Synthesis of 1H-pyrazole-1-carboxamide derivatives and their antiproliferative activity against melanoma cell line.

Synthesis of a new series of 1H-pyrazole-1-carboxamide derivatives is described. Their antiproliferative activity against A375 human melanoma cell line was tested and the effect of substituents on the diarylpyrazole scaffold was investigated. The pharmacological results indicated that most of the newly synthesized compounds showed moderate activity against A375, compared with sorafenib. Among all of these derivatives, compound IIe which has N-methylpiperazinyl and phenolic moieties showed the most potent antiproliferative activity against A375 human melanoma cell line.

Synthesis of aminoquinazoline derivatives and their antiproliferative activities against melanoma cell line.

The synthesis of a novel series of aminoquinazoline derivatives 1a-r and their antiproliferative activities against A375 human melanoma cell line were described. Among them, six compounds showed superior antiproliferative activities to Sorafenib as a reference compound. In particular, the representative compound 1q bearing chromen-4-one moiety exhibited excellent antiproliferative activity (IC(50)=0.006 µM) and good selectivity over HS27 fibroblast cell line.

Synthesis and antiproliferative activity of pyrrolo[3,2-b]pyridine derivatives against melanoma.

Synthesis of a new series of diarylureas and amides having pyrrolo[3,2-b]pyridine scaffold is described. Their in vitro antiproliferative activity against human melanoma cell line A375 and HS 27 human fibroblast cell line was tested and the effect of substituents on the pyrrolo[3,2-b]pyridine was investigated. The newly synthesized compounds, except meta-substituted derivatives (Ij-k and Iv-w), generally showed superior or similar activity against A375 to Sorafenib. Among all of these derivatives, compounds Ir and It having 5-benzylamide substituted 4'-amide moieties showed the most potent antiproliferative activity against A375.

Aminoquinoline derivatives with antiproliferative activity against melanoma cell line.

The synthesis of a novel series of aminoquinoline derivatives 1a-p and their antiproliferative activities against A375 human melanoma cell line were described. Most compounds showed superior antiproliferative activities to Sorafenib as a reference compound. Among them, quinolinyloxymethylphenyl compounds 1k and 1l exhibited potent activities (IC(50)=0.77 and 0.79microM, respectively) and excellent selectivity against melanoma and fibroblast cell lines.

Synthesis of pyrrolo[2,3-d]pyrimidine derivatives and their antiproliferative activity against melanoma cell line.

Synthesis of a new series of diarylureas and amides having pyrrolo[2,3-d]pyrimidine scaffold is described. Their in vitro antiproliferative activities against A375 human melanoma cell line and HS 27 fibroblast cell line were tested and the effect of substituents on pyrrolo[2,3-d]pyrimidine was investigated. The newly synthesized compounds, except N-acetyl derivatives (Id, Ie, and Im), generally showed superior or similar activity against A375 to Sorafenib. Among all of these derivatives, compounds Iq and Ir having imidazole and morpholine moieties, respectively, showed the most potent antiproliferative activity against A375.

Tools for target identification and validation.

Reliable technologies for addressing target identification and validation are the foundation of successful drug development. Microarrays have been well utilized in genomics/proteomics approaches for gene/protein expression profiling and tissue/cell-scale target validation. Besides being used as an essential step in analyzing high-throughput experiments such as those involving microarrays, bioinformatics can also contribute to the processes of target identification and validation by providing functional information about target candidates and positioning information to biological networks. Antisense technologies (including RNA interference technology, which is recently very 'hot') enable sequence-based gene knockdown at the RNA level. Zinc finger proteins are a DNA transcription-targeting version of knockdown. Chemical genomics and proteomics are emerging tools for generating phenotype changes, thus leading to target and hit identifications. NMR-based screening, as well as activity-based protein profiling, are trying to meet the requirement of high-throughput target identification.

A New Coupling Reaction of Alkyl Iodides with Electron Deficient Alkenes Using Nickel Boride (cat.)-Borohydride Exchange Resin in Methanol.

The radical addition reaction of alkyl iodides with alpha,beta-unsaturated esters, nitriles, and ketones proceeds in moderate to excellent yields (50-95%) using Ni(OAc)(2) (0.05-0.2 equiv)-BER (3-5 equiv) in methanol in 1-9 h at room temperature or at 65 degrees C. Nickel boride on borohydride exchange resin (BER) is a good alternative reagent to tributyltin hydride for the coupling of alkyl iodides with the electron deficient alkenes in methanol. Compared with tributyltin hydride method, this method has an advantage of simple workup, since nickel boride-BER can be removed readily by filtration.

Novel inhibitors targeted to methionine aminopeptidase 2 (MetAP2) strongly inhibit the growth of cancers in xenografted nude model.

