Oroidin

A few natural products, mostly polyphenols and fatty acids, are low micromolar inhibitors of Fabl. Based on a different template, (E)-oroidin (33) displays an uncompetitive binding mechanism, similar to the one observed for triclosan [54]. 

Marine animals, such as sponges and soft-bodied invertebrates, are well known to synthesize a large number of organohalogens or to harbor microbial symbionts that synthesize these compounds. Many have physiological activities that made them useful as marine natural products. Examples of these are provided in Chapter 28, namely furanone (S5), oroidin (S9), Tyrian purple (S20), spisulosine (S25), and salinosporamide A (S39). 

Oroidine (138) and its dimer mauritiamine (139) from the sponge Agelas mauritiana inhibit larval metamorphosis at ED50 values of 19 and 15 (jg/ml, whereas 4,5-dibromopyrrole-2-carbamide promotes larval metamorphosis of the ascidian Ciona savignyi at a concentration of 2.5 (jg/ml [109]. 

Tsukamoto S, Kato H, Hirota H, Fusetani N (1996) Mauritiamine, a New Antifouling Oroidin Dimer from the Marine Sponge Agelas mauritiana. J Nat Prod 59 501... 

Patel J, Pelloux-Leon N, Minassian F, Vallee Y (2006) Total Synthesis of (S)-(-)Cyclo-oroidin. Tetrahedron Lett 47 5561... 

Grube A, Kdck M (2006) Oxocyclostylidol, an Intramolecular Cyclized Oroidin Derivative from the Marine Sponge Stylissa caribica. J Nat Prod 69 1212... 

Gautschi JT, Whitman S, Holman TR, Crews P (2004) An Analysis of Phakellin and Oroidin Structures Stimulated by Further Study of an Agelas Sponge. J Nat Prod 67 1256... 

Mourabit AA, Potier P (2001) Sponge s Molecular Diversity Through the Ambivalent Reactivity of 2-Aminoimidazole A Universal Chemical Pathway to the Oroidin-Based Pyrrole-Imidazole Alkaloids and Their Palau amine Congeners. Eur J Org Chem 237... 

These reactions allow access to chlorins, bacteriochlorins, and isobacteriochlo-rins having biological activity (Scheme 27).132 The key marine metabolite oroidin... 

Stevensine (17), which is related to oroidin (13) by oxidative cyclization, was isolated from an unidentified Micronesian sponge (43). The identical compound (17), named odiline, was obtained from aqueous extracts of a New Caledonian sponge, Pseudaxinyssa cantharella (44). This sponge also contained many other oroidin analogs dibromocantharelline [(+) -18], compounds 19, 20, 21, and (+)-dibromophakeline (22). The... 

Tsukamoto, S., Kato, H., Hirota, H., and Fusetani, N., Mauritiamine, a new antifouling oroidin dimer from the marine sponge Agelas mauritiana, J. Nat. Prod., 59, 501, 1996. 

It has been suggested that oroidin (135) and dibromophakellin (137) might be biogenetically related through a dihydrooroidin-type (138) intermediate, via an overall derivation of both sea sponge products from proline and histidine (181). 

Recently a new bromo compound was isolated from the Red Sea sponge Acanthella auzantiaca. X-ray analysis established the structure 4-(2-amino- 4-oxo-2- imidazolin-5-ylidene)-2-bromo- 4,5,6,7-tetrahydropyrrolo [2,3-c]azepin-8-one which shows structural relationship with (mono-bromo)oroidin (182b). 

Pyrrole-imidazole Alkaloids Oroidin -Related Alkaloids... 

This class of compounds is extensively described in Chapter 10. Oroidin (64) is considered the precursor in the elaboration of polycyclic CjjNs oroidin derivatives isolated from sponges belonging to the Axinellidae and Agelasidae families. These include the antiangiogenic compounds agelastatin A (65) and ageladine A (70). 

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