scholarly journals The Isolation and Structure Elucidation of Secondary Metabolites from Tongan Marine Invertebrates

2021 ◽  
Author(s):  
◽  
Victoria Helen Woolner
Keyword(s):  
Antifungal Activity ◽  
Secondary Metabolites ◽  
Structure Elucidation ◽  
Sea Cucumber ◽  
Marine Invertebrates ◽  
Marine Sponges ◽  
Marine Organisms ◽  
New Members ◽  
Ic50 Values ◽  
New Compounds

<p>During the course of this study, Tongan marine organisms were investigated for new secondary metabolites. A combination of reversed- and normal-phase chromatographic techniques and NMR spectroscopy was employed, to aid in the isolation and structure elucidation of the five known and four new compounds isolated in this study. A brief investigation into the antifungal activity of Tongan holothurian saponins was instigated in order to compare the activity against saponins isolated from the common New Zealand sea cucumber, Australostichopus mollis. A yeast-based chemical genetics study, determined the antifungal activity, for four partially purified Tongan holothurian extracts, against Saccharomyces cerevisiae, to be similar to neothyonidioside (44), a saponin from A. mollis. This result suggested the antifungal activity to be a common characteristic to sea cucumber saponins. Further interest in secondary metabolites from Tongan marine organisms led this study towards the investigation of Tongan marine sponges. Five sponges were selected for screening, and two chosen for further study which yielded five known compounds (51–53, 61, 62) and four new fascaplysin derivatives; 7-bromoreticulatine,10-bromo-6,7-dimethoxyhomofascaplysin C,10-bromo-6, 7-dimethoxyhomofascaplysin D, and 10-bromohomofascaplysin A (63–66, respectively). Although 63 and 66 are new members of the fascaplysin family solely due to the position of the bromine, it appears that bromination on the A-ring is comparatively rare, with only three of the 24 literature examples displaying A-ring bromination. On the other hand, 64 and 65 present a new sub-class of fascaplysin derivatives due to the presence of a dimethoxy functionality. Both 7-bromoreticulatine (63) and 10-bromohomofascaplysin A (66) were found to be potently cytotoxic in the HL-60 cell line, exhibiting IC50 values of 33.8 and 498 nM, respectively. 10-Bromo-6,7-dimethoxyhomofascaplysins C (64) and D (65) were significantly less cytotoxic with respective IC₅₀ values of 2.7 and 6.0 μΜ. (Abstract continues with diagrams).</p>

scholarly journals The Isolation and Structure Elucidation of Secondary Metabolites from Tongan Marine Invertebrates

2021 ◽  
Author(s):  
◽  
Victoria Helen Woolner
Keyword(s):  
Antifungal Activity ◽  
Secondary Metabolites ◽  
Structure Elucidation ◽  
Sea Cucumber ◽  
Marine Invertebrates ◽  
Marine Sponges ◽  
Marine Organisms ◽  
New Members ◽  
Ic50 Values ◽  
New Compounds

<p>During the course of this study, Tongan marine organisms were investigated for new secondary metabolites. A combination of reversed- and normal-phase chromatographic techniques and NMR spectroscopy was employed, to aid in the isolation and structure elucidation of the five known and four new compounds isolated in this study. A brief investigation into the antifungal activity of Tongan holothurian saponins was instigated in order to compare the activity against saponins isolated from the common New Zealand sea cucumber, Australostichopus mollis. A yeast-based chemical genetics study, determined the antifungal activity, for four partially purified Tongan holothurian extracts, against Saccharomyces cerevisiae, to be similar to neothyonidioside (44), a saponin from A. mollis. This result suggested the antifungal activity to be a common characteristic to sea cucumber saponins. Further interest in secondary metabolites from Tongan marine organisms led this study towards the investigation of Tongan marine sponges. Five sponges were selected for screening, and two chosen for further study which yielded five known compounds (51–53, 61, 62) and four new fascaplysin derivatives; 7-bromoreticulatine,10-bromo-6,7-dimethoxyhomofascaplysin C,10-bromo-6, 7-dimethoxyhomofascaplysin D, and 10-bromohomofascaplysin A (63–66, respectively). Although 63 and 66 are new members of the fascaplysin family solely due to the position of the bromine, it appears that bromination on the A-ring is comparatively rare, with only three of the 24 literature examples displaying A-ring bromination. On the other hand, 64 and 65 present a new sub-class of fascaplysin derivatives due to the presence of a dimethoxy functionality. Both 7-bromoreticulatine (63) and 10-bromohomofascaplysin A (66) were found to be potently cytotoxic in the HL-60 cell line, exhibiting IC50 values of 33.8 and 498 nM, respectively. 10-Bromo-6,7-dimethoxyhomofascaplysins C (64) and D (65) were significantly less cytotoxic with respective IC₅₀ values of 2.7 and 6.0 μΜ. (Abstract continues with diagrams).</p>

scholarly journals Isolation of New Secondary Metabolites from New Zealand Marine Invertebrates

