Sensitive and effective method with 96-well plate for determination of levamlodipine in human plasma using LC-MS/MS.

we developed an effective protein precipitation method for determination of levamlodipine in human plasma using LC-MS/MS. Sample extraction was carried out by using liquid-liquid extraction in 96-well plate format. (S)-Amlodipine-d4 was used as internal standard (IS). The chromatographic separation was achieved using Philomen Chiral MX (2) column (3 µm, 2.1 × 100 mm). Mobile phase A was comprised of Acetonitrile (ACN), Mono ethanol amine (MEA) and Iso-Propyl alcohol (IPA) (1000:1:10, v/v/v), Mobile phase B was IPA-ACN (2:1, v/v). The flow rate was 0.4 mL/min. The total run time of each sample was 4.0 min with gradient elution. LC-MS/MS spectra were generated in positive ion mode, and multiple reaction monitoring (MRM) was used to detect the following transitions: m/z 409.20 â†’ 238.15 for levamlodipine and 415.25 â†’ 240.20 for (S)-Amlodipine-d4 (the IS). The method was linear from 50 to 10000 pg/mL（R2＝0.9988489）,and the lower limit of quantification (LLOQ) was 50 pg/mL. This method was applied to a bioequivalence study of levamlodipine.

Curcumin nicotinate increases LDL cholesterol uptake in hepatocytes through IDOL/LDL-R pathway regulation.

BACKGROUND: Curcumin nicotinate (Curtn), derived from curcumin and niacin, reduces serum LDL-C levels, partly due to its influence on PCSK9. This study investigates IDOL's role in Curtn's lipid-lowering effects. OBJECTIVE: To elucidate Curtn's regulation of the IDOL/LDLR pathway and potential molecular mechanisms in hepatocytes. METHODS: Differential metabolites in Curtn-treated HepG2 cells were identified via LC-MS. Molecular docking assessed Curtn's affinity with IDOL. Cholesterol content and LDLR expression effects were studied in high-fat diet Wistar rats. In vitro evaluations determined Curtn's influence on IDOL overexpression's LDL-C uptake and LDLR expression in hepatocytes. RESULTS: Lipids were the main differential metabolites in Curtn-treated HepG2 cells. Docking showed Curtn's higher affinity to IDOL's FERM domain compared to curcumin, suggesting potential competitive inhibition of IDOL's binding to LDLR. Curtn decreased liver cholesterol in Wistar rats and elevated LDLR expression. During in vitro experiments, Curtn significantly enhanced the effects of IDOL overexpression in HepG2 cells, leading to increased LDL-C uptake and elevated expression of LDL receptors. CONCLUSION: Curtn modulates the IDOL/LDLR pathway, enhancing LDL cholesterol uptake in hepatocytes. Combined with its PCSK9 influence, Curtn emerges as a potential hyperlipidemia therapy.

Curcumin nicotinate decreases serum LDL cholesterol through LDL receptor-mediated mechanism.

Curcumin nicotinate (Curtn) is a synthesized ester derivative of curcumin and niacin. Our previous study has shown that Curtn lowers serum low-density lipoprotein cholesterol (LDL-C) levels in apoE-/- mice and promotes LDL-C uptake into HepG2 cells in vitro. The present study was to test the hypothesis that Curtn decreases serum LDL-C levels through decreased expression of pro-protein convertase subtilisin/kexin type 9 (PCSK9) and subsequent increase in LDL receptor expression. Male Wistar rats on high-fat diet (HFD) were treated with Curtn or rosuvastatin. Curtn or rosuvastatin treatment significantly decreased serum levels of total cholesterol (TC) and LDL-C in rats on HFD with increased liver LDL receptor expression. LDL-C-lowering effect of Curtn was not observed in LDL receptor deficient (LDLR-/-) mice on HFD, while rosuvastatin still decreased serum lipid levels in LDLR-/- mice, indicating that the reduction of serum LDL-C levels by Curtn treatment was LDL receptor-dependent. Curtn treatment also significantly decreased the protein expression of PCSK9 in Wistar rats and LDLR-/- mice. In HepG2 cells with overexpression of human PCSK9, Curtn treatment significantly increased LDL-C uptakes into hepatocytes, and increased LDL receptor distribution on cell surface in association with decreased PCSK9 protein expression. RNAi-LDLR significantly attenuated the effect of Curtn on LDLR distribution on cell surface. These data indicates that Curtn would decrease serum LDL-C level at least partially through inhibition of PCSK9 expression, and subsequent increase in LDL receptor expression and distribution in hepatocytes, serving as a potential novel compound to treat hyperlipidemia.

