The discovery of 2,5-isomers of triazole-pyrrolopyrimidine as selective Janus kinase 2 (JAK2) inhibitors versus JAK1 and JAK3.

Members of the Janus kinase (JAK) family are potential therapeutic targets. Abnormal signaling by mutant JAK2 is related to hematological malignancy, such as myeloproliferative neoplasms (MPNs), and tyrosine kinase inhibitor (TKI)-resistance in non-small cell lung cancer (NSCLC). We discovered a potent and highly selective inhibitor of JAK2 over JAK1 and -3 based on the structure of 4-(2,5-triazole)-pyrrolopyrimidine. Among all triazole compounds tested, 2,5-triazole regioisomers more effectively inhibited JAK2 kinase activity than isomers with substitutions of various alkyl groups at the R2 position, except for methyl-substituted 1,5-triazole, which was more potent than the corresponding 1,4- and 2,5-triazoles. None of the synthesized 1,4-isomers inhibited all three JAK family members. Compounds with phenyl or tolyl group substituents at the R1 position were completely inactive compared with the corresponding analogues with a methyl substituted at the R1 position. As a result of this structure-activity relationship, 54, which is substituted with a cyclopropylmethyl moiety, exhibited significant inhibitory activity and selectivity (IC50=41.9nM, fold selectivity JAK1/2 10.6 and JAK3/2 58.1). Compound 54 also exhibited an equivalent inhibition of wild type JAK2 and the V617F mutant. Moreover, 54 inhibited the proliferation of HEL 92.1.7 cells, which carry JAK2 V617F, and gefitinib-resistant HCC827 cells. Compound 54 also suppressed STAT3 phosphorylation at Y705.

Synthesis of some benzimidazole derivatives endowed with 1,2,3-triazole as potential inhibitors of hepatitis C virus.

New derivatives of 2-thiobenzimidazole incorporating triazole moiety were synthesized, characterized and tested in vitro for antiviral activity against hepatitis C virus (HCV) and hepatitis B virus (HBV). Their cytotoxicity was determined by the reduction in the number of viable cell. All of the synthesized compounds are inactive against HBV and some showed activity against HCV. In particular, two compounds showed significant activity, 2-{4-[(1-benzoylbenzimidazol-2-ylthio)methyl]-1H-1,2,3-triazol-1-yl}-N-(p-nitro-phenyl)-acetamide (13) and 2-(4-{[1-(p-chlorobenzoyl)-benzimidazol-2-ylthio)methyl]-1H-1,2,3-triazol-1-yl}-N-(p-nitrophenyl)-acetamide (17). The results give an insight into the importance of the substituent at position 2 of benzimidazole for the inhibition of HCV.

Non-randomized controlled prospective study on perioperative levels of stress and dysautonomia during dental implant surgery.

PURPOSE: The purpose of this study was to compare pre- and postoperative autonomic activities and changes in salivary stress biomarkers between patients who received only local anesthesia and those who received local anesthesia together with intravenous sedation in dental implant surgery. METHODS: A total of 21 patients were enrolled in this non-randomized controlled prospective study; 7 subjects underwent implant surgery under local anesthesia with intravenous sedation and 14 subjects underwent surgery under only local anesthesia. Stress was evaluated by measuring salivary levels of chromogranin A (CgA) and a spectral analysis of heart rate variability (HRV) at baseline (on a day other than the day of surgery), 1h preoperatively, and 1h postoperatively. HRV analysis yields low- (LF) and high-frequency (HF) components, the LF/HF ratio, and the component coefficient of variance (CCV[HF]), which provide indices of sympathetic and parasympathetic regulatory activity. RESULTS: CgA levels were significantly higher (p<0.05) at baseline in patients who received sedation than those who did not, but CgA levels did not differ prior to surgery. Also, the values of most parameters, including LF, HF, LF/HF (L/H), and CCV(HF), did not significantly differ between groups or among the three time points. Only ΔL/H and ΔCCV(HF) were significantly lower (p<0.05) at 1h preoperatively in patients who received sedation than those who received only local anesthesia. CONCLUSIONS: CgA levels were high in both groups immediately before surgery, and thus CgA values immediately before surgery may not be a reliable indicator of the need for intravenous sedation. Also, spectral analysis of HRV, especially ΔL/H and ΔCCV(HF), could be useful for assessing tension and anxiety.

