Characterization of hypotensive and vasorelaxant effects of PHAR-DBH-Me a new cannabinoid receptor agonist.

The effect of PHAR-DBH-Me, a cannabinoid receptor agonist, on different cardiovascular responses in adult male rats was analyzed. The blood pressure was measured directly and indirectly. The coronary flow was measured by Langendorff preparation, and vasomotor responses induced by PHAR-DBH-Me in aortic rings precontracted with phenylephrine (PHEN) were analyzed. The intravenous injection of the compound PHAR-DBH-Me (0.018-185 µg/kg) resulted in decreased blood pressure; maximum effect was observed at the dose of 1,850 µg/kg. A concentration-dependent increase in the coronary flow was observed in a Langendorff preparation. In the aortic rings, with and without endothelium, pre-contracted with PHEN (10-6 M), the addition of PHAR-DBH-Me to the superfusion solution (10-12-10-5 M), produced a vasodilator response, which depends on the concentration and presence of the endothelium. L-NAME inhibited these effects. Addition of CB1 receptor antagonist (AM 251) did not modify the response, while CB2 receptor antagonist (AM630) decreased the potency of relaxation elicited by PHAR-DBH-Me. Indomethacin shifted the curve concentration-response to the left and produced an increase in the magnitude of the maximum endothelium dependent response to this compound. The maximum effect of PHAR-DBH-Me was observed with the concentration of 10-5 M. These results show that PHAR-DBH-Me has a concentration-dependent and endothelium-dependent vasodilator effect through CB2 receptor. This vasodilation is probably mediated by the synthesis/release of NO. On the other hand, it is suggested that PHAR-DBH-Me also induces the release of a vasoconstrictor prostanoid.

The critical role of the aldehyde dehydrogenase PauC in spermine, spermidine, and diaminopropane toxicity in Pseudomonas aeruginosa: Its possible use as a drug target.

The opportunistic human pathogen Pseudomonas aeruginosa exhibits great resistance to antibiotics; so, new therapeutic agents are urgently needed. Since polyamines levels are incremented in infected tissues, we explored whether the formation of a toxic aldehyde in polyamines degradation can be exploited in combating infection. We cloned the gene encoding the only aminoaldehyde dehydrogenase involved in P. aeruginosa polyamines-degradation routes, PaPauC, overexpressed this enzyme, and found that it oxidizes 3-aminopropionaldehyde (APAL) and 3-glutamyl-3-aminopropionaldehyde (GluAPAL) - produced in spermine (Spm), spermidine (Spd), and diaminopropane (Dap) degradation, as well as 4-aminobutyraldehyde (ABAL) and 4-glutamyl-4-aminobutyraldehyde (GluABAL) - formed in putrescine (Put) degradation. As the catalytic efficiency of PaPauC with APAL was 30-times lower than with GluAPAL, and GluAPAL is predominantly formed, APAL will be poorly oxidized 'in vivo'. We found polyamines-induced increases in the PaPauC activity of cell crude-extracts and in the expression of the PapauC gene that were diminished by glucose. Spm, Spd, or Dap, but not Put, were toxic to P. aeruginosa even in the presence of other carbon and nitrogen sources, particularly to a strain with the PapauC gene disrupted. APAL, but not GluAPAL, was highly toxic even to wild-type cells, suggesting that its accumulation, particularly in the absence of, or low, PaPauC activity is responsible for the toxicity of Spm, Spd, and Dap. Our results shed light on the toxicity mechanism of these three polyamines and strongly support the critical role of PaPauC in this toxicity. Thus, PaPauC emerges as a novel potential drug target whose inhibition might help in combating infection by this important pathogen.

Synergistic action between a synthetic cannabinoid compound and tramadol in neuropathic pain rats.

