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New psychoactive substance (NPS) opioids have proliferated within the international drug market. While synthetic opioids are traditionally composed of fentanyl analogues, benzimidazole-derived isotonitazene and its derivatives are the current NPS opioids of concern. Hence, in this study, we implement immunopharmacotherapy wherein antibodies are produced with high titers and nanomolar affinity to multiple benzimidazole-derived NPS opioids (BNO). Notably, these antibodies blunt psychoactive and physiological repercussions from BNO exposure, which was observed through antinociception, whole-body plethysmography, and blood-brain biodistribution studies. Moreover, we detail previously unreported pharmacokinetics of these drugs, which explains the struggle of traditional pharmaceutical opioid antagonists against BNO substances. These findings provide further insight into the

Unintentional overdose deaths related to opioids and psychostimulants have increased in prevalence due to the adulteration of these drugs with fentanyl. Synergistic effects between illicit compounds and fentanyl cause aggravated respiratory depression, leading to inadvertent fatalities. Traditional small-molecule therapies implemented in the expanding opioid epidemic present numerous problems since they interact with the same opioid receptors in the brain as the abused drugs. In this study, we report an optimized dual hapten for use as an immunopharmacotherapeutic tool in order to develop antibodies capable of binding to fentanyl-contaminated heroin in the periphery, thus impeding the drugs’ psychoactive effects on the central nervous system. This vaccine produced antibodies with nanomolar affinities and effectively blocked opioid analgesic effects elicited by adulterated heroin. These findings provide further insight into the development of chemically contiguous haptens for broad-spectrum immunopharmacotherapies against opioid use disorders.

NF00659B1 is a novel α-pyrone diterpenoid natural product with potent anti-colon cancer activity. A stereoselective approach to the 2,2-dimethyl oxepanol core of NF00659B1 is described enlisting a sequence of olefinic ester ring-closing metathesis, epoxidation, and Grignard addition. This strategy paves the way to a total synthesis of NF00659B1 for further biological studies.

Autoimmune diseases are chronic inflammatory diseases associated with high morbidity and mortality. Treatment options for autoimmune diseases have increased over the past several decades, but they are, in general, limited in their clinical efficacy due to high toxicity and lack of selectivity. Thus, efforts must be made to identify new immunomodulatory agents that are effective through a novel mechanism to circumvent existing side effects. To define the structural requirements of subglutinols for immunomodulatory activity and to provide guiding principles on future therapeutic development, we prepared and evaluated several subglutinol analogs for their immunomodulatory activities. Our efforts identified a subglutinol analog with reduced structural complexity as a potential lead compound for future autoimmune drug development. Our study will provide an important framework for the design of potent and nontoxic immunomodulating agents derived from subglutinols.

Rhodojaponin III is a grayanane-type diterpenoid natural product with a novel chemical scaffold. It shows potent antinociceptive activity and may represent a new class of natural non-opioid analgesics with a novel mode of action. We explored the Au(I)-catalyzed Conia-ene cyclization and the Mn(III)-mediated radical cyclization of alkynyl ketones for the synthesis of the bicyclo[3.2.1]octane fragment of rhodojaponin III. These strategies will be applicable in the synthesis of rhodojaponin III and analogs for future biological studies.

5-HT7 receptor (5-HT7R) agonists and antagonists have been reported to be used for treatment of neuropathic pain and depression, respectively. In this study, as a novel scaffold for 5-HT7R modulators, we designed and prepared a series of biphenyl-3-yl-methanamine derivatives with various amino groups. Evaluation of functional activities as well as binding affinities of the title compounds identified partial agonists (EC50 = 0.55–3.2 μM) and full antagonists (IC50 = 5.57–23.1 μM) depending on the amino substituents. Molecular docking study suggested that the ligand-based switch in functional activity from agonist to antagonist results from the size of the amino groups and thereby different binding modes to 5-HT7R. In particular, interaction of the ligand with Arg367 of 5-HT7R is shown to differentiate agonists and antagonists. In the pharmacophore model study, two distinct pharmacophore models can tell whether a ligand is an agonist or an antagonist. Taken together, this study provides valuable information for designing novel compounds with selective agonistic or antagonistic properties against 5-HT7R.

