128 μg ml，展现出对分支杆菌的高选择性抗菌活性。

XT-4，一种抗菌肽，源自热带爪蟾 (Xenopus tropicalis) 皮肤分泌物，对E.coli表现出高效的抑菌作用，最小抑制浓度 (MIC) 为18 μM。