Scalalactams A⁻D, Scalarane Sesterterpenes with a γ-Lactam Moiety from a Korean Spongia Sp. Marine Sponge.

Intensive study on the chemical components of a Korean marine sponge, Spongia sp., has led to the isolation of four new scalarane sesterterpenes, scalalactams A⁻D (1⁻4). Their chemical structures were elucidated from the analysis of spectroscopic data including 1D-and 2D-NMR as well as MS data. Scalalactams A⁻D (1⁻4) possess a scalarane carbon skeleton with a rare structural feature of a γ-lactam moiety within the molecules. Scalalactams A and B (1 and 2) have an extended isopropanyl chain at the lactam ring, and scalalactams C and D (3 and 4) possess a phenethyl group at the lactam ring moiety. Scalalactams A⁻D (1⁻4) did not show FXR antagonistic activity nor cytotoxicity up to 100 µM.

Cadiolides J-M, antibacterial polyphenyl butenolides from the Korean tunicate Pseudodistoma antinboja.

Activity-guided fractionations of the tunicate Pseudodistoma antinboja yielded four new compounds of the cadiolide class (cadiolides J-M, 1, 3-5) along with a known one (cadiolide H, 2). The structures were defined by spectroscopic methods including X-ray crystallographic analysis. These compounds were evaluated for their antibacterial activity and exhibited potent antibacterial activity against all of the drug resistant strains tested with MICs comparable to those of marketed drugs such as vancomycin and linezolid.

Acredinone C and the Effect of Acredinones on Osteoclastogenic and Osteoblastogenic Activity.

A new inhibitor, acredinone C (1), of receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation was isolated from the culture broth of the fungus Acremonium sp. (F9A015) along with acredinones A (2) and B (3). The structure of acredinone C (1), which incorporates benzophenone and xanthone moieties, was established by the analyses of combined spectroscopic data including 1D and 2D NMR and MS. All of the acredinones studied efficiently inhibited the RANKL-induced formation of TRAP(+)-MNCs in a dose-dependent manner without any cytotoxicity up to 10 µM. Acredinone A showed dual activity in both osteoclast and osteoblast differentiation in vitro and good efficacy in an animal disease model of bone formation.

The Halicylindramides, Farnesoid X Receptor Antagonizing Depsipeptides from a Petrosia sp. Marine Sponge Collected in Korea.

Three new structurally related depsipeptides, halicylindramides F-H (1-3), and two known halicylindramides were isolated from a Petrosia sp. marine sponge collected off the shore of Youngdeok-Gun, East Sea, Republic of Korea. Their planar structures were elucidated by extensive spectroscopic data analyses including 1D and 2D NMR data as well as MS data. The absolute configurations of halicylindramides F-H (1-3) were determined by Marfey's method in combination with Edman degradation. The absolute configurations at C-4 of the dioxyindolyl alanine (Dioia) residues of halicylindramides G (2) and H (3) were determined as 4S and 4R, respectively, based on ECD spectroscopy. The C-2 configurations of Dioia in 2 and 3 were speculated to both be 2R based on the shared biogenesis of the halicylindramides. Halicylindramides F (1), A (4), and C (5) showed human farnesoid X receptor (hFXR) antagonistic activities, but did not bind directly to hFXR.

Acredinones A and B, voltage-dependent potassium channel inhibitors from the sponge-derived fungus Acremonium sp. F9A015.

Two new benzophenones, acredinones A (1) and B (2), were isolated from a marine-sponge-associated Acremonium sp. fungus. Their chemical structures were elucidated on the interpretation of spectroscopic data. The structure of 1 was confirmed by palladium-catalyzed hydrogenation, followed by spectroscopic data analysis. Acredinones A (1) and B (2) inhibited the outward K(+) currents of the insulin secreting cell line INS-1 with IC50 values of 0.59 and 1.0 µM, respectively.

Monanchosterols A and B, bioactive bicyclo[4.3.1]steroids from a Korean sponge Monanchora sp.

Chemical investigation of a Korean marine sponge, Monanchora sp., led to the isolation of three new steroids (1-3). Compounds 1 and 2, designated as monanchosterols A and B, respectively, represent the first examples of steroids possessing the bicyclo[4.3.1] A/B ring system from a natural source. Compounds 1-3 were investigated for their anti-inflammatory activity by evaluating their inhibitory effects on the mRNA expression of IL-6, TNF-α, and COX-2 in the LPS-stimulated murine RAW264.7 macrophage cells. Compounds 2 and 3 exhibited significant inhibitory effects on the mRNA expression of IL-6 without notable cytotoxicity to the cells in a dose-dependent manner.

