Lead selection of antiparasitic compounds from a focused library of benzenesulfonyl derivatives of heterocycles.

A library of 89 synthetic benzenesulfonyl derivatives of heterocycles with drug-like properties was assayed for in vitro antiparasitic activity and the results were added to our previously reported derivatives for a comprehensive SAR evaluation. Four compounds showed an IC50 between 0.25 and 3µM against Leishmania donovani and low cytotoxicity. Compound G{16} (1-(2,3,5,6-tetramethylphenylsulfonyl)-2-methylindoline), was particularly interesting with an IC50 similar to the reference drug miltefosine. Seven compounds showed an IC50 below 6µM against Trypanosoma cruzi, and three of them (E{3}, E{9} and G{3}) were identified as lead scaffolds for further optimization based on their activity-toxicity profile. Two promising structures (B{15} and G{15}) showed moderate inhibitory activity against Plasmodium falciparum. In general, the presence of a benzenesulfonyl moiety improves the antiparasitic activity of the heterocycles included in this study (with the exception of Trypanosoma brucei rhodesiense), validating the criteria used in the selection of the privileged structures and diversification used to generate this library. SAR analysis showed that the presence of lipophilic and electron withdrawing groups were favorable for the antiparasitic activity.

Indole and Indoline Scaffolds in Antimicrobials: Overview, Synthesis and Recent Advances in Antimicrobial Research.

At present, a pandemic of antibiotic-resistant infectious diseases is an evergrowing threat. The need for new antibiotics and ways to combat antibiotic resistance is glaring. This review will focus on two different privileged scaffolds, the indole and the indoline, as useful nuclei for novel antibacterial compounds. The indole, a moiety found in numerous approved drugs for many disease states, has recently been studied for its usefulness as a scaffold for compounds that have activity against antibiotic-resistant bacteria, especially against methicillin-resistant Staphylococcus aureus (MRSA). The indoline is a scaffold with significantly less historical studies and FDA-approved drugs and it has attracted new interest in drug design and development. In recent years, indoline-containing compounds have been shown to have antibacterial activity as well as activity as a resistance- modifying agent (RMA), which act to improve the effectiveness of current antibiotic therapies that have known resistance.

A unique binding epitope for salvinorin A, a non-nitrogenous kappa opioid receptor agonist.

Salvinorin A is a potent kappa opioid receptor (KOP) agonist with unique structural and pharmacological properties. This non-nitrogenous ligand lacks nearly all the structural features commonly associated with opioid ligand binding and selectivity. This study explores the structural basis to salvinorin A binding and selectivity using a combination of chimeric and single-point mutant opioid receptors. The experiments were designed based on previous models of salvinorin A that locate the ligand within a pocket formed by transmembrane (TM) II, VI, and VII. More traditional sites of opioid recognition were also explored, including the highly conserved aspartate in TM III (D138) and the KOP selectivity site E297, to determine the role, if any, that these residues play in binding and selectivity. The results indicate that salvinorin A recognizes a cluster of residues in TM II and VII, including Q115, Y119, Y312, Y313, and Y320. Based on the position of these residues within the receptor, and prior study on salvinorin A, a model is proposed that aligns the ligand vertically, between TM II and VII. In this orientation, the ligand spans residues that are spaced one to two turns down the face of the helices within the receptor cavity. The ligand is also in close proximity to EL-2 which, based on chimeric data, is proposed to play an indirect role in salvinorin A binding and selectivity.

Antinociceptive profile of salvinorin A, a structurally unique kappa opioid receptor agonist.

Salvinorin A, is a structurally unique, non-nitrogenous, kappa opioid receptor (KOP) agonist. Given the role of KOPs in analgesic processes, we set out to determine whether salvinorin A has antinociceptive activity in thermal and chemo-nociceptive assays. The tail-flick assay was employed to investigate 1) salvinorin A's (0.5, 1.0, 2.0, and 4.0 mg/kg) dose-response and time-course (10, 20, and 30 min) effects in a thermal nociceptive assay, and 2) the ability for the KOP antagonist norBNI (10.0 mg/kg) to prevent salvinorin A antinociception. The hotplate assay was utilized as a second thermal nociceptive measure to test salvinorin A's dose-response effects. The acetic acid abdominal constriction assay was used to study salvinorin A's dose-response and time-course (over 30 min) effects in a chemo-nociceptive assay. Together, these studies revealed that salvinorin A produces a dose-dependent antinociception that peaked at 10 min post-injection but rapidly returned to baseline. Additionally, pretreatment with the KOP antagonist norbinaltorphimine (norBNI) reversed salvinorin A-induced antinociception. These findings demonstrate that salvinorin A produces a KOP mediated antinociceptive effect with a short duration of action.

Survey of Pharmacy Schools' Approaches and Attitudes toward Curricular Integration.