2021 ◽  
Author(s):  
◽  
Joanna M Wojnar
Keyword(s):  
New Zealand ◽  
Methyl Ester ◽  
Secondary Metabolites ◽  
Chromatographic Separation ◽  
Structure Elucidation ◽  
Screening Tool ◽  
Marine Invertebrates ◽  
Toxic Metabolites ◽  
The Family ◽  
New Compounds

<p>This study describes the isolation and structure elucidation of several known and 13 new compounds from New Zealand marine organisms. Furthermore, it describes the development of a digital mask program for the analysis of HSQC spectra of crude sponge extracts. This was used as a screening tool to identify secondary metabolite producers that warranted further analysis. As reports of metabolites from New Zealand nudibranchs are poorly represented in the literature, a study of five New Zealand nudibranch species was undertaken. These coloured and seemingly undefended nudibranchs are known to concentrate or sequester toxic metabolites from their prey, facilitating rapid isolation and structure elucidation of these metabolites. This study resulted in the isolation of a variety of metabolite classes; two new compounds, 13alpha- acetoxypukalide diol (30) and lopholide diol (31) from the nudibranch Tritonia incerta, are described. Examination of the sponge Raspailia agminata resulted in the isolation of a novel family of partially acetylated glycolipids which contain up to six glucose residues. The chromatographic separation of these compounds was a challenge due to the similarity of the congeners and their lack of a chromophore. MSguided isolation eventually led to the purification of agminosides A-E (145-149). An unidentified sponge of the order Dictyoceratida was found to contain a new isomer (186) of the known sesterterpene variabilin. As variabilin-type compounds are predominantly found from sponges of the family Irciniidae, the unidentified sponge is most likely an irciniid. In addition, the sponge contained two prenylated quinones, one of which, 189, is a new isomer of a known sponge metabolite. The sponge Darwinella oxeata contained four new nitrogenous diterpenes of the aplysulphurane (rearranged spongian) skeleton, oxeatamide A (214), isooxeatamide A (215), oxeatamide A 23-methyl ester (216) and oxeatamide B (217).</p>

scholarly journals ID2017 Cytotoxic activities of Philippine marine sponges against colon cancer cells

2017 ◽  
Vol 4 (S) ◽  
pp. 50
Author(s):  
Mylene Uy
Keyword(s):  
Secondary Metabolites ◽  
Marine Invertebrates ◽  
The Philippines ◽  
Marine Sponges ◽  
Marine Organisms ◽  
Cytotoxic Activities ◽  
Terrestrial Environment ◽  
Bioactive Secondary Metabolites ◽  
Colon Cell ◽  
Diversity Of Life

Although the diversity of life in the terrestrial environment is exceptional, the greatest biodiversity is in the marine environment. Among the marine organisms, the sponges (Porifera) are the most prolific sources of bioactive secondary metabolites. The Philippines, with its long coastal lines, has drawn on its marine capital only to a small extent. Only a few marine organisms (ascidians, sponges, other marine invertebrates and their associated microorganisms) collected from various parts of the Philippines have been documented and investigated in terms of their potential as source of bioactive secondary metabolites, particularly anticancer compounds.  Thirty-seven sponges from the coasts off Mindanao, Philippines were collected, identifies and extracted to give a total of seventy-four polar and nonpolar extracts. The corresponding sponge extracts were screened for the sponge extracts were investigated for cytotoxicity towards colon cell lines (HCT116) using the the tetrazolium dye  (3-(4,5-Dimethylthiazol-2-yl)- 2,5- diphenyltetrazolium bromide) [MTTmethod. The results indicated fifteen (15) sponge extracts to be active at 100- microgram/mL  concentration among which seven (7) were still active at 10 microgram/mL while two (2) still exhibited activity at 1 microgram/mL. Further investigation of the active sponge extracts is currently in progress

scholarly journals Isolation of New Secondary Metabolites from New Zealand Marine Invertebrates