Cumulative potential and half-life of [imazapic + imazapyr] in lowland soils of Rio Grande Do Sul grown with clearfield® rice.

The objectives of this study were to estimate the residual and half-life of [imazapic + imazapyr] and to infer on the impact of these residuals over time. The first experiment comprised the application of [imazapic + imazapyr] to Clearfield® rice. On the following summer cropping season (365 days later), undeformed soil samples 0-5 cm depth were collected and seeds of six species or varieties were sown as bioindicators of residuals (experiment 2), being assessed plant height and dry mass 20 days after emergence start. The third experiment comprised the cultivation of the same species submitted to ten increasing herbicide doses (0-280 g ha-1) to establish standard response curves, also assessing plant height and dry mass 20 days after emergence start. About 2.1-5.8% of the applied imazapic remains in soil after one year, for the label doses. Imazapyr was considered to be at negligible doses as its half-life is short, and less than 0.0000001% of the applied dose is expected to be in soil 365 days later. The expected imazapic half-life in lowland areas of Southern Brazil is longer than for dryland, being estimated as between 63 and 77 days (95% confidence interval), contrasting to the 60 days half-life previously estimated for dryland soils.

Total Synthesis of Euonymine and Euonyminol Octaacetate.

Euonymine (1) and euonyminol octaacetate (2) share the core structure of euonyminol (3), the most hydroxylated member of the dihydro-ß-agarofuran family. In 2, eight of the nine hydroxy groups of 3 are acetylated, and 1 has six acetyl groups and a 14-membered bislactone comprising a pyridine dicarboxylic acid with two methyl groups. The different acylation patterns provide distinct biological activities: 1 and 2 display anti-HIV and P-glycoprotein inhibitory effects, respectively. The 11 contiguous stereocenters and 9 oxygen functionalities of the ABC-ring system of 1 and 2 represent a formidable challenge, which is further heightened by the macrocyclic structure of 1. Here we disclose an efficient synthetic strategy for enantioselective total synthesis of 1 and 2. Starting from (R)-glycerol acetonide, we constructed the B-ring by an Et3N-accelerated Diels-Alder reaction, the C-ring by intramolecular iodoetherification, and the A-ring by ring-closing olefin metathesis. The 10 stereocenters were installed through a series of substrate-controlled stereoselective C-C and C-O bond formations by exploiting the three-dimensional structures of judiciously designed substrates. These newly developed reaction sequences led to protected euonyminol 5, which served as a common intermediate for assembling 1 and 2. Global deprotection of 5 and subsequent acetylation produced 2. Alternatively, the discriminative protective groups of 5 allowed for site-selective bis-esterification to generate bislactone. Combining [3 + 2]-cycloaddition and reductive desulfurization introduced the last remaining stereocenters of the two methyl groups on the macrocycle. Finally, deprotection and acetylation gave rise to fully synthetic 1 for the first time.

Mapping vitamin B6 metabolism by hydrazoCEST magnetic resonance imaging.

A new CEST-MRI contrast agent, 2-HYNIC, capable of sensing aromatic aldehydes is reported. Pyridoxal 5'-phosphate, a key Vitamin B6 metabolite necessary for >140 biotransformations was mapped by CEST-MRI in vitro and in vivo in lung cancer. 2-HYNIC provided access to this key biomarker associated with a variety of human diseases.

