Synthesis and antifungal activity of new N-(1-phenyl-4-carbetoxypyrazol-5-yl)-, N-(indazol-3-yl)- and N-(indazol-5-yl)-2-iodobenzamides

N-(1-Phenyl-4-carbetoxypyrazol-5-yl)-, N-(indazol-3-yl)- and N-(indazol-5-yl)-2-iodobenzamides 6, with a Benodanil-like structure, were synthesized by refluxing in acetic acid the corresponding benzotriazinones 5 with potassium iodide for 1 h in order to study the role on the antifungal activity of the N-substitution with an aromatic heterocyclic system on benzamide moiety. Among the tested iododerivatives, compounds 6d,f,g,h possess interesting activities toward some phytopathogenic fungal strains.     

A rapid vesicle electrokinetic chromatography method for the in vitro prediction of non-specific binding for potential PET ligands

High non-specific binding (NSB) is one of the most common reasons for candidate failure in potential positron emission tomography (PET) radiotracer development. It is of interest to develop high throughput in vitro methods for predicting non-specific binding prior to radiolabeling, which would help guide radiotracer candidate selection and assist decision making in new radiotracer discovery. We evaluated several electrokinetic chromatographic (EKC) systems to help identify PET ligands with low non-specific binding characteristics by mimicking the ligand-brain tissue interaction. The measured retention factors of tracers in clinical use or terminated candidates within AOT vesicle EKC systems were compared with literature in vitro or in vivo NSB data. We conclude that there is a statistical correlation between the chromatographic retention parameters of tested drugs and their NSB. The AOT vesicle EKC method can provide NSB in vitro trend analysis for a large number of drug candidates early in the novel radiotracer discovery process with minimal resources.     

Synthesis and Antimicrobial Activity of Some New 2-(3-(4-Aryl)-1-phenyl-1H-pyrazol-4-yl) Chroman-4-ones

Seven new 2-(3-(4-aryl)-1-phenyl-1H-pyrazol-4-yl) chroman-4-ones (4a-4g) have been synthesized by cyclization of 2-hydroxychalcone analogues of pyrazole 3a-3g using conc. HCl in acetic acid. The structures of the compounds 4a-4g were established by the combined use of (1)HNMR, IR and mass spectra. All the seven compounds were tested in vitro for their antibacterial activity against two Gram positive bacteria namely Staphylococcus aureus and Bacillus subtilis and two Gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The compounds 4b, 4c, 4e, 4f, 4g have displayed good antibacterial activity when compared with commercially available antibiotic, ciprofloxacin. These compounds also were screened for their antifungal activity against two ear pathogenic fungi, namely Aspergillus Niger and A. flavus. The compounds 4a, 4c, 4d, 4g exhibited good antifungal activity when compared with commercially available antifungal, fluconazole.     

Genotoxic effects of (-)-cubebin in somatic cells of mice

(?)‐Cubebin belongs to the dibenzylbutyrolactone lignan group, which is widely distributed in the plant kingdom. Because this compound shows interesting biological activities, it is extremely important to evaluate its possible genotoxic activity to allow its safe use in humans. Thus, the present study was performed to investigate the genotoxicity potential activity of (?)‐cubebin assessed by two assays: micronucleus in bone marrow cells and comet test in peripheral blood leukocytes of Swiss mice. In the (?)‐cubebin dose range‐finding assays, the maximum tolerated dose was greater than 2000 mg kg^?1. The compound was administered by an oral route at single doses of 250, 500 and 2000 mg kg^?1 body weight. Cytotoxicity was assessed by scoring 200 consecutive total polychromatic (PCE) and normochromatic (NCE) erythrocytes (PCE/NCE ratio). Under our experimental conditions, micronucleus and comet assays, respectively, showed that (?)‐cubebin caused dose‐related clastogenic and genotoxic effects in the somatic cells investigated. PCE/NCE ratio showed no cytotoxicity for the three doses of the compound. The data suggest caution in the ingestion of (?)‐cubebin by humans, especially at high doses. Copyright © 2010 John Wiley & Sons, Ltd.     

