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Background: Bupivacaine (BP) is commonly used as a local anaesthetic(LA) in the clinic, but it can also cause neurotoxicity, especially in patients with diabetes. Previous studies have found that high-glucose environments can aggravate BP-induced DNA damage in nerve cells. Ku70 is subunit of the DNA damage repair enzyme DNA-PK. This study was designed to determine whether high-glucose conditions enhance BP neurotoxicity and DNA damage by inhibiting Ku70 expression., Methods: We examined the effect of BP on apoptosis and DNA damage in murine dorsal root ganglion (DRG) neurons under hyperglycaemic conditions. Untreated DRG cells and DRG cells pretreated with NU7441, a DNA-PK inhibitor, were cultured for 3 days under normal culture conditions or with 50 mM glucose, and the cells were then treated with BP for 3 h. DNA damage was investigated via comet assays, the ratio of early to late apoptotic cells was assessed by Annexin V-FITC/PI staining, and cell viability was measured by CCK-8 assays. The protein expression levels of DNA-PK, Ku70, Bax, Bcl-2 and γH2ax were measured by immunofluorescence or Western blotting., Results: Compared to its effect under normal culture conditions, BP treatment led to decreased cell viability and increased DNA damage in DRG cells grown under high-glucose conditions. The rate of DRG cell apoptosis and the expression of γH2ax, the ratio of Bax to Bcl-2 also increased under the high-glucose conditions. Furthermore, Ku70 expression was inhibited. The DNA-PK inhibitor, NU7441, could significantly inhibit DNA-PK and Ku70 expression, simultaneously further aggravating BP-induced apoptosis and DNA damage under high-glucose conditions., Conclusion: These data indicate that hyperglycaemia may enhance BP-induced neurotoxicity and DNA damage by inhibiting the DNA repair protein Ku70., (Copyright © 2019 Elsevier B.V. All rights reserved.)

SPH3127, a newly developed oral nonpeptide direct renin inhibitor with good tolerance and favorable ADME (absorption distribution metabolism excretion) properties in preclinical species, is now being evaluated in phase Ι clinical trial. In this work, the subchronic toxicity of SPH3127 in Sprague-Dawley rats and cynomolgus monkeys has been characterized. Rats and monkeys received SPH3127 orally (30, 300, 900 and 20, 100, 450 mg/kg/day, respectively) on a consecutive daily dosing schedule for 28 days followed by a 28-days recovery period for one third of the animals. The adverse effects of SPH3127 on rats and monkeys mainly included kidney and cardiovascular toxicity, which were consistent with pharmacologic perturbations of physiologic processes associated with the intended molecular targets for this class of renin signaling inhibitors. Moderate liver weight increases accompanied by CYP3A induction were seen in 300 and 900 mg/kg/day rats but not in monkeys or in vitro human hepatocytes. One 450 mg/kg/day monkey died early at day 23 with apparent myelosuppression characterized by atrophy of thymus and spleen, and the relevance to the action of SPH3127 remained unclear. Most of the treatment-induced effects were reversible upon discontinuation of treatment. The no-observed-adverse-effect level (NOAEL) of SPH3127 was determined to be 30 mg/kg/day for Sprague-Dawley rats and 20 mg/kg/day for cynomolgus monkeys based on the kidney and cardiovascular changes found at mid- and high-dose animals., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Lysosomes generally maintain the weak acidic microenvironment, to ensure highly efficient activity and functions of hydrolytic enzymes and proteins. Aberrations of the lysosomal pH may result in cellular functional changes and influence human physiology, possibly causing serious diseases. Small-molecular fluorescent probes based imaging techniques capable of providing information on target locations are considerably appreciated. Herein, by reducing the size of the typical lysosome targetable group 4-(2-aminoethyl) morpholine, we rationally designed a rhodamine analogue probe Ly-HN2AM with N-Aminomorpholine as the ring-closed switch and the lysosome targetable moiety for visualizing lysosomal pH changes. With the benefit of constructing multi-pentacyclic intramolecular hydrogen bond when binding with the H + , Ly-HN2AM gives a highly sensitive response towards pH values ranging from 4.79 to 6.07, with a remarkable higher pK a 5.35 over the typical 4-(2-aminoethyl) morpholine modified probes. The new probe was successfully applied to visualize pH value changes in lysosome-associated physiological and pathological processes with excellent photostability and low cytotoxicity, indicating the potential applications of lysosome specific bioimaging., (Copyright © 2019 Elsevier B.V. All rights reserved.)

