Review of synthesis, assay, and prediction of β and γ-secretase inhibitors

Alzheimer's disease (AD) is characterize with several pathologies this disease, amyloid plaques, composed of the β-amyloid peptide and β-amyloid peptide are hallmark neuropathological lesions in Alzheimer's disease brain. Indeed, a wealth of evidence suggests that β-amyloid is central to the pathophysiology of AD and is likely to play an early role in this intractable neurodegenerative disorder. AD is the most prevalent form of dementia, and current indications show that twenty-nine million people live with AD worldwide, a figure expected rise exponentially over the coming decades. Clearly, blocking disease progression or, in the best-case scenario, preventing AD altogether would be of benefit in both social and economic terms. However, current AD therapies are merely palliative and only temporarily slow cognitive decline, and treatments that address the underlying pathologic mechanisms of AD are completely lacking. While familial AD (FAD) is caused by autosomal dominant mutations in either amyloid precursor protein (APP) or the presenilin (PS1, PS2) genes. First, we revised Desing, synthesis, and Biological assay of β and γ-secretase inhibitors. Next, we review 2D QSAR, 3D QSAR, CoMFA, CoMSIA and Docking with different compound to find out the structural requirements. Next, we revised QSAR studies using method of Artificial Neural Network (ANN) in order to understand the essential structural requirement for binding with receptor for β and γ-secretase inhibitors.     

Naltrexone and β-funaltrexamine antagonism of the antinociceptive and response rate-decreasing effects of morphine, dezocine, and d-propoxyphene

  Rationale: Patterns of competitive and insurmountable antagonism provide important data to guide the classification and characterization of different types of opioid agonists as well as infer the mechanism of action for agonists. Objective: Experiments with the competitive antagonist, naltrexone, and the insurmountable antagonist, β-funaltrexamine (β-FNA), were conducted to determine whether the antinociceptive and rate-decreasing effects of the opioid agonists dezocine and d-propoxyphene are 1) mediated through μ opioid receptors in rats, and 2) differ from morphine with respect to relative efficacy. Methods: The rat tail-withdrawal assay was used to measure antinociception and a fixed ratio 20 (FR20) schedule of food delivery was used to measure rate suppression. Results: Naltrexone (0.01–1.0 mg/kg) was approximately equipotent as an antagonist of the antinociceptive and rate-decreasing effects of both morphine and dezocine and as an antagonist of the antinociceptive effects of d-propoxyphene. Naltrexone failed to block the rate-decreasing effects of d-propoxyphene. β-FNA (5 and 10 mg/kg) also antagonized the antinociceptive and rate-decreasing effects of morphine and dezocine as well as the antinociceptive effects of d-propoxyphene. β-FNA failed to produce a dose-dependent antagonism of the rate-decreasing effects of d-propoxyphene. Conclusions: These data suggest that the antinociceptive effects of morphine, dezocine, and d-propoxyphene and the rate-decreasing effects of morphine and dezocine are mediated through μ opioid receptors. Overall, high doses of β-FNA produced a greater degree of antagonism of the behavioral effects of dezocine than morphine or d-propoxyphene, confirming other reports that dezocine is a lower efficacy agonist than morphine. Additionally, the degree of antagonism produced by β-FNA was greater for the antinociceptive effects of all three compounds than for the rate-decreasing effects. Received: 14 August 1998 / Final version: 4 December 1998     

Hydrolysis of Carbonates,Thiocarbonates, Carbamates,and Carboxylic Esters of α-Naphthol, β-Naphthol,and p-Nitrophenol by Human,Rat, and Mouse Liver Carboxylesterases