A selective plasmin inhibitor, trans-aminomethylcyclohexanecarbonyl-L-(O-picolyl)tyrosine-octylamide (YO-2), induces thymocyte apoptosis

The treatment of rat thymocytes with YO-2, a novel inhibitor of plasmin, resulted in an increase in DNA fragmentation. DNA fragmentation was also induced by another YO compounds such as YO-0, -3, -4 and -5. These YO compounds are the inhibitor of plasmin activity. On the other hand, YO-1, -6 and -8 that hardly inhibit plasmin activity had no effect on DNA fragmentation. Analysis of fragmented DNA from thymocytes treated with YO-2 by agarose gel electrophoresis revealed that the compound caused internucleosomal DNA fragmentation. In addition, judging from a laser scanning microscopy, annexin V-positive and propidium iodide-negative cells were increased by the treatment of the cells with the compound. Moreover, chromatin condensation was observed in thymocytes treated with the compound. These results demonstrated that YO-2 induces thymocyte apoptosis. There seemed to be some correlation between the apoptosis induced by YO compounds and their plasmin inhibitory effect. However, because the other protease inhibitors including pepstatin A, leupeptin, AEBSF, DFP and E-64-d did not affect DNA fragmentation, YO compounds are likely to have unique mechanism on plasmin or to show the effect on the other plasmin-like proteases. The plasmin inhibitory activity may have an important role in YO-2-induced apoptosis. Furthermore, the stimulations of caspase-8, -9 and -3-like activities were observed in thymocytes treated with YO-2. These results suggest that YO-2 induces thymocyte apoptosis via activation of caspase cascade.     

Spin adducts of several N-2-(2-alkoxycarbonyl-propyl)-alpha-pyridylnitrone derivatives with superoxide, alkyl and lipid-derived radicals

Several derivatives of N-t-butyl-alpha-phenylnitrone (PBN) such as N-2-(2-ethoxycarbonyl-propyl)-alpha-phenylnitrone (EPPN) have recently been reported to form superoxide spin adducts (t(1/2) ca. 2-7 min at pH 7.0), which are considerably more stable than their respective PBN or DMPO adducts (t(1/2) ca. 10 and 45 s, respectively). In continuation of our studies on structure optimization of EPPN derivatives, a series of 12 novel spin traps with 2-, 3- and 4-pyridinyl substituents was synthesized and fully characterized by 1H NMR, 13C NMR and IR spectroscopy. In addition to the replacement of the phenyl ring by a 2-, 3- or 4-pyridinyl substituent, the ethoxy group of the parent compound EPPN was replaced by either a propoxy, iso-propoxy, or cyclopropylmethoxy moiety. Superoxide adducts of all PPyN derivatives were considerably more stable than those of the respective EPPN derivatives with half-lives ranging from about 6 to 11 min. In addition, alkoxyl radical adducts were also considerably more stable than those of the EPPN series. Hydroxyl radical adducts were not detected, on the other hand, very stable spin adducts were formed from a series of carbon centered radicals, e.g. from the methyl or hydroxymethyl radical. The novel spin traps are offering an alternative to PBN or POBN, especially where the higher stability of oxygen-centered radical adducts is of major importance. All of them can easily be synthesized from commercially available compounds in two or three steps.     

Synthesis and antileukemic activity of new 3-(5-methylisoxazol-3-yl) and 3-(pyrimidin-2-yl)-2-styrylquinazolin-4(3H)-ones

3-(3-Methylisoxazol-5-yl) and 3-(pyrimidin-2-yl)-2-styrylquinazolin-4(3H)-ones 8a-l and 9a,c-e,h-l were synthesized by refluxing in acetic acid the corresponding 2-methylquinazolinones 6 and 8 with the opportune benzoic aldehyde for 12 h. The synthesized styrylquinazolinones 8a-l and 9a,c-e,h-l were tested in vitro for their antileukemic activity against L-1210 (murine leukemia), K-562 (human chronic myelogenous leukemia) and HL-60 (human leukemia) cell lines showing in some cases good activity.     

2-(E)-(4-甲磺酰基)亚苄基环戊酮Mannich碱类化合物的合成及其抗炎活性

目的设计合成2-(E)-(4-甲磺酰基)亚苄基环戊酮Mannich碱类化合物,并对其抗炎活性进行初步评价.方法以环戊酮、4-甲磺酰基苯甲醛及胺类化合物为原料,经多步反应合成目标化合物,并以二甲苯致小鼠耳肿胀模型测试目标化合物的抗炎活性.结果与结论共合成10个新化合物,经1H-NMR和MS确证其结构.初步药理实验结果显示9个目标化合物均具有一定的抗炎活性.     

Further studies on pumiliotoxin 251D and hydroquinone content of the skin secretion of Melanophryniscus species (Anura, Bufonidae) from Uruguay.

