Evaluation of subchronic (13 weeks) and reproductive toxicity potential of intravaginal gel-microemulsion formulation of a dual-function phenyl phosphate derivative of bromo-methoxy zidovudine (compound WHI-05) in B(6)C(3)F(1) mice

Heterosexual transmission of human immunodeficiency virus (HIV) accounts for 90% of all new infections worldwide and significantly contributes to new acquired immunodeficiency syndrome (AIDS) cases in the United States. In a systematic effort to develop a microbicidal contraceptive capable of preventing HIV transmission as well as providing fertility control, we previously identified novel phenyl phosphate derivatives of 3'-azido-3'-deoxythymidine (zidovudine) which exhibit potent anti-HIV and spermicidal activities. This study reports the preliminary preclinical study of our lead compound WHI-05, 5-bromo-6-methoxy-5, 6-dihydro-3'-azidothymidine-5'-(p-methoxyphenyl) methoxyalaninyl phosphate, for use as a dual-function topical microbicide. Acute toxicity studies have shown that WHI-05 has no detectable adverse effects on laboratory animals. The 13-week subchronic and reproductive toxicity potential of intravaginal gel-microemulsion formulation of WHI-05 were studied in mice to support its further development as a virucidal spermicide. Groups of 10 female B(6)C(3)F(1) mice were exposed intravaginally to a gel-microemulsion formulation containing 0%, 0.5%, 1.0%, or 2.0% WHI-05, 5 days/week for 13 consecutive weeks. On a molar basis, these concentrations represent 300 to 1200 times their in vitro spermicidal potency, and 1.5x10(4) to 6.1x 10(4) times their in vitro anti-HIV activity. After 13 weeks of intravaginal treatment, one half of treated mice were evaluated for toxicity, and the other half were mated with untreated males to evaluate potential reproductive and developmental effects. Repetitive intravaginal application of WHI-05 to yield a local concentration 6.1x10(4) times higher than its in vitro HIV IC(50) value and 1200 times higher than its spermicidal EC(50)96%), or pup development. These findings collectively show that the experimental dual-function anti-HIV and contraceptive agent, WHI-05, did not cause significant acute or subchronic and reproductive toxicity under the test conditions.     

Non-nucleoside HIV-1 reverse transcriptase inhibitors. Part 11: structural modulations of diaryltriazines with potent anti-HIV activity

A series of novel 6-naphthyloxy substituted DATA analogues bearing different substituents on the C-6 position of triazine ring were synthesized and evaluated for their in vitro anti-HIV activity in MT-4 cells. The results demonstrated that most of the compounds in this series are potent activity against HIV-1 with moderate to high selectivity. Among these analogues, two compounds exhibited excellent effect in inhibiting HIV-1 replication at nanomolar concentration (for compound 9h: IC(50)=9.3 nM, SI=15,385; for compound 9i: IC(50)=9.4 nM, SI=14,094), which are about 15-fold more active than nevirapine. In addition, several compounds are active against both HIV-1 and HIV-2, whose mechanism may be different from typical NNRTIs.     

Discovery of a novel nitroimidazolyl-oxazolidinone hybrid with potent anti Gram-positive activity: Synthesis and antibacterial evaluation

A number of linezolid analogues containing a nitroaryl-1,3,4-thiadiazole moiety, were prepared and evaluated as antibacterial agents against a panel of Gram-positive and Gram-negative bacteria. Among synthesized compounds, nitrofuran analogue 1b exhibited more potent inhibitory activity, with respect to other synthesized compounds and reference drug linezolid. The target compounds were also assessed for their cytotoxic activity against normal mouse fibroblast (NIH/3T3) cells using MTT assay. The results indicated that compound 1c exhibit potent antibacterial activity against Gram-positive bacteria at non-cytotoxic concentrations.     

