Tatsufumi Okino

Microginin, an angiotensin-converting enzyme inhibitor from the blue-green alga Microcystis aeruginosa

Abstract Microginin, an angiotensin-converting enzyme inhibitory pentapeptide, was isolated from the freshwater blue-green alga Microcystis aeruginosa . Its structure was elucidated to be 1 on the basis of 2D NMR data and chemical degradation.

Aeruginosins, protease inhibitors from the cyanobacterium Microcystis aeruginosa

Abstract Five new protease inhibitors, related to aeruginosins 298-A (5), 98-A (1) and 98-B (2), were isolated from the cyanobacterium Microcystis aeruginosa. Aeruginosins 98-C (3) and 101 (4) differed from 1 in the Hpla unit. Aeruginosin 298-B (6) lacked the argininol unit in 5. Aeruginosins 89-A (7) and 89-B (8) were observed as the tautomers in HPLC because of the presence of the argininal units. Structures 3, 4 and 6–8 were determined on the basis of spectral data and chromatographic analyses of degradation products. The absolute stereochemistry of 1–8 was deduced by a combination of spectral and chemical studies. Aeruginosins 98-A to 98-C, 101, 298-A, 298-B, 89-A and 89-B were isolated from the cyanobacterium Microcystis aeruginosa. These compounds except aeruginosin 298-B had trypsin, plasmin and thrombin inhibitory activities. Their structures were determined on the basis of spectral data and amino acid analysis. Their absolute stereochemistries were deduced by a combination of spectral and chemical studies.

Aeruginosin 298-A, a thrombin and trypsin inhibitor from the blue-green alga Microcystis aeruginosa (NIES-298)

Abstract Aeruginosin 298-A was isolated from the freshwater blue-green alga Microcystis aeruginosa (NIES-298). Its structure was elucidated to be 1 on the basis of 2D NMR data. This linear peptide inhibited thrombin and trypsin potently.

Aeruginosins 98-A and B, trypsin inhibitors from the blue-green alga Microcystis aeruginosa (NIES-98)

Aeruginosins 98-A and B, trypsin inhibitors, were isolated from the cultured freshwater blue-green alga Microcystis aeruginosa. Their structures were elucidated to be 1 and 2 respectively on the basis of 2D NMR data and chemical degradation. These peptides inhibited trypsin potently with an IC50 of 0.6 μg/ml.

New antifouling sesquiterpenes from four nudibranchs of the family Phyllidiidae

Abstract Three new antifouling sesquiterpene isocyanides were isolated from nudibranchs of the family Phyllidiidae along with a new sesquiterpene peroxide and six known sesquiterpenes. Their structures were determined mainly on the basis of 2D NMR data. These compounds showed potent antifouling activity against larvae of the barnacle Balanus amphitrite.

Micropeptins A and B, plasmin and trypsin inhibitors from the blue-green alga Microcystis aeruginosa

Abstract Micropeptins A and B were isolated from the cultured freshwater blue-green alga Microcystis aeruginosa. Their structures were elucidated to be 1 and 2 on the basis of 2D NMR data and chemical degradation. These cyclic depsipeptides inhibited plasmin and trypsin potently.

Antifouling kalihinenes from the marine sponge Acanthella cavernosa

Three new kalihinenes were isolated from the marine sponge Acanthella cavernosa together with kalihinol A and 10-formamidokalihinene. Their structures were elucidated to be 1–3 on the basis of 2D NMR data. These compounds showed potent antifouling activities against the barnacle larvae of Balanus amphitrite.

Aeruginosins 102-A and B, new thrombin inhibitors from the cyanobacterium Microcystis viridis (NIES-102)

Abstract Aeruginosins 102-A and B were isolated from the freshwater cyanobacterium Microcystis aeruginosa (NIES-102). Their structures were elucidated to be 1 and 2 on the basis of 2D NMR data and chemical degradation. These peptides inhibited thrombin potently.

Methyl farnesoate induces larval metamorphosis of the barnacle, Balanus amphitrite via protein kinase C activation

NOBUHIRO FUSETANIFusetani Biofouling Project, ERATO, Research Development Corporation ofJapan, c/o Niigata Engineering Co. Ltd., Yokohama 235, JapanABSTRACT Methyl farnesoate (MF) and juvenile hormone III (JH-III) induced the metamor-phosis of unattached juveniles in cyprid larvae of the barnacle, Balanus amphitrite, in a dose-dependent manner. Because these effects were similar to PKC activation by phorbol esters, theeffects of assorted protein kinase inhibitors on the activity of MF and JH-III were examined.Staurosporine, a PKC inhibitor, and H7(1-(5-isoquinonylsulfonyl)-2-methylpiperazine), a proteinkinase inhibitor, significantly inhibited larval metamorphosis-inducing activity of MF and JH-III,suggesting that both MF and JH-III are involved in the PKC signal transduction system. More-over, the existence of MF in cyprids and adult barnacles was demonstrated by partial purificationfollowed by GCMS and HPLC analyses. These results may suggest that MF induces larval meta-morphosis via PKC signal transduction system in B. amphitrite cyprids. J. Exp. Zool. 278:349–355, 1997.

New microviridins, elastase inhibitors from the blue-green alga Microcystis aeruginosa

Abstract Microviridios B and C were isolated from the freshwater blue-green alga Microcystis aeruginosa (NIES-298). Their structures were elucidated to be 1 and 2 on the basis of 2D NMR data and chemical degradation. These peptides inhibited elastase potently.