Novel pteridines of formula (I), ##SPC1## wherein R is a lower alkyl group, optionally substituted with a hydroxy group and R.sup.1 and R.sup.2 are the same or different and each is a lower alkyl group having together at least 3 carbon atoms or R.sup.1 and R.sup.2, together with the carbon atom in the pteridine ring structure, form a spirocycloalkyl ring system having 4 to 6 carbon atoms outside the pteridine ring structure, and their method of preparation. The above compounds have bacteriostatic activity.
式(I)的新型
喜树碱,其中R是较低的烷基,可选地被羟基取代,而R.sup.1和R.sup.2相同或不同,每个都是较低的烷基,共同具有至少3个碳原子,或者R.sup.1和R.sup.2与
喜树碱环结构中的碳原子一起形成一个spirocycloalkyl环系统,该系统在
喜树碱环结构外具有4至6个碳原子,以及它们的制备方法。上述化合物具有细菌抑制活性。