Synthesis, antiarrhythmic and hypotensive activity of some novel 1,3-disubstituted ureas and phenyl N-substituted carbamates

Some new 1,3-disubstituted ureas and phenyl N-substituted carbamates were prepared and evaluated in vivo for their antiarrhythmic and hypotensive properties. The compound 1-tert.-butyl-1-(3-cyclopentyloxy-2-hydroxypropyl)-3-methylurea 2c exhibited a strong hypotensive action. The compounds 2-(1-tert.-butyl-3-methylureido)-1-(cyclopentyloxymethyl)ethyl N-isopropylcarbamate 3c and 2-(1-tert.-butyl-3-ethylureido)-1-(cyclopentyloxymethyl)ethyl N-isopropylcarbamate 3f showed an antiarrhythmic activity comparable to that of the reference drug Propranolol.     

Rhodium(II) acetate-catalyzed stereoselective synthesis, SAR and anti-HIV activity of novel oxindoles bearing cyclopropane ring

Novel oxindole derivatives bearing substituted cyclopropane ring have been designed on the basis of docking studies with HIV-1 RT using the software DS 2.5 and synthesized as probable NNRTIs against HIV-1 using rhodium(II) acetate-catalyzed stereoselective cyclopropanation reaction. The cyclopropane isomer, having trans relationship with respect to carbonyl of lactam moiety and functional group on the cyclopropane ring, was the major product in all cases along with a small amount of cis and methylene products. The trans isomers interacted well with HIV-1 RT through H-bonding with amino acids, like Lys101, Lys103, His235, Tyr318, constituting the non-nucleoside inhibitor binding pocket (NNIBP) during docking experiments. However, the compounds showed very little activity when subjected to in vitro anti-HIV-1 screening using β-galactosidase assay (TZM-bl cells) and GFP quantification (CEM-GFP cells). The very low level of in vitro HIV inhibition, in comparison to predicted EC₅₀ values on the basis of computational studies, during CEM-GFP screening using AZT as positive control indicated that probably the HIV RT is not the viral target and the molecules work through some different mechanism.     

Prophylactic activity of dihydroheptaprenol, a synthetic polyprenol derivative, against Sendai virus infection in mice.

The effect of a chemically synthesized polyprenol derivative, dihydroheptaprenol (DHP), on the non-specific resistance of mice to Sendai virus infection was investigated. The mice that received 200 micrograms of DHP intranasally twice, at 3 days and 1 day before the infection, showed a significant protection against Sendai virus infection. Treatment of mice twice even with as much as 2000 micrograms of DHP through the subcutaneous route, however, had no protective effect against infection. Excess interferon and tumour necrosis factor production in intranasally DHP-treated mice was seen 1 day after the infection when compared with Sendai virus alone controls or with DHP alone controls. Variance analysis of these findings indicates a prophylactic activity of DHP in pulmonary viral infections.     

Discovery of LASSBio-772, a 1,3-benzodioxole N-phenylpiperazine derivative with potent alpha 1A/D-adrenergic receptor blocking properties

We described herein the discovery of 1-(2-(benzo[d] [1,3]dioxol-6-yl)ethyl)-4-(2-methoxyphenyl) piperazine (LASSBio-772), as a novel potent and selective alpha 1A/1D adrenoceptor (AR) antagonist selected after screening of functionalized N-phenylpiperazine derivatives in phenylephrine-induced vasoconstriction of rabbit aorta rings. The affinity of LASSBio-772 for alpha 1A and alpha 1B AR subtypes was determined through displacement of [³H]prazosin binding. We obtained Ki values of 0.14 nM for the alpha 1A-AR, similar to that displayed by tamsulosin (K_i = 0.13 nM) and 5.55 nM for the alpha 1B-AR, representing a 40-fold higher affinity for alpha 1A-AR. LASSBio-772 also presented high affinity (K_B = 0.025 nM) for the alpha 1D-AR subtype in the functional rat aorta assay, showing to be equipotent to tamsulosin (K_B = 0.017 nM).     