2021 ◽  
Author(s):  
◽  
Joanna M Wojnar
Keyword(s):  
New Zealand ◽  
Methyl Ester ◽  
Secondary Metabolites ◽  
Chromatographic Separation ◽  
Structure Elucidation ◽  
Screening Tool ◽  
Marine Invertebrates ◽  
Toxic Metabolites ◽  
The Family ◽  
New Compounds

<p>This study describes the isolation and structure elucidation of several known and 13 new compounds from New Zealand marine organisms. Furthermore, it describes the development of a digital mask program for the analysis of HSQC spectra of crude sponge extracts. This was used as a screening tool to identify secondary metabolite producers that warranted further analysis. As reports of metabolites from New Zealand nudibranchs are poorly represented in the literature, a study of five New Zealand nudibranch species was undertaken. These coloured and seemingly undefended nudibranchs are known to concentrate or sequester toxic metabolites from their prey, facilitating rapid isolation and structure elucidation of these metabolites. This study resulted in the isolation of a variety of metabolite classes; two new compounds, 13alpha- acetoxypukalide diol (30) and lopholide diol (31) from the nudibranch Tritonia incerta, are described. Examination of the sponge Raspailia agminata resulted in the isolation of a novel family of partially acetylated glycolipids which contain up to six glucose residues. The chromatographic separation of these compounds was a challenge due to the similarity of the congeners and their lack of a chromophore. MSguided isolation eventually led to the purification of agminosides A-E (145-149). An unidentified sponge of the order Dictyoceratida was found to contain a new isomer (186) of the known sesterterpene variabilin. As variabilin-type compounds are predominantly found from sponges of the family Irciniidae, the unidentified sponge is most likely an irciniid. In addition, the sponge contained two prenylated quinones, one of which, 189, is a new isomer of a known sponge metabolite. The sponge Darwinella oxeata contained four new nitrogenous diterpenes of the aplysulphurane (rearranged spongian) skeleton, oxeatamide A (214), isooxeatamide A (215), oxeatamide A 23-methyl ester (216) and oxeatamide B (217).</p>

scholarly journals New Holostan-type Triterpene Glycosides from the Sea Cucumber Apostichopus Japonicus

2012 ◽  
Vol 7 (11) ◽  
pp. 1934578X1200701 ◽  
Author(s):  
Zenglei Wang ◽  
Wei Gong ◽  
Guoquan Sun ◽  
Hua Tang ◽  
Baoshu Liu ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Sea Cucumber ◽  
Spectroscopic Analysis ◽  
Apostichopus Japonicus ◽  
Triterpene Glycosides ◽  
New Compounds

Two new holostan-type glycosides, holotoxin D1 (1) and 25,26-dihydroxy-holotoxin A1 (2), together with two known analogues, stichlorosides C1 (3) and bivittoside D (4), were isolated from the sea cucumber Apostichopus japonicus Selenka. The structures of the new compounds were elucidated on the basis of detailed spectroscopic analysis. Glycosides 1 and 3 exhibited potent antifungal activity.

scholarly journals Cryptic Secondary Metabolites from the Sponge-Associated Fungus Aspergillus ochraceus

Marine Drugs ◽  
2019 ◽  
Vol 17 (2) ◽  
pp. 99 ◽  
Author(s):  
Marian Frank ◽  
Ferhat Özkaya ◽  
Werner Müller ◽  
Alexandra Hamacher ◽  
Matthias Kassack ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Carcinoma Cells ◽  
Aspergillus Ochraceus ◽  
Nitrobenzoic Acid ◽  
Ovarian Carcinoma Cells ◽  
White Bean ◽  
Ic50 Values ◽  
Rice Medium ◽  
Human Ovarian Carcinoma ◽  
New Compounds

The fungus Aspergillus ochraceus was isolated from the Mediterranean sponge Agelas oroides. The initial fermentation of the fungus on solid rice medium yielded 16 known compounds (4–19). The addition of several inorganic salts to the rice medium mainly influenced the accumulation of these secondary metabolites. Fermentation of the fungus on white bean medium yielded the new waspergillamide B (1) featuring an unusual p-nitrobenzoic acid as partial structure. Moreover, two new compounds, ochraspergillic acids A and B (2 and 3), which are both adducts of dihydropenicillic acid and o- or p-aminobenzoic acid, were isolated from the co-culture of the fungus with Bacillus subtilis. Compound 2 was also detected in axenic fungal cultures following the addition of either anthranilic acid or tryptophan to the rice medium. The structures of the new compounds were established by 1D and 2DNMR experiments as well as from the HRMS data. The absolute configuration of 1 was elucidated following hydrolysis and derivatization of the amino acids using Marfey’s reagent. Viomellein (9) and ochratoxin B (18) exhibited strong cytotoxicity against the A2780 human ovarian carcinoma cells with IC50 values of 5.0 and 3.0 µM, respectively.

