A novel inhibitor of farnesyltransferase with a zinc site recognition moiety and a farnesyl group.

Protein prenylation such as farnesylation and geranylgeranylation is associated with various diseases. Thus, many inhibitors of prenyltransferase have been developed. We report novel inhibitors of farnesyltransferase with a zinc-site recognition moiety and a farnesyl/dodecyl group. Molecular docking analysis showed that both parts of the inhibitor fit well into the catalytic domain of farnesyltransferase. The synthesized inhibitors showed activity against farnesyltransferase in vitro and inhibited proliferation of the pancreatic cell line AsPC-1. Among the compounds with farnesyl and dodecyl groups, the inhibitor with a farnesyl group was found to have stronger and more selective activity.

Homogeneous Pd-catalyzed transformation of terminal alkenes into primary allylic alcohols and derivatives.

Synthesis of primary alcohols from terminal alkenes is an important process in both bulk and fine chemical syntheses. Herein, a homogeneous Pd-complex-catalyzed transformation of terminal alkenes into primary allylic alcohols, by using 5 mol % [Pd(PPh3)4] as a catalyst, and H2O, CO2, and quinone derivatives as reagents, is reported. When alcohols were used instead of H2O, allylic ethers were obtained. A proposed mechanism includes the addition of oxygen nucleophiles at the less-hindered terminal position of π-allyl Pd intermediates.

Synthesis and Preliminary Evaluation of Duocarmycin Analogues Incorporating the 1,2,11,11a-Tetrahydrocyclopropa[c]naphtho[2,3-e]indol-4-one (CNI) and 1,2,11,11a-Tetrahydrocyclopropa[c]naphtho[1,2-e]indol-4-one (iso-CNI) Alkylation Subunits.

Efficient syntheses and a preliminary evaluation of 1,2,11,11a-tetrahydrocyclopropa[c]-naphtho[2,3-e]indole (CNI) and 1,2,11,11a-tetrahydrocyclopropa[c]naphtho[1,2-e]indole (iso-CNI), and their derivatives containing an anthracene and phenanthrene variant of the CC-1065 or duocarmycin alkylation subunit are detailed.

Antiviral activities against herpes simplex virus type 1 by HPH derivatives and their structure-activity relationships.

The compound named Histidine-pyridine-histidine (HPH) is an oxygen-activating ligand derived from the structure of bleomycin. We synthesized HPH derivatives, namely HPH-1 to -8, and investigated their antiviral activities against herpes simplex virus type 1. HPH-8 showed potent antiviral activity with an EC50 of 15 microM, and relatively high cytotoxicity with a CC50 of 37 microM. In contrast, HPH-4 indicated a weaker antiviral activity with an EC50 of 79 microM, but exhibited a far more less cytotoxicity (CC50 500 microM). Other HPH derivatives showed no effects against antiviral activities and cytotoxicities.

Blockade of TGF-ß/Smad signaling by the small compound HPH-15 ameliorates experimental skin fibrosis.