We report the design, synthesis and biological evaluation of 17 novel 8-aryl-2-morpholino-3,4-dihydroquinazoline derivatives based on the standard model of DNA-PK and PI3K inhibitors. Novel compounds are sub-divided into two series where the second series of five derivatives was designed to have a better solubility profile over the first one. A combination of in vitro and in silico techniques suggested a plausible synergistic effect with doxorubicin of the most potent compound 14d on cell proliferation via DNA-PK and poly(ADP-ribose) polymerase-1 (PARP-1) inhibition, while alone having a negligible effect on cell proliferation., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The emergence of synthetic cannabinoids (SCBs) as drugs of abuse in readily available "Spice" smoking blends has exposed users to much more potent cannabinoids than the phytocannabinoids present in Cannabis sativa L. Increasing reports of adverse reactions are emerging in the clinical literature. SCBs may disrupt the endocannabinoid signalling, which has been shown to be crucial within human endometrium remodelling process. Within this study, a telomerase-immortalised human endometrial stromal cell line (St-T1b) and primary human decidual fibroblasts (HdF) were used to determine the impact of SCBs JWH-122, UR-144 and WIN55,212-2 (WIN) on endometrial stromal cells. Our findings indicate that JWH-122 and UR-144 (0.01-25 μM) induce prompt ROS/RNS formation and endoplasmic reticulum (ER) stress without reduction in cell viability. Disturbances in the normal functions of the ER lead to cell stress response, which is after compensated with the increase in reduced/oxidized glutathione ratio (GSH/GSSG). Instead, WIN induces ER stress, mitochondrial dysfunction and apoptotic cell death. The addition of the CB1 antagonist AM281 significantly reduces the effects on cell viability, suggesting that CB1 plays a key role in WIN-induced apoptosis. Collectively, our data suggests that SCBs have dissimilar effects on human endometrial stromal cells and, thus, may impact human reproductive function through distinct mechanisms that are crucial for the understanding of the pathophysiological outcomes from its abuse., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Lysosome fluorescent imaging has been widely used in the field of biological staining and diagnostics, which plays a key role in understanding intracellular metabolism and various physiological processes. However, for most currently used small-molecule lysotrackers, the photostability is often unsatisfactory when used for long-term and real-time visualization of lysosomal dynamics. Herein, we reported a new lysosome-targetable photostable fluorescent probe (i.e. MPL-NPA), and results showed that MPL-NAP possesses superior photostability, appreciable tolerance to pH change, low cytotoxicity and high lysosome targeting ability. These findings confirm that MPL-NAP is a well-suited imaging agent for targeting lysosome and enables long-term and real-time monitor of lysosome morphological changes under physiological processes., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Buparlisib is an oral pan-class I phosphotidyinositol-3-kinase (PI3K) inhibitor. The present phase I study evaluated the safety, pharmacokinetics, and efficacy of buparlisib with capecitabine in patients with metastatic breast cancer., Patients and Methods: Patients received buparlisib once daily (range, 50 to 100 mg) for 3 weeks with capecitabine twice daily (range, 1000 to 1250 mg/m 2 ) for 2 weeks with a 1-week break. Dose escalation used a traditional "3 + 3" design with standard definitions of dose-limiting toxicity (DLT) and maximum tolerated dose., Results: Of the 25 patients enrolled, 23 were evaluable for DLT and 17 were evaluable for response. The maximum tolerated dose of the combination was buparlisib 100 mg daily and capecitabine 1000 mg/m 2 twice daily. DLTs included grade 3 hyperglycemia and grade 3 confusion. The most common grade 3 toxicities were diarrhea and elevation of aspartate aminotransferase and alanine transaminase. One patient exhibited a complete response to treatment and four had a confirmed partial response. In cohorts 3 and 4, in which the buparlisib dose remained constant but the capecitabine dose was increased, significant increases in the buparlisib plasma concentration were noted., Conclusion: The combination of buparlisib with capecitabine in patients with metastatic breast cancer was generally well-tolerated, with several patients demonstrating prolonged responses. Unexpectedly low rates of PIK3CA mutations (3 of 17) were seen, and only 2 of 7 tumors with subtyping were luminal, making exploration of these putative predictive markers impossible. Further study of the combination is not unreasonable, with expanded pharmacokinetics and sequencing analysis to better elucidate potential drug-drug interactions and more accurate predictive biomarkers of response., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Parkinson's disease (PD) is a progressive neurodegenerative disorder for which there is no existing therapeutic approach to delay or stop progression. Genetic, biochemical and pre-clinical studies have provided evidence that leucine-rich-repeat-kinase-2 (LRRK2) kinase is involved in the pathogenesis of PD, and small molecule LRRK2 inhibitors represent a novel potential therapeutic approach. However, potentially adverse target-related effects have been discovered in the lung and kidneys of LRRK2 knock-out (ko) mice and rats. It is unclear if the LRRK2 ko effect in the kidneys and lung is also induced by pharmacological inhibition of the LRRK2 kinase. Here, we show that treatment with the LRRK2 inhibitor PFE-360 in rats induces a morphological kidney phenotype resembling that of the LRRK2 ko rats, whereas no effects were observed in the lung. The PFE-360 treatment induced morphological changes characterised by darkened kidneys and progressive accumulation of hyaline droplets in the renal proximal tubular epithelium. However, no histopathological evidence of renal tubular injury or changes in the blood and urine parameters that would be indicative of kidney toxicity or impaired kidney function were observed after up to 12 weeks of treatment. Morphological changes were detected in the kidney after 2 weeks of treatment and were partially reversible within a 30 day treatment-free period. Our findings suggest that pharmacological LRRK2 inhibition may not have adverse consequences for kidney function., (Copyright © 2018 H. Lundbeck A/S. Published by Elsevier B.V. All rights reserved.)