Thirty carbonates, thiocarbonates, carbamates, and carboxylic esters of -naphthol, -naphthol, and p-nitrophenol were synthesized and tested as substrates for liver carboxylesterases from the crude microsomal fractions of human and mouse, and purified isozymes, hydrolases A and B, from rat liver microsomes. The carbonates, thiocarbonates, and carboxylic esters of -naphthol were cleaved more rapidly than the corresponding -naphthol isomers by the mammalian liver esterases. -Naphthyl esters of acetic, propionic, and butyric acids were among the best substrates tested for these enzymes. The majority of the substrates was consistently hydrolyzed at higher rates by hydrolase B compared with hydrolase A, although the Michaelis–Menten constant (K _m) values of selected substrates differed widely with these two isozymes. Malathion was a 15-fold better substrate for hydrolase B than for hydrolase A. Compared with the corresponding carboxylates, the carbonate moiety of - and -naphthol and p-nitrophenol lowered the specific activities of the enzymes by about fivefold but improved stability under basic conditions. The optimum pH of mouse liver esterase with the acetate, methylcarbonate, and ethylthiocarbonate of -naphthol was between pH 7.0 and pH 7.6. Human and mouse liver microsomal esterase activities were about five orders of magnitude lower than the esterase activities of purified rat liver hydrolase B. A relationship between the catalytic activity of the enzymes and the lipophilicity of the naphthyl substrates indicated that (i) in the - and -naphthyl carbonate series, an inverse relationship between enzyme activity and lipophilicity of the substrates was observed, whereas (ii) in the -naphthyl carboxylate series, an increase in enzyme activity with increasing lipophilicity of the substrates up to a log P value of about 4.0 was observed, after which the enzyme activity decreased.     

Effect of β-Endorphin and naloxone on acquisition,memory, and retrieval of shuttle avoidance and habituation learning in rats

Naloxone impairs acquisition of shuttle avoidance behavior (0.8 mg/kg IP) and habituation to a rearing response to a tone (1.6 mg/kg IP) in rats. -Endorphin (2 g/kg IP) has no effect on acquisition, but, when given prior to test sessions, facilitates retrieval of the two tasks. Naloxone has no effect of its own upon retrieval. In addition to these effects, the pretraining administration of -endorphin disrupts, and that of naloxone facilitates retention of the two tasks. The results are consistent with the hypothesis that these two forms of learning are state-dependent on the release of -endorphin (and, perpaps, of other opiate peptides as well), that this substance is released during training in a sufficient amount for this purpose, and that, in addition, there is a physiological amnesic mechanism mediated by opiate peptides. Furthermore, the results are also consistent with previous observations that -endorphin is released from the rat brain during training, but not during test sessions of the two tasks (Izquierdo et al., 1980b). The possibility is discussed that state-dependency and the amnesic effect comprise one single, rather than two separate mechanisms.     

Biological actions and molecular effects of resveratrol,pterostilbene, and 3′-hydroxypterostilbene

Stilbenes are a class of polyphenolic compounds, naturally found in a wide variety of dietary sources such as grapes, berries, peanuts, red wine, and some medicinal plants. There are several well-known stilbenes including trans-resveratrol, pterostilbene, and 3′-hydroxypterostilbene. The core chemical structure of stilbene compounds is 1,2-diphenylethylene. Recently, stilbenes have attracted extensive attention and interest due to their wide range of health-beneficial effects such as anti-inflammation, -carcinogenic, -diabetes, and -dyslipidemia activities. Moreover, accumulating in vitro and in vivo studies have reported that stilbene compounds act as inducers of multiple cell-death pathways such as apoptosis, cell cycle arrest, and autophagy for chemopreventive and chemotherapeutic agents in several types of cancer cells. The aim of this review is to highlight recent molecular findings and biological actions of trans-resveratrol, pterostilbene, and 3′-hydroxypterostilbene.     

Levels and circadian rhythmicity of plasma ACTH,cortisol, and β-endorphin as a function of family history of alcoholism