In the present study the interaction of cannabinoid, PhAR-DBH-Me [(R, Z)-18-((1S,4S)-5-methyl-2,5-diazabicyclo[2.2.1]heptan-2-yl)-18-oxooctadec-9-en-7-ylphenyl-acetate] and tramadol in two neuropathy models, as well as their possible toxic effects, was analyzed. The anti-allodynic effect of PhAR-DBH-Me, tramadol, or their combination, were evaluated in neuropathic rats. Furthermore, the effective dose 35 (as the 35 % of the anti allodynic effect) was calculated from the maximum effect of each drug. Moreover, the isobolographic analysis was performed to determine the type of interaction between the drugs. A plasma acute toxicity study was carried out to assess the hepatic, renal, and heart functions after an individual or combined administration of the drugs, as well as histology using the hematoxylin-eosin or Masson-trichome method. PhAR-DBH-Me, tramadol, and their combination produced an antiallodynic effect on spinal nerve ligation (SNL) and cisplatin-induced neuropathic pain in rats. Moreover, PhAR-DBH-Me and tramadol combination showed a synergistic interaction in neuropathic pain rats induced by SNL but not for cisplatin-induced neuropathy. On the other hand, changes in renal and hepatic functions were not observed. Likewise, analysis of liver, kidney and heart histology showed no alterations compared with controls. Results show that the combination of PhAR-DBH-Me and tramadol attenuates the allodynia in SNL rats; the acute toxicology analysis suggests that this combination could be considered safe in administered doses.

Preclinical safety evaluation of amphotericin A21: A novel antifungal.

Safety studies are essential in drug development. This study evaluates the safety of Amphotericin A21 (AmB-A21), a derivative of amphotericin B with antifungal therapeutic potential. We performed a chronic toxicity study, a targeted organ study and a dermal irritation test. To evaluate chronic toxicity, 18 male adult rats were treated orally with AmB-21 (2 mg/kg) for 26 weeks. The effects on body-weight and animal health were measured, and haematological, clinical chemistry and histopathological tests were conducted on various organs. In the target organ toxicity study, male adult rats received a daily oral dose of AmB-21 (2 mg/kg) for 6 and 17 weeks; testicle histology and testosterone levels were then evaluated. For the dermal irritation study, AmB-21 (200 and 1000 mg/kg) was placed on the skin of adult male rabbits; macroscopic and microscopic studies, as well as haematological and clinical chemistry tests were then conducted. The chronic toxicity study revealed that AmB-21 caused testicle damage, and the testicle-targeted study showed structural alterations and changes in testosterone levels at 17 weeks. However, these alterations were no longer observed 8 weeks after discontinuation of treatment, and the testes showed very similar characteristics to those in the control group. The dermal irritation study showed skin thickening and reddening in rabbits treated with 2000 mg of AmB-A21 after 14 days of exposure. This same group also showed changes in liver enzymes, renal parameters and platelet levels. Based on our results, we consider AmB-21 to be a potential candidate for safe, long-term antifungal treatment given its reduced side effects.

Antiallodynic effect of PhAR-DBH-Me involves cannabinoid and TRPV1 receptors.

The antiallodynic effect of PhAR-DBH-Me was evaluated on two models of neuropathic pain, and the potential roles of CB1, CB2, and TRPV1 receptors as molecular targets of PhAR-DBH-Me were studied. Female Wistar rats were submitted to L5/L6 spinal nerve ligation (SNL) or repeated doses of cisplatin (0.1 mg/kg, i.p.) to induce experimental neuropathy. Then, tactile allodynia was determined, and animals were treated with logarithmic doses of PhAR-DBH-Me (3.2-100 mg/kg, i.p.). To evaluate the mechanism of action of PhAR-DBH-Me, in silico studies using crystallized structures of CB1, CB2, and TRPV1 receptors were performed. To corroborate the computational insights, animals were intraperitoneally administrated with antagonists for CB1 (AM-251, 3 mg/kg), CB2 (AM-630, 1 mg/kg), and TRPV1 receptors (capsazepine, 3 mg/kg), 15 min before to PhAR-DBH-Me (100 mg/kg) administration. Vagal stimulation evoked on striated muscle contraction in esophagus, was used to elicited pharmacological response of PhAR-DBH-ME on nervous tissue. Systemic administration of PhAR-DBH-Me reduced the SNL- and cisplatin-induced allodynia. Docking studies suggested that PhAR-DBH-Me acts as an agonist for CB1, CB2, and TRPV1 receptors, with similar affinity to the endogenous ligand anandamide. Moreover antiallodynic effect of PhAR-DBH-Me was partially prevented by administration of AM-251 and AM-630, and completely prevented by capsazepine. Finally, PhAR-DBH-Me decreased the vagally evoked electrical response in esophagus rat. Taken together, results indicate that PhAR-DBH-Me induces an antiallodynic effect through partial activation of CB1 and CB2 receptors, as well as desensitization of TRPV1 receptors. Data also shed light on the novel vanilloid nature of the synthetic compound PhAR-DBH-Me.