Novel tetrahydroisoquinoline derivatives with inhibitory activities against acyl-CoA: cholesterol acyltransferase and lipid peroxidation.

To find a novel acyl-CoA: cholesterol acyltransferase (ACAT) inhibitor with anti-lipid peroxidative activity, a series of tetrahydroisoquinoline derivatives were synthesized and evaluated. A compound with a N-(4-hydroxy-2,3,5-trimethylphenyl)carbamoyl moiety at the 3-position and an octanoyl moiety at the 2-position (7) was demonstrated to show anti-foam cell formation activity stronger than and anti-lipid peroxidative activity comparable to those of Pactimibe, while it was hardly absorbed orally. To increase its bioavailability, the acyl chain at the 2-position was shortened and various polar or basic moieties were introduced at the 7-position of 7. Among the synthesized derivatives, (S)-7-dimethylamino-N-(4-hydroxy-2,3,5-trimethylphenyl)-2-isobutyryl-1,2,3,4-tetrahydroisoquinoline-3-carboxamide hydrochloride (21) showed about 16-fold stronger anti-foam cell formation activity, 3-fold stronger hepatic ACAT inhibitory activity, similar anti-low density lipoprotein (LDL) oxidative activity and 2-fold more potent protective activity against macrophage cell death by oxidative stress in comparison with Pactimibe. Compound 21 was efficiently absorbed after oral administration at 10 mg/kg in rats and dogs and its C(max) values were higher than its IC(50) values for in vitro activities. In conclusion, a tetrahydroisoquinoline structure is a useful scaffold for designing a phenolic anti-oxidative ACAT inhibitor, and compound 21 is expected to effectively prevent atherosclerosis.

Investigation of the role of breast cancer resistance protein (Bcrp/Abcg2) on pharmacokinetics and central nervous system penetration of abacavir and zidovudine in the mouse.

Many anti-human immunodeficiency virus 1 nucleoside reverse-transcriptase inhibitors have low central nervous system (CNS) distribution due in part to active efflux transport at the blood-brain barrier. We have previously shown that zidovudine (AZT) and abacavir (ABC) are in vitro substrates for the efflux transport protein breast cancer resistance protein (Bcrp) 1. We evaluated the influence of Bcrp1 on plasma pharmacokinetics and brain penetration of zidovudine and abacavir in wild-type and Bcrp1-deficient (Bcrp1-/-) FVB mice. There was no difference in either area under the concentration-time profiles for plasma (AUC(plasma)) or brain (AUC(brain)) for zidovudine between the wild-type and Bcrp1-/- mice. The AUC(plasma) of abacavir was 20% lower in the Bcrp1-/- mice, whereas the AUC(brain) was 20% greater. This difference resulted in a 1.5-fold increase in abacavir brain exposure in the Bcrp1-/- mice. The effect of selective and nonselective transport inhibitors on the ABC brain/plasma ratio at a single time point was evaluated. 3-(6-Isobutyl-9-methoxy-1,4-dioxo-1,2,3,4,6, 7,12,12a-octahydropyrazino[1',2':1,6]pyrido[3,4-b]indol-3-yl)-propionicacid tert-butyl ester (Ko143), N[4[2-(6,7-dimethoxy-3,4-dihydro-1H-isoquinolin-2-yl)ethyl]phenyl]-5-methoxy-9-oxo-10H-acridine-4-carboxamide (GF120918), probenecid, and Pluronic P85 increased abacavir plasma concentrations in the wild-type mice. Abacavir plasma concentrations in Bcrp1-/- mice were increased by (R)-4-((1aR,6R,10bS)-1,2-difluoro-1,1a,6,10b-tetrahydrodibenzo (a,e)cyclopropa(c)cycloheptan-6-yl)-alpha-((5-quinoloyloxy)methyl)-1-piperazineethanol trihydrochloride (LY335979), GF120918, and probenecid, but not by Ko143. Brain/plasma concentration ratios in both the wild-type and Bcrp1-/- mice were increased by the P-glycoprotein inhibitors LY335979 and GF120918, but not by BCRP-selective inhibitors. These data indicate that deletion of Bcrp1 has little influence on the pharmacokinetics or brain penetration of AZT. However, for abacavir, deletion of Bcrp1 reduces plasma exposure and enhances brain penetration. These findings suggest that Bcrp1 does not play a significant role in limiting the CNS distribution of zidovudine and abacavir; however, brain penetration of abacavir is dependent on P-glycoprotein-mediated efflux.

