In addition to the known peptide alkaloid jubanine-B, a new peptide alkaloid, nummularine-O, has been isolated from the stem bark of Zizyphus nummularia and their structures have been elucidated by chemical and spectroscopic methods.

From the bark of Zizyphus sativa, previously undescribed cyclopeptide alkaloid, sativanine-F has been isolated. The structure was deduced by spectroscopic methods and chemical degradation. It is a 13-membered cyclopeptide alkaloid and provides the first example of such a naturally occurring N-formyl cyclopeptide alkaloid.

From the bark of Zizyphus sativa a new type of 13-membered cyclopeptide alkaloid, sativanine-D (1) has been isolated. Its structure was proved mainly by mass spectrometry and chemical degradation.

From the bark of Zizyphus sativa a new type of 13-membered cyclopeptide alkaloid, sativanine-D (1) has been isolated. Its structure was proved mainly by mass spectrometry and chemical degradation.

From the bark of Zizyphus sativa , previously undescribed cyclopeptide alkaloid, sativanine-F has been isolated. The structure was deduced by spectroscopic methods and chemical degradation. It is a 13-membered cyclopeptide alkaloid and provides the first example of such a naturally occurring N-formyl cyclopeptide alkaloid.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMass Spectrometry of Aristolochic AcidsGert Eckhardt, Alejandro Urzûa, and Bruce K. CasselsCite this: J. Nat. Prod. 1983, 46, 1, 92–97Publication Date (Print):January 1, 1983Publication History Published online1 July 2004Published inissue 1 January 1983https://pubs.acs.org/doi/10.1021/np50025a007https://doi.org/10.1021/np50025a007research-articleACS PublicationsRequest reuse permissionsArticle Views184Altmetric-Citations6LEARN 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

The larval stages of Battus archidamas, the only Papilionoid butterfly living in Chile, feed on the aerial parts of Aristolochia chilensis. The food material contains aristolochic acids, and so do the insects, which retain these compounds after metamorphosis. The compositions of the acid fractions of plant and herbivore extracts are different, however, indicating selective uptake and/or metabolic transformation by the insect. Aristolochic acids I (I) and Ia (II) are major components of the leaves and tender stems of A. chilensis, while aristolochic acids I (I) and (probably) IVa (III) appear to be the main acid components of B. archidamas imagines. The selective sequestration of aristolochic acids by B. archidamas and other Aristolochia-feeders is discussed.

A new quinolizidine alkaloid, (+)-9α-hydroxymatrine, was isolated from the leaves of Sophora macrocarpa. Its structure was determined by a combination of spectroscopic methods, among which nuclear Overhauser enhancement experiments played a crucial role. Some generalizations are made regarding the mass spectra of matrinoids.

The major components of the acid fraction of the leaves and tender stems of Aristolochia chilensis Miers are aristolochic acids I and Ia. Aristolochic acid Ia has been isolated from plant material for the fïrst time, and its PMR spectrum is discussed.

From the mixture of acetylated phenols of Laminaria ochroleuca several fractions consisting of one or more components were isolated and analysed. Several substances, new or known from other seaweeds were identified: tetraphlorethol-A-nonacetate, fucophlorethol-B-octacetate, fucodiphlorethol-C-decacetate, pentafuhaloltridecacetate, and heptafuhaloloctadecacetate. A structure for an isomer of tetraphlorethol-A-nonacetate named tetraphlorethol-B-nonacetate was suggested. Additional phlorotannins were shown to be present, for which only partial structures could be proven.

From the fraction of acetylated phenols the following substances have been isolated and characterized in Fucus vesiculosus:

From the bark extracts of Ziziphus hysodrica, Z. mauritiana, Scutia buxifolia and Araliorhamnus vaginata, in addition to known peptide alka

Aus Ziziphus nummularia wurden neben den bereits beschriebenen Nummularinen-A, -B, -C, -D, -E und -F drei weitere Peptidalkaloide, Nummularin-G, -H und -K isoliert und deren Konstitution geklärt (1, 3 und 5). Die Nummularine-G und -K besitzen 14 gliedrige Cyclopeptidringe. Als Besonderheit weist 1 einen zusätzlichen Ring in der Seitenkette auf. Nummularin-H (3) gehört zu den 13 gliedrigen Cyclopeptidalkaloiden und besitzt die Konstitution eines N-Desmethyl-jubanins-A. Alkaloids from Rhamnaceae, XXVIII. Nummularin-G, -H and -K, New Alkaloids from Ziziphus nummularia From Ziziphus nummularia in addition to the known alkaloids, nummularine-A, -B, -C, -D, -E, and -F, three further peptide alkaloids nummularine-G, -H, and -K have been isolated and their structures elucidated (1, 3, and 5). Nummularine-G and -K are fourteen-membered cyclopeptide ring systems. In 1 the nitrogen atom of the terminal amino acid is linked via a methylene group to the nitrogen atom of the hydroxyamino acid to form a five-membered ring. Nummularine-H (3) belongs to the thirteen-membered ring peptide alkaloids and has the structure of N-desmethyl-jubanine-A.

In the urine of rats the following metabolites of the xantinol derivative 2-(1,3-dimethyl-xanthinyl-(7)-methyl)-4-methyl-morpholine were found: 2-[1,3-dimethyl-xanthinyl-(7)-methyl]-morpholine and 2-[1,3-dimethyl-xanthinyl-(7)-methyl]-4-methyl-morpholin-5-one. These compounds represent about 13.7% of the p.o. applied 2-[1,3-dimethyl-xanthinyl-(7)-methyl]-4-methyl-morpholine. Their structure has been elucidated by IR-, PMR- and mass spectrometry.

The known alkaloids mauritine-A, mucronine-D, amphibine-H, nummularine-A and -B and the previously undescribed jubanine-A and -B have been isolated from the stem bark of Ziziphus jujuba. The structures of the new compounds were elucidated by spectroscopic methods and by chemical degradation reactions.

From the fraction of acetylated phenols of Fucus vesiculosus were isolated: phloroglucinol triacetate, difucol hexaacetate (2,2′,4,4′,6,6′-hexaacetoxydiphenyl), trifucol nonaacetate [1,5-di (2,4,6-triacetoxyphenyl)-2,4,6-triacetoxybenzene] and a mixture of two isomeric tetrafucol dodecaacetates A and B.