Effects of Oleamide on the Vasomotor Responses in the Rat.

Introduction: Cardiovascular effects of endocannabinoids (eCBs) have generated considerable interest since it has been suggested that the eCB system could become the new pharmacological target, either by blocking its activity or by promoting its effects on several cardiovascular diseases such as hypovolemic and septic shock or hypertension. The purpose of this study was to examine the effects of oleamide on several vasomotor responses in adult rats. Materials and Methods: Blood pressure (BP) was measured both directly and indirectly. Coronary flow was quantified with Langendorf preparation, and the vasomotor responses induced by oleamide were analyzed in the aortic rings. Results: Oleamide induced a decrease in BP, by both direct and indirect methods, which were dose dependent. An increase in coronary flow was observed with Langendorf preparation depending on the dose. Oleamide produced a vasodilator response in aortic rings pre-contracted with phenylephrine (10-5 M), which was concentration and endothelium dependent. This relaxing effect was of minor magnitude than that induced with the same dose on BP. L-NAME did not modify these effects. However, indomethacin induced a shift to the left of the concentration-response curve to oleamide and an increase in the magnitude of maximum vasodilation in rings with endothelium. Oleamide produced the maximal relaxant response at 10-5 M concentration. Conclusions: Oleamide has both in vivo and in vitro vasodilator effects. Vasodilator effects could be mediated by compounds synthesized/released by the endothelium (hyperpolarizing factor) or acting directly on vascular smooth muscle in aortic rings. The TRPV1 and CB1R receptors could mediate these effects. Finally, the results suggest that oleamide probably induces the synthesis/release of a vasoconstrictor prostanoid.

Identification of (1S,4S)-2,5-diazabicyclo[2.2.1]heptane-dithiocarbamate-nitrostyrene hybrid as potent antiproliferative and apoptotic inducing agent against cervical cancer cell lines.

The present study seeks to describe the design and synthesis of six new Michael adducts of (1S,4S)-2,5-diazabicyclo[2.2.1]heptane-dithiocarbamate with nitrostyrenes and their in vitro antiproliferative activity against human cervical cancer cell lines [HeLa (HPV 18 positive), CaSki (HPV 16 positive) and ViBo (HPV negative) cervical cancer cell lines]. Virtual screening of the physicochemical properties of all compounds have also been presented. All the compounds exploited significant antiproliferative activity on the three cervical cancer cell lines. Compound 8a was found to be most potent, displaying in vitro antiproliferative activity against HeLa, CaSki and ViBo cervical cancer cell lines superior to Cisplatin and Paclitaxel with IC50 values 0.99 ±â€¯0.007, 2.36 ±â€¯0.016 and 0.73 ±â€¯0.002 µM respectively. In addition, compound 8a did not trigger the necrosis cell death to the test cancer cell lines. Further mechanistic study revealed that compound 8a could inhibit the cancer cell proliferation by inducing apoptosis through caspase-3 activation. Moreover, cell cycle analysis indicated that compound 8a could arrest the cell cycle at the G1 phase for HeLa and CaSki cancer cells. At the predetermined IC50 values on cancer cells, compound 8a did not induce any necrotic (cytotoxic) death to the normal human lymphocytes. In the present design, (1S,4S)-2,5-diazabicyclo[2.2.1]heptane system was found to be superior than the piperazine counterpart 11.

Multicomponent synthesis of some new (1S,4S)-2,5-diazabicyclo[2.2.1]heptane-dithiocarbamates and their in vitro anti-proliferative activity against CaSki, MDA-MB-231 and SK-Lu-1 tumour cells as apoptosis inducing agents without necrosis.

