Lipid conjugation of TLR7 agonist Resiquimod ensures co-delivery with the liposomal Cationic Adjuvant Formulation 01 (CAF01) but does not enhance immunopotentiation compared to non-conjugated Resiquimod+CAF01.

Pattern recognition receptors, including the Toll-like receptors (TLRs), are important in the induction and activation of two critical arms of the host defence to pathogens and microorganisms: the rapid innate immune response (as characterised by the production of Th1 promoting cytokines and type 1 interferons) and the adaptive immune response. Through this activation, ligands and agonists of TLRs can enhance immunotherapeutic efficacy. Resiquimod is a small (water-soluble) agonist of the endosome-located Toll-like receptors 7 and 8 (TLR7/8). However due to its molecular attributes it rapidly distributes throughout the body after injection. To circumvent this, these TLR agonists can be incorporated within delivery systems, such as liposomes, to promote the co-delivery of both antigen and agonists to antigen presenting cells. In this present study, resiquimod has been chemically conjugated to a lipid to form a lipid-TLR7/8 agonist conjugate which can be incorporated within immunogenic cationic liposomes composed of dimethyldioctadecylammonium bromide (DDA) and the immunostimulatory glycolipid trehalose 6,6' - dibehenate (TDB). This DDA:TDB-TLR7/8 formulation offers similar vesicle characteristics to DDA:TDB (size and charge) and offers high retention of both resiquimod and the electrostatically adsorbed TB subunit antigen Ag85B-ESAT6-Rv2660c (H56). Following immunisation through the intramuscular (i.m.) route, these cationic DDA:TDB-TLR7/8 liposomes form a vaccine depot at the injection site. However, immunisation studies have shown that this biodistribution does not translate into notably increased antibody nor Th1 responses at the spleen and draining popliteal lymph node compared to DDA:TDB liposomes. This work demonstrates that the conjugation of TLR7/8 agonists to cationic liposomes can promote co-delivery but the immune responses stimulated do not merit the added complexity considerations of the formulation.

Analgesic Effects of 5-Alkyloxy-4-amino-2(5H)-furanones as Cholecystokinin-2 Antagonists.

4-Amino-2(5H)-furanones were synthesized in high yields over two synthetic steps from readily available mucochloric acid. These 5-alkyloxy-4-amino-2(5H)-furanones were screened in a ([125]) I-CCK-8 radioligand receptor binding assay for CCK2 affinity and novel active ligands in the nanomolar range were identified. SAR was optimized leading to the cyclohexyl derivative 25 with an IC50 of 27 nM. Furanone 18 was obtained as a stable crystalline material with an IC50 of 85 nM, but had a higher CCK2 selectivity. It was subsequently tested in the isolated guinea pig ileum assay with sulfated CCK8 , and the CCK antagonizing properties of the ligand were confirmed. The CCK2 selective antagonist 18 was found to potentiate analgesia in the tail flick assay in mice, for the strong opiate morphine, the partial opiate agonist tramadol and the tricyclic antidepressant desimipramine.

Novel, isoform-selective, cholecystokinin A receptor antagonist inhibits colon and pancreatic cancers in preclinical models through novel mechanism of action.

Colon and pancreatic cancers contribute to 90,000 deaths each year in the USA. These cancers lack targeted therapeutics due to heterogeneity of the disease and multiple causative factors. One important factor that contributes to increased colon and pancreatic cancer risk is gastrin. Gastrin mediates its actions through two G-protein coupled receptors (GPCRs): cholecystokinin receptor A (CCK-A) and CCK-B/gastrin receptor. Previous studies have indicated that colon cancer predominantly expresses CCK-A and responds to CCK-A isoform antagonists. However, many CCK-A antagonists have failed in the clinic due to poor pharmacokinetic properties or lack of efficacy. In the present study, we synthesized a library of CCK-A isoform-selective antagonists and tested them in various colon and pancreatic cancer preclinical models. The lead CCK-A isoform, selective antagonist PNB-028, bound to CCK-A at 12 nM with a 60-fold selectivity towards CCK-A over CCK-B. Furthermore, it inhibited the proliferation of CCK-A-expressing colon and pancreatic cancer cells without affecting the proliferation of non-cancerous cells. PNB-028 was also extremely effective in inhibiting the growth of MAC-16 and LoVo colon cancer and MIA PaCa pancreatic cancer xenografts in immune-compromised mice. Genome­wide microarray and kinase-array studies indicate that PNB-028 inhibited oncogenic kinases and angiogenic factors to inhibit the growth of colon cancer xenografts. Safety pharmacology and toxicology studies have indicated that PNB-028 is extremely safe and has a wide safety margin. These studies suggest that targeting CCK-A selectively renders promise to treat colon and pancreatic cancers and that PNB-028 could become the next-generation treatment option.

