Aiya Sato

Norcembrene diterpenoids from pacific soft-corals of the genus sinularia (Alcyonacea; octocorallia)

Abstract Four new norcembrene diterpenoids, 2–5, have been isolated from several species of the soft-coral Sinularia collected in Palau, Western Caroline Islands. These new compounds are closely related to a unique norcembrenolide, 1, previously reported from the Australian soft-coral Sinularia leotoclados . The structure assignments of these new compounds were provided by interpretation of spectral data, and the structures of norcembrenes 2 and 3 were confirmed by single crystal X-ray analysis.

Gramine-derived bromo-alkaloids from the marine bryozoan zoobotryon verticillatum

Abstract Two new natural products, 2,5,6-tribromo-N-methylgramine ( 1 ) and its corresponding side-chain N-oxide, 2 , have been isolated from the subtropical marine bryozoan Zoobotryon verticillatum . The structures of these compounds were illustrated by spectral analyses and by chemical synthesis.

Aldose reductase inhibitors from the red alga, asparagopsis taxiformis.

Separation of an extract of the red alga Asparagopsis taxiformis guided by the inhibition of bovine lens aldose reductase gave pentabromopropen-2-yl tribromo-(1a) and dibromoacetate (1b), whose structures were determined by spectral data and chemical synthesis.

Poilaneic acid, a cembranoid diterpene from Croton poilanei

Abstract Poilaneic acid, a cembranoid diterpene from Croton poilanei , has been characterized as (1 R *,2 E ,4 Z ,7 E , 11 Z )-12-carboxyl-1-isopropyl-4,8-dimethylcyclotetradecatetraene.

Nahocols and isonahocols, endothelin antagonists from the brown alga, sargassum autumnale

Novel endothelin antagonists, nahocols A, A1, B, C, D1 and D2, and isonahocols D1 and D2, were isolated from the brown alga, Sargassum autumnale. Their structures were determined through detailed analysis of NMR spectra and chemical reactions. Nahocols have an aryl prenyl ether structure, which are speculated to be biogenetic precursors of the ubiquitous prenyl hydroquinones or prenyl benzoquinones in the plant and animal kingdoms.

Acyclic diterpenes from Croton kerrii

Abstract Croton kerrii ; Euphorbiaceae; acyclic diterpenes; anti-reserpine ulcer; ( E,E,Z )-11- hydroxymethyl-3,7,15-trimethyl-2,6,10,14-hexadecatetraen-1-ol; ( E,E,E )-11-formyl-3,7,15-trimethyl-2,6,10,14-hexadecatetraen-1-ol.