Chung J. Sim

Petrocortynes and petrosiacetylenes, novel polyacetylenes from a sponge of the genus Petrosia

Abstract Petrocortynes A-C ( 1–3 ) and petrosiacetylenes A-D ( 4–7 ), novel long-chain polyacetylenes and related metabolites have been isolated from a sponge of the genus Petrosia . Compounds 1 and 2 are C 46 linear tetraacetylenes structurally related to petroformynes while 3 possesses an unusual γ-pyrone ring formed by an oxidative cyclization of a diacetylenic carbinol functionality. Compounds 4–7 are highly symmetric C 30 linear polyacetylenes in that 6 and 7 were isolated as unseparable mixtures of diastereomers. The structures of these compounds have been elucidated by combined chemical and spectral methods. Absolute stereochemistry has been determined by the modified Moshers method. These compounds exhibited significant brine-shrimp lethality, RNA-cleaving activity, and/or moderate inhibitory activity against PLA 2 and Na + /K + ATPase.

Discorhabdins from the Korean marine sponge Sceptrella sp.

Two new pyrroloiminoquinone alkaloids of the discorhabdin class, along with 12 compounds including one previously described synthetic derivative of the same and related skeletal classes, were isolated from the sponge Sceptrella sp., collected from Gageodo, Korea. The structures of these new compounds, designated as (-)-3-dihydrodiscorhabdin D (11) and (-)-discorhabdin Z (12), were determined by combined spectroscopic analyses. Compound 12 possesses an unusual hemiaminal group among the discorhabdin alkaloids. These compounds exhibited moderate to significant cytotoxicity, antibacterial activity, and inhibitory activity against sortase A.

Haliclonin A, a New Macrocyclic Diamide from the Sponge Haliclona sp.

Haliclonin A (1), a macrocyclic diamide of a novel skeletal class, was isolated from the marine sponge Haliclona sp. collected from Korean waters. The structure of this compound was determined using a combination of spectroscopic and chemical analyses. The new compound exhibited moderate cytotoxicity and antibacterial activity against diverse microbial strains.

Sarcotragins A and B, new sesterterpenoid alkaloids from the sponge Sarcotragus sp.

Abstract Sarcotragins A ( 1 ) and B ( 2 ), two terpenoid alkaloids of an unusual structural class, have been isolated from the sponge Sarcotragus sp. collected from Jaeju Island, Korea. The structures of these compounds have been determined as linear trisnorsesterterpenes containing a phenethylamine lactam or the corresponding glycine lactam moiety by combined chemical and spectral methods.

Sesterterpenes from the tropical sponge Coscinoderma sp.

Eight new sesterterpenes (2, 5, and 10-15), including structurally related pentaprenyl hydroquinones (2 and 5), and seven known ones of the same structural classes were isolated from the sponge Coscinoderma sp., collected from Chuuk Island, Micronesia. On the basis of the results of combined spectroscopic analyses, the new compounds were determined to be derivatives of the halisulfates and suvanine. These compounds exhibited moderate cytotoxicity against the K562 cell line and inhibitory activities against isocitrate lyase, sortase A, and Na+/K+-ATPase; significant structure-activity relationships were evident.

Gombamide A, a Cyclic Thiopeptide from the Sponge Clathria gombawuiensis

A new peptide, gombamide A (1), was isolated from the marine sponge Clathria gombawuiensis, collected from Korean waters. On the basis of the results of combined spectroscopic analyses, the structure of this compound was determined to be a cyclic C-terminally modified thiohexapeptide containing the unusual amino acid residues para-hydroxystyrylamide (pHSA) and pyroglutamic acid (pyroGlu). The absolute configurations of all amino acid residues were determined to be l by advanced Marfeys analysis. The new compound exhibited weak cytotoxicity against A549 and K562 cell lines as well as moderate inhibitory activity against Na(+)/K(+)-ATPase.

Wondonins A and B, new bis(dihydroxystyryl)imidazoles from a two-sponge association

Abstract Wondonins A and B, two alkaloids of an unprecedented structural class, along with the previously described dihydroxystyryl sulfates, have been isolated from an association of the sponges Poecillastra wondoensis and Jaspis sp. collected from Keomun Island, Korea. The structures of these compounds have been determined as imidazole alkaloids containing a bis(dihydroxystyrene) moiety by combined spectroscopic methods. The new compounds exhibited antiangiogenic activity against human umbilical vein endothelial cells.

Identification of Novel Acetylenic Alcohols and a New Dihydrothiopyranone from the Tropical Sponge Reniochalina sp.

Two new acetylenic alcohols (1–2) and a new dihydrothiopyranone (3) were isolated from the tropical sponge Reniochalina sp. Their structures were determined by spectroscopic and chemical methods to be (3R)-hydroxyoctatriacont-(4E)-en-1-yne (1), 5-hydroxyheptatriacont-(3Z)-en-1-yne (2) and 2-hexadecyl-2,3-dihydrothiopyran-4-one (3). The acetylenic alcohol (1) exhibited significant growth inhibitory effect against human tumor cell lines.

Cyclic Bis-1,3-dialkylpyridiniums from the sponge Haliclona sp.

Eight novel cyclic bis-1,3-dialkylpyridiniums, as well as two known compounds from the cyclostellettamine class, were isolated from the sponge Haliclona sp. from Korea. Structures of these novel compounds were determined using combined NMR and FAB-MS/MS analyses. Several of these compounds exhibited moderate cytotoxic and antibacterial activities against A549 cell-line and Gram-positive strains, respectively. The structure-activity relationships of cyclostellettamines are discussed based on their bioactivities.

Scalarane Sesterterpenes from the Sponge Smenospongia sp.

Ten new sesterterpene compounds (4-13) and seven known metabolites (1-3, 14-17) were isolated from the sponge Smenospongia sp. collected from Korean coastal waters. On the basis of combined spectroscopic analyses, the new compounds exhibited diverse functionalities on a common scalarane sesterterpene structure. The presence of a 23-aldehyde on compound 6 and a 20-carboxylic acid on 11 is unprecedented among sponge-derived scalarane sesterterpenes. Several of the new compounds showed significant cytotoxicity and antimicrobial activity, as well as moderate inhibitory activity against isocitrate lyase.