Rationale Individuals with a family history of alcoholism may present a dysfunction in the activity of the hypothalamic–pituitary–adrenal (HPA) axis that predates the development of alcoholism. Objective The present study investigated the hypothesis that this HPA-axis dysfunction is associated with alterations in the pattern of the circadian (24 h) secretions of adrenal corticotropic hormone (ACTH), cortisol, and β-endorphin. Methods Men with [high risk (HR)] or without [low risk (LR)] family history of alcoholism participated in the study. Blood samples were drawn every 30 min for 24 h for estimation of the plasma hormone levels. Participants ingested meals at predetermined intervals and filled out mood questionnaires prior to the placement of the catheter and 1 h after each meal. Results The circadian peaks for β-endorphin, ACTH, and cortisol occurred between 0800 and 0830 hours in both LR and HR participants. The plasma ACTH and β-endorphin concentrations were lower in HR than LR participants, while the plasma cortisol concentrations were similar between HR and LR participants. For each hormone, the total 24-h secretion was estimated from the area under the 24-h time–concentration curve (AUC). For ACTH and β-endorphin, but not the cortisol, AUC were lower in HR than LR participants. LR participants reported being more nervous than HR participants. For the LR participants, but not HR participants, the initial mood ratings of “nervous” were positively correlated with the initial plasma cortisol and β-endorphin concentrations as well as with the cortisol and β-endorphin AUC. Conclusions HR participants presented lower plasma concentrations as well as lower AUC for β-endorphin and ACTH but not for cortisol. This suggests a dysfunction of the HPA-axis in HR participants that predates the development of alcoholism and a dissociation between plasma ACTH and cortisol levels as a function of family history of alcoholism.     

Comparative studies of saponins in 1–3-year-old main roots, fibrous roots, and rhizomes of Panax notoginseng, and identification of different parts and growth-year samples

Notoginsenosides R₁, R₄, Fa, and K (N-R₁, N-R₄, N-Fa, and N-K), as well as ginsenosides Rg₁, Rb₁, Rd, Re, Rf, Rg₂ and Rh₁ (G-Rg₁, G-Rb₁, G-Rd, G-Re, G-Rf, G-Rg₂ and G-Rh₁) in 47 Notoginseng samples including 1-, 2- and 3-year-old main roots, rhizomes and fibrous roots of Panax notoginseng were determined by high-performance liquid chromatography-diode array detection method. Total contents (%) of the 11 saponins were 9.82–14.57 for 2-year old and 14.20–16.00 for 3-year-old rhizomes; 2.72–4.50 for 2-year-old and 1.98–4.92 for 3-year-old fibrous roots; 1.75–3.05 for 1-year-old whole roots; and 3.71–8.98 for 2-year-old and 7.03–11.23 for 3-year-old main roots. Contents of most saponins and total content of 11 saponins were in the order 3- >2- >1-year-old main root samples. G-Rf content, sum of G-Rf and G-Rh₁ were, respectively, 0.08–0.18 and 0.14–0.32 for 2- or 3-year-old rhizomes, and 0.01–0.07 and 0.03–0.10 for 2- or 3-year-old main roots. Combined contents of N-R₁, G-Rg₁ and G-Rb₁ were 5.78–9.37 in 3-year-old main roots, and 2.99–7.13 in 2-year-old main roots, of which nearly one-third of samples were lower than the limit (5 %) in the Chinese Pharmacopoeia. Those of 2- or 3-year-old fibrous roots (1.47–3.83) and 1-year-old whole roots (1.41–2.44) were much lower than the limit, and were considered not suitable for use as Notoginseng. Two-year-old main roots are not appropriate for collection as Notoginseng. Different parts and growth years of P. notoginseng can be identified from each another according to differences in saponin content.     

Design, synthesis, and antiviral evaluation of purine-β-lactam and purine-aminopropanol hybrids

Purine-β-lactam chimera were prepared as a novel class of hybrid systems through N-alkylation of 6-benzylamino- or 6-benzyloxypurine with (ω-haloalkyl)-β-lactams, followed by reductive ring opening of the β-lactam ring by LiEt(3)BH to provide an entry into the class of purine-aminopropanol hybrids. Both new types of hybrid systems were assessed for their antiviral activity and cytotoxicity, resulting in the identification of eight purine-β-lactam hybrids and two purine-aminopropanol hybrids as promising lead structures.     

Théodore Guilloz, pharmacist and physician, pioneer and victim of radiology

After the discovery of X rays, the first radiographies were obtained in France in January 1896. In Nancy, Guilloz obtained some of them on March 11. Pharmacist and physician, assistant professor and fellow at the Faculty of medicine, all his professional life was devoted to electrotherapy and radiology. This paper reports successively his studies in Besan?on and his coming to Nancy, his career in hospital and university, his researchs and honours, his relations with the College of pharmacy, his illness consecutive to repeated irradiations, his activity during world War I and finally his death on March 26 1916.     