JM-20 treatment prevents neuronal damage and memory impairment induced by aluminum chloride in rats.

The number of people with dementia worldwide is estimated at 50 million by 2018 and continues to rise mainly due to increasing aging and population growth. Clinical impact of current interventions remains modest and all efforts aimed at the identification of new therapeutic approaches are therefore critical. Previously, we showed that JM-20, a dihydropyridine-benzodiazepine hybrid molecule, protected memory processes against scopolamine-induced cholinergic dysfunction. In order to gain further insight into the therapeutic potential of JM-20 on cognitive decline and Alzheimer's disease (AD) pathology, here we evaluated its neuroprotective effects after chronic aluminum chloride (AlCl3) administration to rats and assessed possible alterations in several types of episodic memory and associated pathological mechanisms. Oral administration of aluminum to rodents recapitulates several neuropathological alterations and cognitive impairment, being considered a convenient tool for testing the efficacy of new therapies for dementia. We used behavioral tasks to test spatial, emotional- associative and novel object recognition memory, as well as molecular, enzymatic and histological assays to evaluate selected biochemical parameters. Our study revealed that JM-20 prevented memory decline alongside the inhibition of AlCl3 -induced oxidative stress, increased AChE activity, TNF-α and pro-apoptotic proteins (like Bax, caspase-3, and 8) levels. JM-20 also protected against neuronal damage in the hippocampus and prefrontal cortex. Our findings expanded our understanding of the ability of JM-20 to preserve memory in rats under neurotoxic conditions and confirm its potential capacity to counteract cognitive impairment and etiological factors of AD by breaking the progression of key steps associated with neurodegeneration.

JM-20 Treatment After Mild Traumatic Brain Injury Reduces Glial Cell Pro-inflammatory Signaling and Behavioral and Cognitive Deficits by Increasing Neurotrophin Expression.

Traumatic brain injury (TBI) is considered a public health problem and is often related to motor and cognitive disabilities, besides behavioral and emotional changes that may remain for the rest of the subject's life. Resident astrocytes and microglia are the first cell types to start the inflammatory cascades following TBI. It is widely known that continuous or excessive neuroinflammation may trigger many neuropathologies. Despite the large numbers of TBI cases, there is no effective pharmacological treatment available. This study aimed to investigate the effects of the new hybrid molecule 3-ethoxycarbonyl-2-methyl-4-(2-nitrophenyl)-4,11-dihydro1H-pyrido[2,3-b][1,5]benzodiazepine (JM-20) on TBI outcomes. Male Wistar rats were submitted to a weight drop model of mild TBI and treated with a single dose of JM-20 (8 mg/kg). Twenty-four hours after TBI, JM-20-treated animals showed improvements on locomotor and exploratory activities, and short-term memory deficits induced by TBI improved as well. Brain edema was present in TBI animals and the JM-20 treatment was able to prevent this change. JM-20 was also able to attenuate neuroinflammation cascades by preventing glial cells-microglia and astrocytes-from exacerbated activation, consequently reducing pro-inflammatory cytokine levels (TNF-α and IL-1ß). BDNF mRNA level was decreased 24 h after TBI because of neuroinflammation cascades; however, JM-20 restored the levels. JM-20 also increased GDNF and NGF levels. These results support the JM-20 neuroprotective role to treat mild TBI by reducing the initial damage and limiting long-term secondary degeneration after TBI.

Exposure impacts of Imazapyr formulation on larval development and thyroid histology of Xenopus laevis.

