Oroidin derivatives

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

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). 

This class of cyclic oroidin derivatives also parallels the above N-7/C-11 + N-1/ C-12 class in the presence of complex derivatives in which the isophakellin skeleton appears to be conjugated with an aminoimidazolyl propene unit. These isomers of palau amines are called styloguanidines (58-60) they have been isolated from the same sponge that contains palau amines, Stylotella aurantium [90]. 

This class includes only agelastatins A-D (60-65), a family of tetracyclic oroidin derivatives isolated from Agelas dendromorpha [92,93] and Cymbastela sp. [94]. The absolute configuration of these molecules was deduced through the application of exciton-coupling techniques [93]. 

Grube and Kock [47] reported the characterization of oxocyclostylidol (12), an intramolecular cyclized oroidin derivative from the marine sponge, Stylissa caribica. 

The imidazole molecule is incorporated into many biologically relevant molecules. For example, the amino acid histidine is present in proteins and enzymes, while histamine (its decarboxylated product) is important in the body s immune response system. The imidazole ring has been found in a number of natural products, particularly the oroidin-derived alkaloids. One of the structurally simple compounds in this class of natural products is girolline, containing a 2-amino-imidazole attached to a chlorohydrin moiety. ... 

A. Grube, M. Kock, Oxocyclostylidol, an intramolecular cychzed oroidin derivative from the marine sponge Stylissa caribica, J. Nat. Prod. 69 (2006) 1212—1214. 

Dransfield, P.J., Ddley, AS., Wang, S., and Romo, D. (2006) A unified synthetic strategy toward oroidin-derived alkaloids premised on a biosynthetic proposal. Tetrahedron, 62, 5223-5247. 

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