Moroxydine hydrochloride (Mor) is known to have multi-antiviral activities against DNA and RNA viruses but very little information exists on its pharmacology. The paper was undertaken to explore the antiviral response and antiapoptotic mechanism of Mor against grass carp reovirus (GCRV) in Ctenopharyngodon idella kidney (CIK) cells. The results showed that exposing GCRV-infected cell to 6.3 μg mL(-1) of Mor for 96 h avoid ca. 50% apoptosis. Meanwhile, Mor had lower cytotoxicity than ribavirin (Rib) as the value of safe concentration was threefold higher than effective concentration and the compound could ensure sufficient into and out of cells within 4 h when tested at the maximal safe concentration. Mor blocked the GCRV-induced cytopathic effects and eliminated nucleocapsids in CIK cells to keep the normal morphological structure. Moreover, the expressions of viral protein genes were significantly inhibited especially the guanylyl transferase and RNA-dependent RNA polymerase related expression. Furthermore, GCRV caused Bcl-2 down-regulation and Bax mitochondrial translocation was prevented by treatment of CIK cells with Mor. The downstream effector, caspase activity was also significantly inhibited in Mor treated cells. The potential mechanism might be that mitochondrial apoptotic signals were not activated by the intervention of Mor for targeting viral gene expression. Taken together, Mor showed high anti-GCRV activity and had been proved as a secure and promising agent in viral controlling in aquaculture industry., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Rivaroxaban is a direct factor Xa inhibitor approved for prevention of stroke, prevention and treatment of venous thromboembolism and secondary prevention of acute coronary syndrome in many countries. As the use of this agent increases, so does the potential for overdose, both intentional and unintentional. Clinical data on overdoses of rivaroxaban in humans are limited. We report the case of a 42-year-old man who took an overdose of 1400 mg of rivaroxaban and describe how resolution of the anticoagulant effect was monitored using readily available coagulation assays., (© 2014 International Society on Thrombosis and Haemostasis.)

