Epoxy Lipids From the Australian Epiphytic Brown Alga Notheia anomala. II.

1991 ◽  
Vol 44 (6) ◽  
pp. 843 ◽  
Author(s):  
LM Murray ◽  
RA Barrow ◽  
RJ Capon
Keyword(s):  
Arachidonic Acid ◽  
Secondary Metabolite ◽  
Brown Alga ◽  
Structure Elucidation ◽  
Spectroscopic Analysis ◽  
Chemical Degradation

Continuation of a study into the chemistry of the brown alga Notheia anomala has resulted in the isolation and structure elucidation of six new C21 lipids. These include the first reported occurrence of a secondary metabolite (3), O-acylated by arachidonic acid, along with three new bisepoxy lipids (4)-(6), and two novel trisepoxy lipids (7) and (8). The structures were secured by detailed spectroscopic analysis and chemical degradation.

Structure Elucidation of Azotobactin 87, Isolated from Azotobacter vinelandii ATCC 12837*, **

1996 ◽  
Vol 51 (3-4) ◽  
pp. 139-150 ◽  
Author(s):  
E. M. Schaffner ◽  
R. Hartmann ◽  
K. Taraz ◽  
H. Budzikiewicz
Keyword(s):  
Structure Elucidation ◽  
Culture Medium ◽  
Azotobacter Vinelandii ◽  
2D Nmr ◽  
Chemical Degradation ◽  
Spectroscopic Methods ◽  
Hydroxybutyric Acid ◽  
Iron Deficient ◽  
N Terminus ◽  
Sequential Information

Abstract Chromopeptide siderophores (azotobactin 87-1 and -II) were isolated from an iron deficient culture medium of Azotobacter vinelandii ATCC 12837 (=DSM 87). Their structures were elu­ cidated by chemical degradation studies and spectroscopic methods, especially 2D-NMR-tech-niques. Total assignments of 1H-, 13C-, and 15N-resonances based on 2D-HOHAHA-, 1H/13C-HMQC-, 1H /13C-HMBC-, 1H /15N-HMQC/TOCSY-, and 1H/15N-HMBC-experiments are given as well as sequential information derived from 1H/1H-NOESY-, 1H /13C-HMBC-and 1H/ 13N-HMBC-experiments. Both Az 87-1 and Az 87-11 consist of a tetracyclic chromophore -(1S)8,9-dihydroxy-4-oxo-2,3,4,5-tetrahydro-1H,10cH-3a,5,10b-triazaacephenantrylene-1-carb-oxylic acid -and a decapeptide chain linked with the N-terminus to the carboxy group of the chromophore containing also modified, non-proteinogenic amino acids. The sequence L-Ser-D-Ser-L-Hse-Gly-D-threo-OHAsp-Hse-Hse-Hse-D-N5OH-N5-R-Hbu-Om-L-Hse was determined for Az 87-1, while Az 87-11 contains a C-terminal L-Hse-lactone instead. Iron is chelated by the catecholic group of the chromophore, the β-hydroxy aspartic acid, and the hydroxamate function formed by N5-hydroxyornithine and R-β-hydroxybutyric acid.

Trachycladindoles H–M: Molecular Networking Guided Exploration of a Library of Southern Australian Marine Sponges

2020 ◽  
Vol 73 (4) ◽  
pp. 338 ◽  
Author(s):  
Shamsunnahar Khushi ◽  
Laizuman Nahar ◽  
Angela A. Salim ◽  
Robert J. Capon
Keyword(s):  
Chemical Analysis ◽  
Natural Product ◽  
Structure Elucidation ◽  
Spectroscopic Analysis ◽  
Marine Sponges ◽  
Single Specimen ◽  
Guided Search ◽  
Guided Exploration ◽  
Rare Class ◽  
Great Australian Bight

A global natural product social (GNPS) molecular network guided search of a library of 960 southern Australian marine sponge extracts successfully detected a deep-water Great Australian Bight sponge, Geodia sp. (CMB-01063), as a new source of a rare class of indolo-imidazole alkaloids previously believed to be unique to a single specimen of Trachycladus laevispirulifer (CMB-03397). Chemical analysis of CMB-01063 detected the known trachycladindoles A–G (1–7), and led to the isolation, characterisation, and structure elucidation of the new trachycladindoles H–M (8–13). Structures for 8–13 were assigned on the basis of detailed spectroscopic analysis, with comparison to authentic standards of 1–7.