There are increased concerns about the thyroidal effects of many anthropogenic substances in the environment. These substances include agricultural pesticides and industrial and pharmaceutical chemicals among others. Their potential thyroidal effects are of serious health and ecological concerns, as thyroid hormones mediate numerous physiological processes, including growth regulation, general metabolism and metamorphosis in metamorphic animals. This study assessed thyroidal activities of Arsenal formulation (Imazapyr) at environmentally relevant concentrations of 0.5, 2.0 and 3.5 mg/L following a Xenopus metamorphosis assay (XEMA). The result shows that the Arsenal formulation significantly delayed the tadpole development, reduced the hind-limb length (HLL) and increased the whole-body mass (WBM) at a concentration of 3.5 mg/L relative to the control exposure. In histopathology, the formulation increased the epithelium height, at all exposure concentrations, but reduced the colloidal area at 0.5 and 2 mg/L, respectively, and the gland area at 2 mg/L relative to the control. Consequently, the Arsenal formulation is thyroid-active at environmentally relevant concentrations and poses a threat to both human and wildlife, especially metamorphic organisms. With this exposure impact, more studies are imperative to further characterise other endocrine-disrupting potential of this formulation, while future applications should be reduced or restricted to less risk environment, if it cannot be stopped from sensitive aquatic systems.

Nicotinate-curcumin inhibits AngII-induced vascular smooth muscle cell phenotype switching by upregulating Daxx expression.

Phenotypic switching is the main cause of the abnormal proliferation and migration of vascular smooth muscle cells (VSMCs). We previously showed that Daxx exerted negative regulatory effect on AngII-induced VSMC proliferation and migration. However, the function of Daxx in VSMC phenotype switching remained unknown. Nicotinate-curcumin (NC) is an esterification derivative of niacin and curcumin that can prevent the formation of atherosclerosis. We found that NC significantly decreased AngII-induced VSMC phenotype switching. Furthermore, NC significantly inhibited AngII-induced cell proliferation and migration. Moreover, NC upregulated Daxx expression and regulated the PTEN/Akt signaling pathway. We concluded that NC inhibited AngII-induced VSMC phenotype switching by regulating the PTEN/Akt pathway, and through a mechanism that might be associated with the upregulation of Daxx expression.

Pterostilbene and its nicotinate derivative ameliorated vascular endothelial senescence and elicited endothelium-dependent relaxations via activation of sirtuin 1.

Vascular endothelial cell senescence is a leading cause of age-associated diseases and cardiovascular diseases. Interventions and therapies targeting endothelial cell senescence and dysfunction would have important clinical implications. This study evaluated the effect of 10 resveratrol analogues, including pterostilbene (Pts) and its derivatives, against endothelial senescence and dysfunction. All the tested compounds at the concentrations from 10-9 M to 10-6 M did not show cytotoxicity in endothelial cells by MTT assay. Among the 10 resveratrol analogues, Pts and Pts nicotinate attenuated the expression of senescence-associated ß-galactosidase, downregulated p21 and p53, and increased the production of nitric oxide (NO) in both angiotensin II - and hydrogen peroxide - induced endothelial senescence models. In addition, Pts and Pts nicotinate elicited endothelium-dependent relaxations, which were attenuated in the presence of endothelial NO synthase (eNOS) inhibitor L-NAME or sirtuin 1 (SIRT1) inhibitor sirtinol. Pts and Pts nicotinate did not alter SIRT1 expression but enhanced its activity. Both Pts and Pts nicotinate have high binding activities with SIRT1, according to surface plasmon resonance results and the molecular docking analysis. Inhibition of SIRT1 by sirtinol reversed the anti-senescent effects of Pts and Pts nicotinate. Moreover, Pts and Pts nicotinate shared similar ADME (absorption, distribution, metabolism, excretion) profiles and physiochemical properties. This study suggests that the Pts and Pts nicotinate ameliorate vascular endothelial senescence and elicit endothelium-dependent relaxations via activation of SIRT1. These two compounds may be potential drugs for the treatment of cardiovascular diseases related to endothelial senescence and dysfunction.

Improved effect of a mitochondria-targeted antioxidant on hydrogen peroxide-induced oxidative stress in human retinal pigment epithelium cells.