In whole animal ethanolic extracts from adult specimens of Melanophryniscus atroluteus (27 specimens) and M. devincenzii (16 specimens) as well as of two egg clutches and four tadpole samples from the latter species, the major alkaloid pumiliotoxin (PTX) 251D and hydroquinone were assayed quantitatively by gas chromatography/mass spectrometry. All toad extracts contained high concentrations of PTX 251D and hydroquinone and exhibited considerable variation in the content of these compounds among individual specimens. The extracts of the eggs and tadpoles were entirely free of alkaloids as well as hydroquinone, pointing to a dietary origin of these compounds.     

α-取代的对甲磺酰基苯丙烯酰胺的合成及抗炎活性

目的寻找高效低毒的非甾体抗炎药。方法合成α-取代的对甲磺酰基苯丙烯酰胺，评价其抗炎活性，并考察连续经口给药对大鼠胃肠道（GI）的影响。结果合成了25个新化合物（II1-25），其结构经IR、¹H NMR、MS和元素分析确证。角叉菜胶致大鼠足跖肿胀模型试验结果显示，12个化合物(II1,3,5,7,8,10-12,17,18,20,23)的抗炎活性与双氯芬酸钠（DC）和罗非昔布（RC）相当（P>0.05）。其中II3,8,10,11,18,20的GI副作用均显著小于DC(P<0.01)，与RC和羧甲基纤继素钠(CMC-Na)无明显差别(P>0.05)。结论α-取代的对甲磺酰基苯丙烯酰胺抗炎活性强，GI不良反应低，值得深入研究。     

Synthesis of N-arylsulfonyl DL-phenylserine derivatives exhibiting anti-inflammatory activity in experimental studies

Synthesis and evaluation of anti-inflammatory activity in rats with adjuvant arthritis of aryl sulfonyl derivatives of nonproteinogenic aromatic amino acids is reported. The studied compounds were synthesized by introducing residues of benzene-, p-toluene-, and p-bromobenzene sulfonic acids into threo-DL-phenylserine and erythro-DL-p-nitrophenylserine structures. From the set of 12 compounds tested in animal screening, N-(p-bromobenzenesulfonyl)-erythro-DL-p-nitrophenylserine ethyl ester 12 demonstrated the most pronounced anti-inflammatory activity. This compound inhibited inflammation process in polyarthritis phase by 53% (P < 0.001) though it was slightly toxic (LD50 > 6,000 mg kg(-1) for mice).     

Synthesis and antimycobacterial activity of (3,4-diaryl-3H-thiazol-2-ylidene)-hydrazide derivatives

[5-(pyridin-2-yl)-1,3,4-thiadiazol-2-ylthio]acetic acid (3,4-diaryl-3H-thiazol-2-ylidene)-hydrazide derivatives were synthesized and tested for their in vitro antimycobacterial activity. Some compounds showed an interesting activity against a strain of Mycobacterium tuberculosis H(37)Rv and three clinical isolates of M. tuberculosis.     

Anti-inflammatory effects of compounds alpha-humulene and (-)-trans-caryophyllene isolated from the essential oil of Cordia verbenacea

This study evaluated the anti-inflammatory properties of two sesquiterpenes isolated from Cordia verbenacea's essential oil, alpha-humulene and (-)-trans-caryophyllene. Our results revealed that oral treatment with both compounds displayed marked inhibitory effects in different inflammatory experimental models in mice and rats. alpha-humulene and (-)-trans-caryophyllene were effective in reducing platelet activating factor-, bradykinin- and ovoalbumin-induced mouse paw oedema, while only alpha-humulene was able to diminish the oedema formation caused by histamine injection. Also, both compounds had important inhibitory effects on the mouse and rat carrageenan-induced paw oedema. Systemic treatment with alpha-humulene largely prevented both tumor necrosis factor-alpha (TNFalpha) and interleukin-1beta (IL-1beta) generation in carrageenan-injected rats, whereas (-)-trans-caryophyllene diminished only TNFalpha release. Furthermore, both compounds reduced the production of prostaglandin E(2) (PGE(2)), as well as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) expression, induced by the intraplantar injection of carrageenan in rats. The anti-inflammatory effects of alpha-humulene and (-)-trans-caryophyllene were comparable to those observed in dexamethasone-treated animals, used as positive control drug. All these findings indicate that alpha-humulene and (-)-trans-caryophyllene, derived from the essential oil of C. verbenacea, might represent important tools for the management and/or treatment of inflammatory diseases.     