To cope with hypoxia, tumor cells have developed a number of adaptive mechanisms mediated by hypoxia-inducible factor 1 (HIF-1) to promote angiogenesis and cell survival. Due to significant roles of HIF-1 in the initiation, progression, metastasis, and resistance to treatment of most solid tumors, a considerable amount of effort has been made to identify HIF-1 inhibitors for treatment of cancer. Isolated from Saururus cernuus, manassantins A (1) and B (2) are potent inhibitors of HIF-1 activity. To define the structural requirements of manassantins for HIF-1 inhibition, we prepared and evaluated a series of manassantin analogues. Our SAR studies examined key regions of manassantin’s structure in order to understand the impact of these regions on biological activity and to define modifications that can lead to improved performance and drug-like properties. Our efforts identified several manassantin analogues with reduced structural complexity as potential lead compounds for further development. Analogues MA04, MA07, and MA11 down-regulated hypoxia-induced expression of the HIF-1α protein and reduced the levels of HIF-1 target genes, including cyclin-dependent kinase 6 (Cdk6) and vascular endothelial growth factor (VEGF). These findings provide an important framework to design potent and selective HIF-1α inhibitors, which is necessary to aid translation of manassantin-derived natural products to the clinic as novel therapeutics for cancers.

Structure–activity relationship (SAR) calculations were used to find monoamine oxidase-B (MAO-B) inhibitors by identifying pharmacophores exhibiting high inhibitory activities. Several such chromenylchalcones were designed and synthesized accordingly. Their inhibitory effects on MAO-B were determined using an HPLC-based method and an MAO-B enzyme assay kit. (E)-3-(6-Methoxy-2H-chromen-3-yl)-1-(2-methoxyphenyl)prop-2-en-1-one exhibited a half-maximal inhibitory concentration of 320 nM. Its molecular-level binding mode with the three-dimensional structure of MAO-B was elucidated using an in silico docking study. The chromenylchalcone scaffold, which is derived from natural products including isoflavonoids and chalcones, had not been previously reported as an MAO-B inhibitor.

In this study, as a bioisosteric alternative scaffold of the antiviral aryl diketoacids (ADKs), we used 5-hydroxychromone on which two arylmethyloxy substituents were installed. The 5-hydroxychromones (5b–5g) thus prepared showed anti-HCV activity and, depending on the aromatic substituents on the 2-arylmethyloxy moiety, some of the derivatives (5b–5f) were also active against SCV. In addition, unlike the ADKs which showed selective inhibition against the helicase activity of the SCV NTPase/helicase, the 5-hydroxychromones (5b–5f) were active against both NTPase and helicase activities of the target enzyme. Among those, 3-iodobenzyloxy-substituted derivative 5e showed the most potent activity against HCV (EC50 = 4 μM) as well as SCV (IC50 = 4 μM for ATPase activity, 11 μM for helicase activity) and this might be used as a platform structure for future development of the multi-target or broad-spectrum antivirals., Graphical abstract The 2,6-bis-arylmethyloxy-5-hydroxychromones were identified to have antiviral activity against both hepatitis C virus (HCV) and SARS-associated coronavirus (SCV). Highlights ► Investigation of bioisosteric alternative scaffold of antiviral arylmethyloxy-ADKs. ► 2,6-Bis-arylmethyloxy-5-hydroxychromones active against both HCV and SCV. ► Antiviral activity against HCV (EC50 = 4 μM). ► Inhibition of SCV NTPase (IC50 = 4 μM) as well as ATPase activity (IC50 = 11 μM). ► Potential platform structure for multi-target or broad-spectrum antivirals.

Anti-HCV activity of aryl diketoacid (ADK) has been characterized by its two pharmacophoric elements, α,β-diketo acid moiety and substituted aryl ring. In this study, as a part of our ongoing efforts to discover a novel anti-HCV compound mimicking the ADK scaffold, we designed 2-arylmethylaminomethyl-5,6-dihydroxychromone derivatives of which the dihydroxychromone moiety as well as the arylmethylaminomethyl substituent (R-PhCH 2 NHCH 2 –) were anticipated in exact match with the pharmacophore model of the ADK. The dihydroxychromone derivatives ( 3a – 3u ), thus prepared, showed biological activity in a substituent-dependent fashion, thereby leading to selective anti-HCV effect (EC 50 = 2.0–14.0 μM, CC 50 >100 μM) with the substituent groups such as Cl, Br, I, and Me specifically at the 3-position of the aromatic ring.

In order to increase stability of quercetin, its metabolically and chemically susceptible hydroxyl groups 7-OH and 3-OH respectively were transiently blocked with a pivaloxymethyl (POM) promoiety to provide two novel quercetin conjugates [7-O-POM-Q (2), 3-O-POM-Q (3)]. In the absence of stabilizer (ascorbic acid), the synthesized conjugates showed significantly increased stability in cell culture media [t1/2 = 4 h (2), 52 h (3)] compared with quercetin (t1/2 < 30 min) and quercetin prodrug 1 (t1/2 = 0.8 h). In addition, the quercetin conjugate 2 underwent efficient cellular uptake and intracellular levels of its hydrolysis product, quercetin, were maintained up to 12 h. Stability and intracellular accumulation of 2 were demonstrated by its stabilizer-independent cytostatic effect and induction of apoptotic cell death. Even though 3 was more stable than 2, it failed to penetrate cell membranes. However, the remarkable stability of 3 warrants further investigation of quercetin conjugates with various promoi...