BACKGROUND: Oxidative damage to retinal pigment epithelial (RPE) cells contributes to the development of age-related macular degeneration, which is among the leading causes of visual loss in elderly people. In the present study, we evaluated the protective role of triphenylphosphonium (TPP)-Niacin against hydrogen peroxide (H2O2)-induced oxidative stress in RPE cells. METHODS: The cellular viability, lactate dehydrogenase release, reactive oxygen species (ROS) generation, and mitochondrial function of retinal ARPE-19 cells were determined under treatment with H2O2 or pre-treatment with TPP-Niacin. The expression level of mitochondrial related genes and some transcription factors were assessed using real-time polymerase chain reaction (RT-qPCR). RESULTS: TPP-Niacin significantly improved cell viability, reduced ROS generation, and increased the antioxidant enzymes in H2O2-treated ARPE-19 cells. Mitochondrial dysfunction from the H2O2-induced oxidative stress was also considerably diminished by TPP-Niacin treatment, along with reduction of the mitochondrial membrane potential (MMP) and upregulation of the mitochondrial-associated gene. In addition, TPP-Niacin markedly enhanced the expression of transcription factors (PGC-1α and NRF2) and antioxidant-associated genes (especially HO-1 and NQO-1). CONCLUSION: We verified the protective effect of TPP-Niacin against H2O2-induced oxidative stress in RPE cells. TPP-Niacin is believed to protect against mitochondrial dysfunction by upregulating antioxidant-related genes, such as PGC-1α, NRF2, HO-1, and NQO-1, in RPE cells.

Lethal and Teratogenic Impacts of Imazapyr, Diquat Dibromide, and Glufosinate Ammonium Herbicide Formulations Using Frog Embryo Teratogenesis Assay-Xenopus (FETAX).

Globally, amphibians are experiencing widespread abnormalities and population declines. One potential contributor to these challenges is the use of pesticides, particularly aquatic herbicides applied to aquatic habitats inhabited by amphibians. Critical issues of concern are the potential toxicity and teratogenicity of these herbicides towards amphibians. Using the FETAX protocol, three globally used formulations, including diquat dibromide (Midstream), glufosinate ammonium (Basta), and imazapyr (Arsenal), were assessed for embryotoxicity, teratogenicity, and growth inhibition. Developing Xenopus laevis embryos were exposed for 96 h at concentrations of 0.5-3.0 mg/L, 1.6-3.0 mg/L, and 20-45 mg/L for Midstream, Basta, and Arsenal respectively. The 96-h LC50 estimates were 0.83 mg/L acid equivalent (a.e.), 36 mg/L a.e., and 2.2 mg/L a.e., whereas the EC50 estimates were 0.24 mg/L a.e., 28.13 mg/L a.e., and 2.01 mg/L a.e. for the Midstream, Arsenal, and Basta formulations, respectively. These two estimates produced Teratogenic Index of 3.5, 1.3, and 1.1 for Midstream, Arsenal, and Basta, respectively, indicating a high risk of malformation induction by Midstream and moderate risk for Arsenal. Regarding growth inhibition, lowest observable effect concentrations of 0.5 mg/L, 25 mg/L, and 2.0 mg/L were computed for Midstream, Arsenal, and Basta, respectively, producing the minimum concentration inhibiting growth (MCIG) ratios of 0.62, 0.69, and 0.89 for the three formulations. These MICG values are higher than the standard 0.30 growth inhibitors benchmark, suggesting that the formulations are not growth inhibitors at the evaluated concentrations. This study provides evidence of the embryotoxic and teratogenic status of Midstream and the embryotoxicity of Basta. There is a need to further characterise the physiological and ecological impacts of these formulations to ensure responsible use and the safety of amphibians and other wildlife.

Development of selective preconcentration/clean-up method for imidazolinone herbicides determination in natural water and rice samples by HPLC-PAD using an imazethapyr imprinted poly(vinylimidazole-TRIM).