Preparation, characterization, pharmacokinetics, and bioactivity of honokiol-in-hydroxypropyl-β-cyclodextrin-in-liposome

Entrapping inclusion complexes in liposomes has been proposed to increase the entrapment efficiency (EE) and stability of liposomes compared with conventional liposomes. In the present study, a stable honokiol-in-hydroxypropyl-β-cyclodextrin-in-liposome (honokiol-in-HP-β-CD-in-liposome) was developed as honokiol delivery system by a novel method. The final molar ratio of honokiol/HP-β-CD/lipid was selected as 1:2:2. The mean particle size was 123.5 nm, the zeta potential was -25.6 mV, and the EE was 91.09 ± 2.76%. The release profile in vitro demonstrated that honokiol is released from honokiol-in-HP-β-CD-in-liposome with a sustained and slow speed. Crystallographic study indicated that honokiol was first bound within HP-β-CD and then the inclusion complex was encapsulated within liposomes. Honokiol-in-HP-β-CD-in-liposome without freeze dry kept stable for at least 6 months at 4°C. Pharmacokinetic study revealed that honokiol-in-HP-β-CD-in-liposome significantly retarded the elimination and prolonged the residence time in circulating system. The data of bioactivity showed that honokiol-in-HP-β-CD-in-liposome remained similar antiproliferative activity in A549 and HepG2 tumor cells compared to free honokiol. These results suggested that we had successfully prepared honokiol-in-HP-β-CD-in-liposome. The novel honokiol formulation was easy to push industrialization forward and might be a potential carrier for honokiol delivery in tumor chemotherapy.     

Design,Synthesis, and Pharmacological Evaluation of Fluorescent and Biotinylated Antagonists of ρ1 GABAC Receptors

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Synthesis and Benzodiazepine Receptor Affinity of Nb,Nb'-Diamides of Bistryptamine

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Comparison of tolerance development and dependence capacities of morphine, β-endorphin,and [D-MET2, PRO5]-enkephalinamide

The tolerance-development capacities of -endorphin, [D-Met², Pro⁵]-enkephalinamide, and morphine were compared in rats, and the dependence capacity of morphine was compared with that of the enkephalin analogue in mice. Tolerance to the analgesic effect, as measured by the tail-flick test, developed somewhat more rapidly in the [D-Met², Pro⁵]-enkephalinamide-treated group than in the others. A similar relationship was found for the dependence capacity. Considering that the enkephalin analogue displayed the strongest analgesic activity, the wellknown correlation between antinociceptive and tolerance development/dependence capacities of opiates seems to be valid for opioid peptides as well.     

Safety,tolerability,and efficacy of clozapine in drug-resistant schizophrenia

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Effects of a Corticosteroid,Budesonide, on Alveolar Macrophage and Blood Monocyte Secretion of Cytokines: Differential Sensitivity of GM-CSF,IL-1β, and IL-6

Summary: Down-regulation of cytokine production in activated human blood monocytes (BMs) and alveolar macrophages (AMs) can be achieved in vitro by treatment with corticosteroids. The inhibition of cytokine secretion by corticosteroids may have important therapeutic consequences in e.g. asthma. However, relatively little is known about possible differences in the sensitivity of different cytokines to corticosteroid treatment. Homologous BMs and AMs were obtained from six healthy volunteers. Secretion of interleukin-1β (IL-1β), interleukin-6 (IL-6) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in the cultures of lipopolysaccharide (LPS) stimulated adherent BMs and AMs was analysed using specific immunoassays. Sensitivity of the IL-1β, IL-6, and GM-CSF secretion to the in vitro treatment with a synthetic corticosteroid, budesonide, was compared. BMs and AMs displayed significant differences in both cytokine secretion and susceptibility to regulation by budesonide. When added to the BM cultures concomitantly with LPS, budesonide suppressed IL-1β and IL-6 only partially (to 30% of the control level). In contrast, GM-CSF release in these cultures was almost totally inhibited by budesonide (⩾10^-8 M). The IC₅₀ for inhibition of the GM-CSF secretion was as low as 2 × 10^-10 M. In the AM cultures, budesonide had very little effect on IL-1β and IL-6 secretion (inhibition to 80% and 60% of control levels, respectively), while GM-CSF secretion was suppressed to 20% of control by budesonide concentrations ⩾10^-7 M. These in vitro studies suggest that GM-CSF secretion from BMs and AMs is more sensitive to corticosteroid treatment than IL-1β and IL-6 secretion. Moreover, these data support the view that human monocytes derived from different compartments or at different stages of differentiation exhibit different responsiveness to corticosteroids.     

