Analysis of omarigliptin forced degradation products by ultra-fast liquid chromatography, mass spectrometry, and in vitro toxicity assay.

Omarigliptin (OMG) is an antidiabetic drug indicated for the treatment of type 2 diabetes mellitus. Forced degradation studies are practical experiments to evaluate the stability of drugs and to establish degradation profiles. Herein, we present the investigation of the degradation products (DPs) of OMG formed under various stress conditions. OMG was subjected to hydrolytic (alkaline and acidic), oxidative, thermal, and photolytic forced degradation. A stability-indicating ultra-fast liquid chromatography method was applied to separate and quantify OMG and its DPs. Five DPs were adequately separated and detected in less than 6 min, while other published methods detected four DPs. MS was applied to identify and obtain information on the structural elucidation of the DPs. Three m/z DPs confirmed previously published research, and two novel DPs were described in this paper. The toxicity of OMG and its DPs were investigated for the first time using in vitro cytotoxicity assays, and the sample under oxidative conditions presented significant cytotoxicity. Based on the results from forced degradation studies, OMG was found to be labile to hydrolysis, oxidation, photolytic, and thermal stress conditions. The results of this study contribute to the quality control and stability profile of OMG.

Fezolinetant treatment of moderate-to-severe vasomotor symptoms due to menopause: effect of intrinsic and extrinsic factors in two phase 3 studies (SKYLIGHT 1 and 2).

OBJECTIVE: This study aimed to assess the efficacy of the neurokinin 3 receptor antagonist, fezolinetant, according to several intrinsic (individual related) and extrinsic (external influence) factors that may influence the frequency and severity of moderate-to-severe vasomotor symptoms (VMS) using pooled 12-week data from SKYLIGHT 1 and 2. METHODS: SKYLIGHT 1 and 2 were two phase 3, randomized, double-blind studies conducted from July 2019 to August 2021 (SKYLIGHT 1) or April 2021 (SKYLIGHT 2). Participants were initially randomized to receive daily doses of placebo, fezolinetant 30 mg, or fezolinetant 45 mg. After 12 weeks, placebo participants were rerandomized to receive fezolinetant 30 mg or 45 mg, whereas those receiving fezolinetant continued on the same dose. Change in VMS frequency from baseline to week 12 was used to assess efficacy according to several intrinsic and extrinsic factors. Overall efficacy and safety were also investigated. RESULTS: Overall, 1,022 individuals were included. Fezolinetant was efficacious in reducing VMS frequency across all intrinsic and extrinsic factors. Efficacy was most notable for participants who self-identify as Black (least squares mean difference for fezolinetant 45 mg versus placebo, -3.67; 95% CI, -5.32 to -2.01), current smokers (-3.48; -5.19 to -1.77), and current alcohol users (-3.48; -4.42 to -2.54). Overall efficacy was -2.51 (95% CI, -3.20 to -1.82) for fezolinetant 45 mg versus placebo. Similar findings were observed for the fezolinetant 30 mg dose. Comparable incidences of treatment-emergent adverse events were observed for placebo (132 of 342 individuals [38.6%]), fezolinetant 30 mg (132 of 340 individuals [38.8%]), and fezolinetant 45 mg (135 of 340 individuals [39.7%]). CONCLUSIONS: None of the intrinsic and extrinsic factors analyzed substantially reduced the efficacy response to fezolinetant in SKYLIGHT 1 and 2. These data provide additional confidence for using fezolinetant in a diverse population of individuals with VMS.

Anti-herbivory defences delivered by Epichloë fungal endophytes: a quantitative review of alkaloid concentration variation among hosts and plant parts.

