Induction of Erythroid Differentiation of HumanErythroleukemia K-562 Cells by Mutactimycin

Mutactimycin,a new anthracycline antibiotic,consists of 5 components: mutac-timycin A,B,C,D and 7-deoxymutactimycinone A. Mutactimycin components differ from each other in suppressing proliferation and inducing differentiation of human erythroleukemia K-562 cells. Determined by benzidine staining, the percentage of K-562 cells with hemoglobin expression was86% by mutactimycin C. The peak percentage of benzidine positive cells appeared on day 5 or 6.The differentiated cells were partially reversed after drug removal.The induced cells lost the clonogenicity in soft-agar. The kinetics of differentiation induced by mutactimycin C, in comparison with other known anthracycline antibiotics,was similar to that by doxorubicin, epirubicin anddaunorubicin. Mutactimycin C was more active than aclarubicin A. The structure-activity relationship for mutactimycin components suggested that the substituting groups on C_3, C_11, and the saccharide on C_7 might be important for their activities.

新抗病毒抗生素变活霉素A

变活霉素A为一新的蒽环类广谱抗病毒抗生素,在组织培养内对4株单纯疱疹Ⅰ型病毒(HSV-1),4株单纯疱疹Ⅱ型病毒,流感甲_3病毒及柯萨奇B_6病毒的致细胞病变作用均有抑制活性,IC_(50)为6.25～12.5μg/ml。相同剂量可降低HSV-1繁殖量 1.5～3.5个对数值(log10)。细胞感染HSV-1后 4～10小时再用变活霉素A处理,仍可抑制,推迟细胞病变的发展.250～500μg/ml变活霉素A在无细胞系统内对HSV-2 DNA聚合酶,人免疫缺陷病毒(HIV-1)逆转录酶,鸭乙型肝炎病毒DNA聚合酶及牛胸腺DNA聚合酶α均无抑制活性。