Actinomycetes
Actinomycetes play a major role in producing antibiotics and other metabolites such as extracellular enzymes, pigments, and growth-promoting factors.113 Marine actinomycetes have furnished new and unique antibiotics.114 The marine environment could be a rich source of new actinomycetes and new antibiotics. Antagonistic properties of actionmycetes from Molluscs of the Porio Novo region, South India, have been reported.115 Twenty two ethanolic extracts of seaweeds collected from Karachi Coast,...
Preface
Marine natural products have attracted the attention of biologists and chemists the world over for the last five decades. To date approximately 16,000 marine natural products have been isolated from marine organisms and reported in approximately 6,800 publications. In addition to these publications there are approximately another 9,000 publications which cover syntheses, reviews, biological activity studies, ecological studies etc. on the subject of marine natural products. Several of the...
Concluding Remarks Pzh
Marine organisms exhibit a wide range of biological activities. The activity in some cases varies with ecological variation and the time of collection. A number of marine organisms exhibit toxic properties. Marine toxins have drawn attention because of their involvement in human intoxication and the socioeconomic impacts brought by those incidents. Many of the toxins have been found to be useful tools for probing biological or pharmacological phenomenon. Although the majority of marine toxins...
Concluding Remarks Ctm
There is no specific technique that could be followed for the separation of the constituents of the complex mixture present in the ethanolic or methanolic extract of a marine organisms since the chemical nature of the bioactive compounds is not known. However, a broad separation of the mixture can be achieved by fractionation with organic solvents. If the separation is effective, the biological activity may concentrate in a particular fraction. The abundance of salts carried over from seawater...
Separation Techniques
There are a number of problems associated with the separation of water soluble compounds. The abundance of salts carried over from seawater into the water extracts, makes the separation of water solube compounds more perplexing. This and other problems have been dealt in detail by Shimizu.1 In handling aqueous extract of marine organisms or aqueous fraction of the ethanolic methanolic extract of the organism, an inevitable problem is bacterial and fungal growth, which often degrades the active...
Bioactivity of Marine Organisms 1
The green, brown and red algae have been extensively screened for antibacterial and antifungal activity.1 The active principles isolated from Symphycladia gracillis, Rhodomela larix and Polysiphonia lanosa39'41 are 2,3-dibromobenzyl alcohol, 4,5-disulphate dipotassium salt, 2,3-dibromo-4,5-dihydroxybenzaldehyde, 2,3-dibromo-4,5-dihydroxybenzyl alcohol, 3,5-dibromo-p-hydroxybenzyl alcohol, and 5-bromo-3,4-dihydroxybenzaldehyde. Virtually nothing is known about the physiological importance of...
Marine Toxins
A variety of organic compounds containing nitrogen as part of a heterocyclic system have been isolated from marine animals. These compounds are mostly toxic. The toxicology, isolation, pharmacology and in some cases the chemistry76-80 of these compounds have been reviewed. The toxin has been known for many years. Its origin until recently was pufferfish of the family tetraodontidae. In recent years several derivatives of tetrodotoxin have been isolated from crabs, an octopus, a goby, molluscs,...
Screening Models and Activity
Excellent accounts of various models are published6,25 for screening antibacterial, antifungal, antileishmanial, anthelmintic, antitapeworm, antimalarial, antiviral, antiinflammatory, analgesic, antiallergic, antiarhythmic, hypolipidaemic, hypoglycemic, antihypertensive, diuretic adaptogenic, immunomodulatory, hepatoprotective, choleretic, anticholesteric, CNS, activities and toxicity. 3.1 Antibacterial and Antifungal Activities The need for effective antibacterial and antifungal drug has been...
Concluding Remarks 1
The marine sponges, jelly fishes, sea anemones, gorgonians, corals, bryozoans, molluscs, echinoderms, tunicates, and crystaceans during the last two decades have furnished a large variety of metabolites with unusual structures. Several of these metabolites exhibit high order of biological activities and some have biomedical potential. Investigation of sponges, jelly fish, sea anemones and corals from worldover furnished bioactive unusual sterols, steroidal alkaloids, unusual terpenoids,...
Concluding Remarks Rbb
There are special problems encountered in biological screening of extracts of marine plants and animals. Generally, the active principles in the crude extract are present in a very low concentration 1 1000 , therefore, the test system for their detection should be very sensitive. The screening should also be selective and specific. The methodology must be adaptable to materials which are highly coloured, tarry, poorly soluble in water and chemically complex. The assay must be insensitive to...
Isolation Procedures
Several amino acids, amino sulphonic, iodoamino acids and simple peptides have been isolated from marine algae.5-8 Analysis of algal amino acids is generally carried out, as is done in the analysis of terrestrial plants. The algal material is homogenized with ethanol furnishing a concentrate of about 70 aqueous ethanol. The extract contains nitrogen containing compounds, such as amino acids, amides, small peptides, amino sulfonic acids, amines, chlorophylls, low-molecular weight nucleotides,...