The development of a novel molecularly imprinted solid-phase extraction (MISPE) method for simultaneous preconcentration of imazapyr (IMP), imazapic (IMZ) and imazethapyr (IMT) with determination by HPLC-PAD (High performance liquid chromatography - photodiode-array detector) is proposed. The polymer synthesis was performed using imazethapyr as template molecule and 1-vinylimidazole as functional monomer. The method is based on preconcentration of 100.0 mL of sample through 200.0 mg of molecularly imprinted poly(vinylimidazole-TRIM) (MIP-1VN) at pH 4.0, followed by elution with 2.0 mL of MeOH:CH2Cl2:HAc (34:62:4, v/v). The range of analytical curve (0.29-200.0, 0.21-200.0 and 0.15-200.0 µg L-1), limits of detection (0.09, 0.06 and 0.04 µg L-1) and preconcentration factors (92, 96 and 98) determined for the herbicides, IMP, IMZ and IMT, respectively, were greatly superior when compared with those ones obtained with commercial adsorbents. The analytical method was successfully applied to spiked surface water and rice samples with good results of recovery values (86-107%).

Effectiveness of Levoamlodipine Maleate for Hypertension Compared with Amlodipine Besylate: a Pragmatic Comparative Effectiveness Study.

PURPOSE: Antihypertensive treatment is the most important method to reduce the risk of cardiovascular events in hypertensive patients. However, there is scant evidence of the benefits of levoamlodipine maleate for antihypertensive treatment using a head-to-head comparison in the real-world. This study aims to examine the effectiveness of levoamlodipine maleate used to treat outpatients with primary hypertension compared with amlodipine besylate in a real-world setting. METHODS: This was a pragmatic comparative effectiveness study carried out at 110 centers across China in outpatients with primary hypertension treated with levoamlodipine maleate or amlodipine besylate, with 24 months of follow-up. The primary outcomes used for evaluating the effectiveness were composite major cardiovascular and cerebrovascular events (MACCE), adverse reactions, and cost-effectiveness. RESULTS: Among the included 10,031 patients, there were 482 MACCE, 223 (4.4%) in the levoamlodipine maleate group (n = 5018) and 259 (5.2%) in the amlodipine besylate group (n = 5013) (adjusted hazard ratio = 0.90, 95%CI: 0.75-1.08, P = 0.252). The levoamlodipine maleate group had lower overall incidences of any adverse reactions (6.0% vs. 8.4%, P < 0.001), lower extremity edema (1.1% vs. 3.0%, P < 0.001) and headache (0.7% vs. 1.1%, P = 0.045). There was a nearly 100% chance of the levoamlodipine maleate being cost-effective at a willingness to pay threshold of 150,000 Yuan per quality-adjusted life years (QALYs) gained, resulting in more QALYs (incremental QALYs: 0.00392) and cost savings (saving 2725 Yuan or 28.8% reduction in overall costs) per patient. CONCLUSION: In conclusion, levoamlodipine maleate could reduce cost by 29% with a similar MACCE incidence rate and lower occurrence of adverse reactions (especially edema and headache) compared with amlodipine besylate. TRIAL REGISTRATION: Clinicaltrials.gov NCT01844570 registered at May 1, 2013.

Investigation of the binding properties between levamlodipine and HSA based on MCR-ALS and computer modeling.

Levamlodipine (LEE) is a drug commonly used for antihypertensive treatment in clinical therapy. The overlapping fluorescence spectra of LEE and human serum albumin (HSA) cause some trouble in analysis of interactions between them by using the classic fluorescence method. Here, the multivariate curve resolution-alternating least squares (MCR-ALS) approach was used to overcome this disadvantage. Meanwhile, the binding properties of LEE-HSA complex were then explored through computer modeling. The MCR-ALS results suggested that LEE-HSA complex was present in the mixture solution of LEE and HSA. This conclusion was then confirmed by the Stern-Volmer equation and time-resolved fluorescence experiment. The binding constant (Ka) was 2.139 × 104 L·mol-1 at 298 K. LEE was located close to the Trp-214 residue of HSA, with van der Waals forces and hydrogen bonding as main driving forces for this interaction. LEE can alter the conformation of HSA, in which the content of α-helix reduced from 57.2% to 52.3%. The Pi-Alkyl interactions contributed to maintaining the stability of the LEE-HSA complex. The results of molecular dynamics simulations showed that LEE-HSA complex was formed within 5 ns, and the particle size (Rg) of HSA was altered by the binding reaction. This study would promote better understanding of the transportation and distribution mechanisms of LEE in the human body.

