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.

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.

scholarly journals Chemical Derivatization and Characterization of Novel Antitrypanosomals for African Trypanosomiasis

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4488
Author(s):  
Aboagye Kwarteng Dofuor ◽  
Temitayo Samson Ademolue ◽  
Cynthia Mmalebna Amisigo ◽  
Kwaku Kyeremeh ◽  
Theresa Manful Gwira
Keyword(s):  
Structural Modification ◽  
Spectroscopic Analysis ◽  
Microscopic Analysis ◽  
The Novel ◽  
Chemical Derivatization ◽  
African Trypanosomiasis ◽  
Chemical Structures ◽  
Normal Ratio

The search for novel antitrypanosomals and the investigation into their mode of action remain crucial due to the toxicity and resistance of commercially available antitrypanosomal drugs. In this study, two novel antitrypanosomals, tortodofuordioxamide (compound 2) and tortodofuorpyramide (compound 3), were chemically derived from the natural N-alkylamide tortozanthoxylamide (compound 1) through structural modification. The chemical structures of these compounds were confirmed through spectrometric and spectroscopic analysis, and their in vitro efficacy and possible mechanisms of action were, subsequently, investigated in Trypanosoma brucei (T. brucei), one of the causative species of African trypanosomiasis (AT). The novel compounds 2 and 3 displayed significant antitrypanosomal potencies in terms of half-maximal effective concentrations (EC50) and selectivity indices (SI) (compound 1, EC50 = 7.3 μM, SI = 29.5; compound 2, EC50 = 3.2 μM, SI = 91.3; compound 3, EC50 = 4.5 μM, SI = 69.9). Microscopic analysis indicated that at the EC50 values, the compounds resulted in the coiling and clumping of parasite subpopulations without significantly affecting the normal ratio of nuclei to kinetoplasts. In contrast to the animal antitrypanosomal drug diminazene, compounds 1, 2 and 3 exhibited antioxidant absorbance properties comparable to the standard antioxidant Trolox (Trolox, 0.11 A; diminazene, 0.50 A; compound 1, 0.10 A; compound 2, 0.09 A; compound 3, 0.11 A). The analysis of growth kinetics suggested that the compounds exhibited a relatively gradual but consistent growth inhibition of T. brucei at different concentrations. The results suggest that further pharmacological optimization of compounds 2 and 3 may facilitate their development into novel AT chemotherapy.

scholarly journals Dechdigliotoxins A–C, Three Novel Disulfide-Bridged Gliotoxin Dimers from Deep-Sea Sediment Derived Fungus Dichotomomyces cejpii

Marine Drugs ◽  
2019 ◽  
Vol 17 (11) ◽  
pp. 596 ◽  
Author(s):  
Zhaoming Liu ◽  
Zhen Fan ◽  
Zhanghua Sun ◽  
Hongxin Liu ◽  
Weimin Zhang
Keyword(s):  
Tumor Cell ◽  
Quantum Chemical Calculations ◽  
Cell Lines ◽  
Deep Sea ◽  
Quantum Chemical ◽  
Biosynthetic Pathway ◽  
Spectroscopic Analysis ◽  
Tumor Cell Lines ◽  
Disulfide Linkage ◽  
Deep Sea Sediment

Dechdigliotoxins A–C (1–3), which represented the first examples of gliotoxin dimers with an unprecedented exocyclic disulfide linkage, were obtained from a deep-sea derived fungus Dichotomomyces cejpii FS110. The structures of these compounds were elucidated on the basis of spectroscopic analysis and the absolute configurations were unambiguously determined through quantum chemical calculations, as well as DP4+ probability simulations. The proposed biosynthetic pathway suggested 1–3 were generated from unusual L-Phe and D-Ser. All the isolates were evaluated for their cytotoxicity against four tumor cell lines.

