Marine metabolite

Hashimoto, Y. Marine Toxins and Other Bioactive Marine Metabolites Japan Scientific Societies Press Tokyo, 1979 pp. 1-151. 

Tricyclic systems found as a number of marine metabolites have attracted attention in recent years. The dihydropyrrolopyrazinone 165 was synthesized by Austin and co-workers as part of the synthesis of ( )-dibromo-phakellstatin by reaction of 163 with trichloroacetylpyrrole 164 (Equation 40) <20040L3881>. 

Since the discovery of this new class or marine metabolites, the origin of the isocyano group and its relation to its congeners has continued to draw the interest of investigators. While the chemical transformations of these functions are firmly established, progress in understanding the biogenetic details within the -NC/-NCS/-NHCHO series has been slow. 

Barrow KD (1983) Biosynthesis of marine metabolites. In Scheuer PJ (ed) Marine natural products (vol V), Academic, New York, p 51... 

Anionic oxy-Cope rearrangement was also employed for the enantioselective total synthesis of compounds related to marine metabolites (equation 230)305 307, as well as for the preparation of diterpenoide vinigrol (equation 231)308 and cerorubenic acid-in... 

Hashimoto, Y. In "Marine Toxins and Other Bioactive Marine Metabolites" Japan Scientific Societies Tokoyo, 1979 ... 

These examples represent only a fraction of the endoperoxide-containing marine metabolites and the number of peroxide metabolites discovered with cytotoxic properties is likely to continue to expand. 

Perhaps the most unusual marine metabolites from the Caribbean are con lex polyketides, called brevetoxins, produced by a toxic dinoflagellate, Gymnodinium breve (Chart 7.3.FA/PO). 

The widespread distribution of natural products in the oceans The widespread distribution of certain marine metabolites in the oceans can be explained on similar lii s as for common metabolites on land either they play a key role in taxonomically, phylogenetically, and ecologicalfy distant organisms, or the producing organisms are highly dispersed. 

It may be surprising that losses in marine natural product diversity (Table 16.2.5.II) are better documented than for natural products on land, in spite of the difficulty in collecting rare and low-yielding marine species. The paradox finds an explanation. Marine biodiversity has constituted in the past few years the largest untapped resource of novel natural products. The pharmaceutical industry entered the game early, but abandoned the scene soon now it is back to marine natural products, albeit mainly for funding research at universities. In a time of powerful methodologies for the purification and structural elucidation of compounds, this has rapidly secured many unusual marine metabolites of a type never found on land. 

Wipf, P. Yoshikazu, U. (2000A) Total synthesis and revision of stereochemistry of the marine metabolite trunkamide A. J. Org. Chem., 65, 1037-49. 

Halicholactone 214, a marine metabolite with lipoxygenase inhibitory activity, belongs to the family of oxylipins which all contain a lactone moiety substituted by a /ra r-disubstituted cyclopropane subunit. Stereoselective RCM for the formation of the nine-membered lactone core in 214 was the penultimate step (212 —> 213) in a asymmetric... 

Scalaradial, a dialdehyde-containing marine metabolite that causes an unexpected non-covalent PLA2 Inactivation. Chembiochem 8, 1585-1591. 

In this review, data have been presented to illustrate the diversity of organisms living in the sea and the plethora of chemical compounds that have been discovered from them. Since the late 1970s, there has been a veritable explosion of activity and many new marine metabolites have been isolated and identified. Therefore, the present review will cover only recent development in this area. The information was obtained from a review of the scientific literature, and the sources are referenced at the end of the chapter. Bioactive compounds found in marine environments include... 

Bryostatins are a unique family of emerging cancer chemotherapeutic candidates isolated from marine bryozoa [457], They were first discovered in the bryozoan Bugula neritina, but problems with supply of sufficient quantities of this natural product hampered the study of this interesting group of marine metabolites for many years. Although the biochemical basis for their therapeutic activity is not known, these macrolactones exhibit high affinities for PKC isoenzymes, compete for the phorbol ester binding site on PKC and stimulate kinase activity in vivo and in vitro. Bryostatin 1, Fig. (54), one member of this family, is a PKC modulator in a variety of tumor systems [458,459], Bryostatin 1 is currently in phase II... 

More than 460 compounds are included. It is worth noting that while sulfated marine metabolites are mostly found in the phylum Echinodermata (350 out of 500), the non-sulfated systems are more widely distributed among all the phyla. 

Most of the marine metabolites bearing a sulfide group correspond to well-defined families of alkaloid compounds and they have mainly been obtained from tunicates and sponges. To a lesser extent they have also been found in bryozoans, molluscs, and algae. 

Since the discovery of amphimedine by Schmitz and co-workers in 1983 [36], the polycyclic alkaloids based on the pyrido[, /]acridine skeleton have emerged as a well-defined class of marine metabolites, with significant biological activities, isolated from sponges and tunicates [37]. The less common group of sulfide pyridoacridines were only obtained from tunicates and they include the shermilamines, the varamines-lissoclins-diplamine group, and tintamine, another polycyclic alkaloid closely related to them. 

The sulfide marine metabolites having a pyrroloquinoline skeleton can be divided into three groups the batzellines-isobatzellines, the prianosins-discorhabdins, and the makaluvamines. All of these types of compounds have been isolated from sponges. 

---