Cytotoxic 5α,8α-epidioxy sterols from the marine sponge Monanchora sp.

Three new sterols, 5α,8α-epidioxy-24-norcholesta-6,9(11),22-trien-3ß-ol (1), 5α,8α-epidioxy-cholesta-6,9(11),24-trien-3ß-ol (2), and 5α,8α-epidioxy-cholesta-6,23-dien-3ß,25-diol (3), with four known sterols (4-7) were isolated from a marine sponge Monanchora sp. Their chemical structures were elucidated by extensive spectroscopic analysis. Compounds 1 and 3-7 showed moderate cytotoxicity against several human carcinoma cell lines including renal (A-498), pancreatic (PANC-1 and MIA PaCa-2), and colorectal (HCT 116) cancer cell lines.

Phorbaketals L-N, cytotoxic sesterterpenoids isolated from the marine sponge of the genus Phorbas.

Three new sesterterpenoids, phorbaketals L-N (1-3), were isolated from a marine sponge of the genus Phorbas and their complete structures were elucidated via analysis of HRFABMS and NMR spectroscopic data. Phorbaketal N (3) showed potent cytotoxicity against human pancreas cancer cells (IC50=11.4 µM).

Anmindenols A and B, inducible nitric oxide synthase inhibitors from a marine-derived Streptomyces sp.

Anmindenols A (1) and B (2), inhibitors of inducible nitric oxide synthase (iNOS), were isolated from a marine-derived bacterium Streptomyces sp. Their chemical structures were elucidated by interpreting various spectroscopic data, including IR, MS, and NMR. Anmindenols A and B are sesquiterpenoids possessing an indene moiety with five- and six-membered rings derived from isoprenyl units. The absolute configuration of C-4 in anmindenol B was determined by electronic circular dichroism (ECD) of a dimolybdenum complex. Anmindenols A (1) and B (2) inhibited nitric oxide production in stimulated RAW 264.7 macrophage cells with IC50 values of 23 and 19 µM, respectively.

Placotylene A, an inhibitor of the receptor activator of nuclear factor-κB ligand-induced osteoclast differentiation, from a Korean sponge Placospongia sp.

A new inhibitor, placotylene A (1), of the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation, and a regioisomer of placotylene A, placotylene B (2), were isolated from a Korean marine sponge Placospongia sp. The chemical structures of placotylenes A and B were elucidated on the basis of 1D and 2D NMR, along with MS spectral analysis and revealed as an iodinated polyacetylene class of natural products. Placotylene A (1) displayed inhibitory activity against RANKL-induced osteoclast differentiation at 10 µM while placotylene B (2) did not show any significant activity up to 100 µM, respectively.

Cytotoxic scalarane sesterterpenes from a Korean marine sponge Psammocinia sp.

Three novel scalarane sesterterpenes were isolated from a Korean marine sponge, Psammocinia sp., along with four known derivatives. Their structures were elucidated on the basis of NMR, MS and IR spectroscopic data. The three new compounds are 12-deacetoxy-23-hydroxyscalaradial (1), 12-dehydroxy-23-hydroxyhyrtiolide (2) and 12-O-acetyl-16-deacetoxy-23-acetoxyscalarafuran (3), respectively, and the four known compounds are 12-deacetoxy-23-hydroxyheteronemin (4), 12-deacetoxy-23-acetoxy-19-O-acetylscalarin (5), 12-deacetoxy-23-O-acetoxyheteronemin (6) and 12-deacetoxyscalaradial (7). They exhibited cytotoxicity against intractable human cancer cell lines A498, ACHN, MIA-paca and PANC-1, with an IC50 range of 0.4-48 µM.

Discovery, design and synthesis of Y-shaped peroxisome proliferator-activated receptor δ agonists as potent anti-obesity agents in vivo.

We have discovered and demonstrated the in vitro and in vivo PPARδ-selective activity of novel Y-shaped agonists. These compounds activated hPPARδ with EC(50) values between 1 and 523 nM. Surprisingly, compounds 10a, 11d, 11e and 11f were the most potent and most selective hPPARδ agonists with 10(4)-fold selectivity over the other two subtypes, namely, hPPARα and hPPARγ. The PPARδ ligands 10a, 11e and 11f showed good bioavailability and in vivo efficacy.

Sterols from a soft coral, Dendronephthya gigantea as farnesoid X-activated receptor antagonists.

