In the course of screening for antimalarial agents, five tropolone compounds were isolated from the culture broth of Penicillium sp. FKI-4410. Two were known compounds, puberulic acid and stipitatic acid. Three were new analogs of puberulic acid, designated viticolins A-C. Among them, puberulic acid exhibited potent antimalarial inhibition, with IC 50 values of 0.01 lg ml À1 against chloroquine-sensitive and -resistant Plasmodium falciparum strains in vitro. Furthermore, puberulic acid showed weak cytotoxicity against human MRC-5 cells, with an IC 50 value of 57.2 lg ml À1 . The compound also demonstrated a therapeutic effect in vivo, which compared well against the currently used antimalarial drugs, and thus shows promise as a leading candidate for development into a new antimalarial compound.

An actinomycete strain K07-0460 T producing new antitrypanosomal antibiotics, spoxazomicins, was isolated from the roots of a variety of orchid collected in the subtropical Okinawa prefecture. The 16S ribosomal RNA gene sequence analysis indicated that the strain belonged to the genus Streptosporangium and showed high similarities with S. amethystogenes subsp. amethystogenes DSM 43179 T (99.4%), S. amethystogenes subsp. fukuiense IFO 15365 T (99.2%) and S. longisporum DSM 43180 T (98.7%). The DNA-DNA hybridization relatedness values between strain K07-0460 T and the three strains were below 70%. On the basis of phylogenetic analysis, DNA-DNA hybridization relatedness and physiological characteristics, the strain should be classified as a new species Streptosporangium oxazolinicum sp. nov. in the genus Streptosporangium. The type strain of S. oxazolinicum is K07-0460 T (¼JCM 17388 T ).

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