Several epidemiological studies show an increase in cannabis use among adolescents, especially in Morocco for being one of the major producers in the world. The neurobiological consequences of chronic cannabis use are still poorly understood. In addition, brain plasticity linked to ontogeny portrays adolescence as a period of vulnerability to the deleterious effects of drugs. The aim of this study was to investigate the behavioral neurogenic effects of chronic exposure to the cannabinoid agonist WIN55,212-2 during adolescence, by evaluating the emotional and cognitive performances, and the consequences on neurogenesis along the dorso-ventral axis of the hippocampus in adult rats. WIN55,212 was administered intraperitoneally (i.p.) once daily for 20 days to adolescent (27-30 PND) and adult Wistar rats (54-57 PND) at the dose of 1mg/kg. Following a 20 day washout period, emotional and cognitive functions were assessed by the Morris water maze test and the two-way active avoidance test. Twelve hours after, brains were removed and hippocampal neurogenesis was assessed using the doublecortin (DCX) as a marker for cell proliferation. Our results showed that chronic WIN55,212-2 treatment significantly increased thigmotaxis early in the training process whatever the age of treatment, induced spatial learning and memory deficits in adolescent but not adult rats in the Morris water maze test, while it had no significant effect in the active avoidance test during multitrial training in the shuttle box. In addition, the cognitive deficits assessed in adolescent rats were positively correlated to a decrease in the number of newly generated neurons in dorsal hippocampus. These data suggest that long term exposure to cannabinoids may affect more potently spatial learning and memory in adolescent compared to adult rats via a negative action on hippocampal plasticity., (Copyright © 2014 Elsevier Inc. All rights reserved.)

N-alkyl-N-methylmorpholinium and N-alkyl substituted 1,4-diazabicyclo[2.2.2]octane (DABCO) based ionic liquids (ILs), N-alkyl-DABCO, bearing short alkyl chains are characterised by a low toxicity to Vibrio fischeri, although toxicity significantly increases on increasing the alkyl chain length. Alkyl chain length affects also biodegradability in the 28 days tests; the higher level of biodegradation was found in both the series in the case of the ethyl (C2) derivatives. In the case of N-ethyl DABCO based IL, although biodegradability is still around 40%, and consequently this IL cannot be classified as "readily biodegradable", this value is similar to the more biodegradable functionalized imidazolium based ILs., (Copyright © 2010 Elsevier Inc. All rights reserved.)

The aim of this study was to determine the effect of WIN 55,212-2 mesylate (WIN--a non-selective cannabinoid CB1 and CB2 receptor agonist) on the protective action of four classical antiepileptic drugs (carbamazepine, phenytoin, phenobarbital, and valproate) in the mouse maximal electroshock seizure (MES) model. The results indicate that WIN (10 mg/kg, i.p.) significantly enhanced the anticonvulsant action of carbamazepine, phenytoin, phenobarbital and valproate in the MES test in mice. WIN (5 mg/kg) potentiated the anticonvulsant action of carbamazepine and valproate, but not that of phenytoin or phenobarbital in the MES test in mice. However, WIN administered alone and in combination with carbamazepine, phenytoin, phenobarbital and valproate significantly reduced muscular strength in mice in the grip-strength test. In the passive avoidance task, WIN in combination with phenobarbital, phenytoin and valproate significantly impaired long-term memory in mice. In the chimney test, only the combinations of WIN with phenobarbital and valproate significantly impaired motor coordination in mice. In conclusion, WIN enhanced the anticonvulsant action of carbamazepine, phenytoin, phenobarbital and valproate in the MES test. However, the utmost caution is advised when combining WIN with classical antiepileptic drugs due to impairment of motor coordination and long-term memory and/or reduction of skeletal muscular strength that might appear during combined treatment., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Though neurokinin(1) (NK(1)) receptors are implicated in depressed states and their treatment, selective antagonists have disappointed in clinical trials. Accordingly, we designed a novel ligand, S41744 (2-piperazin-1-yl-indan-2-carboxylic-acid-(3-chloro-5-fluoro-benzyl)-methyl-amide), which both blocks NK(1) receptors and interferes with serotonin (5-HT) reuptake. S41744 mimicked the selective antagonist aprepitant in binding human (h)NK(1) receptors and in antagonising Substance-P-mediated Extracellular-Regulated-Kinase phosphorylation (pK(B), 7.7). Further, it dose-dependently (0.63-40.0 mg/kg, i.p.) displaced ex vivo [(3)H]-[Sar(9),Met(O(2))(11)]-Substance P binding to gerbil striatum, attenuated formalin-induced hind-paw licking in gerbils, and antagonised locomotion induced by i.c.v. administration of the NK(1) agonist GR73632 to guinea pigs. Like paroxetine, S41744 recognised h5-HT transporters, reduced synaptosomal uptake of 5-HT (pK(B), 7.9), and dose-dependently (0.63-10.0 mg/kg) elevated dialysis levels of 5-HT in the hippocampus and frontal cortex of freely-moving guinea pigs. Further, S41744 increased extracellular levels of 5-HT in frontal cortex and hippocampus of rats to a greater extent than paroxetine, and its inhibitory influence upon serotonergic perikarya was blunted relative to its affinity for 5-HT transporters. S41744 more potently blocked stress-induced vocalizations in guinea pigs than aprepitant and paroxetine, and it was active in forced-swim and marble-burying procedures of putative antidepressant properties in mice. While aprepitant displayed anxiolytic actions in stress-induced foot-tapping and social interaction tests in gerbils, paroxetine was anxiogenic and S41744 "neutral", reflecting balanced NK(1) antagonism and suppression of 5-HT reuptake. Moreover, S41744 shared anxiolytic actions of aprepitant in the rat Vogel Conflict Test. In conclusion, S41744 is an innovative NK(1) antagonist/5-HT reuptake inhibitor justifying further evaluation for treatment of stress-related disorders., (Copyright 2010 Elsevier B.V. All rights reserved.)