Epoxy Lipids From the Australian Epiphytic Brown Alga Notheia anomala

1990 ◽  
Vol 43 (5) ◽  
pp. 895 ◽  
Author(s):  
RA Barrow ◽  
RJ Capon
Keyword(s):  
Brown Alga ◽  
Biosynthetic Pathway ◽  
Spectroscopic Analysis ◽  
Chemical Derivatization

A detailed reinvestigation of the chemistry of Notheia anomala has resulted in the isolation of the known C19 lipid (1) together with 13 new C19 lipids (2), (3), (3a,b,c) (4), (4a,b,c) (8), (10),(13) and (14), one new C21 lipid (15) and two known C21 lipids, (17) and (18), and a new C17 lipid (19). The structures of these metabolites were established by spectroscopic analysis together with chemical derivatization and degradation. Absolute stereochemistries were determined by chemical and biosynthetic correlation to (1). A common biosynthetic pathway is proposed for all the oxygenated lipids from N. Anomala.

9-(5'-Deoxy-5'-thio-β-D-xylofuranosyl)adenine Disulfide from the Southern Australian Marine Sponge Trachycladus laevispirulifer: the First Natural Occurrence of a Nucleoside Disulfide

2010 ◽  
Vol 63 (6) ◽  
pp. 873 ◽  
Author(s):  
Chongsheng Peng ◽  
G. M. Kamal B. Gunaherath ◽  
Andrew M. Piggott ◽  
Zeinab Khalil ◽  
Melissa Conte ◽  
...  
Keyword(s):  
Marine Sponge ◽  
Structure Elucidation ◽  
Spectroscopic Analysis ◽  
Chemical Fractionation ◽  
Natural Occurrence ◽  
Model Compounds ◽  
Anticancer Properties ◽  
Synthetic Model ◽  
Natural And Synthetic

Chemical fractionation of a southern Australian marine sponge, Trachycladus laevispirulifer, yielded 9-(5′-deoxy-5′-thio-β-d-xylofuranosyl)adenine disulfide as the first recorded natural occurrence of a nucleoside disulfide, and only the second of a xylo-nucleoside. Structure elucidation of the disulfide was achieved by detailed spectroscopic analysis and comparison to synthetic model compounds. The antibacterial, antifungal, and anticancer properties of the disulfide are documented and the literature surrounding natural and synthetic thionucleosides is reviewed.

Beyond Polygodial: New Drimane Sesquiterpenes From a Southern Australian Marine Sponge, Dysidea sp.

1993 ◽  
Vol 46 (8) ◽  
pp. 1255 ◽  
Author(s):  
MS Butler ◽  
RJ Capon
Keyword(s):  
Marine Sponge ◽  
Structure Elucidation ◽  
Spectroscopic Analysis ◽  
Marine Metabolites ◽  
Ecological Relationship ◽  
Chemical Correlation ◽  
The Absolute ◽  
First Time ◽  
Absolute Stereochemistry

This report describes the isolation and structure elucidation of four new drimane sesquiterpenes (14)-(17) from a southern Australian marine sponge Dysidea sp. The structures for (14)-(17) were secured by detailed spectroscopic analysis, chemical interconversion and derivatization. Also reported are the known metabolites (+)- euryfuran (7), dihydropallescensin-2 (18), (-)- pallescensin-A (19) and (-)-7-deacetoxyolepupane (6). The rare co-occurrence of two antipodes, (7) and (19), in the same specimen highlights the dangers in assigning absolute stereochemistry based on 'unproven' biosynthetic relationships. The absolute stereochemistry for (6) has been unambiguously established for the first time by chemical interconversion to (7). Furthermore, the absolute stereochemistry of the new marine metabolites listed above, (14)-(17), were determined by chemical correlation to (6). A biosynthetic and ecological relationship is proposed between the metabolites from Dysidea sp. with the known marine and terrestrial antifeedant polygodial (8). Chemical investigations are reported that support this proposition.

Alkyl and Alkenyl Resorcinols From an Australian Marine Sponge, Haliclona Sp (Haplosclerida : Haliclonidae)

1991 ◽  
Vol 44 (10) ◽  
pp. 1393 ◽  
Author(s):  
RA Barrow ◽  
RJ Capon
Keyword(s):  
Natural Products ◽  
Marine Sponge ◽  
Spectroscopic Analysis ◽  
Chemical Degradation ◽  
Plant Source ◽  
Marine Plant ◽  
Plant Sources ◽  
Structure Class

Eleven alkyl and alkenyl resorcinols have been isolated from the Australian marine sponge Haliclona sp. Three of these, (3), (5) and (10), have previously been described from Australian terrestrial and marine plant sources. The remaining eight, (13)-(20), are new natural products whose structures have been secured by a combination of spectroscopic analysis and chemical degradation. This report represents the first account of this structure class being isolated from a non-plant source.