BACKGROUND: Transforming growth factor-ß (TGF-ß)/Smad signaling is well known to play a critical role in the pathogenesis of systemic sclerosis (SSc). We previously developed an artificial molecule, the histidine-pyridine-histidine ligand derivative HPH-15, which may have an antifibrotic effect. The purpose of the present study was to clarify the effects of this drug in human skin fibroblasts and in a preclinical model of SSc. METHODS: The effects of HPH-15 on expression of extracellular matrix components and TGF-ß signaling in human dermal fibroblasts were analyzed. The antifibrotic properties of HPH-15 and its mechanisms were also examined in a bleomycin-induced skin fibrosis mouse model. RESULTS: HPH-15 suppressed the TGF-ß-induced phosphorylation of Smad3 and inhibited the expression of collagen I, fibronectin 1, connective tissue growth factor, and α-smooth muscle actin induced by TGF-ß in cultured human skin fibroblasts. In the bleomycin-induced skin fibrosis model, oral administration of HPH-15 protected against the development of skin fibrosis and ameliorated established skin fibrosis. Additionally, HPH-15 suppressed the phosphorylation of Smad3 in various cells, including macrophages in the bleomycin-injected skin. Further, in the treated mice, dermal infiltration of proinflammatory macrophages (CD11b+Ly6Chi) and M2 profibrotic macrophages (CD11b+CD204+ or CD11b+CD206+) was significantly decreased during the early and late stages, respectively. HPH-15 treatment resulted in decreased messenger RNA (mRNA) expression of the M2 macrophage markers arginase 1 and Ym-1 in the skin, whereas it inversely augmented expression of Friend leukemia integration 1 and Krüppel-like factor 5 mRNAs, the transcription factors that repress collagen synthesis. No apparent adverse effects of HPH-15 were found during the treatment. CONCLUSIONS: HPH-15 may inhibit skin fibrosis by inhibiting the phosphorylation of Smad3 in dermal fibroblasts and possibly in macrophages. Our results demonstrate several positive qualities of HPH-15, including oral bioavailability, a good safety profile, and therapeutic effectiveness. Thus, this TGF-ß/Smad inhibitor is a potential candidate therapeutic for SSc clinical trials.

Efficient Decarbonylation of Furfural to Furan Catalyzed by Zirconia-Supported Palladium Clusters with Low Atomicity.

Decarbonylation of furfural to furan was efficiently catalyzed by ZrO2 -supported Pd clusters in the liquid phase under a N2 atmosphere without additives. Although Pd/C and Pd/Al2 O3 have frequently been used for decarbonylation, Pd/ZrO2 exhibited superior catalytic performance compared with these conventional catalysts. Transmission electron microscopy and X-ray absorption fine structure measurements revealed that the size of the Pd particles decreased with an increase in the specific surface area of ZrO2 . ZrO2 with a high surface area immobilized Pd as clusters consisting of several (three to five) Pd atoms, whereas Pd aggregated to form nanoparticles on other supports such as carbon and Al2 O3 despite their high surface areas. The catalytic activity of Pd/ZrO2 was enhanced with a decrease in particle size, and the smallest Pd/ZrO2 was the most active catalyst for decarbonylation. When CeO2 was used as the support, a decrease in Pd particle size with an increase in surface area was also observed. Single Pd atoms were deposited on CeO2 with a high surface area, with a strong interaction through the formation of a Pd-O-Ce bond, which led to a lower catalytic activity than that of Pd/ZrO2 . This result suggests that zero-valent small Pd clusters consisting of more than one Pd atom are the active species for the decarbonylation reaction. Recycling tests proved that Pd/ZrO2 maintained its catalytic activity until its sixth use.

Direct C-H arene homocoupling over gold nanoparticles supported on metal oxides.

The direct CH/CH bond coupling of dimethyl phthalate was performed successfully over supported gold nanoparticle catalysts. Gold on reducible metal oxides, such as Co3 O4 , and on inert oxides that have an oxygen-releasing capacity, such as ZrO2 , showed the highest catalytic activity for the production of biphenyl tetracarboxylate using O2 as the sole oxidant. Supported Pd(OH)2 also catalyzed the reaction, but the catalytic activity was inferior to that of gold. Moreover, the gold catalysts exhibited excellent regioselectivity for the synthesis of valuable 3,3',4,4'-tetrasubstituted biphenyls by coupling with each other at the 4-position without the need for additional ligands. Gold catalysts also promoted the oxidative homocoupling of arenes including o-xylene to give symmetrical biaryls with high regioselectivity. X-ray absorption fine structure measurements revealed that the catalytically active species was Au(0) and that the lattice oxygen of Co3 O4 played an important role in the gold-catalyzed oxidative coupling. The results of the kinetic studies were consistent with an electrophilic aromatic substitution pathway. Regioselectivity is not controlled by directing groups or the electronic character of the substituents but by steric hindrance, which suggests that gold nanoparticles not only catalyze the oxidative coupling but also act as bulky ligands to control the regioselectivity.

