Atsushi Numata

Fumiquinazolines A–G, novel metabolites of a fungus separated from a Pseudolabrus marine fish

Seven new fumiquinazolines (FQs) A–G have been isolated from a strain of Aspergillus fumigatus originally separated from the marine fish Pseudolabrus japonicus, and their stereostructures and conformations have been established on the basis of spectral and X-ray analyses and some chemical transformations. All the compounds exhibited moderate cytotoxicity against cultured P388 cells.

Gliocladins A - C and glioperazine; Cytotoxic dioxo- or trioxopiperazine metabolites from a Gliocladium sp. separated from a sea hare

New dioxo- or trioxopiperazine metabolites named gliocladins A-C (1 - 3 ) and glioperazine (4) have been isolated from a strain of Gliocladium sp., originally separated from the sea hare. Their structures have been elucidated by spectroscopic analyses using various NMR spectroscopic techniques. Structurally unique trioxopiperazine (3) exhibited significant cytotoxicity against cultured P388 cells.

Gymnasterones, novel cytotoxic metabolites produced by a fungal strain from a sponge

Abstract Gymnastatins A-C, produced by a strain of Gymnasella dankaliensis from the sponge Halichondria japonica , are novel compounds with significant cytotoxicity against tumour cells in culture. Their stereostructures have been established on the basis of spectral analyses.

Absolute stereostructures of novel cytotoxic metabolites, penostatins A–E, from a Penicillium species separated from an Enteromorpha alga

Abstract Penostatins A – E have been isolated from a strain of Penicillium sp. originally separated from the marine alga Enteromorpha intestinalis , and their absolute stereostructures and conformations have been established on the basis of spectral analyses and some chemical transformations. All the compounds except for penostatin D exhibited significant cytotoxicity against cultured P388 cells.

Chaetomugilins, New Selectively Cytotoxic Metabolites, Produced by a Marine Fish-derived Chaetomium Species

Chaetomugilins A∼F have been isolated from a strain of Chaetomium globosum originally isolated from the marine fish Mugil cephalus, and their absolute stereostructures have been elucidated on the basis of spectroscopic analyses, including 1D and 2D NMR techniques, some chemical transformations and an X-ray analysis. These compounds exhibited significant growth inhibition against cultured P388 cells and HL-60 cells. In addition, chaetomugilins A, C and F showed selective cytotoxic activities against 39 human cancer cell lines.

Cell-adhesion Inhibitors Produced by a Sea Hare-derived Periconia sp. : III Absolute Stereostructures of Peribysin J and Macrosphelide M

Peribysin J and macrosphelide M have been isolated from a strain of Periconia byssoides originally isolated from the sea hare Aplysia kurodai. Their absolute stereostructures have been elucidated on the basis of spectroscopic analyses using 1D and 2D NMR techniques and some chemical transformations including the modified Moshers method. These fungal metabolites inhibited the adhesion of human-leukemia HL-60 cells to human-umbilical-vein endothelial cells (HUVEC).

Leptosins, antitumour metabolites of a fungus isolated from a marine alga

Leptosins A B, C, D, E and F, chaetocin derivatives, have been isolated from the mycelium of a strain of Leptosphaeria sp. attached to the marine alga Sargassum tortile. Their stereostructures, with a different configuration from that of related compounds, have been elucidated by spectroscopic analyses using various 1D and 2D NMR techniques and some chemical transformations. All the compounds showed potent cytotoxicity against cultured P388 cells, and leptosins A and C exhibited significant antitumour activity against Sarcoma 180 ascites.

Absolute stereostructures of cell-adhesion inhibitors, peribysins A, E, F and G, produced by a sea hare-derived Periconia sp.

Peribysins E∼G (1∼3) have been isolated from a strain of Periconia byssoides originally separated from the sea hare Aplysia kurodai. Their absolute stereostructures have been elucidated on the basis of spectroscopic analyses using 1D and 2D NMR techniques and some chemical transformations. In addition, the absolute configuration of peribysin A (4), previously undetermined, has been established by conversion to 2 and 3. All these metabolites inhibited the adhesion of human-leukemia HL-60 cells to HUVEC.

Leptosins O-S, Cytotoxic Metabolites of a Strain of Leptosphaeria Sp. Isolated from a Marine Alga

Leptosins O (1), P (2), Q (3), R (4) and S (5) have been isolated from a strain of Leptosphaeria sp. originally separated from the marine alga Sargassum tortile. Their absolute stereostructures have been elucidated on thebasis of spectroscopic analyses of their acetate derivatives (6-10) using various ID and 2D NMR techniques and some chemical transformations. The NMR and NOE spectral analyses of 6-10 revealed that they exist in a single conformer of B type in CDCl 3 . Among these metabolites, leptosins O (1) and P (2) exhibited significant cytotoxicity against cultured P388 cells.

Dankasterone, a new class of cytotoxic steroid produced by a Gymnascella species from a marine sponge

Dankasterone, produced by a strain of Gymnascella dankaliensis from the marine sponge Halichondria japonica, is a novel class of steroid with significant cytotoxicity against tumour cells in culture.