Inhibition of angiogenesis is emerging as a promising strategy for the treatment of cancer. In our study reported here, the effects of 4 highly potent methionine aminopeptidase 2 (MetAP2) inhibitors, IDR-803, IDR-804, IDR-805 and CKD-732 (designed by structure-based molecular modeling), on angiogenesis and tumor growth were assessed. Concentrations of these inhibitors as low as 2.5 nM were able to inhibit the growth of human umbilical vein endothelial cells (HUVEC) by as much as 50%, arresting growth in the G1 stage of mitosis. An intracellular accumulation of p21(WAF1/Cip1) protein was also observed. Furthermore, at higher concentrations (25 nM) of these 4 MetAP2 inhibitors, a significant induction of apoptosis was apparent in the same HUVEC cultures. As a result of these findings, the possible anticancer effects of these inhibitors were examined, utilizing the SNU-398 hepatoma cell line. Interestingly, pretreatment with these inhibitors led to an increased number of apoptotic cells of up to 60% or more, compared to untreated controls. Moreover, utilizing an in vivo xenografted murine model, these inhibitors suppressed the growth of engrafted tumor. In conclusion, these 4 inhibitory compounds potently exert an antiangiogenic effect to inhibit the growth of cancers in vivo and could potentially be useful for the treatment of a variety of cancers.

Enantiospecific synthesis of carbapentostatins.

In this paper we describe enantioselective syntheses of (+)-carbapentostatin (8) and its cyclopentyl analogue 12b. A new and efficient one-pot, two-step preparation of aldehyde 15 has been developed, based on the borane reduction of N-Pf-protected L-aspartic acid gamma-methyl ester (13) and Swern oxidation of the resulting alcohol. Homologation to diester 18 and ring formation by Dieckman cyclization, followed by reduction and dehydration steps, afford the 4-amino-1-cyclopentenemethanol derivative 22. Hydroboration and oxidation transform this compound stereospecifically into aminocyclopentanol 26, the key aminocyclitol component for an asymmetric synthesis of (+)-carbapentostatin.

An efficient procedure for the preparation of (1S,3R)- and (1S,3S)-1-amino-3-(hydroxymethyl)cyclopentanes.

Enantiomerically pure (1S,3S)- and (1S,3R)-1-amino-3-(hydroxymethyl)cyclopentanes have been efficiently synthesized from L-aspartic acid. The title compounds are isosteres of ribose and may be used to construct nucleoside analogs with important antiviral and antineoplastic activities as demonstrated by a concise total synthesis of (+)-4'-deoxycarbapentostatin nucleoside.

Efficient synthesis of enantiomerically pure 2-acylaziridines: Facile syntheses of N-Boc-safingol, N-Boc-D-erythro-sphinganine, and N-Boc-spisulosine from a common intermediate.

Various enantiomerically pure 2-acylaziridines were prepared efficiently from the corresponding aziridine-2-carboxylate via Weinreb's amide and the subsequent treatment of organometallic compounds. The carbonyl group of those 2-acylaziridines was stereoselectively reduced by NaBH4in the presence of ZnCl2 to give erythro-1,2-amino alcohols with high diastereoselectivities and chemical yields. Using this methodology, we prepared (1R,2S)-N-Boc-norephedrine 5, N-Boc-safingol 8, N-Boc-D-erythro-sphinganine 9, and N-Boc-spisulosine 10 in high yields.

A novel synthesis of 5-functionalized oxazolidin-2-ones from enantiomerically pure 2-substituted N-[(R)-(+)-alpha-methylbenzyl]aziridines.

5-Funtionalized enantiomerically pure oxazolidin-2-ones were prepared in one pot from commercially available chiral aziridines bearing an electron-withdrawing group at C-2 with retention of the configuration in high yields by regioselective aziridine ring-opening followed by intramolecular cyclization.

Synthesis and antihyperglycemic activity of erythrose, ribose and substituted pyrrolidine containing thiazolidinedione derivatives.

A series of erythrose, ribose, and substituted pyrrolidine containing 2,4-thiazolidinediones were synthesized. Among them, thirteen unsaturated thiazolidinediones, six saturated thiazolidinediones and two unsaturated malonates were evaluated for their ability to enhance glucose utilization in cultured L6 myocytes. On the basis of the in vitro activity, 5-[4-[2-(1-benzyl-3,4-bis-benzyloxypyrrolidin-2-yl)ethoxy]benzylidene]thiazolidine-2,4-dione 24b was selected as the candidate for further pharmacological studies.

Novel stereoselective synthesis of functionalized oxazolidinones from chiral aziridines.

Enantiomerically pure N-(R)-alpha-methylbenzyl-4(R)-(chloromethyl)oxazolidinones (4R)-5a-k were synthesized in one step and high yields from various aziridine-2-methanols (S)-2a-k by intramolecular cyclization with phosgene. The alpha-methylbenzyl substituent on the nitrogen was easily cleaved to give both enanatiomers of 4-(chloromethyl)oxazolidinones (R)-7a and (S)-7a. (R)-7a was used for the efficient syntheses of (L)-homophenylalaninol analogues (S)-12a-j. We also applied the same methodology to prepare oxazolidinones 9a-c containing a heteroatom-substituted alkyl group at C-4 in high yields.