Hydrolytic enantioselective protonation of cyclic dienyl esters and a ß-diketone with chiral phase-transfer catalysts.

Hydrolytic enantioselective protonation of dienyl esters and a ß-diketone catalyzed by phase-transfer catalysts are described. The latter reaction is the first example of an enantio-convergent retro-Claisen condensation. Corresponding various optically active α,ß-unsaturated ketones having tertiary chiral centers adjacent to carbonyl groups were obtained in good to excellent yields and enantiomeric ratios (83-99%, up to 97.5:2.5 er).

Enhancement of reaction efficiency by functionalized alcohols on gold(I)-catalyzed intermolecular hydroalkoxylation of unactivated olefins.

Intermolecular hydroalkoxylation of unactivated olefins catalyzed by the combination of gold(I) and electron deficient phosphine ligands has been developed. Although pairings of unactivated olefins and common aliphatic alcohols gave unsatisfactory results in gold catalyzed hydroalkoxylations, the use of alcohol substrates bearing coordination functionalities such as halogen or alkoxy groups showed great improvement of reactivity.

One-pot synthesis of indoles and aniline derivatives from nitroarenes under hydrogenation condition with supported gold nanoparticles.

One-pot sequences of hydrogenation/hydroamination to form indoles from (2-nitroaryl)alkynes and hydrogenation/reductive amination to form aniline derivatives from nitroarenes and aldehydes were catalyzed by Au nanoparticles supported on Fe(2)O(3). Nitro group selective hydrogenations and successive reactions were efficiently catalyzed under the conditions.

Two novel 1,2,4,5-tetrazines that participate in inverse electron demand Diels-Alder reactions with an unexpected regioselectivity.

[reaction: see text] Two new unsymmetrical 1,2,4,5-tetrazines, 3-methylsulfinyl-6-methylthio-1,2,4,5-tetrazine (4) and 3-(benzyloxycarbonyl)amino-6-methylsulfinyl-1,2,4,5-tetrazine (5), were prepared, and the scope of their participation in intermolecular inverse electron demand Diels-Alder reactions was defined. As anticipated, sulfoxides 4 and 5 (4 > 5) display a reactivity that is substantially greater than that of their corresponding sulfides (2 and 3), being derived from their enhanced electron-deficient character and resulting in a wider range of potential dienophile choices or the use of milder reaction conditions. The cycloaddition reactions were expectedly regioselective, typically producing a single cycloadduct, ensuring their synthetic utility, but both were found to proceed with a regioselectivity opposite what would be anticipated and complementary to that observed with 2 and 3.

Total synthesis of ningalin D.

A concise (nine-step) and effective (19% overall yield) total synthesis of ningalin D (1a) is disclosed and is based on a key 1,2,4,5-tetrazine --> 1,2-diazine --> pyrrole Diels-Alder strategy to assemble a fully substituted pyrrole core central to its structure. Additional highlights of the synthesis include a double Dieckmann condensation to introduce the C and D aryl rings enlisting substituents judiciously placed on the dienophile and intrinsic to the widely used tetrazine 2, a highly effective Suzuki coupling of the resulting C and D phenol triflates for introduction of the sterically demanding F and G aryl rings, and an unusually effective formal oxidative decarboxylation reaction cascade initiated by a Curtius rearrangement to directly provide the biphenylene quinone methide found imbedded in the structure of ningalin D. The cytotoxic and multidrug resistance (MDR) reversal activity of ningalin D, its derivatives, and the key synthetic intermediates are detailed.

A novel metal-chelating inhibitor of protein farnesyltransferase.

A novel metal chelator comprising a 4-(naphthalen-1-yl)pyridine and 2-aminoethanethiol was synthesized. This showed inhibitory activity against human protein farnesyltransferase with IC(50) 1.9 microM, induced morphological change in K-ras-NRK cells at 0.5 microg/mL and showed growth inhibition of K-ras-NRK cells with IC(50) 0.32 microg/mL.