Aquatic plants take up, transform and sequester organic contaminants and may therefore be used in phytoremediation for the removal of pollutants from wastewaters. A better understanding of factors affecting the rate of contaminant uptake by aquatic plants is needed to improve engineered systems for removal of pollutants from wastewaters. This work focused on the influence of initial concentrations of pesticide and population density of plants on toxicity and uptake of the fungicide dimethomorph by two duckweed species. An increased sensitivity to dimethomorph was observed with increasing duckweed population density. Less light, due to crowding, may explain this higher sensitivity and reduced removal rate. A positive relationship was also found between toxicity or contaminant uptake and initial pesticide concentration with a maximal removal of 41 and 26 microg g(-1) fresh weight of dimethomorph (at 600 microg L(-1) of dimethomorph and an initial density of 0.10g E-flask(-1)) by Lemna minor and Spirodela polyrhiza, respectively. This research also indicated that these aquatic plants can efficiently eliminate organic contaminants and may ultimately serve as phytoremediation agents in the natural environment., (Copyright 2010 Elsevier B.V. All rights reserved.)

Background: Release of serotonin and activation of serotonin 5HT2A receptors on platelet surfaces is a potent augmentative stimulus for platelet aggregation. However, earlier-generation serotonin receptor antagonists were not successfully exploited as antiplatelet agents, possibly owing to their lack of specificity for the 5HT2A receptor subtype., Objective: To assess whether targeted inhibition of the serotonin 5HT2A receptor attenuates recurrent thrombosis and improves coronary patency in an in vivo canine model mimicking unstable angina., Methods: In protocol 1, anesthetized dogs were pretreated with a novel, selective inverse agonist of the 5HT2A receptor (APD791) or saline. Recurrent coronary thrombosis was then initiated by coronary artery injury+stenosis, and coronary patency was monitored for 3 h. Protocol 2 was similar, except that: (i) treatment with APD791 or saline was begun 1 h after the onset of recurrent thrombosis; (ii) template bleeding time was measured; and (iii) blood samples were obtained for in vitro flow cytometric assessment of platelet responsiveness to serotonin., Results: APD791 attenuated recurrent thrombosis, irrespective of the time of treatment: in both protocols, flow-time area (index of coronary patency; normalized to baseline coronary flow) averaged 58-59% (P<0.01) following administration of APD791 vs. 21-28% in saline controls. Moreover, the in vivo antithrombotic effect of APD791 was not accompanied by increased bleeding, but was associated with significant and selective inhibition of serotonin-mediated platelet activation., Conclusion: 5HT2A receptor inhibition with APD791, even when initiated after the onset of recurrent thrombosis, improves coronary patency in the in vivo canine model.