Potential cancer chemopreventive activity of simple isoquinolines, 1-benzylisoquinolines, and protoberberines.

Seventeen simple isoquinolines, 15 1-benzylisoquinolines, and 19 protoberberines were tested for their inhibitory activities against Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells. Among the tested alkaloids, the inhibitory activity of all 1-benzylisoquinolines and 11 protoberberines was higher than that of beta-carotene. The 1-benzylisoquinolines 19, 21, 22, 29, and 34 and protoberberines 41, 47-49, 51, 52, and 55 showed potent inhibitory effects on EBV-EA induction (96-100% inhibition at 1 x 10(3) mol ratio/TPA). These alkaloids were more active than the naturally occurring alkaloids, 23, 25, 33, 53, and 54. In addition, fifteen simple isoquinolines, eighteen 1-benzylisoquinolines and eight protoberberines were evaluated with respect to their ability to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. Nine simple isoquinolines, ten 1-benzylisoquinolines, and four protoberberines were more potent than alpha-tocopherol, and four 1-benzylisoquinolines, 20 and 28-30, exhibited potent activities (SC50 4.5-5.8 microM). Their activities were higher than the naturally occurring alkaloids, 23, 25, and 33. Therefore, some of the isoquinoline alkaloids indicating the high activity on both assays may be potentially valuable cancer chemopreventive agents. Structure-activity relationships are discussed for both tests.

Causative agent of vascular pain among photodegradation products of dacarbazine.

The photodegradation products of the anticancer drug, dacarbazine, cause adverse reactions including local venous pain when injected intravenously. In this study, we attempted to identify which of these products is responsible. We synthesized or purchased five photodegradation products of dacarbazine (dimethylamine, 5-diazoimidazole-4-carboxamide (Diazo-IC), 4-carbamoylimidazolium-5-olate, 5-carbamoyl-2-(4-carbamoylimidazol-5-ylazo)imidazolium-5-olate and 2-azahypoxanthine) and examined the pain reaction induced by their intraperitoneal administration in mice using an abdominal stretching or constriction assay. Only Diazo-IC clearly induced pain reaction in mice in a dose-dependent manner, the other products caused no pain reaction. The threshold concentration for pain reaction in mice was estimated to be about 0.1 mg mL-1. While diclofenac sodium significantly reduced acetic-acid-induced pain reaction in mice, it did not influence those induced by Diazo-IC. This result suggests that the mechanism of Diazo-IC-induced pain is different from that of acetic-acid-induced inflammatory pain. Dacarbazine itself produced marked relaxation of rat thoracic aorta strips in a concentration-dependent manner, but there was no difference between the activity of dacarbazine and its photo-exposed solution, so constriction or relaxation of blood vessels is unlikely to be a factor in the pain reaction. In conclusion, Diazo-IC generated by photodegradation of dacarbazine solution causes the side-effect of venous pain. Dacarbazine solution that has turned pink should not be used, because Diazo-IC is an intermediate in the formation of the reddish product, 5-carbamoyl-2-(4-carbamoylimidazol-5-ylazo)imidazolium-5-olate. Drip infusion preparations of dacarbazine should be shielded from light.