Anticancer Effects of Curcuma C20-Dialdehyde against Colon and Cervical Cancer Cell Lines.

BACKGROUND: Recent attention on chemotherapeutic intervention against cancer has been focused on discovering and developing phytochemicals as anticancer agents with improved efficacy, low drug resistance and toxicity, low cost and limited adverse side effects. In this study, we investigated the effects of Curcuma C20-dialdehyde on growth, apoptosis and cell cycle arrest in colon and cervical cancer cell lines. MATERIALS AND METHODS: Antiproliferative, apoptosis induction, and cell cycle arrest activities of Curcuma C20-dialdehyde were determined by WST cell proliferation assay, flow cytometric Alexa fluor 488-annexin V/propidium iodide (PI) staining and PI staining, respectively. RESULTS: Curcuma C20 dialdehyde suppressed the proliferation of HCT116, HT29 and HeLa cells, with IC50 values of 65.4±1.74 µg/ml, 58.4±5.20 µg/ml and 72.0±0.03 µg/ml, respectively, with 72 h exposure. Flow cytometric analysis revealed that percentages of early apoptotic cells increased in a dose-dependent manner upon exposure to Curcuma C20-dialdehyde. Furthermore, exposure to lower concentrations of this compound significantly induced cell cycle arrest at G1 phase for both HCT116 and HT29 cells, while higher concentrations increased sub-G1 populations. However, the concentrations used in this study could not induce cell cycle arrest but rather induced apoptotic cell death in HeLa cells. CONCLUSIONS: Our findings suggest that the phytochemical Curcuma C20-dialdehyde may be a potential antineoplastic agent for colon and cervical cancer chemotherapy and/or chemoprevention. Further studies are needed to characterize the drug target or mode of action of the Curcuma C20-dialdehyde as an anticancer agent.

Antipyretic, analgesic and anti-oxidative activities of Aquilaria crassna leaves extract in rodents.

In Thailand, the leaves of Aquilaria crassna have been used traditionally for the treatments of various disorders, but without any scientific analysis. In this study, the antipyretic, analgesic, anti-inflammatory and anti-oxidative properties of A. crassna leaves extract were investigated at a wide dose range in rodents. Experimental animals were treated orally with an aqueous extract of Aquilaria crassna leaves (ACE). They were tested for antipyretic (Baker's yeast-induced fever in rats), analgesic (hot plate test in mice) and anti-inflammatory (carrageenan-induced paw edema in rats) activities. An anti-oxidative effect of ACE was evaluated by using the DPPH anti-oxidant assay. The results showed that, after 5 hours of yeast injection, 400 and 800 mg/kg ACE significantly reduced the rectal temperature of rats. Mice were found significantly less sensitive to heat at an oral dose of 800 mg/kg ACE, after 60 and 90 min. No anti-inflammatory activity of ACE at an 800 mg/kg dose could be observed in the rat paw assay. An anti-oxidative activity of ACE was observed with an IC (50)value of 47.18 µg/ ml. No behavioral or movement change could be observed in mice after oral administration of ACE (800 or 8,000 mg/kg) for seven consecutive days. Interestingly, from the second day of treatment, animals had a significant lower body weight at the 8,000 mg/kg dose of ACE compared to the control. No toxicity was identified and the results of this study state clearly that Aquilaria crassna leaves extracts possess antipyretic, analgesic and anti-oxidative properties without anti-inflammatory activity.

Microscopy imaging of liposomes: from coverslips to environmental SEM.

