Isolation and synthesis of 1-methylisoguanosine,a potent pharmacologically active constituent from the marine sponge tenadiadigitata

A new pharmacologically active agent isolated from the marine sponge $\text{Tedania}$$\text{digitata}$ has been identified as 1-methylisoguanosine ($\text{1}$) by spectral and degradative chemical methods and synthesis from a β-D-ribofuranosylimidazole ($\text{2}$).     

Cavernicolin-1 and cavernicolin-2, epimeric dibromolactams from the mediterranean sponge aplysina (venongia) cavernicola

Cavernicolin-1 and Cavernicolin-2, two epimeric compounds having a γ-lactam ring fused to a dibromocyclohexenone ring, have been isolated from the Mediterranean sponge $\text{Aplysina}$$\text{(Verongia)}$$\text{cavernicola}$.     

Minor and trace sterols in marine invertebrates 30. Isolation,structure elucidation and partial synthesis of 26-methylstrongylosterol and 28-methylxestosterol - two marine sterols arising by a novel quadruple biomethylation sequence

Two new sterols, 26-methylstrongylosterol ($\text{4}$) and 28-methylxestosterol ($\text{5}$), arising from a hitherto unknown quadruple biomethylation sequence, together with the biogenetically important “missing link”, durissimasterol ($\text{6}$), were isolated from the Indo-Pacific sponge $\text{Strongylophora}$$\text{durissima}$.     

Novel bisabolene-type sesquiterpenoids with a conjugated diene isolated from the okinawan sea sponge theonella cf. swinhoei

Three Novel sesquiterpenoids have been isolated from the Okinawan see sponge $\text{Theonella}$ cf. $\text{swinhoei}$ and the structures have been determined on the basis of the spectral data and chemical reactions.     

Isolation and structure of aaptamine a novel heteroaromatic substance possessing α-blocking activity from the sea sponge Aaptosaaptos

A novel heteroaromatic substance, aaptamine possessing an α-adrenoceptor blocking activity has been isolated from the tropical sea sponge $\text{Aaptos}$$\text{aaptos}$ and its structure has been determined to be $\text{1}$ on the basis of spectral data and chemical degradation.     

Chemical constituents of the nudibranch chromodoris marislae

The major metabolite of Chromodoris marislae, marislin ($\text{1a}$) was identified from spectral data and converted into the sponge metabolite pleraplysillin-2 ($\text{1b}$).     

Ichthyotoxic sesterterpenoids from the neo guinean sponge carteriospongia foliascens

Six 20,24-dimethylscalarane derivatives ($\text{5}$, $\text{12}$, $\text{15}$, $\text{17}$, $\text{19}$, and $\text{21}$) have been isolated from the Neo Guinean sponge Carteriospongia foliascens. Compound $\text{12}$ is identical with a C₂₇ tetracyclic terpene previously isolated from an Australian specimen of the same sponge. The five other derivatives are new and their structures have been established on the basis of their spectral data. The structure of $\text{5}$ was confirmed by single-crystal X-ray diffraction and that of $\text{15}$ by chemical correlation with $\text{12}$. The configuration at C-4 for all these compounds has been determined through ¹³C NMR data. Evidence leading to reverse the configuration at this centre in previously reported C₂₇ tetracyclic terpenes is discussed. An ecological function is suggested for these molecules.     

Muqubilin,a new c24-isoprenoid from a marine sponge

The Red Sea sponge $\text{Prianos}$ sp. contains a cyclic peroxide C₂₄ - nor sesterterpene, Muqubilin ($\text{1}$). The structure of $\text{1}$ was deduced from spectroscopic data and by chemical degradation.     

A triterpenoid pigment with the isomalabaricane skeleton from the marine sponge stelletta sp.

