Ascomycin (Immunomycin, FR-900520, FK520, FR900520, FK-520)，又称长川霉素或子囊霉素，是从链霉菌中分离的FK506乙基类似物，是一种中性大环聚酮类抗生素，具有抗真菌、抗疟疾和免疫抑制的作用，临床上用于湿疹治疗。

参考文献

1Hatanaka H, et al. FR-900520 and FR-900523, novel immunosuppressants isolated from a Streptomyces. II. Fermentation, isolation and physico-chemical and biological characteristics. J Antibiot (Tokyo). 1988 Nov;41(11):1592-601.

2.Krishika Sambyal, et al. Bioprocess and genetic engineering aspects of ascomycin production: a review. J Genet Eng Biotechnol. 2020 Nov 19;18(1):73.

3.Germán Sierra-Paredes, et al. Ascomycin and FK506: pharmacology and therapeutic potential as anticonvulsants and neuroprotectants. CNS Neurosci Ther. Spring 2008;14(1):36-46.

冰袋运输。粉末直接保存于-20℃，有效期3年。建议分装后-20℃干燥保存，避免反复冻融。