Synthesis, biological activity, and evaluation of the mode of action of novel antitubercular benzofurobenzopyrans substituted on A ring

The 8-, 9-, 10-, and 11-halo, hydroxy, and methoxy derivatives of the antimycobacterial 3,3-dimethyl-3H-benzofuro[3,2-f][1]benzopyran were synthesized by condensation of the diazonium salts of 2-chloroanilines (13-17) with 1,4-benzoquinone (18), reduction of the intermediate phenylbenzoquinones 19-22 to dihydroxybiphenyls, cyclisation to halo-2-hydroxydibenzofurans 24-27, and construction of the pyran ring by thermal rearrangement of the corresponding dimethylpropargyl ethers 35-38. Palladium catalyzed nucleophilic aromatic substitution permitted conversion of the halo to the corresponding hydroxy derivatives which were methylated to methoxy-3,3-dimethyl-3H-benzofuro[3,2-f][1]benzopyran. All compounds substituted on the A ring were found more potent than the reference compound 1 against Mycobacterium bovis BCG and the virulent strain Mycobacterium tuberculosis H37Rv. The effect of the most active derivatives on mycolate synthesis was explored in order to confirm the preliminary hypothesis of an effect on mycobacterial cell wall biosynthesis. The linear 9-methoxy-2,2-dimethyl-2H-benzofuro[2,3-g][1]benzopyran (46) exhibiting a good antimycobacterial activity and devoid of cytotoxicity appeared to be the most promising compound.     

A killed, genetically engineered derivative of a wild-type extraintestinal pathogenic E. coli strain is a vaccine candidate

Infections due to extraintestinal pathogenic E. coli (ExPEC) result in significant morbidity, mortality and increased healthcare costs. An efficacious vaccine against ExPEC would be desirable. In this report, we explore the use of killed-whole E. coli as a vaccine immunogen. Given the diversity of capsule and O-antigens in ExPEC, we have hypothesized that alternative targets are viable vaccine candidates. We have also hypothesized that immunization with a genetically engineered strain that is deficient in the capsule and O-antigen will generate a greater immune response against antigens other than the capsular and O-antigen epitopes than a wild-type strain. Lastly, we hypothesize that mucosal immunization with killed E. coli has the potential to generate a significant immune response. In this study, we demonstrated that nasal immunization with a formalin-killed ExPEC derivative deficient in capsule and O-antigen results in a significantly greater overall humoral response compared to its wild-type derivative (which demonstrates that capsule and/or the O-antigen impede the development of an optimal humoral immune response) and a significantly greater immune response against non-capsular and O-antigen epitopes. These antibodies also bound to a subset of heterologous ExPEC strains and enhanced neutrophil-mediated bactericidal activity against the homologous and a heterologous strain. Taken together, these studies support the concept that formalin-killed genetically engineered ExPEC derivatives are whole cell vaccine candidates to prevent infections due to ExPEC.     

Synthesis, anti-inflammatory activity and COX-1/COX-2 inhibition of novel substituted cyclic imides. Part 1: Molecular docking study

A group of cyclic imides (1-13) was designed for evaluation as selective COX-2 inhibitors and investigated in vivo for their anti-inflammatory activities using carrageenan-induced rat paw edema model. Compounds 5b, 6b, 11b, 11c, 12b and 12c were proved to be potent COX-2 inhibitors with IC₅₀ range of 0.1-1.0 μM. In vitro COX-1/COX-2 inhibition structure-activity studies identified compound 5b as a highly potent (IC₅₀ = 0.1 μM), and an extremely selective [COX-2 (SI) = 400] comparable to celecoxib [COX-2 (SI) > 333.3], COX-2 inhibitor that showed superior anti-inflammatory activity (ED₅₀ = 104 mg/kg) relative to diclofenac (ED₅₀ = 114 mg/kg). A Virtual screening was carried out through docking the designed compounds into the COX-2 binding site to predict if these compounds have analogous binding mode to the COX-2 inhibitors. Molecular modeling (docking) study showed that the CH₃O substituents of 5b inserted deep inside the 2°-pocket of the COX-2 active site, where the O-atoms of such group underwent a H-bonding interaction with His⁹⁰ (2.43, 2.83 Å), Arg⁵¹³ (2.89 Å) and Tyr³⁵⁵ (3.34 Å). Docking study of the synthesized compound 5b into the active site of COX-2 revealed a similar binding mode to SC-558, a selective COX-2 inhibitor.     