BACKGROUND AND AIMS: In the subfamily Poöideae (Poaceae), certain grass species possess anti-herbivore alkaloids synthesized by fungal endophytes that belong to the genus Epichloë (Clavicipitaceae). The protective role of these symbiotic endophytes can vary, depending on alkaloid concentrations within specific plant-endophyte associations and plant parts. METHODS: We conducted a literature review to identify articles containing alkaloid concentration data for various plant parts in six important pasture species, Lolium arundinaceum, Lolium perenne, Lolium pratense, Lolium multiflorum|Lolium rigidum and Festuca rubra, associated with their common endophytes. We considered the alkaloids lolines (1-aminopyrrolizidines), peramine (pyrrolopyrazines), ergovaline (ergot alkaloids) and lolitrem B (indole-diterpenes). While all these alkaloids have shown bioactivity against insect herbivores, ergovaline and lolitrem B are harmful for mammals. KEY RESULTS: Loline alkaloid levels were higher in the perennial grasses L. pratense and L. arundinaceum compared to the annual species L. multiflorum and L. rigidum, and higher in reproductive tissues than in vegetative structures. This is probably due to the greater biomass accumulation in perennial species that can result in higher endophyte mycelial biomass. Peramine concentrations were higher in L. perenne than in L. arundinaceum and not affected by plant part. This can be attributed to the high within-plant mobility of peramine. Ergovaline and lolitrem B, both hydrophobic compounds, were associated with plant parts where fungal mycelium is usually present, and their concentrations were higher in plant reproductive tissues. Only loline alkaloid data were sufficient for below-ground tissue analyses and concentrations were lower than in above-ground parts. CONCLUSIONS: Our study provides a comprehensive synthesis of fungal alkaloid variation across host grasses and plant parts, essential for understanding the endophyte-conferred defence extent. The patterns can be understood by considering endophyte growth within the plant and alkaloid mobility. Our study identifies research gaps, including the limited documentation of alkaloid presence in roots and the need to investigate the influence of different environmental conditions.

Vericiguat in patients with coronary artery disease and heart failure with reduced ejection fraction.

AIMS: Coronary artery disease (CAD) portends worse outcomes in heart failure (HF). We aimed to characterize patients with CAD and worsening HF with reduced ejection fraction (HFrEF) and evaluate post hoc whether vericiguat treatment effect varied according to CAD. METHODS AND RESULTS: Cox proportional hazards were generated for the primary endpoint of cardiovascular death or HF hospitalization (CVD/HFH). CAD was defined as previous myocardial infarction, percutaneous coronary intervention, or coronary artery bypass grafting. Of 5048 patients in VICTORIA with available data on CAD status, 2704 had CAD and were older, were more frequently male, diabetic, and had a lower glomerular filtration rate than those without CAD (all p <0.0001). Use of implantable cardioverter defibrillators and cardiac resynchronization therapy (CRT) was higher in patients with versus without CAD (33.5% vs. 21.1%; p <0.0001 and 16.3% vs. 12.8%; p = 0.0006). The primary endpoint of CVD/HFH was higher in those with versus without CAD (40.6 vs. 30.1/100 patient-years; adjusted hazard ratio [HR] 1.23; p <0.001) as was all-cause mortality (17.9% vs. 12.7%; adjusted HR 1.32; p <0.001). The primary outcome of CVD/HFH associated with vericiguat in patients with or without CAD was 38.8 versus 27.6 per 100 patient-years and for placebo was 42.6 versus 32.7 per 100 patient-years (interaction p = 0.78). CONCLUSION: In this post hoc study, CAD was associated with more CVD and HFH in patients with HFrEF and worsening HF. Vericiguat was beneficial and safe regardless of concomitant CAD.

Supramolecular co-encapsulation of a photosensitizer and chemotherapeutic drug in cucurbit[8]uril for potential chemophototherapy.

