[show abstract][hide abstract] ABSTRACT: Hec1 (NDC80) is an integral part of the kinetochore and is overexpressed in a variety of human cancers, making it an attractive molecular target for the design of novel anticancer therapeutics. A highly potent first-in-class compound targeting Hec1, TAI-1, was identified and is characterized in this study to determine its potential as an anticancer agent for clinical utility.
The in vitro potency, cancer cell specificity, synergy activity, and markers for response of TAI-1 were evaluated with cell lines. Mechanism of action was confirmed with western blotting and immunofluorescent staining. The in vivo potency of TAI-1 was evaluated in three xenograft models in mice. Preliminary toxicity was evaluated in mice. Specificity to the target was tested with a kinase panel. Cardiac safety was evaluated with hERG assay. Clinical correlation was performed with human gene database.
TAI-1 showed strong potency across a broad spectrum of tumor cells. TAI-1 disrupted Hec1-Nek2 protein interaction, led to Nek2 degradation, induced significant chromosomal misalignment in metaphase, and induced apoptotic cell death. TAI-1 was effective orally in in vivo animal models of triple negative breast cancer, colon cancer and liver cancer. Preliminary toxicity shows no effect on the body weights, organ weights, and blood indices at efficacious doses. TAI-1 shows high specificity to cancer cells and to target and had no effect on the cardiac channel hERG. TAI-1 is synergistic with doxorubicin, topotecan and paclitaxel in leukemia, breast and liver cancer cells. Sensitivity to TAI-1 was associated with the status of RB and P53 gene. Knockdown of RB and P53 in cancer cells increased sensitivity to TAI-1. Hec1-overexpressing molecular subtypes of human lung cancer were identified.
The excellent potency, safety and synergistic profiles of this potent first-in-class Hec1-targeted small molecule TAI-1 show its potential for clinically utility in anti-cancer treatment regimens.
Journal of Experimental & Clinical Cancer Research 01/2014; 33(1):6. · 3.07 Impact Factor
[show abstract][hide abstract] ABSTRACT: Patients with lupus nephritis show an impaired oxidative status and increased levels of interleukin (IL)-1β and IL-18, which are closely linked to inflammation and correlated with disease activity. Although epigallocatechin-3-gallate (EGCG), the major bioactive polyphenol present in green tea with antioxidant and free radical scavenging activities, has been reported to have anti-inflammatory effects by inhibiting nuclear factor-kappa B (NF-κB)-mediated inflammatory responses in vivo, its effectiveness for the treatment of lupus nephritis is still unknown. In the present study, 12-week-old New Zealand black/white (NZB/W) F1 lupus-prone mice were treated daily with EGCG by gavage until sacrificed at 34 weeks old for clinical, pathological, and mechanistic evaluation. We found that the administration (1) prevented proteinuria, renal function impairment, and severe renal lesions; (2) increased renal nuclear factor E2-related factor 2 (Nrf2) and glutathione peroxidase activity; (3) reduced renal oxidative stress, NF-κB activation, and NLRP3 mRNA/protein expression and protein levels of mature caspase-1, IL-1β, and IL-18; and (4) enhanced splenic regulatory T (Treg) cell activity. Our data clearly demonstrate that EGCG has prophylactic effects on lupus nephritis in these mice that are highly associated with its effects of enhancing the Nrf2 antioxidant signaling pathway, decreasing renal NLRP3 inflammasome activation, and increasing systemic Treg cell activity.
[show abstract][hide abstract] ABSTRACT: A thermal plasma process for the recovery of the spent alumina-supported platinum catalyst (Pt/Al2O3) and reduction of platinum oxide (PtO2) was developed. The spent Pt/Al2O3 and PtO2 catalysts were sintered at >1500 K under plasma condition and were reformed or reduced to metallic platinum, which were proven by XRD and EDX. Results from SEM and BET specific surface area analyses indicated that the organic tar with the intermolecular and intramolecular water on the surface of the spent catalysts was decomposed and converted to syngas (CO, CO2, and H2), which might be the reducing agents in the process. Time-programmed hydrogenation study of urocanic acid was carried out to compare the catalytic efficacy of recovery and fresh Pt/Al2O3 catalysts. The experimental result indicated that the plasma sintered Pt/Al2O3 catalyst showed the similar catalytic efficacy with respect to the fresh catalyst.