A plethora of techniques for the imaging of liposomes and other bilayer vesicles are available. However, sample preparation and the technique chosen should be carefully considered in conjunction with the information required. For example, larger vesicles such as multilamellar and giant unilamellar vesicles can be viewed using light microscopy and whilst vesicle confirmation and size prior to additional physical characterisations or more detailed microscopy can be undertaken, the technique is limited in terms of resolution. To consider the options available for visualising liposome-based systems, a wide range of microscopy techniques are described and discussed here: these include light, fluorescence and confocal microscopy and various electron microscopy techniques such as transmission, cryo, freeze fracture and environmental scanning electron microscopy. Their application, advantages and disadvantages are reviewed with regard to their use in analysis of lipid vesicles.

Antidepressant/anxiolytic and anti-nociceptive effects of novel 2-substituted 1,4-benzodiazepine-2-ones.

Oxazepam (4a) has been used as overall starting material in the synthesis of novel 2-substituted 1,4-benzodiazepines.By reacting Oxazepam 4a with commercially available hydrazines, hydrazides, semicarbazide, aminoguanidine and N,N-dimethylamino aniline in ethanol under acetic conditions, a series of diazenyl-1,4-benzodiazepines 5aâ5i and 2-amino-1,4-benzodiazepine 5k were obtained in good yields.These novel compounds served as new chemical entities (NCE) for testing in mice. The diazo-benzodiazepine 5d has shown a promising antidepressant effect in initial experiments in vivo at a dose of 5 mg/kg. The highly coloured 2-aminobenzodiazepine derivative 5k showed over a dose range from 5â50 mg/kg an analgesic effect in mice.

In-vitro and in-vivo antivenin activity of 2-[2-(5,5,8a-trimethyl-2-methylene-decahydro-naphthalen-1-yl)-ethylidene]-succinaldehyde against Ophiophagus hannah venom.

OBJECTIVES: Curcuma zedoaroides A. Chaveerach & T. Tanee, locally known as Wan-Paya-Ngoo-Tua-Mia, is commonly used in the North-Eastern part of Thailand as a 'snakebite antidote'. The aim of this study was to isolate the active compound from the rhizome of C. zedoaroides, to determine its structure and to assess its antagonistic activity in vitro and in vivo against King cobra venom. METHODS: The active compound was obtained from C. zedoaroides by extraction with acetone followed by purification using column chromatography; its X-ray structure was determined. Its inhibition of venom lethality was studied in vitro in rat phrenic nerve-hemidiaphragms and in vivo in mice. KEY FINDINGS: The acetone extract of the Curcuma rhizomes contained a C20 dialdehyde, [2-(5,5,8a-trimethyl-2-methylene-decahydro-naphthalen-1-yl)-ethylidene]-succinaldehyde, as the major component. The isolated curcuma dialdehyde was found active in vitro and in vivo for antivenin activity against the King cobra venom. Using isolated rat phrenic nerve-hemidiaphragm preparations, a significant antagonistic effect on the inhibition of neuromuscular transmission was observed in vitro. Inhibition on muscle contraction, produced by the 4 microg/ml venom, was reversed by 2-16 microg/ml of Curcuma dialdehyde in organ bath preparations over a period of 2 h. Mice intraperitoneally injected with 0.75 mg/kg venom and dialdehyde at 100 mg/kg had a significantly increased survival time. Injection of Curcuma dialdehyde (100 mg/kg) 30 min before the subcutaneous injection of the venom resulted in a 100% survival time after 2 h compared with 0% for the control group. CONCLUSIONS: The in vitro and in vivo evaluation confirmed the medicinal use of traditional snake plants against snakebites. The bioactivity is linked to an isolated molecule and not a result of synergistic effects of a mixture. The active compound was isolated and the structure fully elucidated, including its stereochemistry. This dialdehyde is a versatile chemical building block and can be easily obtained from this plant source.

In vivo evaluation of substituted 3-amino-1,4-benzodiazepines as anti-depressant, anxiolytic and anti-nociceptive agents.