The rate of removal of two fungicides (dimethomorph and pyrimethanil) from water by five macrophyte species (L. minor, S. polyrhiza, C. aquatica, C. palustris and E. canadensis) was assessed in laboratory tests. In order to assure that these studies were performed with healthy plants the effects of the fungicides on chlorophyll fluorescence were studied as well. At exposure concentrations of 600microgL(-1) the effects of the fungicides on chlorophyll fluorescence were minor, so that this initial concentration level was selected for the fungicide removal rate tests. The removal yields during the 4-d test periods varied from 10% to 18% and 7% to 12% for dimethomorph and pyrimethanil, respectively. The maximum removal rate during the 4-d test period was 48microgg(-1) fresh weight (FW) for dimethomorph and 33microgg(-1) FW for pyrimethanil. L. minor and S. polyrhiza showed the highest removal efficiency for the two fungicides.

Automated sediment toxicity testing and biomonitoring has grown rapidly. This study tested the suitability of the marine amphipod Corophium volutator (Pallas, 1766) for sediment biomonitoring using the Multispecies Freshwater Biomonitor (MFB). Two experiments were undertaken to (1) characterize individual behaviors of C. volutator using the MFB and (2) examine behavioral changes in response to sediment spiked with the pesticide Bioban. Four behaviors were visually identified (walking, swimming, grooming and falling) and characterized in the MFB as different patterns of locomotor activity (0-2 Hz range). Ventilation was not visually observed but was detected by the MFB (2-8 Hz). No clear diel activity patterns were detected. The MFB detected an overall increase in C. volutator locomotor activity after Bioban addition to the sediments (56, 100, 121 mg kg(-1)). C. volutator was more active (both locomotion and ventilation) in the water column than the spiked sediment. C. volutator appears a sensitive and appropriate species for behavioral sediment toxicity assessment and biomonitoring.

The genotoxicity of endogenously formed N-nitrosamines from secondary amines and sodium nitrite (NaNO(2)) was evaluated in multiple organs of mice, using comet assay. Groups of four male mice were orally given dimethylamine, proline, and morpholine simultaneously with NaNO(2). The stomach, colon, liver, kidney, urinary bladder, lung, brain, and bone marrow were sampled 3 and 24 h after these compounds had been ingested. Although secondary amines and the NaNO(2) tested did not yield DNA damage in any of the organs tested, DNA damage was observed mainly in the liver following simultaneous oral ingestion of these compounds. The administration within a 60 min interval also yielded hepatic DNA damage. It is considered that DNA damage induced in mouse organs with the coexistence of amines and nitrite in the acidic stomach is due to endogenously formed nitrosamines. Ascorbic acid reduced the liver DNA damage induced by morpholine and NaNO(2). Reductions in hepatic genotoxicity of endogenously formed N-nitrosomorpholine by tea polyphenols, such as catechins and theaflavins, and fresh apple, grape, and orange juices were more effective than was by ascorbic acid. In contrast with the antimutagenicity of ascorbic acid in the liver, ascorbic acid yielded stomach DNA damage in the presence of NaNO(2) (in the presence and absence of morpholine). Even if ascorbic acid acts as an antimutagen in the liver, nitric oxide (NO) formed from the reduction of NaNO(2) by ascorbic acid damaged stomach DNA.

The synthesis of 5-(6-methyl-2-substituted 4-pyrimidinyloxymethyl)-2,3-dihydro-1,3,4-oxadiazole-2-thiones and their 3-morpholinomethyl derivatives and the results of anti-inflammatory activity in vivo are described. Most of the tested compounds exhibited anti-inflammatory activity and some of them were more active than acetylsalicylic acid.

Since morpholino oligos were first introduced as a means to inhibit gene function in embryos, in the Spring of 2000, they have been tested in a range of model organisms, including sea urchin, ascidian, zebrafish, frog, chick, and mouse. This review surveys the results of these studies and examines the successes and limitations of the approach for targeting maternal and zygotic gene function. The evidence so far suggests that, with careful controls, morpholinos provide a relatively simple and rapid method to study gene function., ((C)2002 Elsevier Science (USA).)