Journal of the Taiwan Institute of Chemical Engineers. 01/2011;
[show abstract][hide abstract] ABSTRACT: A series of N,N-disubstituted-N'-[1-aryl-1H-pyrazol-5-yl]-methnimidamides was synthesized by a newly developed microwave reaction and their antiproliferative activities were evaluated. Microwave irradiation of 5-amino-1,3-disubstituted pyrazoles with various amide solvents in the presence of POCl(3) provided the corresponding 2a-2k, 3a-3c, and 4a-4f in good to excellent yields. The obtained methnimidamides were tested against NCI-H661, NPC-TW01, and Jurkat cancer cell lines and the results indicated that compounds 2d and 2e were the most potent with IC(50) values in low micromolar range.
[show abstract][hide abstract] ABSTRACT: A series of 3-O-acylated (-)-epigallocatechins were synthesized and their inhibition of steroid 5α-reductase was studied. They were prepared from the reaction of EGCG with tert-butyldimethylsilyl chloride followed by reductive cleavage of the ester bond. The resultant (-)-epigallocatechins penta-O-tert-butyldimethylsilyl ether was esterified with different fatty acids then desilylated to provide the corresponding products. The activity of 3-O-acylated (-)-epigallocatechins increased with the increasing carbon numbers of the fatty acid moiety, reaching maximum for 16 carbon atoms (compound 4h) with an IC50 of 0.53 μM, which was ∼12-fold more potent than EGCG (IC50=6.29 μM). Introduction of monounsaturated fatty acid provided the most potent compound 6 (IC50=0.48 μM), which showed moderate anti-tumor activity in vivo.
European journal of medicinal chemistry 10/2010; 45(12):6068-76. · 3.27 Impact Factor
[show abstract][hide abstract] ABSTRACT: A series of pyrrole-indolin-2-ones were synthesized, and their inhibition profile for Aurora kinases was studied. The potent compound 33 with phenylsulfonamido at the C-5 position and a carboxyethyl group at the C-3' position selectively inhibited Aurora A over Aurora B with IC50 values of 12 and 156 nM, respectively. Replacement of the carboxyl group with an amino group led to compound 47, which retained the activity for Aurora B and lost activity for Aurora A (IC50=2.19 microM). Computation modeling was used to address the different inhibition profiles of 33 and 47. Compounds 47 and 36 (the ethyl ester analogue of 33) inhibited the proliferation of HCT-116 and HT-29 cells and suppressed levels of the phosphorylated substrates of Aurora A and Aurora B in the Western blots.
Journal of Medicinal Chemistry 08/2010; 53(16):5929-41. · 5.61 Impact Factor
[show abstract][hide abstract] ABSTRACT: The reaction of α-chloroformylarylhydrazines hydrochloride with quinoline under air provided the corresponding 2-aryl-2H-[1,2,4]triazoloquinolin-3-ones 3a–3d in 33–42% yields and unexpected isomeric 2-aryl-2H-[1,2,4]triazoloisoquinolin-3-ones 4a–4d in 30–42% yields. These two isomers were isolated and fully characterized by spectroscopic methods including X-ray crystallography. By employing 3-methylquinoline as the starting material under the same condition, the reaction only gave compound 3e–3h as sole products in 70–82% yields without the formation of isomers. A plausible mechanism was proposed through electrophilic aromatic reaction, the tandem ring cyclization and ring-opening, and oxidation for the generation of 2-aryl-2H-[1,2,4]triazoloisoquinolin-3-ones (4).
