Aesthetic Values
What is aesthetic value? A property in an object? An experience of a perceiving person? An ideal object existing in a mysterious sphere, inaccessible to normal cognition? Does it appear in one form only, or in many forms, perhaps infinitely many? Is it so
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Mini-review J Mar Biotechnol (1997) 5:187–193
Marine Biotechnology © Springer-Verlag New York Inc. 1997
Isolating bioactive compounds from marine organisms Ricardo Riguera Departamento de Quı´mica Orga´nica and Instituto de Acuicultura, Universidad de Santiago, 15706 Santiago de Compostela, Spain Received: 30 October 1996 / Accepted: 30 November 1996
Abstract. The strategies used for isolation and structural elucidation of pharmacologically active metabolites from marine organisms are discussed, with examples of cytotoxic and antihistaminic compounds from marine equinoderms, sponges, gorgonians, ascidians, and tunicates from the author’s laboratory. Special attention will be paid to isolation procedures adapted to the physical and chemical characteristics of the compounds isolated, particularly to their polarity and lipo- or hydrophilic character. Examples of isolation from water-soluble material of highly polar metabolites such as saponins, polyhydroxysteroids, alkaloids, and amino acids will be presented. Sesquiterpene quinones, polypropionates, peptides, and depsipeptides from the extracts of medium or low polarity are also described. The relevance of recent spectroscopic techniques—especially exhaustive 2D NMR and MS analysis—in the structural elucidation of complex structures and the usefulness of new reagents for the assignment of absolute configuration by 1H NMR are presented.
In the last 25 years, marine organisms—algae, invertebrates, and microbes—have provided key structures and compounds that proved their potential in several fields, particularly as new therapeutic agents for a variety of diseases. The interest in the field is reflected by the number of scientific publications, the variety of new structures, and the wide scope of organisms investigated (Faulkner 1996). As indicated in a recently published review (Bongiorni and Pietra 1996), covering the patents on different aspects of marine natural products applications filed during the last 25 years, human health, health food, and cosmetics account for more than 80% of the applications filed during this period, and this explains why most of the research on marine natural products is in fact a search for useful bioactive compounds. This objective requires effort and takes such a very *This paper was presented at the 1st UK Marine Biotechnology Conference, 22–23 August 1996. Correspondence to: Ricardo Riguera. Fax: +34-81-591091; e-mail: [email protected]
long time that only big pharmaceutical companies or national-based agencies can tackle it with success. A general view of this process is presented in Fig. 1. Sample collection is the first step in these projects and may be much more difficult in the marine environment than if working with terrestrial organisms. This is so not only due to difficulties inherent to collection in the marine environment but also due to problems associated with taxonomy and lack of sufficient biological material. The presence of symbionts (fungi, bacteria, microalgae) living on or inside the macroorganisms being studied in
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