6-取代苯基-3(2H)哒嗪酮的合成、抗惊活性及其构效关系的研究

本文报道了14个6-取代苯基-4,5-二氢-3(2H)哒嗪酮和15个6-取代苯基-3(2H)哒嚎酮的合成及其抗电惊活性。其ED₅₀值表明,以2′,4′-二氯苯基-3(2H)哒嗪酮的抗惊作用为最强。构效分析表明,苯环上的取代基对化合物的抗惊活性有明显影响,吸电子取代基和疏水性参数值较大的取代基有利于提高化合物的抗惊活性。     

Enhanced DNA excision repair in CCRF-CEM cells resistant to 1,3-bis(2-chloroethyl)-1-nitrosourea,quantitated using the single cell gel electrophoresis (Comet) assay

Enhanced DNA repair activity is important for the development of cellular resistance to alkylating agents. Here, we quantitated the kinetics of DNA excision repairs initiated by 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) in human leukemia CCRF-CEM cells. CEM cells that had been established resistant to BCNU (CEM-R) were evaluated in comparison with parental CEM cells (CEM-S). The excision repair kinetics were quantitated as the amount of DNA single strand breaks, which were generated from the incision/excision of the damaged DNA and were diminished by the rejoining of renewed DNA, using the single cell gel electrophoresis (Comet) assay. CEM-R cells were 10-fold more resistant to BCNU than CEM-S cells, and also showed cross-resistance to melphalan and cisplatin. In response to the treatment with BCNU, both CEM-S and CEM-R cells initiated an incision/excision reaction at the end of the incubation period, and completed the rejoining process within 4 hr. While CEM-S cells could not repair the damage induced by the high concentration of BCNU, CEM-R cells completed the repair process regardless of BCNU concentrations, suggesting enhanced excision repairs in CEM-R cells. The excision repair activity of CEM-R cells was increased with regard to the incision reaction and to the rate of the repair. Similar results were obtained using ultraviolet C, suggesting enhanced nucleotide excision repair in CEM-R cells. Thus, the enhanced DNA excision repairs were successfully quantitated in the resistant leukemic cell line using the Comet assay. The evaluation of the repair activity may predict the sensitivity of cancer cells to chemotherapy and provide a clue to overcome the resistance.     

Synthesis of 5-(2-,3- and 4-methoxyphenyl)-4H-1,2,4-triazole-3-thiol derivatives exhibiting anti-inflammatory activity

New S-alkylated 5-(2-,3- and 4-methoxyphenyl)-4H-1,2,4-triazole-3-thiols (5a-c, 6a-c) and 5-(2-,3- and 4-methoxyphenyl)-4-phenyl-4H-1,2,4-triazole-3-thiols (7a-c, 8a-c, 9a-c) were synthesized by the alkylation of 3-(2-,3- and 4-methoxyphenyl)-4,5-dihydro-1H-1,2,4-triazole-5-thiones (3a-c) or 3-(2-,3- and 4-methoxyphenyl)-4-phenyl-4,5-dihydro-1H-1,2,4-triazole-5-thiones (4a-c) with 1-iodobutane or 1-(1,3-benzodioxol-5-yl)-2-bromo-1-ethanone, 2-bromo-1-(2,3-dihydro-1,4-benzodioxin-6-yl)-1-ethanone and 2-bromo-1-(3,4-dihydro-2H-1,5-benzodioxepin-7-yl)-1-ethanone. Compounds 3a-c and 4a-c were synthesized by the acylation of thiosemicarbazide or 4-phenyl-3-thiosemicarbazide with 2-, 3- and 4-methoxybenzoyl chlorides and further cyclization of the obtained acylderivatives 1a-c and 2a-c. The synthesized compounds 4a-c, 5a, 6a-c, 7a-c, 8a-c, 9b,c exhibit anti-inflammatory activity.     