JM-20 protects against 6-hydroxydopamine-induced neurotoxicity in models of Parkinson's disease: Mitochondrial protection and antioxidant properties.

We have previously shown that JM-20, a new chemical entity consisting of 1,5-benzodiazepine fused to a dihydropyridine moiety, protects against rotenone-induced neurotoxicity in an experimental model of Parkinson's disease (PD). The aim of this study was to investigate the effect of a novel hybrid molecule, named JM-20, in in vitro and in vivo models of PD induced by 6-hydroxydopamine (6-OHDA). PC-12 cells were exposed to 6-OHDA and treated with JM-20. Protection against mitochondrial damage induced by 6-OHDA was also investigated using isolated rat brain mitochondria. We found that JM-20 protected PC-12 cells against cytotoxicity induced by 6-OHDA and inhibited hydrogen peroxide generation, mitochondrial swelling and membrane potential dissipation. For in vivo experiments, adult male Wistar rats were lesioned in the substantia nigra pars compacta (SNpc) by 6-OHDA administration. JM-20 was orally administered (10, 20 or 40 mg/kg), intragastric via gavage, 24 h after surgery and daily for seven days. Treatment with JM-20 significantly reduced the percentage of motor asymmetry and increased vertical exploration. It improved the redox state of the SNpc and the striatal tissue of these animals. Also, JM-20 reduced glial fibrillary acidic protein overexpression and increased tyrosine hydroxylase-positive cell number, both in SNpc. Altogether, these results demonstrate that JM-20 is a potential neuroprotective agent against 6-OHDA-induced damage in both in vitro and in vivo models. The mechanism underlying JM-20 neuroprotection against 6-OHDA appears to be associated with the control of oxidative injury and mitochondrial impairment.

Nature-inspired remodeling of (aza)indoles to meta-aminoaryl nicotinates for late-stage conjugation of vitamin B3 to (hetero)arylamines.

Despite the availability of numerous routes to substituted nicotinates based on the Bohlmann-Rahtz pyridine synthesis, the existing methods have several limitations, such as the inevitable ortho-substitutions and the inability to conjugate vitamin B3 to other pharmaceutical agents. Inspired by the biosynthesis of nicotinic acid (a form of vitamin B3) from tryptophan, we herein report the development of a strategy for the synthesis of meta-aminoaryl nicotinates from 3-formyl(aza)indoles. Our strategy is mechanistically different from the reported routes and involves the transformation of (aza)indole scaffolds into substituted meta-aminobiaryl scaffolds via Aldol-type addition and intramolecular cyclization followed by C-N bond cleavage and re-aromatization. Unlike previous synthetic routes, this biomimetic method utilizes propiolates as enamine precursors and thus allows access to ortho-unsubstituted nicotinates. In addition, the synthetic feasibility toward the halo-/boronic ester-substituted aminobiaryls clearly differentiates the present strategy from other cross-coupling strategies. Most importantly, our method enables the late-stage conjugation of bioactive (hetero)arylamines with nicotinates and nicotinamides and allows access to the previously unexplored chemical space for biomedical research.

Bioequivalence of levamlodipine besylate tablets in healthy Chinese subjects: a single-dose and two-period crossover randomized study.