The safety,stability, and compatibility of fragrances in skin and hair products†

Abstract

The efforts of the formulating chemist, perfumer, and toxicologist represent the creative forces that ultimately merge to accomplish a finished formulation. Because the ingredients in a compounded fragrance are proprietary to the company that produces them, the formulating chemist must add a mixture of unknown substances to his basic formulation with the hope that they will be compatible in functionality, stability, and safety. A well-controlled stability and safety testing program is needed to assure complete compatibility between the base formulation and the fragrance.

Potential stability problems include changes in viscosity, color, odor, clarity of transparent systems, and emulsion stability. These changes may be caused by hydrolysis, oxidation, reaction to light, reaction to metals, insolubilities, reaction to processing conditions, and packaging materials. The interactions which occur during these changes can cause the formation of new materials that may have irritation or sensitization potential. We recommend that samples of product that have successfully passed shelf-life testing be furnished to the toxicologist for a complete battery of safety tests, including controlled use testing. This procedure should help to assure that untoward reactions do not occur during consumer use.     

Exposure and recovery response of isomers of HCH, metabolites of DDT and estradiol-17β in the female catfish, Heteropneustes fossilis

Effects of 40 days of exposure and 20 days of recovery response at sublethal concentration of technical grades of gamma isomer of hexachlorocyclohexane (γ-HCH, 0.025 ppm, 99.8%) and dichlorodiphenyltrichloroethane (DDT, 5.0 ppm) in tissue (liver, brain and ovary) bioconcentrations, gonadosomatic index (GSI) and plasma levels of estradiol-17β (E2) have been estimated during prespawning phase in the catfish Heteropneustes fossilis (Bloch). The results indicated that the tissue bioconcentrations of both HCHs (HCH isomers) and DDTs (metabolites of DDT) in liver, brain and ovary were in preferential order (liver > brain > ovary). The GSI and plasma levels of E2 were declined in response to exposure of γ-HCH and DDT. On withdrawal of exposure of pesticide there was recovery of HCHs in exposed fish for all tissues studied, whereas DDTs exposed fish showed recovery only in liver. Recovery of E2 production was also recorded in γ-HCH exposed fish whereas very little recorded in DDT exposed fish. It is suggested that HCHs and DDTs have preferential order (liver > brain > ovary) of their tissue bioconcentrations and HCH/DDT-withdrawal-dependent recovery during studied phase.     

Microstructure of Tablet—Pharmaceutical Significance,Assessment, and Engineering

Purpose

To summarize the microstructure – property relationship of pharmaceutical tablets and approaches to improve tablet properties through tablet microstructure engineering.

Method

The main topics reviewed here include: 1) influence of material properties and manufacturing process parameters on the evolution of tablet microstructure; 2) impact of tablet structure on tablet properties; 3) assessment of tablet microstructure; 4) development and engineering of tablet microstructure.

Results

Microstructure plays a decisive role on important pharmaceutical properties of a tablet, such as disintegration, drug release, and mechanical strength. Useful information on mechanical properties of a powder can be obtained from analyzing tablet porosity—pressure data. When helium pycnometry fails to accurately measure true density of a water-containing powder, non-linear regression of tablet density—pressure data is a useful alternative method. A component that is more uniformly distributed in a tablet generally exerts more influence on the overall tablet properties.

Conclusion

During formulation development, it is highly recommended to examine the relationship between any property of interest and tablet porosity when possible. Tablet microstructure can be engineered by judicious selection of formulation composition, including the use of the optimum solid form of the drug and appropriate type and amount of excipients, and controlling manufacturing process.