Bioactive Metabolites of Marine Sponges
Marine sponges are a good source of unusual sterols. Some of these sterols have phylogenetic significance. These sterols are also of interest to understand the function of biological membranes. The sulphated and alkaloidal sterols exhibit antimicrobial activity. Halistanol 38 82 from Halichondria mooriei and the sterols 39-41 from Toxadocia zumi83 inhibited the growth of Staphylococcus aureus and Bacillus subtitis at 100 g disc and 50 g disc. A hydroxy sterol 42 with unusual features is...
Types of Screening
2.1 Individual Activity Screening Individual activity screening is used to detect a particular biological property of an extract or compound, such as antibacterial,8 anticancer9 and antifertility10 etc. Broad biological screening is employed to know whether an extract or compound has any exploitable biological potential. A broad biological screening is being done at the Central Drug Research Institute, Lucknow, India, for several years for evaluation of terrestrial plant extracts, extracts of...
Marine Invertebrates of the Andaman and Nicobar Islands
About 50 species of marine sponges occur in these Islands and only a few of them have been investigated. Even their classification is in a confused state. Several bioactive metabolites of considerable interest have been isolated from Agelas species182 183 found in the Andaman and Nicobar Islands. A. nata the only species reported to occur remains to be investigated. Four species of Cliona, C. ensifera, C. lobata, C. mucronata and C. quadrata occur in the Andaman Islands. However, none of these...
Marine Toxins 1
The majority of marine toxins are produced by microalgae, especially dinoflagellates. Some of the toxins are also produced by bacteria and a few by macroalgae. Schantz et al31 first isolated pure saxitoxin from the Alaskan butter clam using weakly basic Amberlite IRC 50 and alumina chromatography. The Alaskan butter clam is still considered the best source of saxitoxin. The isolation procedure is fairly simple. However, this procedure is not applicable to the isolation of other shellfish...
Marine Nucleosides
Three unusual nucleosides, spongothymidine 34 , spongouridine 35 and spongosine 36 were isolated from the marine sponge Cryptotethia crypta. Chemistry and biology of nucleosides have been reviewed. Bioactive compounds, having nitrogen-sulphur heterocyclic system, have been isolated from marine animals. The marine annelide, Lumbriconereis heteropoda have afforded nereistoxin 37 C5H11NS2 , b.p. 212-13 C and its oxalate m.p. 168-69oC decomp . Nereisotoxin 37 was found to be toxic to insects, fish,...
Marine Bacteria and Fungi
Bacteria and fungi are prime producers of the antagonistic substances in terrestrial environment. A similar role in the oceans from these organisms is expected. Indeed, this had been found true. Antibiotic, antiviral, antifungal, and antiyeast activities of these organisms had been reported.75 Besides, a few growth stimulant properties which may be useful in studies on wound healing, carcinogenic properties, and in the study of cancers are reported. Among the many bacteria showing antimicrobial...
Concluding Remarks
Marine algae have yielded a large variety of bioactive metabolites. Some of them have biomedical potential. Marine bacteria produce some of the most potent toxins such as saxitoxin and tetrodotoxin. The sulphated polysaccharides obtained from seaweeds are economically most important products. These are extensively used in food and medicine. The red algae are the source of agar and agarose. Although these polysaccharides have no direct medicinal use, however, their use in biomedical research is...
Bioactive Metabolites
Chemically the bioactive metabolites of marine flora include brominated phenols, oxygen heterocyclics, nitrogen heterocyclics, sulphur nitrogen heterocyclics, sterols, terpenoids, polysaccharides, peptides and proteins. The chemistry and biological activities of the compounds isolated have been The green, brown and red algae had been extensively analyzed for antibacterial and antifungal activities. The active principles isolated from Symphyocladia gracilis, Rhodomela larix and Polysiphonia...
Bioactive Marine Peptides278
3. Bioactive Marine Peptides 280 8. Marine Peptides and Related Compounds in Clinical Trials 302 9. Miscellenous Peptides 308 10. Concluding Remarks 316
Screening Models and Activity 81
3.1 Antibacterial and antifungal activities 81 3.2 Antileishmanial activity 82 3.6 Antiinflammatory activity 84 3.9 Antiarrhythmic and antithrombotic activities 86 3.10 Hypolipidaemic activity 86 3.13 Antihypertensive activity 87 3.15 Adaptogenic and immunomodulatory activities 87 3.16 Immunomodulation activity 88 3.17 Hepatoprotective activity 89 3.18 Choleretic and anticholestatic activities 89 3.19 Acute toxicity and CNS activities 90