Three new steroids 3-oxocholest-1,22-dien-12ß-ol (1), 3-oxocholest-1,4-dien-20ß-ol (2), 3-oxocholest-1,4-dien-12ß-ol (3), and three known steroids (20S)-20-Hydroxyergosta-1,4,24(28)-trien-3-one (4) [7a], 5α,8α-Epidioxycholesta-6,22-dien-3ß-ol (5) [10] and 5-cholestene-3ß,12ß-diol (6) [11] were isolated from a soft coral Dendronephthya gigantea. Their chemical structures and relative stereochemistry were elucidated by the analysis of HRMS and 2-D NMR spectroscopic data. The steroids 1 and 2 showed notable inhibitory activity against farnesoid X-activated receptor (FXR) with IC(50)'s 14 and 15µM.

Rapid and direct detection of apolipoprotein E genotypes using whole blood from humans.

Polymerase chain reaction (PCR) is a powerful molecular biological tool in the field of toxicity testing and diagnostics. The use of PCR for large-scale genetic testing requires an effective method of sample processing. Unfortunately, isolation of PCR-quality DNA is time-consuming. PCR performed directly on whole blood is preferred because of time efficiency, cost of the procedure, and possible automation for large-scale toxicity evaluation and diagnosis. The apolipoprotein E (APOE) gene contains two single-nucleotide polymorphisms (SNP) located at codons 112 and 158, producing three APOE protein isoforms known to be associated with the risks of developing cardiovascular disease and susceptibility to Alzheimer's disease. In the present study, an attempt was made to use the AnyDirect solution for APOE genotyping by PCR using whole blood directly without DNA purification. Results for two PCR methods, (1) conventional PCR using purified DNA and conventional buffer and (2) direct PCR using whole blood and AnyDirect solution, were compared in four different PCR-based APOE genotyping methods including PCR restriction-fragment-length polymorphism (PCR-RFLP), allele-specific PCR, SNaPshot mini-sequencing, and multiplex tetra-primer amplification refractory mutation system (T-ARMS) PCR. There was complete concordance in the APOE genotypes between conventional PCR and direct PCR, in all four different PCR-based APOE genotyping methods. Data demonstrated that the four different PCR-based APOE genotyping methods are able to determine the APOE genotypes successfully using whole blood directly with the use of AnyDirect solution. The direct multiplex T-ARMS PCR using whole blood may be the most rapid, simple, and inexpensive method for detecting APOE genotypes among four different APOE genotyping methods.

Scalarane sesterterpenes from a marine sponge of the genus Spongia and their FXR antagonistic activity.

Three new scalarane-based sesterterpenes, 1- 3, were isolated from a marine sponge of the genus Spongia, and their chemical structures were elucidated by analysis of HRMS and 2-D NMR spectra. The isolated compounds 1 and 3 showed inhibition against the farnesoid X-activated receptor (FXR) with IC50 values of 2.4 and 24 microM, respectively. In particular, compound 3 directly inhibited the interaction between FXR and a coactivator peptide (SRC-1) as determined by surface plasmon resonance (SPR) spectroscopy.

FOR, a novel orphan nuclear receptor related to farnesoid X receptor.

We have identified and characterized a new amphibian orphan member of the nuclear receptor superfamily and termed it FOR1 (farnesoid X receptor (FXR)-like Orphan Receptor) because it shares the highest amino acid identity with the mammalian FXR. We also identified a variant of FOR1, called FOR2, which has 15 additional C-terminal amino acids. Both variants include an unusual insertion of 33 amino acids in the helix 7 region of the canonical ligand binding domain sequence, suggesting a unique structure for FOR. Northern blot analysis demonstrates that the FOR gene is highly expressed in adult and tadpole liver, kidney, and tail bud stage of the embryo. Detailed expression analysis using in situ hybridization indicates that FOR expression is first detectable at stage 30/31 in the presumptive liver region lasting until stage 41 with a peak level evident at stage 35/36. FOR forms heterodimeric complexes with retinoid X receptor (RXR) as demonstrated by biochemical and mammalian two-hybrid approaches. Gel mobility shift assays demonstrate that FORs form specific DNA-protein complexes on an FXR binding element consisting of an inverted repeat DNA element with 1 nucleotide spacing (IR1) from the phospholipid transfer protein gene promoter. Finally, although FORs do not exhibit constitutive transcriptional activity, frog gallbladder extract significantly augments the transcriptional activities of FORs.