Parguerenes Revisited: New Brominated Diterpenes From the Southern Australian Marine Red Alga Laurencia Filiformis

1996 ◽  
Vol 49 (1) ◽  
pp. 19 ◽  
Author(s):  
SJ Rochfort ◽  
RJ Capon
Keyword(s):  
Natural Product ◽  
Biosynthetic Pathway ◽  
Spectroscopic Analysis ◽  
Red Alga ◽  
Biosynthetic Precursor ◽  
Chemical Correlation ◽  
New Compounds

Five new pargueranes, 15-bromoparguer-9(11)-ene-2,7,16,19-tetrol 2,7,16-triacetate (20), 15-bromoparguer-9(11)-ene-2,7,16-triol 2,7-diacetate (21), 15-bromoparguer-9(11)-ene-2,16-diol 2-acetate (22), 15-bromoparguer-9(11)-en-16-ol (23) and 15-bromoisoparguer-9(11)-en-16-ol (24), together with a plausible biosynthetic precursor, preparguerene (25), two known parguerenes , 15-bromoparguer-9(11)-ene-2,7,16,19-tetrol tetraacetate (4) and 15-bromoparguer-9(11)-ene-2,7,16-triol 2,16 diacetate (7), and the known algal metabolites (-)- aromadendrene (17), austradiol acetate (18) and austradiol diacetate (19), have been isolated from a collection of the southern Australian marine red alga Laurencia filiformis. The known synthetic parguerane 15-bromoparguer-9(11)-ene-2,7-16-triol triacetate (5) was also found for thefirst time as a natural product. In addition to securing the structures of new compounds by chemical correlation and detailed spectroscopic analysis, a lausible biosynthetic pathway has been proposed linking preparguerene, parguerene, isoparguerene and secoparguerene carbon skeletons.

scholarly journals Nanangenines: drimane sesquiterpenoids as the dominant metabolite cohort of a novel Australian fungus, Aspergillus nanangensis

2019 ◽  
Vol 15 ◽  
pp. 2631-2643 ◽  
Author(s):  
Heather J Lacey ◽  
Cameron L M Gilchrist ◽  
Andrew Crombie ◽  
John A Kalaitzis ◽  
Daniel Vuong ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Biosynthetic Pathway ◽  
Spectroscopic Analysis ◽  
Bioinformatics Analysis ◽  
Biosynthetic Gene Cluster ◽  
In Vitro Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Drimane Sesquiterpenoids

Chemical investigation of an undescribed Australian fungus, Aspergillus nanangensis, led to the identification of the nanangenines – a family of seven new and three previously reported drimane sesquiterpenoids. The structures of the nanangenines were elucidated by detailed spectroscopic analysis supported by single crystal X-ray diffraction studies. The compounds were assayed for in vitro activity against bacteria, fungi, mammalian cells and plants. Bioinformatics analysis, including comparative analysis with other acyl drimenol-producing Aspergilli, led to the identification of a putative nanangenine biosynthetic gene cluster that corresponds to the proposed biosynthetic pathway for nanangenines.

Norterpene Dienes From an Australian Marine Sponge Latrunculia brevis

1991 ◽  
Vol 44 (1) ◽  
pp. 77 ◽  
Author(s):  
MS Butler ◽  
RJ Capon
Keyword(s):  
Marine Sponge ◽  
Spectroscopic Analysis ◽  
Methyl Esters ◽  
Chemical Derivatization

The norditerpene diene acid (4) and norsesterterpene diene acid (5), along with their corresponding methyl esters (6) and (7), were isolated from an Australian marine sponge, Latrunculia brevis, and their structures determined by detailed spectroscopic analysis, chemical derivatization and degradation. Comment is made on the possible intermediacy of dienes such as (4)-(7) in the biosynthesis of norterpene cyclic peroxides, common to other Latrunculia species from the same locality.

Lamellarins Q and R: New Aromatic Metabolites From an Australian Marine Sponge, Dendrilla cactos

1995 ◽  
Vol 48 (8) ◽  
pp. 1491 ◽  
Author(s):  
S Urban ◽  
L Hobbs ◽  
JNA Hooper ◽  
RJ Capon
Keyword(s):  
Marine Sponge ◽  
Spectroscopic Analysis ◽  
New South ◽  
New South Wales ◽  
Chemical Derivatization ◽  
South Wales

A specimen of Dendrilla cactos collected off the coast of New South Wales, Australia, has yielded two new alkaloids, lamellarins Q (19) and R (20), the structures of which were secured by spectroscopic analysis and by chemical derivatization.

