Dysidea genus

Xu, Y,-M., Johnson, R.K., and Hecht, S.M. (2005) Polybrominated diphenyl ethers from a sponge of the Dysidea genus that inhibits Tie2 kinase. Bioorg. Med. Chem., 13, 657-659. 

Marine sponges of the genus Dysidea are a rich source of structurally unique and biologically active compounds, including spiro-sesquiterpenes such as spirodysin and dehydroherbadysinolide, furanosesquiterpenes based on the furodysinin and furodysin skeletons, brominated diphenyl ethers, polychlorinated alkaloids and other compounds [99-103],... 

Additionally, three metabolites of this class of compounds, spongionellin (12), dehydrospongionellin (13) [39] and okinonellin B (14) [40], were isolated from a Japanese sponge of genus Spongionella and were shown to inhibit the cell division of fertilised starfish eggs at 2.0-5.0 pg/ml. From an Australian Dysidea sp. was isolated isopalinurin (15) that possessed inhibitory properties against the protein phosphatase enzyme in chicken forebrain [41]. 

A new class of sesterterpenes in which the middle three units of a penta-isoprenoid chain cyclised into a bicyclic system, leaving the first and the last isoprenoids to substitute the decaline moiety, was isolated from sponges of genus Dysidea and Ircinia. From the Palauan Dysidea sp. was isolated dysideapalaunic acid (107) that inhibited the aldose reductase [124]. An inhibitor of aldose reductase is expected to prevent neuropathy or cataract as a complication of diabetes. These diseases are caused by the accumulation of sorbitol in the peripheral nerve or the crystalline lens, as a result of enzymatic reduction of glucose by the aldose reductase in the sorbitol cycle [125,126]. The absolute stereochemistry of dysideapalaunic acid was established by its total synthesis [127,128],... 

The first example of a 6a sulfated sterol was isolated from Dysidea Jfagilis from the lagoon of Venice in 1995, and in 1998 a group of ten 4a sulfated sterols, acanthos-terol sulfates A-J, were characterized in a Japanese sponge of the genus Acanthodendrilla (Dendroceratida). Some of these (I and J) are antifungal. 

Terpenes are ubiquitous but sterols are uncommon these are either polyhydroxysterols and sulfated sterols or seco-9(l l)-sterols, but in most cases there is A7 imsatu-ration and more rarely A8(9) and/or A8(14). Nitrogen derivatives are frequent, often chlorinated, and sometimes atypical, such as the free porphyrin of Darwinella oxeata (see below). The chlorine derivatives foimd in the species Dysidea herbacea derive from symbiotic cyanobacteria (Unson and Faulkner, 1993 Unson et al., 1993). A review of the genus Dysidea was published by Venkateswarlu, Ramesh, and Reddy (1998). 

In Systema Porifera, the family Dysideidae now belongs to the order Dictyoceratida this was already the case in the scheme of Bergquist (1978), but this family had been reclassified among Dendroceratida by Hooper (2000). For chemical data on the genus Dysidea, see Venkateswarlu, Ramesh, and Reddy (1998). 

Meroterpenes are fotmd almost exclusively in the genus Dysidea and they involve either a sesquiterpene of the drimane series, a sesterterpene of the scalarane series, with an aromatic moiety that is most often a hydroquinone or quinone, sometimes substituted with a taurine (the melemeleones of Dysidea amra). There are, however, some atypical structures of the dimeric type, containing an aminoquinone. Figures 19.98-19.104 present some examples of terpenes and meroterpenes of dendroceratid sponges some of these have been found, with or without... 

Sintokamides A-E are polychlorinated dipeptides isolated from an Indonesian sponge of the genus Dysidea collected at Palau Sintok. Sintokamide A inhibit N-termi-nus transactivation of the androgen receptor in prostate cancer cells, and could be a new drug lead to treat prostate cancer (Sadar et al, 2008). 

A thiazole nucleus or a diketopiperazine is associated with one or two trichloromefhyl groups, and munerous examples of such structures have been found in species of Dysidea. Most of these molecules contain 5,5,5-trichloro-N-mefhyl-leucine or 5,5-dichloro-N-methyl-leucine, which thus appear to be specific a-amino acids in the genus Dysidea, but are not present in peptides or depsipeptides. Figures 19.109 and 19.110 show some examples of these polychlorinated nitrogen derivatives. 

The position of the genus Dysidea is still controversial between Dendroceratida and Dictyoceratida. 

Remember diat die position of the genus Dysidea in the Dendroceratida or Dictyoceratida has undergone several changes. 

Formerly grouped in the Dendroceiatida, the genus Dysidea is now considered a dictyoceratid sponge. 

Some examples of aromatic derivatives similar to those formd in dendroceratid sponges of the genus Dysidea (see above) and in some Chlorophyceae (see Chapter 12), were isolated from the spedes Phyllospor ia dendyi harvested in Palau (Hattori et al, 2001 liu et al., 2004) and Lamellodysidea herhacea harvested in Indonesia (Hanif et al., 2007). Many of these derivatives are inhibitors of microtubule assembly, with IC50 dose to 4 pM (Liu et al, 2004). 

Kazlauskas, R., Murphy, P.T, Wells, R.J., Daly, J.J., and Schonholzer, P. (1978a) Two sesquiterpene furans with new carbocyclic ring systems and related thiol acetates from a species of the sponge genus Dysidea. Tetrahedron Lett., 19, 4951-4954. 

It is also known that several halogenated metabolites of the dictyoceratid sponge Dysidea herbacea are produced by the cyanobaderium Oscillatoria spongeliae and that filamentous cyanobacteria of the genus Beggiatoa are the source of many metabolites of lithistid sponges, which are all repellents or toxic to fish (Unson and Faulkner, 1993 Fatdkner et al., 1993 Faulkner, Unson, and Bewley, 1994 Unson, Holland, and Faulkner, 1994 Bewley and Fatdkner, 1998 Schmidt, Bewley, and Faulkner, 1998 D Auria, Zampella, and Zollo, 2002 Ridley et al., 2005). 

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