BACKGROUND: Levamlodipine, a calcium channel blocker, has been show act as a cardiovascular drug. To compare the pharmacokinetic parameters between levamlodipine (test formulation) at a single dose of 5 mg and amlodipine (reference formulation) at a single dose of 10 mg, the bioequivalence study was carried out. METHODS: A single-dose randomized, open-label, two-period crossover study was designed in healthy Chinese subjects. 48 subjects were divided into fasted and fed groups equally. The subjects randomly received the test or reference formulations at the rate of 1:1. Following a 21-day washout period, the alternative formulations were received. The blood samples were collected at 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 24, 36, 48, 72, 96, 120, 144, 168 h later. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was applied to determine the plasma concentrations of levamlodipine. Adverse events were recorded. RESULTS: The 90% confidence intervals (CIs) of the ratio of geometric means (GMRs) of Cmax, AUC0-t, and AUC0-∞ under both fasted and fed conditions were within the prespecified bioequivalence limits between 80 ~ 125%. Under fasted conditions, 24 subjects were enrolled and completed the study. The mean Cmax was (2.70 ± 0.49) ng/mL, AUC0-t was (141.32 ± 36.24) ng × h/mL and AUC0-∞ was (157.14 ± 45.65) ng × h/mL after a single dose of 5 mg levamlodipine. The mean Cmax was (2.83 ± 0.52) ng/mL, AUC0-t was (153.62 ± 33.96) ng × h/mL and AUC0-∞ was (173.05 ± 41.78) ng × h/mL after a single dose of 10 mg amlodipine. Under fed conditions, 24 subjects were enrolled and completed the study. The mean Cmax was (2.73 ± 0.55) ng/mL, AUC0-t was (166.93 ± 49.96) ng × h/mL and AUC0-∞ was (190.99 ± 70.89) ng × h/mL after a single dose of 5 mg levamlodipine. The mean Cmax was (2.87 ± 0.81) ng/mL AUC0-t was (165.46 ± 43.58) ng × h/mL and AUC0-∞ was (189.51 ± 64.70) ng × h/mL after a single dose of 10 mg amlodipine. Serious adverse event was not observed. CONCLUSION: The trial confirmed that levamlodipine at a single dose of 5 mg and amlodipine at a single dose of 10 mg were bioequivalent under both fasted condition and fed condition. TRIAL REGISTRATION: Cinicaltrials, NCT04411875 . Registered 3 June 2020 - Retrospectively registered.

Anti-hypernociceptive and anti-inflammatory effects of JM-20: A novel hybrid neuroprotective compound.

The present study examines the possible effect of the novel hybrid molecule JM-20 (3-ethoxycarbonyl-2-methyl-4-(2-nitrophenyl)-411-dihydro-1H-pyrido[2,3-b] [1,5] benzodiazepine) on pain-related behaviours in a persistent pain model (5% formalin test) and in the neutrophil migration events during the inflammatory process. It further introduces JM-20 in a chronic constriction injury (CCI) model to clarify the possible subjacent mechanisms with its consequent clinical relevance. A single administration of JM-20 (20 or 40 mg/kg, per os [p.o.]) decreased licking/biting exclusively in the tonic phase of the formalin test in a GABA/benzodiazepine (BZD) receptor antagonist flumazenil-sensitive manner. JM-20 reduced in vivo neutrophil migration, rolling and adhesion to the endothelium induced by intraperitoneal administration of carrageenan in mice. In addition, plasma extravasation and tumour necrosis factor alpha production in the peritoneal fluid were decreased. Treatment with JM-20 (20 mg/kg, p.o.) for 7 days after CCI reduced mechanical hypersensitivity in a NG-monomethyl-l-arginine (L-NMMA)/methylene blue/glibenclamide-sensitive manner. Histopathological signs of Wallerian degeneration (WD) of the sciatic nerve were also attenuated, as well as interleukin-1 beta release in the spinal cord. The nitrate/nitrite concentration was increased centrally and did not show differences at the peripheral nerve level. The findings of this study suggest JM-20 can decrease persistent pain. A transient activity of its BDZ portion on nociceptive pathways mediated by GABA/BDZ receptors in association with its anti-inflammatory properties could be at least partially involved in this effect. JM-20 decreased CCI-induced mechanical hypersensitivity via the l-arginine/nitric oxide (NO)/cyclic GMP-sensitive ATP-sensitive potassium channel pathway. Its neuroprotective ability by preventing WD could be implicated in its anti-neuropathic mechanisms.