Jung-Rae Rho

Solandelactones A-I, lactonized cyclopropyl oxylipins isolated from the hydroid Solanderia secunda

Abstract Solandelactones A-I(1–9), cyclopropyl and lactone containing novel docosanoids have been isolated from the hydroid Solanderia secunda. The structures of these compounds have been elucidated by combined spectral and chemical studies. Configuration of the cyclopropyl ring has been assigned as the opposite of related oxylipins by NOESY experiments. Absolute stereochemistry has been determined on the basis of chemical transformations and CD measurements of synthetic derivatives. In addition, the biogenetic origin of solandelactones has been discussed. Solandelactones C, D, and G exhibited moderate inhibitory activity against Farnesyl Protein Transferase.

In Vitro and In Vivo Antibacterial Activity of Punica granatum Peel Ethanol Extract against Salmonella.

Punica granatum is commonly used in Korea as a traditional medicine for the treatment of pathogenic bacteria. In this study, we investigated the in vitro and in vivo antimicrobial activity of P. granatum peel EtOH extract (PGPE) against 16 strains of Salmonella. The minimal inhibitory concentrations of PGPE were in the range of 62.5–1000 x03BCg mL−1. In addition, the in vivo antibacterial activity of the PGPE extract was examined in a S. typhimurium infection mouse model. Mice were initially infected with S. typhimurium and then with PGPE. The extract was found to have significant effects on mortality and the numbers of viable S. typhimurium recovered from feces. Although clinical signs and histological damage were rarely observed in the treated mice, the untreated controls showed signs of lethargy and histological damage in the liver and spleen. Taken together, the results of this study indicate that PGPE has the potential to provide an effective treatment for salmonellosis.

New Bromotyrosine Metabolites from the Sponge Aplysinella rhax

Abstract Four new bromotyrosine metabolites (3–6) along with the previously described compounds psammaplin A (1) and bisaprasin (2) have been isolated from the sponge Aplysinella rhax collected from Guam, Palau, and Pohnpei. Based upon the results of extensive spectroscopic analysis and chemical reaction, the structures of psammaplins A1 (3) and A2 (4) have been determined to be a N,N-dimethylguanidium salt of psammaplin A sulfate and its bis-N,N-dimethylguanidium disulfate derivative, respectively. Aplysinellin A (5) possesses an additional bromotyrosine-derived C9 unit connected directly to the carbon framework of psammaplin A by a biphenylic linkage while aplysinellin B (6) is the corresponding cyclic enol ether. These compounds exhibited moderate cytotoxicity and inhibitory activities against farnesyl protein transferase and leucine aminopeptidase.

Phorbaketals A, B, and C, Sesterterpenoids with a Spiroketal of Hydrobenzopyran Moiety Isolated from the Marine Sponge Phorbas sp.

Three new sesterterpenoids, phorbaketals A (1), B (2), and C (3) which have a spiroketal of the hydrobenzopyran moiety, were isolated from the Korean marine sponge Phorbas sp. Their complete structures were elucidated by spectral and chemical methods. They exhibited moderate cytotoxicity against human colorectal, hepatoma, and lung cancer cell lines. Furthermore, the cultivation of the bacterial fraction from the sponge afforded compound 1.

Two New Monogalactosyl Diacylglycerols from Brown Alga Sargassum thunbergii

Two new monogalactosyl diacylglycerols (MGDGs) along with two known glycolipids were isolated from the moderate polar fraction of the methanolic extract of the brown alga Sargassum thunbergii by using reversed silica flash chromatography. Two new MGDGs were identified as (2S)-1-O-(5Z,8Z,11Z,14Z,17Z-eicosapentaenoyl)-2-O-(9Z,12Z,15Z-octadecatrienoyl)-3-O-β-d-galactopyranosyl-sn-glycerol (1) and (2S)-1-O-(9Z,12Z,15Z-octadecatrienoyl)-2-O-(6Z,9Z,12Z,15Z-octadecatetraenoyl)-3-O-β-d-galactopyranosyl-sn-glycerol (2) by FAB tandem mass spectrometry, NMR techniques, and specific enzyme-catalyzed hydrolysis of the sn-1 fatty acyl linkage. The regiochemical attachment of the acyl chains in the glycerol moiety was established by 2D NMR correlations and confirmed by enzymatic hydrolysis.

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.

Osirisynes A-F, highly oxygenated polyacetylenes from the sponge Haliclona osiris

Abstract Osirisynes A-F( 1–6 ), highly oxygenated C 47 polyacetylenes have been isolated from the sponge Haliclona osiris collected from Guam. These compounds possess a diacetylenic carbinol and an α-acetylenic carboxylic acid as common structural features. The structures of osirisynes have been determined by combined spectroscopic methods. These compounds exhibited moderate cytotoxicity and inhibitory activities against Na + K + -ATPase and reverse transcriptase (RT).

Stylopine fromChelidonium majus inhibits LPS-Induced inflammatory mediators in RAW 264.7 cells

Stylopine is a major component of the leaf ofChelidonium majus L. (Papaveraceae), which has been used for the removal of warts, papillomas and condylomas, as well as the treatment of liver disease, in oriental countries. Stylopineper se had no cytotoxic effect in unstimulated RAW 264.7 cells, but concentration-dependently reduced nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-a (TNF-α) and interleukin-1 β (IL-1β), and the IL-6 production and cyclooxygenase-2 (COX-2) activity caused by the LPS stimulation. The levels of inducible nitric oxide synthase (iNOS) and COX-2 protein expressions were markedly suppressed by stylopine in a concentration dependent manner. These results suggest that stylopine suppress the NO and PGE2 production in macrophages by inhibiting the iNOS and COX-2 expressions. These biological activities of stylopine may contribute to the anti-inflammatory activity ofChelidonium majus.

Gukulenins A and B, Cytotoxic Tetraterpenoids from the Marine Sponge Phorbas gukulensis

Gukulenins A (1) and B (2), both having an unprecedented skeleton with a bis-tropolone moiety, were isolated from the Korean marine sponge Phorbas gukulensis. They exhibited significant cytotoxicity against human pharynx, stomach, colon, and renal cancer cell lines in the range 0.05-0.80 microM.

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.