The inhibitory effect of esters of p-hydroxybenzoic acid (kelletinins I and A), extracted from the marine gastropodBuccinulum corneum, have been tested on eukaryotic and prokaryotic enzymes of DNA metabolism such as DNA polymerasesα and β, DNA polymerase I, Exo III, pancreatic DNAse I, micrococcal DNAse andE. coli RNA polymerase. Kelletinin I and kelletinin A inhibit preferentially DNA polymeraseα. The inhibitory effect of kelletinin I involves the hydroxyl group of p-hydroxybenzoic acid.

Thin-layer chromatography, column chromatography, mass spectrometry and nuclear magnetic resonance were used to investigate the chemical constituents and haptens responsible in 2 different circumstances where allergic contact dermatitis from composite materials was suspected. In an aircraft factory where epoxy resins were used, tetraglycidyl-4,4'-dimethyl dianiline and phenylglycidyl ether were identified as the haptens responsible for an outbreak of contact dermatitis. The role of abietic acid as the main sensitizer in colophony was confirmed in a case of contact dermatitis occurring in a sportsman with an acute eczematous reaction due to a leg bandage. Identification of the chemical sensitizers was possible only by using the aforementioned laboratory methods.

Further studies on the marine sponge Disidea pallesoens gave in addition to the known Disidein (4), the unique until now scalarane sesterterpenoid condensed with a hydroxyhydroquinone moiety, two new closely related halogenated sesterterpenoids isolated as triacetates (6,7). All the 1H- and 13C-NMR chemical shifts of Disidein triacetate (5) were assigned by two-dimensional experiments. Treatment of 5 with chlorine and bromine afforded 6 and 7, respectively. X ray diffraction analysis of 7 has unambiguously determined the absolute stereochemistry of all these molecules.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHomolog of Kelletinin I from the Mediterranean Prosobranch Buccinulum corneumGuido Cimino, Salvatore de Stefano, and Giuseppe StrazzulloCite this: J. Nat. Prod. 1987, 50, 6, 1171–1173Publication Date (Print):November 1, 1987Publication History Published online1 July 2004Published inissue 1 November 1987https://pubs.acs.org/doi/10.1021/np50054a032https://doi.org/10.1021/np50054a032research-articleACS PublicationsRequest reuse permissionsArticle Views66Altmetric-Citations10LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIsolation and X-ray Crystal Structure of a Derivative of 2,6-Diaminopurine from a Sea AnemoneS. de Rosa, S. de Stefano, R. Puliti, C. A. Mattia, and L. MazzarellaCite this: J. Nat. Prod. 1987, 50, 5, 876–880Publication Date (Print):September 1, 1987Publication History Published online1 July 2004Published inissue 1 September 1987https://pubs.acs.org/doi/10.1021/np50053a017https://doi.org/10.1021/np50053a017research-articleACS PublicationsRequest reuse permissionsArticle Views94Altmetric-Citations5LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Reniera sarai, a marine sponge of the Ceractinomorpha subclass easily collectable in the Bay of Naples, is characterized by a series of cyclic nitrogenous compounds, which for many years have resisted all attempts of structural investigation. Complex separation steps have now led to three new compounds, named sarain-1, sarain-2 and sarain-3. Their structures have been partially determined mainly by a 500 MHz NMR study, utilizing the 1 H- 1 H homonuclear and 1 H- 13 c heteronuclear NMR Chemical shift correlation techniques. Sarains belong to a new class of pentacyclic alkaloids, containing in their skeletons a quinolizidine system linked to a tetrahydropyridine moiety. Two linear alkyl chains, placed between the two heterocyclic systems, supply the two remaining cycles. Recently a series of biologically active bis-quinolizidine and 1-oxa-quinolizidine alkaloids have been isolated from the sponges Petrosia seriata and Xestospongia exigua, respectively. A common biogenetic origin should connect these alkaloids to sarains. Sarains show phase transfer catalytic properties.