Supramolecular strategies as well as combinatorial approaches have been proposed to improve cancer therapeutics. In this work, we investigated the encapsulation of the photosensitizer acridine orange (AO) and the chemotherapeutic drug oxaliplatin (OxPt) in cucurbit[8]uril (CB[8]), and tested their effect both separate and combined on tumoral cells cultivated in vitro. Binding constants and enthalpies of reaction for the AO@CB[8], (AO)2@CB[8] and OxPt@CB[8] complexes were determined by isothermal titration calorimetry. In the case of AO, a negative cooperativity for the binding of the second AO molecule was found, in agreement with previous fluorescence titration data. We show herein that the AO@CB[8] complex was effectively incorporated within the cells and showed important phototoxicity, while the OxPt@CB[8] complex was cytotoxic only at long incubation times (24 h). Pre-treatment of the cells with the OxPt@CB[8] complex for 24 h inhibited any photodynamic action by the later treatment with the AO@CB[8] complex. However, when both complexes were co-incubated for 90 min, the combined cytotoxicity/phototoxicity was superior to any of the treatments individually. A cooperative effect was identified that added up to an extra 30% cytotoxicity/phototoxicity. The results point to an interesting system where a photosensitizer and chemotherapeutic drug are co-encapsulated in a macrocycle to develop chemophototherapy applications.

Downregulation of Inflammatory Cytokine Release from IL-1ß and LPS-Stimulated PBMC Orchestrated by ST2825, a MyD88 Dimerisation Inhibitor.

The inflammatory process implicates homeostasis disruption and increased production of inflammatory mediators. Myeloid differentiation primary response 88 (MyD88) is an essential protein recruited after lipopolysaccharide (LPS) and interleukin (IL)-1ß stimulation, a process that converges in nuclear factor kappa B (NF-κB) activation, as well as a transcription of several genes of both pro- and anti-inflammatory cytokines. The inhibition of MyD88 has shown efficacy by decrease inflammatory response, and has demonstrated potential application as a therapeutic target in chronic diseases. In this study, we investigate the effect of MyD88 dimerisation inhibitor ST2825 on cytokine production from rhIL-1ß and LPS-stimulated peripheral blood mononuclear cells (PBMC) from healthy blood donors (HBD). ST2825 significantly downregulates the production of IFN-γ, IL-6, IL-12, IL-2, IL-15, IL-7, VEGF, IL-1Ra, IL-4, IL-5, IL-13 and IL-9 (p < 0.05) in LPS-stimulated PBMC. Moreover, ST2825 had a relatively low impact on IL-1ß signalling pathway inhibition, showing that only a few specific cytokines, such as IFN-γ and IL-1Ra, are inhibited in rhIL-1ß-stimulated PBMC (p < 0.01). In conclusion, MyD88 dimerisation inhibitor ST2825 showed high efficacy by inhibiting pro- and anti-inflammatory cytokine production in LPS-stimulated PBMC. Moreover, although rhIL-1ß induced a sustained cytokine production (p < 0.05), ST2825 did not show a significant effect in the secretion of neither pro- nor anti-inflammatory cytokines in rhIL-1ß-stimulated PBMC.

Effect of the neurokinin 3 receptor antagonist fezolinetant on patient-reported outcomes in postmenopausal women with vasomotor symptoms: results of a randomized, placebo-controlled, double-blind, dose-ranging study (VESTA).

OBJECTIVE: In the primary analysis of the phase 2b VESTA study, oral fezolinetant reduced frequency and severity of menopausal vasomotor symptoms (VMS) compared with placebo. This secondary analysis evaluates effects of fezolinetant on responder rates and patient-reported outcomes (PROs). METHODS: In this 12-week, double-blind study, postmenopausal women with moderate/severe VMS were randomized to fezolinetant 15, 30, 60, or 90 mg BID or 30, 60, or 120 mg QD or placebo. Proportion of responders was based on reductions in VMS from daily diary records. P values for comparisons between active treatment and placebo were calculated using logistic regression. Changes from baseline in PROs (Menopause-Specific Quality of Life questionnaire, Hot Flash-Related Daily Interference Scale, Greene Climacteric Scale) were conducted using a mixed model for repeated measurements and compared post hoc with published minimally important differences (MIDs). RESULTS: Of 356 women randomized, 352 were treated and analyzed. A greater proportion of women receiving fezolinetant versus placebo met definitions of response at week 12. For all doses, mean changes from baseline in Menopause-Specific Quality of Life questionnaire VMS scores exceeded the MID (1.2) at weeks 4 (placebo: -1.8; fezolinetant: range, -1.9 to -3.6) and 12 (placebo: -2.3; fezolinetant: range, -2.9 to -4.4). Mean changes in Hot Flash-Related Daily Interference Scale at weeks 4 (placebo: -2.2; fezolinetant: range, -2.5 to -3.8) and 12 (placebo: -2.9; fezolinetant: range, -3.3 to -4.3) exceeded the MID (1.76). Greene Climacteric Scale-VMS domain scores improved for most fezolinetant doses versus placebo (week 4, placebo: -1.7; fezolinetant: range, -2.1 to -3.3; week 12, placebo: -2.1; fezolinetant: range, -2.7 to -3.6). CONCLUSIONS: Oral fezolinetant was associated with higher responder rates than placebo and larger improvements in QoL and other PRO measures, including a reduction in VMS-related interference with daily life.