Identification of a new class of antitumor agent capable to induce apoptosis without triggering necrotic cell death event is challenging. The present communication describes the multicomponent synthesis of seven new (1S,4S)-2,5-diazabicyclo[2.2.1]heptane-dithiocarbamates and their in vitro antiproliferative activity on cervical cancer cell line (CaSki), breast cancer cell line (MDA-MB231), lung cancer cell line (SK-Lu-1) and human lymphocytes. Among the synthesized dithiocarbamates, compound 9e displayed significant antiproliferative activity without inducing any necrotic cell death (both on tumour cells and lymphocytes) and induced apoptosis in tumor cells by the caspase dependent apoptotic pathway. The compound 9e also exhibited greater tumor selectivity than human lymphocytes. In silico ADME predictions revealed that compound 9e has the potential to be developed as a drug candidate. Rapid chemical modifications of this lead are thus highly necessary for further investigation as a drug like safer antitumor candidate and also to achieve compounds with better activity profile.

An Amphotericin B Derivative Equally Potent to Amphotericin B and with Increased Safety.

Amphotericin B is the most potent antimycotic known to date. However due to its large collateral toxicity, its use, although long standing, had been limited. Many attempts have been made to produce derivatives with reduced collateral damage. The molecular mechanism of polyene has also been closely studied for this purpose and understanding it would contribute to the development of safe derivatives. Our study examined polyene action, including chemical synthesis, electrophysiology, pharmacology, toxicology and molecular dynamics. The results were used to support a novel Amphotericin B derivative with increased selectivity: L-histidine methyl ester of Amphotericin B. We found that this derivative has the same form of action as Amphotericin B, i.e. pore formation in the cell membrane. Its reduced dimerization in solution, when compared to Amphotericin B, is at least partially responsible for its increased selectivity. Here we also present the results of preclinical tests, which show that the derivative is just as potent as Amphotericin B and has increased safety.

Evaluation of the antitumour activity of Rinvanil and Phenylacetylrinvanil on the cervical cancer tumour cell lines HeLa, CaSKi and ViBo.

Capsaicin is a potent inducer of apoptosis in tumourreceptor potential vanilloid 1 (TRPV1). The present study determined the IC50 and cytotoxic and apoptotic activities of the Capsaicin analogues Rinvanil and Phenylacetylrinvanil (PhAR) on three cervical cancer cell lines: HeLa, CaSKi and ViBo. These analogues possess an increased affinity for TRPV1 receptors. The IC50 obtained proved to be cytotoxic for all three cell lines; however, in the cells treated with Capsaicin both active caspase-3 and nuclear fragmentation were present. Capsaicin and its analogues also inhibited the normal proliferation of lymphocytes, suggesting that they are non-selective antitumour compounds. Finally, we discuss the possible loss of the relation between apoptosis and affinity to TRPV1, and the need for other strategies to synthesise Capsaicin analogues that can be useful in cancer treatments.

Antineoplastic activity of rinvanil and phenylacetylrinvanil in leukaemia cell lines.

In the search for novel chemotherapeutic agents for cancer treatment, capsaicin has been shown to inhibit proliferation and induce apoptosis in various types of cancer cell line, including leukaemia cell lines. The capsaicin analogues, rinvanil and phenylacetylrinvanil (PhAR), share a binding affinity for vanilloid receptors and may have biological activities similar to capsaicin; however, their anticancer potential has not yet been reported. This study analyses the antineoplastic activities of rinvanil and PhAR in leukaemia versus normal cells. P388, J774 and WEHI-3 leukaemia cell lines, as well as mouse bone marrow mononuclear cells, were cultured with varying concentrations of rinvanil and PhAR. Following this, proliferation and apoptosis were determined by the sulforhodamine B (SRB) assay and DNA ladder. Cultured leukaemia cell lines and mouse bone marrow mononuclear cells demonstrated a dose-dependent inhibition of proliferation, while non-diseased cells were less sensitive to the cytotoxic effect of capsaicin, rinvanil and PhAR. Rinvanil and PhAR also induced apoptosis in leukaemia cell lines but not in bone marrow. Given the lower IC50 values for apoptosis induction in leukaemia cells compared with that of normal cells, PhAR is a promising selective anticancer agent.

Synthesis of ranolazine derivatives containing the (1S,4S)-2,5-diazabicyclo[2.2.1]heptane moiety and their evaluation as vasodilating agents.

