- Structure Elucidation and Biological Effects of Carrageenans from Red Algae

Isolation and Structure Elucidation of New Secondary Metabolites from New Zealand Marine Red Algae

10.26686/wgtn.16934485 ◽

2021 ◽

Author(s):

◽

Wendy Lynne Popplewell

Keyword(s):

Antibacterial Activity ◽

Natural Products ◽

New Zealand ◽

Secondary Metabolites ◽

Natural Product ◽

Red Algae ◽

Structure Elucidation ◽

Screening Tool ◽

Product Analysis ◽

Algal Extracts

<p>The natural product analysis of New Zealand red algae has been neglected in recent years, and there is obvious scope for the chemical re-evaluation of New Zealand marine red algae. This study describes the isolation and structure elucidation of 12 new and eight known compounds from four different genera of red algae. To aid in this process, 34 red algae were screened in order to generate a digital HSQC spectra mask, a screening tool developed by the VUW Marine Natural Products group to identify extracts of interest for further analysis. All 34 algal extracts were screened using the HSQC mask and four extracts were identified as interesting and analysed in detail. Examination of extracts of the red algae Plocamium costatum and Ballia callitricha lead to the isolation of three known metabolites. Eleven new oxylipins, labillarides A to K, are reported from the alga Phacelocarpus labillardieri. Labillarides A to H are polyunsaturated alpha-pyrone macrocycles, all of which show similarities to the previously reported compounds isolated from southern Australian collections of the algae. Labillarides E to H are of particular interest as they represent the two diastereomeric pairs associated with variation at the C-3 and C-8 chiral centres. Labillarides I and J are related enol macrocycles while labillaride K is a furan-3-one oxylipin, all of which have biogenic significance to the macrocyclic alpha-pyrones. Labillarides A, B and I exhibit moderate cytotoxicity while labillaride C shows moderate antibacterial activity. A new nitrogenous bromophenol, colensolide A, was isolated from the alga Osmundaria colensoi along with five known bromophenols. The presence of nitrogen-containing sidechains in bromophenols is unusual but not unprecedented. The bicyclic nitrogenous moiety observed in colensolide A is proposed to be of histidine origin. Several of the known bromophenols exhibit antibacterial activity and one shows moderate cytotoxicity.</p>

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Isolation and Structure Elucidation of New Secondary Metabolites from New Zealand Marine Red Algae

10.26686/wgtn.16934485.v1 ◽

2021 ◽

Author(s):

◽

Wendy Lynne Popplewell

Keyword(s):

Antibacterial Activity ◽

Natural Products ◽

New Zealand ◽

Secondary Metabolites ◽

Natural Product ◽

Red Algae ◽

Structure Elucidation ◽

Screening Tool ◽

Product Analysis ◽

Algal Extracts

<p>The natural product analysis of New Zealand red algae has been neglected in recent years, and there is obvious scope for the chemical re-evaluation of New Zealand marine red algae. This study describes the isolation and structure elucidation of 12 new and eight known compounds from four different genera of red algae. To aid in this process, 34 red algae were screened in order to generate a digital HSQC spectra mask, a screening tool developed by the VUW Marine Natural Products group to identify extracts of interest for further analysis. All 34 algal extracts were screened using the HSQC mask and four extracts were identified as interesting and analysed in detail. Examination of extracts of the red algae Plocamium costatum and Ballia callitricha lead to the isolation of three known metabolites. Eleven new oxylipins, labillarides A to K, are reported from the alga Phacelocarpus labillardieri. Labillarides A to H are polyunsaturated alpha-pyrone macrocycles, all of which show similarities to the previously reported compounds isolated from southern Australian collections of the algae. Labillarides E to H are of particular interest as they represent the two diastereomeric pairs associated with variation at the C-3 and C-8 chiral centres. Labillarides I and J are related enol macrocycles while labillaride K is a furan-3-one oxylipin, all of which have biogenic significance to the macrocyclic alpha-pyrones. Labillarides A, B and I exhibit moderate cytotoxicity while labillaride C shows moderate antibacterial activity. A new nitrogenous bromophenol, colensolide A, was isolated from the alga Osmundaria colensoi along with five known bromophenols. The presence of nitrogen-containing sidechains in bromophenols is unusual but not unprecedented. The bicyclic nitrogenous moiety observed in colensolide A is proposed to be of histidine origin. Several of the known bromophenols exhibit antibacterial activity and one shows moderate cytotoxicity.</p>