scholarly journals Constituents of the Rhizomes of Sansevieria cylindrica

2018 ◽  
Vol 13 (9) ◽  
pp. 1934578X1801300 ◽  
Author(s):  
Mya Mu Aye ◽  
Hnin Thanda Aung ◽  
Zaw Min Thu ◽  
Myint Myint Sein ◽  
Yoshiaki Takaya ◽  
...  
Keyword(s):  
Hela Cells ◽  
Biosynthetic Pathway ◽  
Spectroscopic Analysis ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Scavenging Activity ◽  
Ergosterol Peroxide ◽  
Type 3

A new sappanin-type 3-benzyl chroman-4-one (homoisoflavanone), (3 S)-3-(4'-methoxybenzyl)-3,5-dihydroxy-7-methoxy-6-methyl chroman-4-one (1), together with known congeners (3 S)-3-(4'-methoxybenzyl)-3,5-dihydroxy-7-methoxy chroman-4-one (2), (3 S)-3-(4'-hydroxybenzyl)-3,5-dihydroxy-7-methoxy-6-methyl chroman-4-one (3), (3 S)-3-(4'-hydroxybenzyl)-3,5-dihydroxy-7-methoxy chroman-4-one (4), 3-(3’,4'-methyledioxybenzyl)-7-hydroxy-8-methoxy chroman-4-one (5), and stigmasterol and ergosterol peroxide have been isolated from the rhizomes of Sansevieria cylindrica, collected in Myanmar. Moreover, the first isolation of the (-)-enantiomer of the dihydrochalcone trifasciatine C (7) from nature is described. The structures of the compounds have been established by extensive spectroscopic analysis. Compounds 4 and 7 showed no significant cytotoxicity against HeLa cells. Compounds 1–4 and 7 exhibited weak radical scavenging activity (DPPH). A new biosynthetic pathway has been proposed for the formation of homoisoflavanone 5 and dihydrochalcone 7.

Sigmosceptrins A - C: New Norditerpenes from a Southern Australian Marine Sponge, Sigmosceptrella sp.

1997 ◽  
Vol 50 (12) ◽  
pp. 1137 ◽  
Author(s):  
Sean Bassett, ◽  
Simon P. B. Ovenden ◽  
Robert W. Gable ◽  
Robert J. Capon
Keyword(s):  
Structural Analysis ◽  
Single Crystal ◽  
Ethyl Ester ◽  
Marine Sponge ◽  
Biosynthetic Pathway ◽  
Spectroscopic Analysis ◽  
Methyl Esters ◽  
Chemical Degradation ◽  
X Ray ◽  
Great Australian Bight

A Sigmosceptrella sp. of sponge collected during trawling operations in the Great Australian Bight, Australia, has yielded a series of new norterpenes. These include a new bisnorditerpene, sigmosceptrin-A (5); two new norditerpenes, sigmosceptrin-B (14) and sigmosceptrin-C (15), isolated as their methyl esters (6) and (7) respectively; and an ethylated artefact, sigmosceptrin-B ethyl ester (8). Complete stereostructures were assigned to the sigmosceptrins by spectroscopic analysis, chemical degradation, derivatization, and by a single-crystal X-ray structural analysis. A biosynthetic pathway is proposed that requires a common biosynthetic precursor to both the sigmosceptrins and norterpene cyclic peroxides.

A New Alkaloid From an Australian Marine Sponge, Spongosorites sp.

1994 ◽  
Vol 47 (12) ◽  
pp. 2279 ◽  
Author(s):  
S Urban ◽  
RJ Capon ◽  
JNA Hooper
Keyword(s):  
Marine Sponge ◽  
Spectroscopic Analysis ◽  
Ethanol Extract ◽  
Chemical Derivatization ◽  
Dihydro Derivative ◽  
Antibiotic Property

A specimen of a marine sponge, Spongosorites sp., collected in Port Phillip Bay, Victoria, Australia, has yielded the alkaloid (2). The structure of (2) was secured by spectroscopic analysis, chemical derivatization and synthesis of a dihydro derivative (4). The antibiotic property of the crude ethanol extract of this sponge was attributed to (2).

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