[show abstract][hide abstract] ABSTRACT: Novel amphiphatic imidazole compounds were evaluated as thermal latent catalysts for the polymerization of diglycidyl ether
of bisphenol A (DGEBA). Amphiphatic compounds 5–9, two commercially available catalysts 1 and 2, and compounds 3 and 4 were used to cure epoxy resin systems for an investigation of their thermal latency and storage stability. The results from
the cure activation energy and viscosity-storage time of the catalysts, the order of thermally latent activity was 3-phenylpropanoic
acid (4) > 2-amino-3-phenylpropinoic acid (5) > 2-amino-3-(imidazole-4-yl)-propionic acid (H-His-OH, 8) > N-tert-butoxycarbonyl-histidine (9) > imidazole-4-acrylic acid (6) > 3-(imidazole-4-yl)propionic acid (7) > 1-cyanoethyl-2-ethyl-4-methyl-imidazole (2) > 2-ethyl-4-methylimidazole (1) > histamine (3). From the results, the amphiphatic imidazole catalysts 5–9 showed better thermal latency than commercialized catalysts 1 and 2, basic catalyst 3 and acidic catalyst 4. Concerning the glass transition temperature (T
), the use of amphiphatic imidazole catalysts 5–9 provided complete or near complete curing systems at temperatures ranging from 152–163 °C, which were similar to two commercially
available catalysts (151–152 °C, 1 and 2) and histamine (159 °C, 3). On the other hand, the T
for compounds 4 and 5 could not be detected at 30–300 °C from the temperature scans because of their weak nucleophilicity and low cross-linking
Macromolecular Research 01/2010; 18(4):324-330. · 1.64 Impact Factor
[show abstract][hide abstract] ABSTRACT: A one-pot ethylnylation and catalytic desilylation reaction was developed for the synthesis of mestranol and levonorgestrel. Addition of trimethylsilylacetylide to the carbonyl group at C-17 of the steroids yielded the C-17α-trimethylsilylacetylenyl adducts, which were desilylated with a catalytic amount of TBAF (0.050equiv) in one pot to provide the corresponding mestranol and levonorgestrel both in 90% yields. A plausible mechanism was proposed for the catalytic desilylation through the regeneration of the fluoride ion from the reaction of alkoxide on the steroid with Me3SiF. The one-pot ethynylation and catalytic desilylation methodology provided an alternative route and avoided the traditional use of flammable and explosive acetylene gas toward the synthesis of mestranol and levonorgestrel.
[show abstract][hide abstract] ABSTRACT: A ‘one-flask’ synthesis of guanidines was developed by reacting isocyanates and isothiocyanates with sodium bis(trimethylsilyl)amide followed by addition of primary or secondary amines with a catalytic amount of AlCl3. The desired guanidines were obtained in good yields and the reaction was applicable to aliphatic and aromatic substrates. A plausible mechanism was proposed through the generation of cyanamide anion from isocyanates or isothiocyanates with sodium bis(trimethylsilyl)amide. Addition of amines and catalytic amount of AlCl3 smoothly converted the cyanamides to the desired guanidines.
[show abstract][hide abstract] ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
[show abstract][hide abstract] ABSTRACT: A new safe and convenient transformation has been developed. In the presence of cesium formate in dry MeOH solution, α-haloketones underwent direct conversion reaction to afford α-hydroxyketone in excellent yields. Furthermore, this methodology can be extended and applied in 2-chloro-N-(1,3-diphenyl-1H-pyrazol-5-yl)acetamide, 2-chloro-N-(2,6-dimethylphen-yl)acetamide, 1-(bromomethylsulfonyl)benzene, and N-(bromomethyl)phthalimide to give the corresponding products in moderate to excellent yields.
Journal of Organometallic Chemistry - J ORGANOMET CHEM. 01/2009; 694(21):3452-3455.
[show abstract][hide abstract] ABSTRACT: An efficient and convenient method for the bromination of pyrazolones and 5-hydroxypyrazoles was developed by using N-bromobenzamide in THF at room temperature. This new method provided di-bromimated pyrazolones in excellent yields (≥90%).