Two diazabicyclic analogues of ranolazine, (S,S,S)-5 and (S,S,R)-5, and their epimeric mixture were synthesized. Furthermore, their vasomotor effects on rat aorta rings precontracted with phenylephrine were analyzed. These compounds showed vasodilating effects significantly greater than ranolazine. The vasodilating activities of these analogues have two components, one that depends on the endothelium, due to the release of NO, and another one due to a direct effect on the vascular smooth muscle. The compounds [(S,S,S)(S,S,R)]-5 and (S,S,R)-5 induce, in a manner similar to ranolazine, the release of a prostanoid from the cyclooxygenase pathway, whose vasoconstrictor effect is masked by the predominant vasodilation induced by these compounds.

Copper versus thioether-centered oxidation: mechanistic insights into the non-innocent redox behavior of tripodal benzimidazolylaminothioether ligands.

A series of Cu(+) complexes with ligands that feature varying numbers of benzimidazole/thioether donors and methylene or ethylene linkers between the central nitrogen atom and the thioether sulfur atoms have been spectroscopically and electrochemically characterized. Cyclic voltammetry measurements indicated that the highest Cu(2+)/Cu(+) redox potentials correspond to sulfur-rich coordination environments, with values decreasing as the thioether donors are replaced by nitrogen-donating benzimidazoles. Both Cu(2+) and Cu(+) complexes were studied by DFT. Their electronic properties were determined by analyzing their frontier orbitals, relative energies, and the contributions to the orbitals involved in redox processes, which revealed that the HOMOs of the more sulfur-rich copper complexes, particularly those with methylene linkers (-N-CH2-S-), show significant aromatic thioether character. Thus, the theoretically predicted initial oxidation at the sulfur atom of the methylene-bridged ligands agrees with the experimentally determined oxidation waves in the voltammograms of the NS3- and N2S2-type ligands as being ligand-based, as opposed to the copper-based processes of the ethylene-bridged Cu(+) complexes. The electrochemical and theoretical results are consistent with our previously reported mechanistic proposal for Cu(2+)-promoted oxidative C-S bond cleavage, which in this work resulted in the isolation and complete characterization (including by X-ray crystallography) of the decomposition products of two ligands employed, further supporting the novel reactivity pathway invoked. The combined results raise the possibility that the reactions of copper-thioether complexes in chemical and biochemical systems occur with redox participation of the sulfur atom.

Effects of ranolazine on vasomotor responses of rat aortic rings.

BACKGROUND AND AIMS: Ranolazine is a piperazine derivative that was approved in 2006 for the treatment of chronic stable angina. Compared with first-line drugs currently used to treat angina, beneficial effects of ranolazine occur without changing hemodynamic parameters such as heart rate and blood pressure. In the present study the effects of ranolazine on vasomotor responses of rat aortic rings were examined. METHODS: Pharmacological evaluation was performed by analyzing the vasomotor responses of ranolazine on aortic rings of adult male Wistar rats precontracted with phenylephrine (10(-5) M). In each experiment we used a pair of rings (with and without endothelium) from the same aorta and superfused in the same bath. RESULTS: Ranolazine (10(-6)-10(-4) M) induced a concentration-dependent relaxation of phenylephrine-precontracted rings. The relaxation was only partially dependent on the presence of the endothelium (56.78 ± 6.81% in rings with endothelium and 47.88 ± 4.70% in rings without endothelium). In rings with endothelium, L-NAME induced a shift to the right of the concentration-response curve to ranolazine. Blocking the cyclooxygenase pathway induced a leftward shift of the concentration relaxation curve to ranolazine in both types of rings and increased the ranolazine-induced relaxation in rings without endothelium. CONCLUSIONS: Ranolazine has a vasodilatory effect that is predominantly endothelium-independent. The synthesis/release of nitric oxide by the endothelium may, however, contribute to its relaxing action. These effects of ranolazine may contribute to its beneficial effects in patients with stable angina.

Phenylpropanoid glycoside analogues: enzymatic synthesis, antioxidant activity and theoretical study of their free radical scavenger mechanism.