Evaluation of 1,3-benzoxathiol-2-one Derivatives as Potential Antifungal Agents.

BACKGROUND: Over the last few years, fungal infections have emerged as a worrisome global public health problem. Candidiasis is a disease caused by Candida species and has been a problem worldwide mainly for immunosuppressed patients. Lately, the resistant strains and side effects have been reported as important issues for treating Candidiasis, which have to be solved by identifying new drugs. OBJECTIVE: The goal of this work was to synthesize a series of 1,3-benzoxathiol-2-one derivatives, XYbenzo[ d][1,3]oxathiol-2-ones, and evaluate their antifungal activity against five Candida species. METHODS: In vitro antifungal screening test and minimum inhibitory concentration determination were performed according to CLSI protocols using ketoconazole as the reference drug. The cytotoxicity of the most active compounds was evaluated by hemolysis and MTT (Vero cells) assays. RESULTS: Compounds 2 (XY = 6-hydroxy-5-nitro, MIC = 4-32 µg/mL) and 7 (XY = 6-acetoxy-5-nitro, MIC =16-64 µg/mL) showed good results when compared with current antifungals in CLSI values (MIC = 0.04-250 µg/mL). These compounds exhibited a safer cytotoxicity as well as a lower hemolytic profile than ketoconazole. CONCLUSION: Overall, the in vitro results pointed to the potential of compounds 2 and 7 as new antifungal prototypes to be further explored.

An Endocannabinoid Uptake Inhibitor from Black Pepper Exerts Pronounced Anti-Inflammatory Effects in Mice.

Guineensine is a dietary N-isobutylamide widely present in black and long pepper (Piper nigrum and Piper longum) previously shown to inhibit cellular endocannabinoid uptake. Given the role of endocannabinoids in inflammation and pain reduction, here we evaluated guineensine in mouse models of acute and inflammatory pain and endotoxemia. Significant dose-dependent anti-inflammatory effects (95.6 ± 3.1% inhibition of inflammatory pain at 2.5 mg/kg ip and 50.0 ± 15.9% inhibition of edema formation at 5 mg/kg ip) and acute analgesia (66.1 ± 28.1% inhibition at 5.0 mg/kg ip) were observed. Moreover, guineensine inhibited proinflammatory cytokine production in endotoxemia. Intriguingly, guineensine and LPS independently induced catalepsy, but in combination this effect was abolished. Both hypothermia and analgesia were blocked by the CB1 receptor inverse agonist rimonabant, but the pronounced hypolocomotion was CB1 receptor-independent. A subsequent screen of 45 CNS-related receptors, ion channels, and transporters revealed apparent interactions of guineensine with the dopamine transporter DAT, 5HT2A, and sigma receptors, uncovering its prospective polypharmacology. The described potent pharmacological effects of guineensine might relate to the reported anti-inflammatory effects of pepper.

A randomised, double-blind, trial of the safety and efficacy of omarigliptin (a once-weekly DPP-4 inhibitor) in subjects with type 2 diabetes and renal impairment.