Oxazepam (CAS 604-75-1) 4a served as building block in the synthesis of substituted 3-amino-1,4-benzodiazepines, which were subsequently tested in various CNS animal models. The hydroxy group of oxazepam was either activated as a chloride (Method A) or as a phosphor-oxy derivative (Method B) giving the desired 3-amino-1,4-benzodiapines 6a-6r in high yields with primary and secondary amines in a typical nucleophilic substitution reaction. Eighteen 3-substituted 1,4-benzodiazepines were prepared and served as new chemical entities and for lead structure discovery. The mixed cholecystokinin (CCK) antagonist 6e showed anxiolytic and antidepressant effects from 10 microg/kg in mice in the elevated x-maze test and the forced swimming test. The CCK1 antagonist 6 g has shown antidepressant effects from the same dose, but lacked anxiolytic properties. Both compounds potentiated at a dose of 0.5 mg/kg morphine antinociception with a maximum possible effect (MPE) about 35%. By assessing initially the MPE of antinocipection for the 18 newly synthesised benzodiazepines in the tail-flick test, 4 other benzodiazepines were found active. In further in vive evaluation the cyclohexyl derivative 6 i displayed anxiolytic, antidepressant and antinociceptive properties as single agent at a dose of 5 mg/kg without toxicity. The benzodiazepines 6i and 6p, which initially showed a higher MPE in terms of morphine potentiation (43/44%) showed analgesic effects as single agents, without having anxiolytic or antidepressant properties. The amino-piperidinyl derivative 6p displayed a similar dose-response relationship to morphine, but was 3 times more potent.

Novel anti-bacterials against MRSA: synthesis of focussed combinatorial libraries of tri-substituted 2(5H)-furanones.

Mucobromic and mucochloric acid were used as building blocks for the construction of a chemical combinatorial library of 3,4,5-trisubstituted 2(5H)-furanones. With these 2 butenolide building blocks, and eight alcohols a sublibrary of 16 dihalogenated 5-alkoxy-2(5H)-furanones was prepared. This sublibrary of 5-alkoxylated furanones was reacted with 16 amines generating a full size focussed combinatorial library of 256 individual compounds. This three dimensional combinatorial library of 3-halogen-4-amino-5-alkoxy-2(5H)-furanones was prepared around the benzimida-zolyl furanone lead structure by applying a solution phase combinatorial chemistry concept. Typical representatives of the library were purified and fully characterized and one x-ray structures was recorded, additionally. The 3-bromo-4-benzimizazolyl-5-methoxy-2(5H)furanone, Br-A-l, showed an MIC of 8 microg/ml against the multiresistant Staphylococcus aureus (MRSA).

Synthesis of substituted 3-anilino-5-phenyl-1,3-dihydro-2H-1,4-benzodiazepine-2-ones and their evaluation as cholecystokinin-ligands.

3-Amino-1,4-benzodiazepines as well as chemically related diverse amines were prepared from oxazepam and subsequently screened on the cholecystokinin receptor in a radiolabel binding assay. Oxazepam 2 was activated via its 3-chloro-1,4-benzodiazepine intermediate 3 and was reacted with a large series of aliphatic and aromatic amines. The substituted 3-anilino-1,4-benzodiazepine structure was identified as lead structure in a diverse series of 3-amino-1,4-benzodiazepines 4-38 and the full SAR (structure-activity relationship) optimisation provided 3-anilinobenzodiazepines 16-38 with CCK1 receptor selectivity to CCK2. The compounds 18, 24, 28 and 33 have shown affinities at the CCK1 receptor of 11, 10, 11 and 9 nM, respectively. These equipotent CCK1 ligands were fully evaluated in behaviour pharmacological essays. An antidepressant effect was identified in the tail suspension- and the Porsolt swimming-test. The ED50 values for 24 and 28 were determined in these assays as 0.46 and 0.49 mg/kg. The mixed antagonist 37 showed in addition to the antidepressant effects anxiolytic properties.

Synthesis and evaluation of N-(3-oxo-2,3-dihydro-1H-pyrazol-4-yl)-1H-indole-carboxamides as cholecystokinin antagonists.

The structure-activity relationship optimization of the pyrazoline template 3a resulted in novel 3-oxo-1,2-diphenyl-2,3-dihydro-1H-pyrazol-4-yl)-indole carboxamides 4a-4e. These non-peptidal CCK ligands have been shown to act as potent CCK1 ligands in a [125]I-CCK-8 receptor binding assay. The best amides (4c and 4d) of this series displayed an IC50 of 20/25 nM for the CCK1 receptor. In a subsequent in-vivo evaluation using various behaviour pharmacological assays, an anxiolytic effect of these novel 3-oxo-1,2-diphenyl-2,3-dihydro-1H-pyrazol-4-yl)-indole carboxamides was found at high doses in the elevated plus-maze. In the despair swimming test, a model for testing antidepressants, an ED50 of 0.33/0.41 mg kg(-1) was determined for amide 4c/4d and the antidepressant effect had a magnitude comparable to desimipramine.