scholarly journals Secondary metabolites from marine microorganisms

2002 ◽  
Vol 74 (1) ◽  
pp. 151-170 ◽  
Author(s):  
ALPHONSE KELECOM
Keyword(s):  
Secondary Metabolites ◽  
Cyclic Peptides ◽  
Marine Invertebrates ◽  
Indole Alkaloids ◽  
Marine Sponges ◽  
Annual Reports ◽  
Marine Microorganisms ◽  
Mature Field ◽  
Bacteria And Fungi ◽  
New Metabolites

After 40 years of intensive research, chemistry of marine natural products has become a mature field. Since 1995, there are signals of decreased interest in the search of new metabolites from traditional sources such as macroalgae and octocorals, and the number of annual reports on marine sponges stabilized. On the contrary, metabolites from microorganisms is a rapidly growing field, due, at least in part, to the suspicion that a number of metabolites obtained from algae and invertebrates may be produced by associated microorganisms. Studies are concerned with bacteria and fungi, isolated from seawater, sediments, algae, fish and mainly from marine invertebrates such as sponges, mollusks, tunicates, coelenterates and crustaceans. Although it is still to early to define tendencies, it may be stated that the metabolites from microorganisms are in most cases quite different from those produced by the invertebrate hosts. Nitrogenated metabolites predominate over acetate derivatives, and terpenes are uncommon. Among the latter, sesquiterpenes, diterpenes and carotenes have been isolated; among nitrogenated metabolites, amides, cyclic peptides and indole alkaloids predominate.

Secondary metabolites of the aspen fungus Stachybotrys cylindrospora

1993 ◽  
Vol 71 (4) ◽  
pp. 487-493 ◽  
Author(s):  
William A. Ayer ◽  
Shichang Miao
Keyword(s):  
Natural Products ◽  
Antifungal Activity ◽  
Secondary Metabolites ◽  
The Other ◽  
Spectroscopic Techniques ◽  
Blue Stain ◽  
New Compounds

The secondary metabolites produced by the fungus Stachybotrys cylindrospora, which is known to be strongly antagonistic to the blue-stain fungus Ceratocystiopsis crassivaginata, have been examined. The compounds responsible for the antifungal activity are trichodermin (5) and trichodermol (6), two previously known mycotoxins belonging to the trichothecene family. The other metabolites, stachybotrydial (1), stachybotramide (8), and 6,8-dihydroxy-3,5,7-trimethylisochroman (7), although not active against C. crassivaginata, are new natural products. The structures of the new compounds were established by spectroscopic techniques.

Ocean acidification reduces sperm flagellar motility in broadcast spawning reef invertebrates

Zygote ◽  
2009 ◽  
Vol 18 (2) ◽  
pp. 103-107 ◽  
Author(s):  
Masaya Morita ◽  
Ryota Suwa ◽  
Akira Iguchi ◽  
Masako Nakamura ◽  
Kazuaki Shimada ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Sea Cucumber ◽  
Marine Invertebrates ◽  
Marine Ecosystems ◽  
Marine Organisms ◽  
Haploid Genome ◽  
Flagellar Motility ◽  
Distant Future ◽  
Broadcast Spawning ◽  
Wide Range

SummaryOcean acidification is now recognized as a threat to marine ecosystems; however, the effect of ocean acidification on fertilization in marine organisms is still largely unknown. In this study, we focused on sperm flagellar motility in broadcast spawning reef invertebrates (a coral and a sea cucumber). Below pH 7.7, the pH predicted to occur within the next 100 years, sperm flagellar motility was seriously impaired in these organisms. Considering that sperm flagellar motility is indispensable for transporting the paternal haploid genome for fertilization, fertilization taking place in seawater may decline in the not too distant future. Urgent surveys are necessary for a better understanding of the physiological consequences of ocean acidification on sperm flagellar motility in a wide range of marine invertebrates.

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