Pohnpei

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. 

In 1992, Kinnel and Scheuer reported the isolation of 11-hydroxystaurosporine (298) and 3,11-dihydroxystaurosporine (299a) from the Pohnpei brown tunicate. 

A further cytotoxic, octapeptide, patellamide E (40), was isolated from L patella from Singapore and the structure was elucidated by chemical and spectral methods [75]. Patellamide F (41) was isolated from L. patella from north-western Australia and was also cytotoxic. The structure and absolute stereochemistry of patellamide F (41) were established by chemical and spectroscopic methods. Patellamide B (22), ulithiacyclamide (16) and lissoclinamide 3 (19) were also isolated from the same sample [76]. The octapeptides, patellamide G (42) and ulithiacyclamides E-G (43-45) were isolated from L. patella from Pohnpei, along with known series members [77]. 

A Didemnum sp. from Palau was the source of didemnaketal C (65), which contains a sulfonic acid group [95]. The in vitro anti-human immuodeficiency virus (anti-HTV) activity of D. molle from Pohnpei is associated with the sulfated mannose polysaccharide kakelokelose (66) [96],... 

Varacin (114), a cytotoxic compound closely related to lissoclinotoxin A (106), was isolated from a Fijian sample of L vareau and a benzopentathiepin structure was proposed on the basis of spectral data [131]. Two total syntheses of varacin (114) have been carried out [132,133] and later, further syntheses were described [134-135]. N,N-dimethyl-5-(methylthio)varacin (115) and the corresponding trithiane (116) were obtained from L. japonicum from Palau and 3,4-desmethylvaracin (117) was isolated from a Eudistoma sp. from Pohnpei [136], An inseparable mixture of 5-(methylthio)varacin (118) and the corresponding trithiane (119) was obtained from a Pohnpeian Lissoclinum sp. [136]. Three additional antimicrobial polysulfides of the varacin family (120-122) were isolated from Polycitor sp., collected by dredging in the Sea of Japan [137]. 

The structure of 5-isothiocyanatopupukeanane (257), a sesquiterpene isothiocyanate from an Axinyssa species from Guam, was determined by X-ray analysis [260]. Two isomeric sesquiterpene thiocyanates, 2-thiocyanatoneopupukeanane (258) and 4-thiocyanatoneopupukeanane (259) were isolated from an unidentified sponge from Pohnpei and from Phycopsis terpnis from Okinawa [261]. A sample of Axinyssa (= Trachyopsis) aplysinoides from Palau yielded a rare thiocyanate, 2-thiocyanatopupukeanane (260), while two specimens from Pohnpei yielded 13-isothiocyanatocubebane (261), 1-isothiocyanatoaromadendrane (262) and 2-thiocyanatoneopupukeanane (258) [262]. This last compound had previously been assigned different stereochemistry at C2 [261]. (-)-4-Thiocyanatoneopupukeanane has been synthesised in an enantiospecific manner (259) [263]. Both enantiomers of 2-thiocyanatoneopupukeanane (258) have been synthesised from (7 )-carvone [264]. 

Four minor metabolites, psammaplins B-D (503-505) and presammaplin A (506) were isolated from Psammaplysilla purpurea, in addition to psammaplin A (500). Psammaplin B (503) is a thiocyanate bromotyrosine derivative, while psammaplin C (502) is a sulfanamide. Psammaplin D (505) displayed antimicrobial activity and mild tyrosine kinase inhibition [429]. The psammaplins Ai (507) and A2 (508) and aplysinellins A (509) and B (510) were isolated from Aplysinella rhax from both Pohnpei and Palau. These compounds inhibit famesyl protein transferase and leucine aminopeptidase [430]. Another sample of A. rhax from the Great Barrier Reef, Australia contained psammaplin A 11 -sulfate (511) and bisaprasin ll -sulfate (512), both of which inhibited [3H]-l,3-dipropyl-8-cyclopentylxanthine binding to rat brain adenosine Ai receptors [431]. 

The stereochemistry of solenolide C (U) is also revised in this study (680). The new briviolides B (539) and C (540) were characterized from a Japanese collection of Briareum sp. (682). A study of octocorals from Pohnpei and Ant atoll in Micronesia led to the novel nui-inoalides A-D (541-544) (683). The absolute configuration of juncin E (W) was also established by these researchers. 

A collection of the red alga Plocamium cartilagineum from Corsica and the Maltese Islands has yielded the four new halogenated homosesquiterpenic fatty acids 767-770 (843). The Pohnpei sponge Dysidea fragilis contains the novel (4 )-... 

Salomon CE, Williams DH, Faulkner DJ (1995) New Azacyclopropene Derivatives from Dysidea fragilis Collected in Pohnpei. J Nat Prod 58 1463... 

Namikoshi M, Negishi R, Nagai H, Dmitrenok A, Kobayashi H (2003) Three New Chlorine-Containing Antibiotics from a Marine-Derived Fungus Aspergillus ositanus Collected in Pohnpei. J Antibiot 56 755... 

Williams DH, Faulkner DJ (1996) A-Methylated Ageliferins from the Sponge Astrosclera willeyana from Pohnpei. Tetrahedron 52 5381... 

Williams, D. H. and Faulkner, D. J., /V-Methylated ageliferins from the sponge Astrosclera willeyana from Pohnpei, Tetrahedron, 52, 5381, 1996. 

Seven new ageliferin derivatives (78-84), characterized by methylation on one or both of the pyrrole nitrogens, together with previously isolated bromoageliferin and dibromoageliferin, were found in Astrosclera willeyana, a calcareous sponge coming from Pohnpei, Micronesia [121],... 

Higher and lower marine fungi Pohnpei Japan Antarctic... 

An examination of the composition of polyaromatic alkaloids of the mollusk Chelynotus semperi and an unidentified tunicate, both collected from Mante channel, Pohnpei, resulted in the identification of shermilamine B [129] and kuanoniamines A-D [130-133] (105). Shermilamine was originally found as a metabolite of a tunicate of the genus TruUdanmon (106). 

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