Pranee Rachtawee

Isariotins E and F, spirocyclic and bicyclic hemiacetals from the entomopathogenic fungus Isaria tenuipes BCC 12625.

New spirocyclic and bicyclic hemiacetals, isariotins E (1) and F (2), together with TK-57-164A (3) were isolated from the entomopathogenic fungus Isaria tenuipes BCC 12625. The absolute configuration of 3 was addressed by application of the modified Moshers method. Isariotin F (2) exhibited activity against the malaria parasite Plasmodium falciparum K1 with an IC(50) value of 5.1 microM and cytotoxic activities against cancer cell lines (KB, BC, and NCI-H187) and nonmalignant (Vero) cells with respective IC(50) values of 15.8, 2.4, 1.6, and 2.9 microM.

Hopane-type triterpenes and binaphthopyrones from the scale insect pathogenic fungus Aschersonia paraphysata BCC 11964.

Two new triterpenes, 17(21)-hopene-6alpha,12beta-diol (1) and 17(21)-hopen-12beta-ol (2), the known 17(21)-hopen-6alpha-ol (zeorinin, 3), and two new biarylic dihydronaphthopyrones, aschernaphthopyrones A (4) and B (5), were isolated from the scale insect pathogenic fungus Aschersonia paraphysata BCC 11964. Hopene 1 and aschernaphthopyrone A (4) exhibited antimalarial activity with IC(50) values of 15 and 7.3 microM, respectively.

Cytotoxic hydroanthraquinones from the mangrove-derived fungus Paradictyoarthrinium diffractum BCC 8704

Two new hydroanthraquinones, paradictyoarthrins A (1) and B (2), were isolated from the mangrove-derived fungus Paradictyoarthrinium diffractum BCC 8704. Structures of the new compounds were elucidated by analyses of the NMR spectroscopic and mass spectrometry data. The absolute configuration of 1 was determined by X-ray crystallography. These compounds exhibited cytotoxic activities.

Two New Drimane Sesquiterpenes, Fudecadiones A and B, from the Soil Fungus Penicillium sp. BCC 17468

Two new drimane sesquiterpenoids, fudecadione A and fudecadione B (1, 2), together with the known brefeldin A (3) and fulvic acid (4), were isolated from the soil fungus Penicillium sp. BCC 17468. Chemical structures were determined based on spectroscopic evidence including 1D and 2D NMR and mass spectral data. The proposed relative stereochemistry of fudecadiones A and B was based upon NOESY spectral data and chemical means. Compounds 1 and 4 exhibited anticancer activity against MCF-7, KB, and NCI-H187, with IC (50) values in the range of 5.05-45.43 µg/mL, while compound 2 was inactive against these tumor cells. Brefeldin (3) also displayed antimalarial activity against PLASMODIUM FALCIPARUM (K1, multidrug-resistant strain), with an IC (50) value of 1.12 µg/mL.

Saccharosporones A, B and C, cytotoxic antimalarial angucyclinones from Saccharopolyspora sp. BCC 21906

Three new angucyclinones, saccharosporones A, B and C, together with (+)-ochromycinone, (+)-rubiginone B2, tetrangulol methyl ether and fujianmycin A, were obtained from fermentation of the terrestrial actinomycete of the genus Saccharopolyspora BCC 21906 isolated from a soil collected in Chanthaburi Province, Thailand. Structures of the new compounds and their relative configurations were assigned by NMR spectral data interpretation. Saccharosporones A and B exhibited antimalarial activity against Plasmodium falciparum K1 with IC50 values of 4.1 and 3.9 μM. Both metabolites also possessed cytotoxic activities against cancer cell lines (KB, MCF-7 and NCI-H187) and nonmalignant Vero cell, while saccharosporone C only showed cytotoxic activity against NCI-H187.