Morpholinoalkyl esters (HCl salts) of diclofenac (1) were synthesized and evaluated in vitro and in vivo for their potential use as prodrugs for oral delivery. Prodrugs were freely soluble in simulated gastric fluid (SGF) and pH 7.4 phosphate buffer and showed a minimum of a 2000-fold increase in solubility over the parent drug. All prodrugs were more lipophilic than 1 as indicated by n-octanol/pH 7.4 buffer partition coefficients, but less lipophilic than 1 in terms of n-octanol/SGF partition coefficients. Potentiometrically determined ionization constants (pKas) were in the range of 7.52 to 8.40 at 25 degrees C. The chemical and enzymatic hydrolyses of prodrugs were evaluated in SGF/pH 7.4 phosphate buffer and rat plasma, respectively, at 37 degrees C. All prodrugs were quantitatively hydrolyzed to 1 by either chemical and/or enzymatic means. An increase in carbon chain length rendered the prodrugs more stable at pH 7.4, but less stable in SGF. In general, the esters were hydrolyzed rapidly in rat plasma at 37 degrees C, the half-lives of hydrolysis being in the range of 4.85 to 23.49 min. Based on in vitro results, prodrug 2 was chosen to evaluate solid-state stability, bioavailability, and in vivo ulcerogenicity. At elevated temperatures, the solid-state decomposition of 2 followed biphasic kinetics, with rapid decomposition occurring initially. The extent, but not the rate, of absorption was significantly greater in rats for prodrug 2 than 1 following single dose oral administration. Prodrug 2 was significantly less irritating to gastric mucosa than 1 following single and chronic oral administration in rats.

L-Thiomorpholine-3-carboxylic acid (L-TMC) is a cyclized analog of S-(2-chloroethyl)-L-cysteine, which is cytotoxic in vitro and nephrotoxic in vivo. To determine whether L-TMC may play a role in S-(2-chloroethyl)-L-cysteine-induced toxicity, the cytotoxicity of L-TMC was studied in isolated rat kidney cells. L-TMC produced time- and concentration-dependent cytotoxicity. Probenecid, an inhibitor of the renal anion transport system, and L-alpha-hydroxyisocaproic acid, a substrate for L-amino acid oxidase, inhibited L-TMC-induced cytotoxicity. Rat kidney cytosol catalyzed the metabolism of L-TMC to a product absorbing at 300 nm. The increase in absorbance at 300 nm was accompanied by an increase in oxygen consumption and was inhibited by L-alpha-hydroxyisocaproic acid; moreover, the absorbance of the metabolite was quenched by addition of potassium cyanide or sodium borohydride, which indicated the formation of an imine. When L-TMC was incubated with rat kidney cytosol and sodium borodeuteride was added at the end of the incubation period, analysis by gas chromatography/mass spectrometry of the tert-butyldimethylsilyl ester of L-TMC showed the formation of [2H]TMC, indicating the intermediate formation of the imine 5,6-dihydro-2H-1,4-thiazine-3-carboxylic acid; chemically synthesized TMC imine showed similar behavior. The enzyme responsible for the metabolism of L-TMC was purified from rat kidney and was identified as L-amino acid oxidase. These observations indicate a role for L-amino acid oxidase in the bioactivation and cytotoxicity of L-TMC.

Morpholine and a series of morpholine derivatives were assayed for the potential to induce DNA repair in the rat hepatocyte primary culture/DNA repair assay. Morpholine did not induce DNA repair at dose concentrations which were not toxic (0.0001-0.1 mg/ml). Two animal metabolites of morpholine, N- methylmorpholine oxide and N- hydroxymorpholine , also did not induce DNA repair at the non-toxic concentrations tested (0.0001-10 mg/ml and 0.0001-1 mg/ml, respectively). A putative metabolite of morpholine, 3- morpholinone , was inactive (0.001-10 mg/ml) and a polyurethane foam catalyst, N- butylmorpholine (0.0001-0.1 mg/ml) was also inactive. The chemical intermediate N- hydroxyethylmorpholine induced DNA repair in the dose range 1-5 mg/ml. It was concluded that genotoxicity of substituted morpholines is a function of the substituent moiety rather than morpholine itself.

A new series of disubstituted tetrahydrocarbazoles were synthesized. They are tested for antidepressive activity by the Porsolt's forced swimming test (one of the acute stress methods) and by the prevention of reserpine induced hypothermia and ptosis in mice. 3-Morpholino-1-[N-(6-methoxy-1,2,3,4- tetrahydrocarbozolyl)2-propanol, fumarate (XI) was demonstrated to be the most promising compound of this series. Besides, this series did not present the most common adverse effects of the conventional tricyclic-antidepressants (loss of locomotor coordination, ataxia and anticholinergic activity).