Phenylpropanoid glycosides (PPGs) are natural compounds present in several medicinal plants that have high antioxidant power and diverse biological activities. Because of their low content in plants (less than 5% w/w), several chemical synthetic routes to produce PPGs have been developed, but their synthesis is a time consuming process and the achieved yields are often low. In this study, an alternative and efficient two-step biosynthetic route to obtain natural PPG analogues is reported for the first time. Two galactosides were initially synthesized from vanillyl alcohol and homovanillyl alcohol by a transgalactosylation reaction catalyzed by Kluyveromyces lactis ß-galactosidase in saturated lactose solutions with a 30%-35% yield. To synthesize PPGs, the galactoconjugates were esterified with saturated and unsaturated hydroxycinnamic acid derivatives using Candida antarctica Lipase B (CaL-B) as a biocatalyst with 40%-60% yields. The scavenging ability of the phenolic raw materials, intermediates and PPGs was evaluated by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) method. It was found that the biosynthesized PPGs had higher scavenging abilities when compared to ascorbic acid, the reference compound, while their antioxidant activities were found similar to that of natural PPGs. Moreover, density functional theory (DFT) calculations were used to determine that the PPGs antioxidant mechanism proceeds through a sequential proton loss single electron transfer (SPLET). The enzymatic process reported in this study is an efficient and versatile route to obtain PPGs from different phenylpropanoid acids, sugars and phenolic alcohols.

The disulfiram metabolites S-methyl-N,N-diethyldithiocarbamoyl sulfoxide and S-methyl-N,N-diethylthiocarbamoyl sulfone irreversibly inactivate betaine aldehyde dehydrogenase from Pseudomonas aeruginosa, both in vitro and in situ, and arrest bacterial growth.

Betaine aldehyde dehydrogenase from the human opportunistic pathogen Pseudomonas aeruginosa (PaBADH) catalyzes the irreversible, NAD(P)(+)-dependent oxidation of betaine aldehyde, producing glycine betaine, an osmoprotectant. PaBADH participates in the catabolism of choline and likely in the defense against the osmotic and oxidative stresses to which the bacterium is exposed when infecting human tissues. Given that choline or choline precursors are abundant in infected tissues, PaBADH is a potential drug target because its inhibition will lead to the build up of the toxic betaine aldehyde inside bacterial cells. We tested the thiol reagents, disulfiram (DSF) and five DSF metabolites-diethyldithiocarbamic acid (DDC), S-methyl-N,N-diethyldithiocarbamoyl sulfoxide (MeDDTC-SO) and sulfone (MeDDTC-SO(2)), and S-methyl-N,N-diethylthiocarbamoyl sulfoxide (MeDTC-SO) and sulfone (MeDTC-SO(2))-as inhibitors of PaBADH and P. aeruginosa growth. As in vitro PaBADH inhibitors, their order of potency was: MeDDTC-SO(2)>DSF>MeDTC-SO(2)>MeDDTC-SO>MeDTC-SO. DDC did not inactivate the enzyme. PaBADH inactivation by DSF metabolites (i) was not affected by NAD(P)(+), (ii) could not be reverted by dithiothreitol, and (iii) did not affect the quaternary structure of the enzyme. Of the DSF metabolites tested, MeDTC-SO(2) and MeDDTC-SO produced significant in situ PaBADH inactivation and arrest of P. aeruginosa growth in choline containing media, in which the expression of PaBADH is induced. They had no effect in media lacking choline, indicating that PaBADH is their main intracellular target, and that arrest of growth is due to accumulation of betaine aldehyde. The in vitro and in situ kinetics of enzyme inactivation by these two compounds were very similar, indicating no restriction on their uptake by the cells. MeDDTC-SO(2) and DSF have no inhibitory effects in situ, probably because their high reactivity towards intracellular nonessential thiols causes their depletion. Our results support that PaBADH is a promising target to treat P. aeruginosa infections, and that some DSF metabolites might be of help in this aim.

Synthesis of the steroidal glycoside (25R)-3ß,16ß-diacetoxy-12,22-dioxo-5α-cholestan-26-yl ß-D-glucopyranoside and its anti-cancer properties on cervicouterine HeLa, CaSki, and ViBo cells.