Nudibranch molluscs, apparently defenseless against potential predators, possess secondary metabolites localized on the body wall which help them to escape from predation. These metabolites are largely of dietary origin; in one case the biosynthetic ability of a nudibranch to elaborate its own chemical defense has been shown.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXT1,2,7-Trihydroxy-8-methoxy-6-methylanthracene, the Putative Precursor of the Marine Pigment HallachromeGuido Cimino, Salvatore De Rosa, Salvatore De Stefano, and Guido SodanoCite this: J. Nat. Prod. 1985, 48, 5, 828–829Publication Date (Print):September 1, 1985Publication History Published online1 July 2004Published inissue 1 September 1985https://pubs.acs.org/doi/10.1021/np50041a023https://doi.org/10.1021/np50041a023research-articleACS PublicationsRequest reuse permissionsArticle Views71Altmetric-Citations2LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIsolation and X-Ray Crystal Structure of a Novel 8-Oxopurine Compound from a Marine SpongeG. Cimino, A. de Giulio, S. de Rosa, S. de Stefano, R. Puliti, C. A. Mattia, and L. MazzarellaCite this: J. Nat. Prod. 1985, 48, 4, 523–528Publication Date (Print):July 1, 1985Publication History Published online1 July 2004Published inissue 1 July 1985https://doi.org/10.1021/np50040a002RIGHTS & PERMISSIONSArticle Views126Altmetric-Citations15LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (370 KB) Get e-Alerts Get e-Alerts

The yellow zoochrome of the sponge Verongia aerophoba , which blackens when exposed to the air, has been isolated and its structure established as 3,5,8-trihydroxy-4-quinolone. The pigment is easily oxidized to an unstable blue quinone which quickly gives rise to an unsoluble black material.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA New Furanosesquiterpene from the Mediterranean Alcyonacean Alcyonum palmatumGuido Cimino, Salvatore De Rosa, Salvatore De Stefano, and Guido SodanoCite this: J. Nat. Prod. 1984, 47, 5, 877–878Publication Date (Print):September 1, 1984Publication History Published online1 July 2004Published inissue 1 September 1984https://pubs.acs.org/doi/10.1021/np50035a024https://doi.org/10.1021/np50035a024research-articleACS PublicationsRequest reuse permissionsArticle Views98Altmetric-Citations8LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

From the brown alga Dilophus fasciola (Dictyotaceae) three new tetraoxygenated diterpenes (1-3) with a dolabellane skeleton were isolated. The structure of these was determined by spectral data and by means of chemical transformation. Two-dimensional NMR spectroscopy was proved to be a potent tool to establish the structures, the stereochemistry and to enable the assignment of all resonances in the NMR spectra. The new compounds were tested in ichthyotoxic and phytotoxic bioassays.

A biosynthetic experiment with mevalonic acid labeled with carbon-14 showed that the nudibranch Dendrodoris limbata elaborates polygodial, a sesquiterpenoid dialdehyde stored in the mantle, which constitutes its chemical defense against predators. Previously described nudibranchs drew defensive chemicals from their preys.

Three novel bromo-compounds have been isolated from the sponge Verongia aerophoba. The sponge previously identified as V. aerophoba, containing related but different bromo-compounds, was indeed the related species V. cavernicola.

1.1. The chemical defense of the Mediterranean nudibranchs Phyllidia pulitzeri, Dendrodoris limbata, Glossodoris valenciennesi and Glossodoris tricolor has been investigated.2.2. By means of bioassays the distastefulness has been shown to be attributable to chemical factors located in the body wall.3.3. All the biologically active compounds isolated in the present investigation were known compounds, mainly deriving from the sponges on which the nudibranchs feed.

A novel bromo-compound, C11H10N5O2Br, has been isolated from the sponges Axinella verrucosa and Acanthella aurantiaca. The structure was determined as 2 on special grounds and by X-ray analysis.

A novel sesquiterpenoid esterified by different fatty acids has been isolated from the digestive gland of the nudibranch Dendrodoris limbata.

The title compound has been isolated from the Mediterranean gorgonian Leptogorgia sarmentosa; upon acetylation it affords a dehydration product and an androstane derivative.