Acetylpinnasterol and pinnasterol,ecdysone-like metabolites,from the marine red alga laurenciapinnata yamada

The structures of two sterols, isolated from the title alga and designated as acetylpinnasterol and pinnasterol, were determined on the basis of the X-ray crystallography. These metabolites are the first marine phytosterols with ecdysone-like structures and biological activity as moulting hormones.     

Structure of spironippol,a new sesquiterpene,from the red alga laurencianipponica yamada

A new sesquiterpene, designated as spironippol, was isolated from the title alga. The structure, which was determined on the basis of the spectral data and X-ray crystallography, represents the biogenetic transition between chamigrane and perforane sesquiterpenes.     

Caraibical,a new aromatic sesquiterpene from the marine alga laurenciacaraibica

Caraibical, a new aromatic sesquiterpene aldehyde, has been isolated from the marine marine red alga $\text{Laurencia}$$\text{caraibica}$. The structure, which possesses an ether cyclization differing from previous compounds, was defined on the basis of its spectral data.     

Laurencienyne,a new acetylenic cyclic ether from the marine red alga laurencia obtusa

The structure and absolute stereochemistry of laurencienyne, a non-isoprenoid cyclic ether isolated from $\text{Laurencia obtusa}$, has been established by X-ray and spectroscopic studies.     

Laurencianol,a new halogenated diterpenoid from the marne alga laurenciaobtusa

The structure of an anitmicrobial dibromomochloroditerpene alcohol, laurencianol, has been determined by spectral and X-ray crystallographic techniques. The compound has been isolated from the Mediterranean red alga $\text{barLaurencia}$$\text{obtusa}$.     

Obtusin,a unique bromine-containing polycyclic ketal from the red marine alga Laurenciaobtusa

The structure of a unique bromine-containing ketal, obtusin ($\text{1}$), has been determined by spectral and X-ray crystallographic techniques. Obtusin is a natural component of the Mediteranean red alga $\text{Laurencia}$$\text{obtusa}$.     

Two chrome derivatives from the brown alga Zonariatournefortii

Two minor lipid components of the brown seaweed $\text{Zonaria}$$\text{tournefortii}$ were characterized as (all Z) - 5′,7′-dihydroxy-2′-nonadeca-4,7,10,13,16-pentenyl-chrome chromone ($\text{3}$) and 5′,7′-dihydroxy-2′-pentadecylchrome ($\text{4}$).     

The isolation of new norcycloartene triterpenoids from the tropical marine alga Tydemaniaexpeditionitis (chlorophyta)

Three new Δ³-norcycloartene triterpenoids, with differing side chain functionalities, have been isolated from the tropical green alga $\text{Tydemania}$$\text{expeditionitis}$ collected in Guam. The structures of these new compounds were secured by x-ray crystallography and by chemical interconversion.     

New tricarbocyclic cycropropanoid diterpenes from the brown alga dictyotadichotoma

The structures $\text{1}$, $\text{2}$, and $\text{3}$ have been proposed for three new diterpenes from $\text{Dictyota}$$\text{dichotoma}$ mainly on the basis of spectroscopic evidence.     

Balearone,a metabolite of the brown alga cystoseirabalearica

The isolation of a new metabolite of mixed biogenesis, balearone $\text{1}$from the brown alga $\text{Cystoscira}$$\text{balearica}$ is described. The structure was determined by an X-ray diffraction analysis.