AIMS: To assess the safety and efficacy of omarigliptin in subjects with type 2 diabetes mellitus (T2DM) and chronic renal impairment (RI). METHODS: Patients with T2DM with moderate RI (estimated glomerular filtration rate [eGFR] ≥30 to <60 mL/min/1.73 m2 ) (N=114), severe RI (eGFR <30 mL/min/1.73 m2 ) (N=55) or end-stage renal disease on dialysis (N=44), who were either not on an antihyperglycaemic agent therapy for at least 12 weeks at screening, washed-off of oral antihyperglycaemic agent monotherapy or low-dose dual combination therapy, or on insulin monotherapy, with baseline glycated haemoglobin (HbA1c) of 6.5%-10.0% were randomised to omarigliptin or to placebo for 24 weeks (primary end-point) followed by a 30-week period with subjects on placebo switched to blinded glipizide (if not on insulin). RESULTS: After 24 weeks, from a mean baseline HbA1c of 8.4% in the omarigliptin group and 8.3% in the placebo group, the least squares mean (95% CI) change from baseline in HbA1c in the overall population (all renal strata combined) was -0.77% (-1.00 to -0.54) in the omarigliptin group and -0.44% (-0.67 to -0.21) in the placebo group; between-group difference of -0.33% (-0.63 to -0.02); P=0.035. After 24 weeks, the incidences of subjects with symptomatic hypoglycaemia, one or more adverse event (AE), drug-related AE, serious AE and discontinuation due to an AE were similar in the omarigliptin and placebo groups. CONCLUSIONS: In this study in subjects with T2DM and RI, relative to placebo, omarigliptin provided clinically meaningful reductions in HbA1c, had a similar incidence of symptomatic hypoglycaemia and was generally well tolerated.

Effect of ST2825 on the proliferation and apoptosis of human hepatocellular carcinoma cells.

The purpose of this study was to investigate the effect of ST2825, an inhibitor of myeloid differentiation factor 88 (MyD88), on the proliferation and apoptosis of human hepatocellular carcinoma (HCC) cells as well as the potential mechanism and clinical significance of ST2825 in the treatment of HCC. Immunohistochemical staining with an MyD88 antibody was performed on tissues from 80 human HCC patients and adjacent normal tissues. In the in vitro experiment, human HCC HepG-2 cells cultured in vitro were divided into the following groups: blank, control (1% DMSO), low-dose (2 µM), medium-dose (10 µM), and high-dose ST2825 (20 µM). Cell apoptosis was detected by the Annexin V-FITC assay, and HepG-2 cell proliferation was detected by the MTT assay. The expression of IκB, p65, cyclin D1, caspase-3, and bcl-2 in the cells after a 48-h treatment was assayed by western blot analysis. MyD88 expression in the HCC tissue was significantly higher than that in the adjacent normal tissue (P < 0.05). The proliferation and apoptosis rates of control HCC cells displayed no significant differences compared with those of the blank group (P > 0.05). Compared with the control, ST2825 significantly inhibited the proliferation of and promoted the apoptosis of HCC cells. Moreover, ST2825 significantly decreased bcl-2 expression, increased cleaved caspase-3 expression (P < 0.05), and reduced p65 nuclear expression (P < 0.05) in a dose-dependent manner. ST2825 inhibits the proliferation of and promotes the apoptosis of HCC cells, thereby suggesting that ST2825 may be a new drug for HCC treatment.

Antipodal crambescin A2 homologues from the marine sponge Pseudaxinella reticulata. Antifungal structure-activity relationships.

Investigation of antifungal natural products from the marine sponge Pseudaxinella reticulata from the Bahamas led to the discovery of new crambescin homologues (1, 2) and enantiomers (3, 4) of known natural products. The cyclic-guanidine structures were solved through analysis of 2D NMR, MS-MS, and CD data. The absolute configurations of 1-4 were established as 13R-opposite of known homologues reported from Crambe crambe obtained from the Mediterranean Sea-by comparison of their CD spectra with predicted Cotton effects obtained from DFT calculations. Antifungal activities of 1-4 against the pathogenic strains Candida albicans and Cryptococcus sp. were observed to correlate potency (MIC50 and MIC90) with the length of the alkyl side chain.