1-[[4-(Aminoalkoxy)phenyl]sulfonyl]indolizines: a novel class of calcium entry blockers. Relationships between chemical structure, stereoelectronic properties and anticalcic activity

The solid-state structures of a series of 1-[[4-(aminoalkoxy)phenyl]sulfonyl]indolizines have been determined by X-ray analysis. These molecules are known to be representative of a novel class of calcium entry blockers characterized by a new binding site associated with the L-type calcium channel. Previous 2-dimensional structure-activity relationship studies have shown that 1-sulfonylindolizines substituted in the 2 position by an isopropyl group and possessing an aralkylamine substructure were among the most potent calcium antagonists. A comparative study of the 3-dimensional X-ray structures and the electronic properties computed at the ab initio HF level of five 1-sulfonyl, 2-alkyl and 2-phenylindolizine calcium antagonists presenting different types of amine substructures indicates important similarities within the series. This has led us to propose the first pharmacophoric elements for this kind of compound.     

Bioavailable dietary phosphate,a mediator of cardiovascular disease,may be decreased with plant-based diets,phosphate binders,niacin, and avoidance of phosphate additives

Increased fasting serum phosphate within the normal physiological range has been linked to increased cardiovascular risk in prospective epidemiology; increased production of fibroblast growth factor 23, and direct vascular effects of phosphate, may mediate this risk. Although dietary phosphate intake does not clearly influence fasting serum phosphate in individuals with normal renal function, increased phosphate intake can provoke a rise in fibroblast growth factor 23, and in diurnal phosphate levels, and hence may adversely influence vascular health. Dietary phosphate absorption can be moderated by emphasizing plant-based dietary choices (which provide phosphate in less bioavailable forms); avoidance of processed foods containing inorganic phosphate food additives; and by ingestion of phosphate-binder drugs, magnesium supplements, or niacin, which precipitate phosphate or suppress its gastrointestinal absorption. The propensity of dietary phosphate to promote vascular calcification may be opposed by optimal intakes of magnesium, vitamin K, and vitamin D; the latter should also counter the tendency of phosphate to elevate parathyroid hormone.     

Experience with a potent LH-RH agonist, buserelin, alone and in combination with testosterone for antispermatogenic activity, reversibility and toxicity in langur monkey

Chronic intermittent treatment of LH-RH superagonist Buserelin alone or in combination with testosterone enanthate were given to adult male langurs for 90 days to evaluate antispermatogenic activity of alone and combination therapy, maintenance of normal androgenicity, possible toxic effects of agonist treatment, related side effects of testosterone supplementation and complete reversibility of the procedure. A gradual decrease in sperm count was recorded in both treatment groups, along with reduced motility and vitality of the spermatozoa. In the combination group, oligospermia was achieved in 4 out of 5 animals, whereas, only 2 animals became oligospermic in the agonist alone group. Significant decrease in serum testosterone levels along with impaired libido and other testosterone withdrawal symptoms were observed in the Buserelin alone group, conversely normal testosterone levels and libido were observed in the combination group. An elevation in haematological variables and serum total protein concomitant with a slight gain in body weight of the animals were recorded in the combination group; these changes were not encountered in the agonist alone group. Reversibility of all the altered parameters to control range was observed in both treatment groups following 75 to 90 days of treatment withdrawal.     