The synthesis of the new glycoside (25R)-3ß,16ß-diacetoxy-12,22-dioxo-5α-cholestan-26-yl ß-D-glucopyranoside starting from hecogenin is described. This compound showed anti-cancer activity against cervicouterine cancer cells HeLa, CaSki and ViBo in the micromolar range. Its effect on cell proliferation, cell cycle and cell death is also described. The cytotoxic effect of the title compound on HeLa, CaSki and ViBo cells and human lymphocytes was evaluated through the LDH released in the culture supernatant, indicating that the main cell death process is not necrosis; the null effect on lymphocytes implies that it is not cytotoxic. The ability of this novel glycoside to induce apoptosis was investigated; several apoptosis events like chromatin condensation, formation of apoptotic bodies, as well as the increase in the expression of active caspase-3 and the fragmentation of DNA confirmed that the compound induced apoptosis in cervicouterine cancer cells. Significantly, the antiproliferative activity on tumor cells did not affect the proliferative potential of normal fibroblasts from cervix and peripheral blood lymphocytes. The glycoside showed selective antitumor activity and greater antiproliferative activity than its aglycon; it therefore serves as a promising lead candidate for further optimization.

Chemoenzymatic synthesis and cannabinoid activity of a new diazabicyclic amide of phenylacetylricinoleic acid.

Endocannabinoids (eCBs) are endogenous neuromodulators of synaptic transmission. Their dysfunction may cause debilitating disorders of diverse clinical manifestation. For example, drug addiction, lack of sex desire, eating disorders, such as anorexia or bulimia and dyssomnias. eCBs also participate in the regulation of core temperature and pain perception. In this context, it is important to recognize the utility of cannabinoid receptor 1 (CB1R) agonists, natural as Delta(9)-tetrahydrocannabinol (THC) or synthetic as Nabilone as useful drugs to alleviate this kind of patients' suffering. Therefore, we have developed a new drug, (R,Z)-18-((1S,4S)-5-methyl-2,5-diazabicyclo[2.2.1]heptan-2-yl)-18-oxooctadec-9-en-7-yl phenylacetate (PhAR-DBH-Me), that appears to bind and activate the CB1R. This diazabicyclic amide was synthesized from phenylacetylricinoleic acid and (1S,4S)-2,5-diazabicyclo[2.2.1]heptane. To test its cannabinergic properties we evaluated its effects on core temperature, pain perception, and the sleep-waking cycle of rats. Results indicate that 20 and 40mg/kg of PhAR-DBH-Me readily reduced core temperature and increased pain perception threshold. In addition, 20mg/kg increased REM sleep in otherwise normal rats. All these effects were prevented or attenuated by AM251, a CB1R antagonist. Place preference conditioning studies indicated that this molecule does not produce rewarding effects. These results strongly support that PhAR-DBH-Me possesses cannabinoid activity without the reinforcement effects.

Synthesis and cardiovascular activity of metoprolol analogues.

The synthesis of four novel analogues of metoprolol, a well-known beta1-blocker used to reduce arterial blood pressure, is described. The preparation of (2S,2'S)-7, (2R,2'S)-7, (2R,2'R)-8, and (2S,2'R)-8 was based on the reaction of racemic 2-[4-(2'-methoxyethyl)-phenoxymethyl]-oxirane (4) with (R)- or (S)-2-amino-1-butanol. Salient characteristics of analogues 7 and 8 relative to metoprolol are the incorporation of an additional stereogenic center, as well as a methyl group and a hydroxyl function on the nitrogen-containing chain. These novel derivatives present significant hypotensive and bradycardiac activity, although no blocking action toward beta1 and beta2 adrenergic receptor.

Preparation of (R) and (S) alpha methyldopa from a chiral hydantoin containing the alpha phenylethyl group.

Chiral hydantoin (S)-1 was prepared in good yield from phenyl isocyanate and N-[(S)-alpha-phenylethyl]glycinate, (S)-3. Enolate (S)-1-Li was methylated in high yield and good diastereoselectivity. In contrast, a second alkylation reaction of methylated enolate (S)-4-Li proceeded with essentially no diastereoselectivity. Nevertheless, dialkylated hydantoins, (S,S)-7 and (S,R)-7, could be readily separated by flash chromatography and subsequent hydrolysis of either derivative afforded the desired (S)-L-alpha-methyldopa or (R)-D-alpha-methyldopa in good yield.