The constitution and stereochemistry of $\text{1}$, a yellow triterpenoid pigment isolated from a Somalian collection of the sponge $\text{Stelletta}$$\text{sp}$., has bben unequivocally established by spectral and x-ray crystallographic methods. The assignment of $\text{trans}$-$\text{barsyn}$-$\text{trans}$ stereochemistry to the tricyclic nucleus of 1 suggests that the structures of several recently described tritepenoids from $\text{Japsis}$$\text{stellifera}$ be reassigned.     

Structures of xestospongin A,B,C and D,novel vasodilativecompounds from marine sponge, xestospongiaexigua

Xestospongin A,B,C and D represent a new class of macrocyclic 1-oxaquinolizidines, have been isolated from Australian sponge $\text{Xestospongia}$$\text{exigua}$. The structure of xestospongin C has been determined by X-ray analysis.     

Absolute stereostructures of halenaquinol and halenaquinol sulfate,pentacyclic hydroquinones from the okinawan marine sponge xestospongia sapra, as determined by theoretical calculation of CD spectra

The absolute stereostructures of two pentacyclic hydroquinones, halenaguinol ($\text{1}$) and halenaquinol sulfate ($\text{2}$) from the Okinawan marine sponge Xestospongia sapra, have been determined by means of theoretical calculation of CD spectra.     

Structure of swinholide-a,a new macrolide from the marine sponge theonella swinhoei

Swinholide-A ($\text{1}$a) a novel 22-membered macrolide has been isolated from a Red Sea sponge. The structure of the tetraformate ($\text{1b}$) has been determined on basis of spectral data using 2D-NMR correlations.     

Brominated tyrosine-derived metabolites from the sponge Ianthella basta

Two novel metabolites, containing four bromotyrosine units, have been isolated from the sponge $\text{Ianthella basta}$.     

Renierone,an antimicrobial metabolite from a marine sponge

The major antibacterial metabolite in the sponge $\text{Reniera}$ sp. was shown to be an isoquinoline quinone, renierone ($\text{1}$). The structure of renierone ($\text{1}$) was defined by X-ray crystallography.     

Marine natural products: fistularin-1, -2 and -3 from the sponge Aplysina fistularis forma fulva

Three new high molecular weight bromotyrosine-related metabolites, $\text{3a}$, $\text{4a}$ and $\text{5a}$, were isolated from the sponge Aplysina ( Verongia) fistularis forma fulva, and their structures were determined from high resolution ¹H NMR and other spectroscopic data. The new metabolites are formally derived by combination of major segments of two known Aplysina metabolites $\text{1a}$ and $\text{2}$.     

Bioactive marine metabolites IX. Mycalisines A and B,novel nucleosides which inhibit cell division of fertilized starfish eggs,from the marine sponge mycale sp.

Two novel nucleosides, mycalisines A and B, have been isolated from a marine sponge and their structures elucidated as 4-amino-5-cyano-7-(3-$\text{O}$-methyl-5-deoxy-β-D-$\text{erythro}$-pent-4-enofuranosyl)-pyrrolo[2,3-$\text{d}$]pyrimidine and 5-cyano-7-(3-$\text{O}$-methyl-5-deoxy-β-D-$\text{erythro}$-pent-4-enofuranosyl)-pyrrolo[2,3-$\text{d}$]pyrimidine-4-one, respectively. Both compounds inhibit cell division of fertilized starfish eggs.     

Two novel sesterterpene hydroxyquinols from the sponge microcionatoxistyla

The structures of two unique sesterpenes, toxislylide A and B, have been deduced by chemical, spectral, and x-ray crystallographic studies. They are components of the sponge $\text{Microciona}$$\text{toxistyla}$.     

An antimicrobial sesterterpene from a Palauan sponge

An unidentified sponge from Palau contained the antimicrobial sesterpene $\text{1}$ that was identified by interpretation of spectral data and conversion into a degradation product of illimaquinone.     

Manoalide,an antibiotic sesterterpenoid from the marine sponge luffariella variabilis (polejaeff)

The structure of manoalide ($\text{1}$), a new sesterterpenoid antibiotic isolated from a marine sponge, has been determined by spectral analysis and chemical transformations.