Anti-oxidative and anti-inflammatory activities of some isolated constituents from the stem bark of Allanblackia monticola Staner L.C (Guttiferae)

Stem bark of Allanblackia monticola has been used in association with others plant in the Cameroonian folk medicine for the treatment of various diseases such amoebic dysentery, diarrhoea, lung infections, and skin diseases. The methylene chloride fraction, its isolated compounds like α-mangostin, lupeol and acid betulinic were screened for antioxidant activity using free radical scavenging method. These isolated compounds were further tested for anti-inflammatory properties using carrageenan-induced model. Methylene chloride fraction, showed concentration-dependent radical scavenging activity, by inhibiting 1,1-diphenyl-1-picryl-hydrazyl radical (DPPH) with an IC₅₀ value of 14.60 μg/ml. α-Mangostin and betulinic acid (500 μg/ml), showed weak radical scavenging activity with a maximum inhibition reaching 38.07 μg/ml and 26.38 μg/ml, respectively. Betulinic acid, lupeol and α-mangostin (5 mg/kg and 9.37 mg/kg) showed anti-inflammatory activity with a maximum inhibition of 57.89%, 57.14% and 38.70%, respectively. Methylene chloride fraction of Allanblackia monticola and some derivatives, have antioxidant and anti-inflammatory activities. Received 7 July 2008; accepted 7 October 2008     

Enhancements of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) metabolism and carcinogenic risk via NNK/arsenic interaction

Epidemiological studies indicated an enhancement of cigarette smoke-induced carcinogenicity, including hepatocellular carcinoma, by arsenic. We believe that arsenic will enhance the expression of hepatic CYP2A enzyme and NNK metabolism (a cigarette smoke component), thus its metabolites, and carcinogenic DNA adducts. Male ICR mice were exposed to NNK (0.5 mg/mouse) and sodium arsenite (0, 10, or 20 mg/kg) daily via gavaging for 10 days and their urine was collected at day 10 for NNK metabolite analysis. Liver samples were also obtained for CYP2A enzyme and DNA adducts evaluations. Both the cyp2a4/5 mRNA levels and the CYP2A enzyme activity were significantly elevated in arsenic-treated mice liver. Furthermore, urinary NNK metabolites in NNK/arsenic co-treated mice also increased compared to those treated with NNK alone. Concomitantly, DNA adducts (N(7)-methylguanine and O(6)-methylguanine) were significantly elevated in the livers of mice co-treated with NNK and arsenic. Our findings provide clear evidence that arsenic increased NNK metabolism by up-regulation of CYP2A expression and activity leading to an increased NNK metabolism and DNA adducts (N(7)-methylguanine and O(6)-methylguanine). These findings suggest that in the presence of arsenic, NNK could induce greater DNA adducts formation in hepatic tissues resulting in higher carcinogenic potential.     

Mitochondrial thioredoxin reductase inhibition by gold(I) compounds and concurrent stimulation of permeability transition and release of cytochrome c

The effects of auranofin, chloro(triethylphosphine)gold(I) (TEPAu), and aurothiomalate on mitochondrial respiration, pyridine nucleotide redox state, membrane permeability properties, and redox enzymes activities were compared. The three gold(I) derivatives, in the submicromolar range, were extremely potent inhibitors of thioredoxin reductase and stimulators of the mitochondrial membrane permeability transition (MPT). Auranofin appeared as the most effective one. In the micromolar range, it inhibited respiratory chain and glutathione peroxidase activity only slightly if not at all. TEPAu and aurothiomalate exhibited effects similar to auranofin, although TEPAu showed a moderate inhibition on respiration. Aurothiomalate inhibited glutathione peroxidase at concentrations where auranofin and TEPAu were without effect. Under nonswelling conditions, the presence of auranofin and aurothiomalate did not alter the redox properties of the mitochondrial pyridine nucleotides indicating that membrane permeability transition occurred independently of the preliminary oxidation of pyridine nucleotides. Under the same experimental conditions, TEPAu showed a moderate stimulation of pyridine nucleotides oxidation. Mitochondrial total thiol groups, in the presence of the gold(I) derivatives, slightly decreased, indicating the occurrence of an oxidative trend. Concomitantly with MPT, gold(I) compounds determined the release of cytochrome c that, however, occurred also in the presence of cyclosporin A and, partially, of EGTA, indicating its independence of MPT. It is concluded that the specific inhibition of thioredoxin reductase by gold(I) compounds may be the determinant of MPT and the release of cytochrome c.     

Synthesis and antifungal activity of (+/-)-1-(5-aryl-3-pyridin-2-yl-4,5-dihydro-pyrazol-1-yl)-2-imidazol-1-yl-ethanone derivatives

(+/-)-1-(5-Aryl-3-pyridin-2-yl-4,5-dihydro-pyrazol-1-yl)-2-imidazol-1-yl-ethanone derivatives were synthesized and tested for their in vitro antifungal activity. The compounds showed a moderate activity against strains of Candida parapsilosis, Candida pseudotropicalis and Candida glabrata.