The prevalence of metabolic syndrome associated with increased risk for cardiovascular disease, type 2 diabetes, or cancer has been increasing over the past decade. While traditional drug discovery efforts have been tackling these diseases by aiming at individual targets, recent studies in humans have suggested the possibility that the collection of the metabolic degenerative processes can be approached as a whole by controlling diet, especially calorie restriction. Studies of calorie restriction in a broad range of animals including primates, mice, worms, and yeast have suggested that a reduction in calorie intake lengthens lifespan and protects against cancer and other age-related diseases. There has therefore been much interest in developing pharmacological agents that mimic the effects of calorie restriction. Resveratrol, a natural product derived from grapes, is the first reported mimetic of calorie restriction. Ever since the mode of action of resveratrol was elucidated to activate SIRT1 [sirtuin (silent mating type information regulation 2 homolog) 1] which, in turn, deacetylates p53 and promotes cell survival in a NAD-dependent manner, numerous efforts have been devoted to discover novel activators of SIRT1. Through high throughput screening of a large selection of small molecules, Milne et al. identified three imidazothiazole derivatives as potent SIRT1 activators, which are structurally unrelated to but 1,000-fold more active than resveratrol. Recently, in order to improve the potency as well as the solubility of the imidazothiazole derivatives, two different libraries of analogues, imidazo[1,2-b]thiazole and oxazolo[4,5-b]pyridine, were constructed and extensively investigated. The aim of the present study is to derive a predictive method for designing novel potent SIRT1 activators through construction of 3D QSAR models. For this purpose, from the literature, SIRT1 activation data of 33 imidazothiazole and oxazolopyridine derivatives were obtained (Fig. 1). At first, the 33 compounds were divided into two groups: 27 compounds as a training set and the other 6 compounds as a test set. The CoMFA (comparative molecular force analysis) and CoMSIA (comparative molecular similarity indices analysis) methods were employed for deriving 3D-QSAR models consisting for a training set of 27 imidazothiazole and oxazolopyridine derivatives, keeping in vitro activity as a dependent variable. The 3D-QSAR models were then validated using a test set of 6 compounds, which were not included in the development of the models. Finally, the contour plots of the 3D-QSAR model were analyzed to

In Parkinson's disease, the motor impairments are mainly caused by the death of dopaminergic neurons. Among the enzymes which are involved in the biosynthesis and catabolism of dopamine, monoamine oxidase B (MAO-B) has been a therapeutic target of Parkinson's disease. However, due to the undesirable adverse effects, development of alternative MAO-B inhibitors with greater optimal therapeutic potential towards Parkinson's disease is urgently required. In this study, we designed and synthesized the oxazolopyridine and thiazolopyridine derivatives, and biologically evaluated their inhibitory activities against MAO-B. Structure-activity relationship study revealed that the piperidino group was the best choice for the R(1) amino substituent to the oxazolopyridine core structure and the activities of the oxazolopyridines with various phenyl rings were between 267.1 and 889.5nM in IC50 values. Interestingly, by replacement of the core structure from oxazolopyrine to thiazolopyridine, the activities were significantly improved and the compound 1n with the thiazolopyridine core structure showed the most potent activity with the IC50 value of 26.5nM. Molecular docking study showed that van der Waals interaction in the human MAO-B active site could explain the enhanced inhibitory activities of thiazolopyridine derivatives.

Aryl diketoacid (ADK) is well known for antiviral activity which can be enhanced by introduction of an aromatic arylmethyl substituent. A natural flavonoid quercetin has a 3,5-dihydroxychromone pharmacophore which is in bioisosteric relationship with the 1,3-diketoacid moiety of the ADK. Thus, it was of our interest to test the antiviral activity of the quercetin derivatives with an arylmethyl group attached. In this study, we prepared a series of the 7-O-arylmethylquercetin derivatives with various aromatic substituents and evaluated their antiviral activity against the SARS-associated coronavirus (SARS-CoV, SCV) as well as hepatitis C virus (HCV). Single difference in the aromatic substituent fine-tuned the biological activity of the 7-O-arylmethylquercetin derivatives to result in two different classes of derivatives selectively active against SCV and HCV.