scholarly journals Complete Reconstitution and Deorphanization of the 3 MDa NOCAP (NOCardiosis-Associated Polyketide) Synthase

2020 ◽  
Author(s):  
Kai P. Yuet ◽  
Corey W. Liu ◽  
Stephen R. Lynch ◽  
James Kuo ◽  
Wesley Michaels ◽  
...  
Keyword(s):  
Structure Elucidation ◽  
Assembly Line ◽  
Polyketide Synthase ◽  
Spectroscopic Analysis ◽  
Hydroxyl Group ◽  
E Coli ◽  
Life Threatening ◽  
Tailoring Enzymes ◽  
Protein Components

ABSTRACTSeveral Nocardia strains associated with nocardiosis, a potentially life-threatening disease, house a nonamodular assembly-line polyketide synthase (PKS) that presumably synthesizes an unknown natural product. Here, we report the discovery and structure elucidation of the NOCAP (NOCardiosis-Associated Polyketide) aglycone by first fully reconstituting the NOCAP synthase in vitro from purified protein components followed by heterologous expression in E. coli and spectroscopic analysis of the purified products. The NOCAP aglycone has an unprecedented structure comprised of a substituted resorcylaldehyde headgroup linked to a 15-carbon tail that harbors two conjugated all-trans trienes separated by a stereogenic hydroxyl group. This report is the first example of reconstituting a trans-acyltransferase assembly-line PKS either in vitro or in E. coli, and of using these approaches to “deorphanize” a complete assembly-line PKS identified via genomic sequencing. With the NOCAP aglycone in hand, the stage is set for understanding how this PKS and associated tailoring enzymes confer an advantage to their native hosts during human Nocardia infections.

New Chromenols From a Southern Australian Tunicate, Aplidium solidum

1996 ◽  
Vol 49 (11) ◽  
pp. 1217 ◽  
Author(s):  
SJ Rochfort ◽  
R Metzger ◽  
L Hobbs ◽  
RJ Capon
Keyword(s):  
Spectroscopic Analysis ◽  
Chemical Degradation ◽  
The Absolute ◽  
Absolute Stereochemistry

Two new chromenols, namely (R)-2-methyl-2-(4-methylpenta-1,3-dienyl)-2H-chromen-6-ol (7) and 1-[(R)-6-hydroxy-2-methyl-2H-chromen-2-yl]-4-methylpentan-2-one (8), have been isolated from a southern Australian tunicate, Aplidium solidum. The structures of (7) and (8) were assigned by spectroscopic analysis, and the absolute stereochemistry of (7) by chemical degradation.

A New Sesterterpene Tetronic Acid From an Australian Sponge, Ircinia sp

1987 ◽  
Vol 40 (7) ◽  
pp. 1327 ◽  
Author(s):  
RJ Capon ◽  
JK Macleod
Keyword(s):  
Antimicrobial Activity ◽  
Structure Elucidation ◽  
Spectroscopic Analysis ◽  
Tetronic Acid

A new sesterterpene tetronic acid* (2), exhibiting antimicrobial activity, has been isolated from an Australian Ircinia species. The structure elucidation was based on detailed spectroscopic analysis of (2), its acetate (3), and two methylated derivatives (4) and (5).

scholarly journals Isolation and Characterization of Sclerienone C from Scleria Striatinux

2016 ◽  
Vol 11 (1) ◽  
pp. 1934578X1601100
Author(s):  
Kennedy D. Nyongbela ◽  
Felix L. Makolo ◽  
Thomas R. Hoye ◽  
Simon MN Efange
Keyword(s):  
Silica Gel ◽  
Column Chromatography ◽  
Structure Elucidation ◽  
Spectroscopic Analysis ◽  
Methylene Chloride ◽  
Isolation And Purification ◽  
Isolation And Characterization ◽  
Combination Of Methods

Herein, we report the isolation and characterization of sclerienone C, a novel sesquiterpene isolated from the methylene chloride/methanol (1:1) extract of Scleria striatinux that we have deduced to have structure 1. This medicinal spice of Cameroon has been shown to display antimicrobial and antiplasmodial activities. The isolation and purification involved a combination of methods including silica gel column chromatography, Sephadex LH-20, and semi-prep HPLC separations. Structure elucidation was carried-out by means of spectroscopic analysis and comparison with previously isolated sesquiterpene derivatives from the plant.

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