Copper(II) complexes with substituted thiosemicarbazones of thiophene-2-carboxaldehyde: synthesis, characterization and antiamoebic activity against E. histolytica

In an effort to develop potent antiamoebic agents, a series of thiosemicarbazone (TSC) ligands 1-5 derived from thiophene-2-carboxaldehyde and N4-substituted thiosemicarbazides has been prepared and characterized using various spectroscopic techniques. Treatment of the ligands with cupric chloride produced the copper(II) complexes [Cu(TSC)2Cl2] 1a-5a where ligand bind through thionic sulfur and the azomethine nitrogen. The possible geometries of the complexes were assigned on the basis of magnetic moment, electronic and thermal patterns as well as infrared spectral studies. The thiosemicarbazones and their copper complexes were tested for their in vitro antiamoebic activity against HK-9 strain of Entamoeba histolytica and showed significant growth inhibition. The results revealed that these complexes are effective chemicals in inhibiting amoebal growth, with compound 5 (having -N(CH3)(C6H5) substituent at N4) and complexes 1a-5a being more effective than the commercial antiamoebic drug, metronidazole, based on IC50 values. These data also indicated that the compounds 3a and 5a are most effective among the complexes studied (IC50=0.26 microM of 3a and IC50=0.21 microM of 5a versus IC50=1.81 microM of metronidazole).     

Design, synthesis and biological evaluation of substituted 11H-benzo[a]carbazole-5-carboxamides as novel antitumor agents

A series of novel 11H-benzo[a]carbazole-5-carboxamide derivatives were designed, synthesized and evaluated for their antitumor activity against human cancer A549 and HCT-116 cell lines. Most of the compounds showed potent antitumor activities, and compound 8 displayed remarkable in vitro and in vivo anticancer activity comparable to that of amonafide.     

Synthesis, stereochemistry and biological activity of some novel long alkyl chain substituted thiazolidin-4-ones and thiazan-4-one from 10-undecenoic acid hydrazide

The synthesis of four novel compounds, (i) [(11-{[2-(3-nitrophenyl)-4-oxo-1,3-thiazolidin-3-yl]amino}-11-oxoundecyl)sulfanyl]acetic acid (4), (ii) N-[5-methyl-2-(3-nitrophenyl)-4-oxo-1,3-thiazolidin-3-yl]undec-10-enamide (5), (iii) 2-[(11-{[5-methyl-2-(3-nitrophenyl)-4-oxo-1,3-thiazolidin-3-yl]amino}-11-oxoundecyl)sulfanyl]propanoic acid (6) and (iv) 3-[(11-{[2-(3-nitrophenyl)-4-oxo-1,3-thiazinan-3-yl]amino}-11-oxoundecenyl) sulfanyl]propanoic acid (8) from 10-undecenoic acid hydrazide (1) via m-nitrobenzaldehyde-10-undecenohydrazone (2) using mercaptoacetic acid in (i), 2-mercaptopropionic acid in (ii and iii) and 3-mercaptopropionic acid in (iv) is described. The uncyclized products, ({11-[(2E)-2-(3-nitrobenzylidene)hydrazino]-11-oxo-undecyl}sulfanyl)acetic acid (3) and 3-({11-[(2E)-2-(3-nitrobenzylidene)hydrazino]-11-oxoundecyl}sulfanyl)propanoic acid (7) are also obtained in (i) and (iv), respectively. The hydrazones (2), (3) and (7) exist in two conformers as synperiplanar and antiperiplanar. Structural assignment, stereochemistry and biological assays are discussed.     

Comparison of two physical activity questionnaires, with a diary, for assessing physical activity in an elderly population.

Measurement of physical activity in epidemiological studies is usually achieved by means of a questionnaire. Little work has been done to determine which questionnaire format has greater validity in an elderly population. In this study of elderly subjects, physical activity as reported in two self-administered questionnaires (A and B), which differed in format and length, were compared to activity reported in a 4 day diary. As compared with the diary, moderate/heavy activity was more accurately reported in Questionnaire A (mean difference 5 min), the longer more detailed questionnaire, than B (mean difference 170 min). Light activity was under reported in Questionnaire A (mean difference 68 min) and over reported in B (mean difference 88 min) as compared with the diary. In contrast, time spent sitting was more accurately reported in Questionnaire B (mean difference 40 min) than in A (mean difference 230 min) as compared with the diary. The longer more detailed questionnaire was the more accurate instrument for assessing moderate/heavy activity in this elderly population. The shorter questionnaire was more accurate for assessing time spent sitting.     