Synthesis and evaluation of N-(5-methyl-3-oxo-1,2- diphenyl-2,3-dihydro-1H-pyrazol-4-yl)-N'-phenylureas as cholecystokinin antagonists.

In the search for new cholecystokinin (CCK) ligands, ureidopyrazolines were identified in combinatorial libraries using 168 chemically diverse amines. The structure-activity relationship optimisation of this pyrazoline template 4a resulted in novel 3-oxo-1,2-diphenyl-2,3-di-hydro-1H-pyrazol-4-yl)-N'-phenylureas 5a-5o. These novel CCK ligands have shown to act as mixed CCK-A/CCK-B ligands in a [125]I-CCK-8 receptor binding assay. The best pyrazoline 5e of this series displayed an IC50 of 20 and 25 nmol/L for the CCK-A, and CCK-B receptor, respectively. In a subsequent in vivo evaluation using various behavior pharmacological assays, an anxiolytic effect of these novel diphenylpyrazolinyl ureas was found in the elevated x-maze with an ED50 of 1.7 mg/kg. In the despair swimming test, a model for testing antidepressants, an ED50 of 0.69 mg/kg was determinated for urea 5e and the antidepressant effect had a magnitude comparable to desimipramine.

Synthesis and antibacterial activities of 5-hydroxy-4-amino-2(5H)-furanones.

Starting from the mucohalogen acids 1a and b 5-hydroxy-2(5H)-furanones 2a-h have been prepared and tested. These novel 4-amino-5-hydroxy 2(5H)-furananones have shown a broad antibiotic activity against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 in the micromolar range. A one step synthesis from mucohalogen acids towards the antibacterials 2a-h was developed, in which the target was obtained from 1a and b under reflux in toluene in presence of a catalytic amount of sulfuric acid. The derivatives 2b and c displayed a MIC and MBC of 4/8mug/ml, against Staphylococcus aureus with a selectivity towards the resistant strains.

Cytotoxicity of 3,4-dihalogenated 2(5H)-furanones.

Mucohalogen acids have been used for the preparation of a variety of 3,4-dihalogenated 2(5H)-furanones. In one synthetic step the carbamates 2a-c and the pseudoanhydrides 4a-e were prepared using isocyanates and acid anhydrides. A series of 5-alkoxylated 3,4-dichloro-2(5H)-furanones 5a-o have been synthesized with a wide range of lipophilicity, using the hydroxy-form of mucohalogen acids 1a and 1b. The 5-allyl-3,4-dichloro-2(5H)-furanone 5f was derived into the dihydro-isoxazol 6 and the oxirane 7. The methyl ester 5a was converted with ammonia into the tetramic acid chloride 11. The pseudo acid chloride 3 was reacted further into the bis aziridine 8. Reduction of the mucochloric acid 1a furnished the trichlorofuranone 3. The cytotoxicity of these simple and bis-cyclic butenolides have been evaluated in tissue culture on MAC13 and MAC16 cancer cell lines using the MTT cytotoxicity assay. The ester 5g, the acetate 4b and the carbamate 2b displayed a cytotoxicity in the low micromolar range. Further, an IC50 (50% inhibitory concentration) of 50 nM and 30 nM was determined for the epoxide 7 and the aziridine 8.

Synthesis and evaluation of 5-arylated 2(5H)-furanones and 2-arylated pyridazin-3(2H)-ones as anti-cancer agents.

