Jiann-Jyh Huang

Epigallocatechin-3-gallate prevents lupus nephritis development in mice via enhancing the Nrf2 antioxidant pathway and inhibiting NLRP3 inflammasome activation

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.

Synthesis of 3α-hydroxy-21-(1′-imidazolyl)-3β-methoxyl-methyl-5α-pregnan-20-one via lithium imidazole with 17α-acetylbromopregnanone

Abstract The synthesis of biologically active 3α-hydroxyl-21-(1′-imidazolyl)-3β-methoxymethyl-5α-pregnan-20-one (11) was accomplished in six steps. The key steps were the improvement of stereoselectivity for acetyl isomers in C-17 and the introduction of imidazole into the core structure by use of lithium imidazole. This latter key step provided the desired product 11 in 82% yield without the formation of 1,3-disubstituted imidazolium salt as impurity, which is generally observed in traditional method.

One-flask synthesis of 1,3,5-trisubstituted 1,2,4-triazoles from nitriles and hydrazonoyl chlorides via 1,3-dipolar cycloaddition

A one-flask strategy for the synthesis of 1,3,5-trisubstituted 1,2,4-triazoles 4a–s and 8a and b from nitriles 5a–i with N-arylhydrazonoyl hydrochlorides 3a–h and 7a and b under basic conditions was developed. The reaction provided the desired 1,2,4-triazoles in moderate to excellent yields (56–98%), and was applicable to aliphatic and aromatic nitriles as well as N-phenylhydrazonoyl hydrochlorides bearing ester and acetyl functionalities. A 1,3-dipolar cycloaddition between imidate and nitrilimine generated from the respective nitrile and N-arylhydrazonoyl chloride in one flask was proposed for the new transformation.

Characterization of the biological activity of a potent small molecule Hec1 inhibitor TAI-1

BackgroundHec1 (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.MethodsThe 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.ResultsTAI-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.ConclusionsThe 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.

Synthesis and structure–activity relationship of 3-O-acylated (–)-epigallocatechins as 5α-reductase inhibitors

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.

Activity of a Novel Hec1-Targeted Anticancer Compound against Breast Cancer Cell Lines In Vitro and In Vivo

Current cytotoxic chemotherapy produces clinical benefit in patients with breast cancer but the survival impact is modest. To explore novel cytotoxic agents for the treatment of advanced disease, we have characterized a new and pharmacokinetically improved Hec1-targeted compound, TAI-95. Nine of 11 breast cancer cell lines tested were sensitive to nanomolar levels of TAI-95 (GI50 = 14.29–73.65 nmol/L), and more importantly, TAI-95 was active on a number of cell lines that were resistant (GI50 > 10 μmol/L) to other established cytotoxic agents. TAI-95 demonstrates strong inhibition of in vivo tumor growth of breast cancer model when administered orally, without inducing weight loss or other obvious toxicity. Mechanistically, TAI-95 acts by disrupting the interaction between Hec1 and Nek2, leading to apoptotic cell death in breast cancer cells. Furthermore, TAI-95 is active on multidrug-resistant (MDR) cell lines and led to downregulation of the expression of P-glycoprotein (Pgp), an MDR gene. In addition, TAI-95 increased the potency of cytotoxic Pgp substrates, including doxorubicin and topotecan. Certain clinical subtypes of breast cancer more likely to respond to Hec1-targeted therapy were identified and these subtypes are the ones associated with poor prognosis. This study highlights the potential of the novel anticancer compound TAI-95 in difficult-to-treat breast cancers. Mol Cancer Ther; 13(6); 1419–30. ©2014 AACR.

The mechanism investigation in substitution of 21-bromo-3α-hydroxyl-3β-methoxymethyl-5α-pregnan-20-one with nucleophiles

Abstract A mechanistic study on the nucleophilic substitution of a strictly geometric 21-bromo-3α-hydroxyl-3β-methoxymethyl-5α-pregnan-20-one was described. Reaction of the α-bromoketone with excess lithium imidazole followed by the addition of extra bases including n -butyllithium, methyllithium, lithium piperidine, and lithium pyrrolidine provided unexpected α-nucleophilic carbonyl adducts that derived from strong base. Data from HPLC and proton NMR suggested an epoxide as the intermediate. Two possible reaction pathways were proposed for the nucleophilic substitution reaction. One pathway is the normal S N 2 substitution reaction, directly provided the imidazoly product without the formation of the unexpected α-substituted products. The other pathway went through an epoxide intermediate, in which imidazole anion or the strong bases added would attack from the less hindered site of the epoxide to give the substitution product.

Vilsmeier–Haack reagent-promoted formyloxylation of α-chloro-N-arylacetamides by formamide

In this study, a Vilsmeier–Haack reagent-promoted formyloxylation of α-chloro-N-arylacetamides by formamide was developed. The reaction successfully provided the desired α-formyloxy-N-arylacetamides 4 and 7a–n in moderate to excellent yields (70–96%) by use of 3.0 equivalents of PBr3 at 80–90 °C and was applicable to substrates bearing electron-donating or withdrawing groups at the aryl moiety. For α-chloro-N-(naphthalenyl)acetamide (8a), α-chloro-N-(quinolin-8-yl)acetamide (8b), and α-chloro-N-(thiazol-2-yl)acetamide (8c) possessing the α-chloro group, the reaction also provided the desired formyloxylated products 9a–c in 70–87% yields. A plausible mechanism was proposed through the activation of α-chloroacetamide by the Vilsmeier–Haack reagent to account for the new transformation.

Design and synthesis of pyrrole–5-(2,6-dichlorobenzyl)sulfonylindolin-2-ones with C-3′ side chains as potent Met kinase inhibitors

Pyrrole–5-(2,6-dichlorobenzyl)sulfonylindolin-2-ones of scaffold 4 with various C-3′ side chains were designed as potent Met kinase inhibitors. Structural optimization led to compounds 10, 20, and 22–24 which demonstrated subnanomolar IC50 values in the biochemical assay. The potent compound 20 inhibited Met with IC50 value of 0.37 nM and the proliferation of MKN45 cells with IC50 of 0.22 μM. It suppressed Met autophosphorylation with the downstream signaling through Gab-1, PLC-γ, FAK, Akt, STAT3, and ERK in cell. Complete inhibition of STAT3 and ERK phosphorylation was observed in MKN45 cells treated with 20 at the concentration of 100 nM. A computation simulation study was performed to reveal the interaction of 20 with Met.

Facile and efficient synthesis of 1-[2-(6,7-dimethyl-3,4-dihydronaphthalen-2-yl)ethyl]pyrrolidine hydrochloride

An efficient and facile procedure for the preparation of 1-[2-(6,7-dimethyl-3,4-dihydronaphthalen-2-yl)ethyl]pyrrolidine hydrochloride from 6,7-dimethyl-1,2,3,4-tetrahydronaphtalen-1-one in four steps is proposed. It includes one-step synthesis of 1-(6,7-dimethyl-1,2,3,4-tetrahydronaphthalen-2-yl)acetic acid as key intermediate and subsequent transformations of functional groups therein.