Bromo-spiroisoxazoline Alkaloids, Including an Isoserine Peptide, from the Caribbean Marine Sponge .

Three new bromotyrosine spiroisoxazoline alkaloids, lacunosins A and B ( and ) and desaminopurealin (), were isolated from a MeOH extract of the marine sponge that showed modest α-chymotrypsin inhibitory activity. The structures of - share the spirocyclohexadienyl-isoxazoline ring system found in purealidin-R and several other Verongid sponge secondary metabolites. Compounds and are coupled to a glycine and an isoserine methyl ester, respectively.

Synergistic Anti- Activity of Bengazole A in the Presence of Bengamide A †.

Bengazoles A⁻G from the marine sponge sp. exhibit potent in vitro antifungal activity against spp. and other pathogenic fungi.

Structure-activity of antifungal compounds inspired by aminobisabolenes from the sponge Halichondria sp.

Structure-activity relationships of the antifungal aminobisabolene natural product, 1 isolated from Halichondria sp., and synthetic analogs were explored, in parallel with the antidermatophytic allylamine, Terbinafine®, against a panel of pathogenic fungi: Candida spp., Cryptococcus spp.

Jamaicensamide A, a Peptide Containing β-Amino-α-keto and Thiazole-Homologated η-Amino Acid Residues from the Sponge Plakina jamaicensis.

A new cyclic peptide, jamaicensamide A, composed of six amino acids, including a thiazole-homologated amino acid, was isolated from the Bahamian sponge Plakina jamaicensis, along with known compounds bitungolide A and franklinolide A. The structure of the title peptide was solved by integrated analysis of MS, 1D and 2D NMR data, oxidation-hydrolyses to α-amino acids, and their stereodetermination by Marfey's method. The close structural resemblance of Western Atlantic-derived jamaicensamide A to known Western Pacific-derived peptides of lithistid sponges in the genus Theonella and Discodermia suggests a common origin: the symbiotic bacterium Entotheonella sp.

Peroxide Natural Products from Plakortis zyggompha and the Sponge Association Plakortis halichondrioides-Xestospongia deweerdtae: Antifungal Activity against Cryptococcus gattii.

Cryptococcus gattii is a human pathogen and causative agent of a pernicious, sometimes fatal, disseminated fungal disease. Investigation of antifungal extracts of the marine sponge association Plakortis halichondrioides-Xestospongia deweerdtae and the sponge Plakortis zyggompha from the Bahamas led to the discovery and isolation of 6-epi-7,8-dihydroplakortide K (1), plakortide AA (2), and three new plakinic acids, N-P (4-6; unstable 1,2-dioxolanes bearing benzyl-substituted conjugated dienes), along with known plakinic acids L, K, and M.5 Chiroptical comparisons and DFT calculations of (13)C NMR chemical shifts were used to assign the absolute stereostructure of 4.

Antipodal crambescin A2 homologues from the marine sponge Pseudaxinella reticulata. Antifungal structure-activity relationships.

Investigation of antifungal natural products from the marine sponge Pseudaxinella reticulata from the Bahamas led to the discovery of new crambescin homologues (1, 2) and enantiomers (3, 4) of known natural products. The cyclic-guanidine structures were solved through analysis of 2D NMR, MS-MS, and CD data. The absolute configurations of 1-4 were established as 13R-opposite of known homologues reported from Crambe crambe obtained from the Mediterranean Sea-by comparison of their CD spectra with predicted Cotton effects obtained from DFT calculations.

Salvadenosine, a 5'-deoxy-5'-(methylthio) nucleoside from the Bahamian tunicate Didemnum sp.

Salvadenosine, (1) a rare 5'-deoxy-5'-(methylthio) nucleoside, was isolated from the deep-water Bahaman tunicate Didemnum sp. The structure was solved by integrated analysis of MS and 1D and 2D NMR data. We revise the structure of the known natural product, hamiguanosinol, which is a constitutional isomer of 1, to 5 by interpretation of the spectroscopic data and comparison with synthesized nucleosides.