Natural Guanidine Derivatives

In this section, natural products with guanidines are studied. A large group of these products consist of cyclic depsipeptides and polypeptides with arginine as an amino acid residue, produced by mainly actinomycete and cyanobacteria in some cases (ex. microcystin-LR, noduralin) [39]. Isolation of aminoglycosides (streptomycins, streptothricins [40] and their 

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Reviews Concerning the Synthesis of Natural Guanidine Derivatives 631... 

Berlinck, R.G.S. (1996) Natural guanidine derivatives. Natural Product Reports, 13, 377 09. 

Free guanidine treated with 1 2-naphthoquinone-4-sodium sulphonate and alkali yields after about ten minutes a brown solution which tmns bright red on addition of nitric acid (Sullivan s test, 1935). Ammonia, methylamine and indole, but none of the natural guanidine derivatives, give similar reactions. 

Chevolot, L. (1981) Guanidine derivatives, In Scheuer P. J. (Ed.) Marine Natural Products Chemical and Biolo cal Perspectives, Vol. 4, Academic Press, London, 53-91. 

Guanidine derivatives of pyrrole series from marine natural products 81MI14. 

Fluorinated biologically active pyrimidines and purines 80YGK1119. Guanidine derivatives of purine from marine natural products 81Mn4. Orotic acid, physiological activity of 85PHA377. 

Micheel and coworkers,in further efforts to prepare glycoproteins resembling those which occur in Nature, synthesized a series of glycosyl-guanidine derivatives by a novel approach. l-D-Glucosyl-2-thiourea (VII) was treated with ethyl bromide, resulting in the formation of 2-ethyl-l-o-glucosyl-2-pseudothiourea hydrobromide (XXXVI). When XXXVI was... 

The excellent reviews of Berlinck [1-5] have surveyed a great number of guanidine-type natural products. In addition, some guanidine-derived marine alkaloids have been reviewed by Kobayashi and Ishibashi [6,7]. Also, a recent book gave accounts of marine alkaloids including the phakellins, palau amines and oroidin-like dimers derived from bromopyrroles and polyketide-derived polycyclic guanidine alkaloids [8]. 

C5H 4N4, Mr 130.19, mp. 101.5-103 °C. A. is a guanidine derivative formed by decarboxylation of L- ar-ginine. It is an intermediate in the, in plants especially widely distributed, biosynthesis of putrescine from arginine. Natural sources include ergot, the Asteraceae Ambrosia artemisifolia, the sea anemone Anthopleura japonica and herring semen. 

The key starting material of one of the first antagonists, argatroban (30-6), comprises a derivative of arginine itself in which the amine is protected as its tert-butoxycarbonyl derivative and an A-nitro group moderates the basic nature of the guanidine group (30-2). That intermediate is first condensed with the piperidine... 

Hypoglycemic natural products comprise flavonoids, xanthones, triterpenoids, glycosides, alkyldisulfides, aminobutyric acid derivatives, guanidine, polysaccharides, and peptides (see Wang and Ng, 1999). The mechanisms of actions of these hypoglycemic plants are uncertain. They either enhance the release of insulin or enhance the peripheral utilization of glucose. 

A wide variety of compounds have been shown to inhibit xanthine oxidase guanidines and some triazines (F7), purine derivatives such as purine 6-aldehyde (G5), 6-mercaptopurine (S20), 2,6-diaminopurine (W8), flavonoids (B13), and Antabuse (R6). Although these compounds and the inhibitions they produce are of interest in understanding the nature of the action of xanthine oxidase, none has been useful clinically in limiting urate production. Antabuse, as a result of its action, produces other effects that (fortunately ) have not been found with allopurinol. 

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