Halichondria sponge

The structure of a diterpenoid isothiocyanate (276) extracted from a Halichondria sponge, was determined from chemical and spectral data [277]. 

Amagata T, Doi M, Ohta T, Minoura K, Numata A (1998) Absolute Stereostructures of Novel Cytotoxic Metabolites, Gymnastatins A-E, from a Gymnascella Species Separated from a Halichondria Sponge. J Chem Soc Perkin Trans 1 3585... 

C44H60N4O12, Mr 836.97, mp. 66-68 °C, [a]c -101° (CH3OH). A macrolide antibiotic with antifungal activity from Halichondria sponges. The structure is similar to those of ulapualides. 

Amagata, T, Doi, M., Ohta, T, Minoura, K and Numata, A. (1998c) Absolute stereostructure of novel cytotoxic metabolites, gynmastatins A-E, from a Gymnascella species separated from a Halichondria sponge. J. Chem. Soc. Perkin Trans. /, 3585-3599. 

Amagata, T, Tanaka, M., Yamada, T., Minoiua, K., and Nmnata, A. (2008) Gymnastatins and dankastatins, growth inhibitory metabolites of a Gymnascella species from a Halichondria sponge. /. Nat. Prod., 71, 340-345. 

Halichlorine 11 is a structurally unique alkaloid that was isolated from the sponge Halichondria okadai and found to act as an inhibitor of the induction of vascular cell adhesion molecule (VCAM-1), a potential target in the development of drugs for the treatment of several vascular diseases. The strategies employed for the construction of its spiroquinolizidine unit are summarized in Scheme 106. 

The first marine isocyano metabolite was appropriately named axisonitrile-1 (1) based on the trivial name isonitrile and the genus of the sponge, Axinella cannabina, which also furnished axisothiocyanate-1 (2) [1] and, subsequently, a minor constituent, axamide-1 (3) [5]. This observation that isonitriles are often accompanied by isothiocyanates (-N=C=S) and formamides (-NHCHO) was later duplicated by the Hawaiian researchers working with a Halichondria sp. In... 

In a recent study, a Fijian sponge, Axinyssa fenestratus, was found to elaborate four isothiocyanatoamorphanes (43-46) [45]. That this series of compounds may be antipodal to 32 from the Hawaiian Halichondria sp. was indicated by the spectral and optical data of 43 [(1 R,6S,1S, 1 OS)- 10-isocyanato-4-amorphene]. 

The epimeric compounds, e.g., 88 and 89 from a Hawaiian Ciocalypta sponge [55] and 90 from a Pohnpei Halichondria sp., may share a common sp2-carbon center in the biosynthesis of the bisabolane skeleton of these compounds. 

Another unique example was observed for the recently isolated marine natural product, alteramide A (209), isolated from a symbiotic bacteria (Alteromonas sp.) found on the sponge Halichondria okaclai96. It was found that the tetraene core of this compound underwent intramolecular [4 + 4]-photocycloaddition upon exposure to sunlight (equation 9). Deliberate irradiation led to a quantitative conversion to cyclooctadiene 210. 

Tachibana, K., et al., Okadaic acid, a cytotoxic polyether from two marine sponges of the genus Halichondria, JACS, 103, 2469, 1981. 

Schneemann, I., Nagel, K., Kajahn, I., Labes, A., Wiese, J., and Imhof, J. F. (2010). Comprehensive investigation of marine actinobacteria associated with the sponge Halichondria panacea. Appl. Environ. Microbiol. 76, 3702-3714. 

We have focused on the identification of natural key compounds that possess biologically and medicinally intriguing functions. Some of bioactive naturally occurring compounds isolated from marine organisms were found to possess unique biological activities. Halichlorine from the marine sponge Halichondria okadai was shown to inhibit the activity of nuclear factor- in endothelial cells and block L-type Ca2+ channels. Thus, it may have therapeutic potentials for diseases such as atherosclerosis and hypertension. 

Kuramoto, M., Chou, T., Yamada, K., Chiba, T., Hayashi, Y., and Uemura, D. (1996). Flalichlorine, an inhibitor of VCAM-1 induction from the marine sponge Halichondria okadai Kadota. Tetrahedron Lett. 37, 3867-3870. 

A Halichondria species of sponge from Oahu, Hawaii contained a complex mixture of sesqui- and diterpenoids. The sesquiterpenoids belonged to the a-amorphene (zizanene) series and included an isothiocyanate (239) [248]. 

A species of Halichondria from the Marshall Islands contained an isothiocyanate (249) [255] and an isothiocyanate based on the guai-6-ene skeleton (250) was isolated from an unidentified sponge from Japanese waters [256]. Acanthella pulcherrima from Australia contained two isothiocyanates (251-252), in addition to known sesquiterpenes [257]. 

Halistanol sulfate (532) from Halichondria cf. moorei is a tris-sodium sulfate salt, which possesses antimicrobial, hemolytic, and ichthyotoxic activity [444]. It was later isolated from two sponges of the genus Topsentia as the free sterol and found to inhibit pp60v-src protein tyrosine kinase activity [445]. The tris(2-aminoimidazolium) salt of halistanol sulfate (533) was isolated from Topsentia sp. from Japan and is also antimicrobial [446]. 

The antifungal macrolide halichondramide (3), isolated from the Kwajalein sponge of the genus Halichondria, showed significant insecticidal activity at 3 ppm, especially against tobacco budworm. We isolated swinholides A (4) and B (5), from the Red Sea sponge The-onella swinhoei. 

The quinolizidine alkaloid halichlorine (203), isolated from the marine sponge Halichondria okadai, inhibits the induction of vascular cell adhesion molecule-1 (VCAM-1) at IC50 7 pg/ml, which may be useful for treating atherosclerosis, coronary artery diseases, angina and noncardiovascular inflammatory diseases [161]. 

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