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Biological Effects of a Sulfated-Polysaccharide Isolated from the Marine Red Algae Champia feldmannii

Biological and Pharmaceutical Bulletin ◽

10.1248/bpb.31.691 ◽

2008 ◽

Vol 31 (4) ◽

pp. 691-695 ◽

Cited By ~ 42

Author(s):

Ana Maria Sampaio Assreuy ◽

Daniel Magalhães Gomes ◽

Michelle Soares Josino da Silva ◽

Valeska Martins Torres ◽

Rômmulo Celly Lima Siqueira ◽

...

Keyword(s):

Red Algae ◽

Biological Effects ◽

Sulfated Polysaccharide

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Ultrastructural Changes in Three Different Mammalian Cells Following Ultraviolet Laser Irradiation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100095017 ◽

1972 ◽

Vol 30 ◽

pp. 350-351

Author(s):

K. Shankar Narayan ◽

Kailash C. Gupta ◽

Tohru Okigaki

Keyword(s):

Ultraviolet Light ◽

Mammalian Cells ◽

Biological Effects ◽

Survival Rates ◽

Chinese Hamster ◽

Cell Types ◽

Differential Sensitivity ◽

Ultrastructural Changes ◽

Ultraviolet Laser

The biological effects of short-wave ultraviolet light has generally been described in terms of changes in cell growth or survival rates and production of chromosomal aberrations. Ultrastructural changes following exposure of cells to ultraviolet light, particularly at 265 nm, have not been reported.We have developed a means of irradiating populations of cells grown in vitro to a monochromatic ultraviolet laser beam at a wavelength of 265 nm based on the method of Johnson. The cell types studies were: i) WI-38, a human diploid fibroblast; ii) CMP, a human adenocarcinoma cell line; and iii) Don C-II, a Chinese hamster fibroblast cell strain. The cells were exposed either in situ or in suspension to the ultraviolet laser (UVL) beam. Irradiated cell populations were studied either "immediately" or following growth for 1-8 days after irradiation.Differential sensitivity, as measured by survival rates were observed in the three cell types studied. Pattern of ultrastructural changes were also different in the three cell types.

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Optimizing NMR Methods for Structure Elucidation

10.1039/9781788010498 ◽

2018 ◽

Keyword(s):

Structure Elucidation ◽

Nmr Methods

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Genomic analysis of C-type lectins

Biochemical Society Symposium ◽

10.1042/bss0690059 ◽

2002 ◽

Vol 69 ◽

pp. 59-72 ◽

Cited By ~ 85

Author(s):

Kurt Drickamer ◽

Andrew J. Fadden

Keyword(s):

Biological Effects ◽

Cell Signalling ◽

Genomic Analysis ◽

Binding Activity ◽

Immunoglobulin Superfamily ◽

Carbohydrate Binding ◽

Carbohydrate Recognition ◽

Calcium Dependent ◽

Binding Domains ◽

Carbohydrate Recognition Domains

Many biological effects of complex carbohydrates are mediated by lectins that contain discrete carbohydrate-recognition domains. At least seven structurally distinct families of carbohydrate-recognition domains are found in lectins that are involved in intracellular trafficking, cell adhesion, cell–cell signalling, glycoprotein turnover and innate immunity. Genome-wide analysis of potential carbohydrate-binding domains is now possible. Two classes of intracellular lectins involved in glycoprotein trafficking are present in yeast, model invertebrates and vertebrates, and two other classes are present in vertebrates only. At the cell surface, calcium-dependent (C-type) lectins and galectins are found in model invertebrates and vertebrates, but not in yeast; immunoglobulin superfamily (I-type) lectins are only found in vertebrates. The evolutionary appearance of different classes of sugar-binding protein modules parallels a development towards more complex oligosaccharides that provide increased opportunities for specific recognition phenomena. An overall picture of the lectins present in humans can now be proposed. Based on our knowledge of the structures of several of the C-type carbohydrate-recognition domains, it is possible to suggest ligand-binding activity that may be associated with novel C-type lectin-like domains identified in a systematic screen of the human genome. Further analysis of the sequences of proteins containing these domains can be used as a basis for proposing potential biological functions.

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