Therapeutic switching: from antidermatophytic essential oils to new leishmanicidal products.

This study examined whether the antidermatophytic activity of essential oils (EOs) can be used as an indicator for the discovery of active natural products against Leishmania amazonensis. The aerial parts of seven plants were hydrodistilled. Using broth microdilution techniques, the obtained EOs were tested against three strains of dermatophytes (Trichophyton mentagrophytes, Microsporum gypseum and Microsporum canis). To compare the EOs antifungal and antiparasitic effects, the EOs activities against axenic amastigotes of L. amazonensis were concurrently evaluated. For the most promising EOs, their antileishmanial activities against parasites infecting peritoneal macrophages of BALB/c mice were measured. The most interesting antifungal candidates were the EOs from Cymbopogon citratus, Otacanthus azureus and Protium heptaphyllum, whereas O. azureus, Piper hispidum and P. heptaphyllum EOs exhibited the lowest 50% inhibitory concentration (IC50) values against axenic amastigotes, thus revealing a certain correspondence between both activities. The P. hispidum EO was identified as the most promising product in the results from the infected macrophages model (IC50: 4.7 µg/mL, safety index: 8). The most abundant compounds found in this EO were sesquiterpenes, notably curzerene and furanodiene. Eventually, the evaluation of the antidermatophytic activity of EOs appears to be an efficient method for identifying new potential drugs for the treatment of L. amazonensis.

AZD6280, a novel partial γ-aminobutyric acid A receptor modulator, demonstrates a pharmacodynamically selective effect profile in healthy male volunteers.

OBJECTIVE: AZD6280 is a novel γ-aminobutyric acid A receptor modulator with higher in vitro efficacy at the α2,3 subtypes as compared to the α1 and α5 subtypes. This study compared the pharmacodynamic effects of single oral dose AZD6280 10 mg and 40 mg on the central nervous system with 2 mg of lorazepam. METHODS: Sixteen healthy males were enrolled into the double-blind, randomized, 4-way crossover study. Two validated central nervous system test batteries, Neurocart and CogState, were administered to measure drug effects on cognition, neurophysiologic function, and psychomotor and subjective feelings. Statistical analysis was performed using mixed model analysis of variance, with fixed factors of treatment, period, time and treatment by time, and random factors of subject, subject by treatment and subject by time, and the average prevalue as covariate. RESULTS: Most pharmacodynamic parameters were affected by lorazepam. AZD6280 induced dose-dependent smaller-than-lorazepam effects on saccadic peak velocity (SPV) (AZD6280, 10 mg vs. AZD6280, 40 mg vs. lorazepam [deg/s]: -22.6 vs. -50.0 vs. -62.9, P < 0.001), whereas the impacts on adaptive-tracking, body-sway, smooth-pursuit, and the one-card-learning tests were significant but much smaller than lorazepam. Thus, the slopes of regression lines for the ΔLog(Sway)-ΔSPV, ΔTracking-ΔSPV, and ΔSmooth-ΔSPV relations were flatter with AZD6280 than with lorazepam. AZD6280 caused a distinct electroencephalography signature from that of lorazepam. CONCLUSIONS: The SPV responses to AZD6280 suggest potential concentration-related anxiolytic effects, whereas the smaller SPV-normalized effects of AZD6280 on various non-SPV pharmacodynamic parameters suggest a more favorable side effect profile compared to lorazepam. Overall, the pharmacodynamic profile of AZD6280 matches the pharmacological specificity and selectivity of this compound at the α2,3 γ-aminobutyric acid A receptor subtypes.

Development of (E)-2-((1,4-dimethylpiperazin-2-ylidene)amino)-5-nitro-N-phenylbenzamide, ML336: Novel 2-amidinophenylbenzamides as potent inhibitors of venezuelan equine encephalitis virus.