Objective. To identify ways in which curricular integration is addressed in US pharmacy schools, the structure of therapeutics and foundational science courses, and perceptions of the effects current curricular integration methods have on student learning. Methods. An electronic survey was sent to academic leaders representing 131 pharmacy schools in the United States. Frequency data was tabulated and demographic analysis was performed. Results. Respondent data represents 94 schools of pharmacy. Arranging similar content from various disciplines in a course, a skills laboratory and pharmacy practice experiences were the most common methods for achieving curricular integration. More than one half of the schools indicated that foundational sciences were integrated with therapeutics. The most common reported challenge to curricular integration was logistics. Conclusion. Pharmacy education in the United States has evolved in addressing curricular integration in the curricula, which is consistent with changes in accreditation standards. Most pharmacy schools reported a variety of methods for achieving the intent of curricular integration.

Synthesis and complement inhibitory activity of B/C/D-ring analogues of the fungal metabolite 6,7-diformyl-3',4',4a',5',6',7',8',8a'-octahydro-4,6',7'-trihydroxy- 2',5',5',8a'-tetramethylspiro[1'(2'H)-naphthalene-2(3H)-benzofuran].

This paper reports the synthesis and the bioassay of 4-methoxy- and 4-hydroxyspiro[benzofuran-2(3H)-cyclohexane] partial analogues (5) of the complement inhibitory sesquiterpene fungal metabolite 6,7-diformyl-3',4',4a',5',6',7',8',8a'-octahydro-4,6',7'-trihydroxy-2',5',5',8a'-tetramethylspiro[1'(2'H)-naphthalene-2(3H)-benzofuran] (1a, K-76) and its silver oxide oxidized product (1b, K-76COOH). The described target compounds represent spirobenzofuran B/C/D-ring analogues lacking the A-ring component of the prototype structure. The target compounds were evaluated by the inhibition of total hemolytic complement activity in human serum. It was observed that the structurally simplified analogue 4-methoxyspiro[benzofuran-2(3H)-cyclohexane]-6-carboxylic acid (5a) exhibited an IC(50) = 0.53 mM similar to the IC(50) = 0.57 mM that was observed for the natural product derivative 1b. Exhibiting an IC(50) = 0.16 mM, the three-ringed partial structure 6-carboxy-7-formyl-4-methoxyspiro[benzofuran-2(3H)-cyclohexane] (5k)was found to be the most potent target compound. Like the natural product, 5k appears to inhibit primarily at the C5 activation step and inhibits both the classical and alternative human complement pathways. Several other analogues inhibited complement activation in vitro at concentrations similar to those required for inhibition by the natural product 1b.

SAR analysis of new dual targeting fluoroquinolones. Implications of the benzenesulfonyl group.

When a benzenesulfonyl moiety (BS) was bound to the N-piperazinyl ring of antibacterial fluoroquinolones (AMFQs) norfloxacin (NOR) or ciprofloxacin (CIP), the resulting benzenesulfonyl-fluoroquinolone (BSFQs) analogs showed an improved in vitro activity against Gram-positive strains. A bioisosterical replacement of the sulfonyl group for a carbonyl group led to the benzenecarboxamide-fluoroquinolones (BCFQs) that showed a similar trend in the antibacterial activity and spectrum. The BSFQs and BCFQs are considered members of the "dual targeting" fluoroquinolones, targeting both DNA gyrase and topoisomerase IV. To disclose the real contribution of the BS/BC moiety in anti-staphylococcal activity, a 3D-QSAR analysis that included calculation of theoretical molecular descriptors and pharmacophore generation was performed. Previous and present QSAR results have confirmed the positive influence on activity of small electron donating p-substituent on the BS or BC moiety. The generated phamacophore model showed that both phenyl and SO2/CO groups are involved in the interaction with receptor. We postulate that the enhanced potency of BSFQs against Staphylococcus aureus compared to CIP and NOR could be caused by the presence of the BS moiety that resulted in enhanced binding to DNA gyrase of Sa. Additionally, their greater ability to enter bacterial cells by diffusion and a reduced susceptibility to FQ-specific efflux pumps could also make a contribution.

Solution-phase parallel synthesis of spirohydantoins.

Spirohydantoins are considered privileged structures, making them attractive for the preparation of compound libraries with the potential for diverse biological activity. However, very few modifications of this scaffold have been reported to date. The spirohydantoin template was elaborated into a library of 168 compounds through a two-step solution-phase parallel synthesis starting from various N-substituted piperidinones. The Strecker reaction was employed to generate alpha-amino nitriles from aniline and TMSCN (or KCN). Subsequent reaction of the anilido nitrogen with a diverse set of isocyanates, followed by refluxing under acidic conditions, afforded the title library in high yield and purity.