Bis-cyclic butenolides, 5-arylated 2(5H)-furanones 6a - c, 7a, b and the 3(2H)-pyridazones 9a - d were prepared by using the aldehyde form of muco halogen acids in electrophilic substitution reactions and in an aldol-like condensation reaction. The cytotoxicity of these simple and bis-cyclic butenolides have been evaluated in tissue culture studies on MAC 13 and MAC 16 murine colon cancer cell lines. The butyl furanone 3 displayed the highest cytotoxicity of 3 microM, as one selected example of a series of dichlorinated pseudoesters. The 5-arylated 2(5H)-furanones 6 and 7 did not show a structure-activity relationship (SAR) depending on the substitution pattern of the aromatic system. An IC50 (concentration inhibiting growth by 50%) was found within a range of 30-50 and 40-50 microM for the MAC 13 and MAC 16 cell lines, respectively. The pyridazine series 9 showed a maximum in-vitro activity for the p-methoxydrivative 9b, having an IC50 of 17 in MAC 13 and 11 microM in MAC 16 cell lines. Selected examples of each series and further novel 2(5H)-furanones such as the hydrazone 5 and the hydantoin 8 have been screened in-vivo in mice and the data are presented. For the pyridazines 9a - d, the in-vitro cytotoxicity correlated with an in-vivo inhibition of tumour growth. The ring expansion of the 5-membered 2(5H)-furanone ring system such as 6a into the 6-membered 3(2H)-pyridazone 9b led to an agent with improved antineoplastic properties. On the resistant MAC 16 cell line the pyridazone 9b displayed 52% tumour inhibition in mice at a dose of 50 mg kg(-1) compared with 27% for the 5-FU standard.

Preparation of 6-thioguanosine phosphoramidite for oligoribonucleotide synthesis.

6-Thioguanosine phosphoramidite was prepared, using 2,4-dinitrophenyl as protection group for thio-function, and its stability towards conditions of RNA synthesis was investigated. The results show that the monomer was stable under the conditions of RNA synthesis and suitable for incorporation of thioguanine into oligoribonucleotides.

Synthesis of S6-(2,4-dinitrophenyl)-6-thioguanosine phosphoramidite and its incorporation into oligoribonucleotides.

The preparation of N(2)-phenoxylacetyl-S(6)-(2,4-dinitrophenyl)-6-thioguanosine phosphoramidite and its subsequent incorporation into oligoribonucleotides is described. The identity of the oligonucleotides was confirmed by UV spectrophotometry and nucleoside composition analysis.

Combinatorial solid phase synthesis of multiply substituted 1,4-benzodiazepines and affinity studies on the CCK2 receptor (part 1).

One hundred sixty-eight multiply substituted 1,4-benzodiazepines have been prepared by a five-step solid-phase combinatorial approach using syn-phase crowns as a solid support and a hydroxymethyl-phenoxy-acetamido linkage (Wang linker). The substituents of the 1,4-benzodiazepine scaffold have been varied in the -3, -5, -7, and 8-positions and the combinatorial library was evaluated in a chole cys to kinin (CCK) radioligand binding assay. 3-Alkylated 1,4-benzodiazepines with selectivity towards the CCK-B (CCK2) receptor have been optimized on the lipophilic side chain, the ketone moiety, and the stereochemistry at the 3-position. Various novel 3-alkylated compounds were synthesized and [S]3-propyl-5-phenyl-1,4-benzodiazepin-2-one, [S]NV-A, has shown a CCK-B selective binding at about 180 nM. Fifty-eight compounds of this combinatorial library were purified by preparative TLC and 25 compounds were isolated and fully characterized by TLC, IR, APCI-MS, and 1H/13C-NMR spectroscopy.

Synthesis and evaluation of N1-substituted-3-propyl-1,4-benzodiazepine-2-ones as cholecystokinin (CCK2) receptor ligands.

A novel synthetic approach towards N1-alkylated 3-propyl-1,4-benzodiazepines was developed in five synthetic steps from 2-amino-4-chlorobenzophenone, in which the N-oxide 4 served as a key intermediate. The structure-activity relationship optimization of this 3-propyl-1,4-benzodiazepine template was carried out on the N1-position by selective alkylation reactions and resulted in a ligand with an improved affinity on the cholecystokinin (CCK2) receptor. The N-allyl-3-propyl-benzodiazepine 6d displayed an affinity towards the CCK2 (CCK-B) receptor of 170 nM in a radiolabelled receptor-binding assay. The anxiolytic activity of this allyl-3-propyl-1,4-benzodiazepine 6d was subsequently determined in in-vivo psychotropic assays. This novel ligand had ED50 values of 4.7 and 5.2 mg kg(-1) in the black and white box test and the x-maze, respectively, and no significant sedation/muscle relaxation was observed.