Venezuelan equine encephalitis virus (VEEV) is an emerging pathogenic alphavirus that can cause significant disease in humans. Given the absence of therapeutic options available and the significance of VEEV as a weaponized agent, an optimization effort was initiated around a quinazolinone screening hit 1 with promising cellular antiviral activity (EC50 = 0.8 µM), limited cytotoxic liability (CC50 > 50 µM), and modest in vitro efficacy in reducing viral progeny (63-fold at 5 µM). Scaffold optimization revealed a novel rearrangement affording amidines, specifically compound 45, which was found to potently inhibit several VEEV strains in the low nanomolar range without cytotoxicity (EC50 = 0.02-0.04 µM, CC50 > 50 µM) while limiting in vitro viral replication (EC90 = 0.17 µM). Brain exposure was observed in mice with 45. Significant protection was observed in VEEV-infected mice at 5 mg kg(-1) day(-1) and viral replication appeared to be inhibited through interference of viral nonstructural proteins.

Synthesis, antifungal and antitumor activity of novel (Z)-5-hetarylmethylidene-1,3-thiazol-4-ones and (z)-5-ethylidene-1,3-thiazol-4-ones.

New hetaryl- and alkylidenerhodanine derivatives 3a-d, 3e, and 4a-d were prepared from heterocyclic aldehydes 1a-d or acetaldehyde 1e. The treatment of several rhodanine derivatives 3a-d and 3e with piperidine or morpholine in THF under reflux, afforded (Z)-5-(hetarylmethylidene)-2-(piperidin-1-yl)thiazol-4(5H)-ones and 2-morpholinothiazol-4(5H)-ones 5a-d, 6a-d, and (Z)-5-ethylidene-2-morpholinothiazol-4(5H)-one (5e), respectively, in good yields. Structures of all compounds were determined by IR, 1D and 2D NMR and mass spectrometry. Several of these compounds were screened by the U.S. National Cancer Institute (NCI) to assess their antitumor activity against 60 different human tumor cell lines. Compound 3c showed high activity against HOP-92 (Non-Small Cell Lung Cancer), which was the most sensitive cell line, with GI50 = 0.62 µM and LC50 > 100 µM from the in vitro assays. In vitro antifungal activity of these compounds was also determined against 10 fungal strains. Compound 3e showed activity against all fungal strains tested, but showed high activity against Saccharomyces cerevisiae (MIC 3.9 µg/mL).

A fragment-based approach for ligand binding affinity and selectivity for the liver X receptor beta.

Selective modulation of liver X receptor beta (LXRß) has been recognized as an important approach to prevent or reverse the atherosclerotic process. In the present work, we have developed robust conformation-independent fragment-based quantitative structure-activity and structure-selectivity relationship models for a series of quinolines and cinnolines as potent modulators of the two LXR subtypes. The generated models were then used to predict the potency of an external test set and the predicted values were in good agreement with the experimental results, indicating the potential of the models for untested compounds. The final 2D molecular recognition patterns obtained were integrated to 3D structure-based molecular modeling studies to provide useful insights into the chemical and structural determinants for increased LXRß binding affinity and selectivity.

Bioactive Cycloperoxides Isolated from the Puerto Rican Sponge Plakortis halichondrioides.

Two new five-membered-ring polyketide endoperoxides, epiplakinic acid F methyl ester (1) and epiplakinidioic acid (3), and a peroxide-lactone, plakortolide J (2), were isolated from the Puerto Rican sponge Plakortis halichondrioides, along with two previously reported cyclic peroxides, 4 and 5. The structures of the new metabolites were determined by spectroscopic and chemical analyses. The absolute stereostructures of 1, 2, and 5 were determined by degradation reactions followed by application of Kishi's method for the assignment of absolute configuration of alcohols. Biological screening of cycloperoxides 1-5 and semisynthetic analogues 7-12 for cytotoxic activity against various human tumor cell lines revealed that compounds 3, 4, and 11 are very active. Upon assaying for antimalarial and antitubercular activity, some of the compounds tested showed strong activity against the pathogenic microbes Plasmodium falciparum and Mycobacterium tuberculosis.