Discovery of a new family of bis-8-hydroxyquinoline substituted benzylamines with pro-apoptotic activity in cancer cells: synthesis, structure-activity relationship, and action mechanism studies

Bis-8-hydroxyquinoline substituted benzylamines have been synthesized and screened for their antitumor activity on KB3 cell line model. Synthesis of this series of new analogues was accomplished using a one pot specific methodology which allows the synthesis of both bis- and mono-8-hydroxyquinoline substituted benzylamines. Among the synthesized compounds two compounds (4a and 5a), respectively, named JLK 1472 and JLK 1486, were particularly potent on KB3 cell line. Their CC(50) values being, respectively, 2.6 and 1.3 nM. Screened on a panel of cell lines showing various phenotype alterations, both compounds were found inactive on some cell lines such as PC3 (prostate cell line) and SF268 (neuroblastoma cell line) while highly active on other different cell lines. Mechanistic studies reveal that these two analogues did not affect tubulin and microtubules neither they exert a proteasomal inhibition effect. In contrast 4a and 5a activate specifically caspase 3/7 and not caspase 8 and 9, suggesting that their biological target should be located upstream from caspase 3/7. Moreover their cytotoxic effect is potentiated by the pro-apoptotic effects of TRAIL.     

Novel cephalosporin derivatives possessing a substituted cinnamoyl moiety at the 7 beta-position. Synthesis, structural characterization and antibacterial activity of 3-acetoxymethyl cephalosporin derivatives

Twenty 3-acetoxymethyl cephalosporin derivatives, with various cinnamoyl (3-phenyl-2-propenoyl) substituted groups at the 7beta-position, were synthesized and evaluated for antibacterial activity in vitro. Some of these cephalosporin derivatives showed good selective activity against Gram-positive bacteria. Although substitution on the aromatic ring of cinnamoyl moiety generally reduced antimicrobial activity against Staphylococcus sp. and Enterococcus sp., a hydroxy group at the para position, and particularly ortho, para di-chloro substitution, improved the activity against methicillin resistant strains of Staphylococcus aureus (MRSA). Substitution on the double bond alpha position of the cinnamoyl moiety also affected the antimicrobial activity. A cyano group attached to this position increased activity against both negative coagulase Staphylococcus and Enterococcus sp. and extended the antibacterial spectrum towards Gram-negative bacteria.     

A potent sperm motility-inhibiting activity of bioflavonoids from an ethnomedicine of Onge, Alstonia macrophylla Wall ex A. DC, leaf extract

The methanol extract (ME) and the n-butanol fractions of methanolic extract of Alstonia macrophylla Wall ex A. DC leaves were investigated on the forward motility (FM) of mammalian (goat and human) spermatozoa. The ME at 600 microg mL-1 as well as fraction B at 100 microg mL-1 concentrations showed marked inhibition of sperm FM in both goat and human species when tested by microscopic and spectrophotometric methods. Approximately 60-80% of the goat spermatozoa lost their FM when treated with 600 microg mL-1 of ME and 100 microg mL-1 of fraction B. At 100 microg mL-1 concentration, fraction B showed 90% loss of FM in human spermatozoa, while fraction B at 400 microg mL-1 concentration showed complete inhibition of sperm FM at 0 min. The inhibitory activity of fraction B increases with increasing concentration in a dose-dependent manner. Phytochemical study of the extract revealed that the leaf contains tannins, flavonoids, sterols, triterpenes, alkaloids and reducing sugars. Further fractionation and purification of the bioactive n-butanol part of ME showed the presence of ursolic acid (fraction B), beta-sitosterol (fraction A), beta-sitosterol glucoside and a mixture of minor compounds (fraction C, detected on thin-layer chromatography). The results reveal that fraction B (ursolic acid), a pentacyclic triterpene, has the potential of sperm motility inhibition and can serve as a topical vaginal contraceptive.