Comparison of anti-aggregatory activities of 5-phenyl-3-(3-pyridyl)isoxazole and 5-phenyl-3-(3-pyridyl)-1,2,4-oxadiazole

Two bioisosteric analogs, 5-phenyl-3-(3-pyridyl)isoxazole and 5-phenyl-3-(3-pyridyl)-1,2,4-oxadiazole, were synthesized so as to compare their antiaggregatory activities, to determine a pharmacologically active fragment in molecules of this type, and to explore the mechanisms of action of potential antiag-gregatory compounds belonging to the class of 3,5-substituted isoxazoles. Antiaggregatory activities of these compounds were studied in vitro using three aggregation inducers, such as arachidonic acid, adenosine diphosphate, and adrenaline. It was shown that 5-phenyl-3-(3-pyridyl)-1,2,4-oxadiazole and 5-phenyl-3-(3-pyridyl)isoxazole completely suppressed platelet aggregation induced by arachidonic acid and the second wave of platelet aggregation induced by adrenaline or adenosine diphosphate. The antiaggregatory activity of substituted isoxasole was 1.1–1.5 times higher than that of substituted oxadiazole. In contrast to the isoxazole analog, 5-phenyl-3-(3-pyridyl)-1,2,4-oxadiazole in concentrations of 300–400 μM partially suppressed the first wave of aggregation induced by adenosine diphosphate. It was demonstrated that both compounds were not thrombin inhibitors in vitro at concentrations up to 250 μM. Thus, introduction of a nitrogen atom into the C4-position of the isoxazole ring changes the molecule properties. It suggests that the pharmacophoric fragment of the molecule should be the whole isoxazole or 1,2,4-oxadiazole ring but not a part of the ring as was supposed previously.     

Antitumor activities of O-sulfonated derivatives of (1-->3)-alpha-D-glucan from different Lentinus edodes

Four water-insoluble (1-->3)-alpha-D-glucans, coded L-II1, L-II2, L-II3 and L-II4, with different molecular weights were isolated from four kinds of fruiting bodies of Lentinus Edodes. The four alpha-D-glucans were O-sulfonated to obtain derivatives (SL-II) having degrees of substitution (DS) from 0.9 to 2.1 respectively. The structure of the samples was analyzed by infrared spectra, elemental analysis, and 13C NMR. The weight-average molecular weight (Mw), radii of gyration (z1/2) and intrinsic viscosity ([eta]) of the native alpha-D-glucans and O-sulfonated derivatives were measured by size-exclusion chromatography combined with laser light scattering (SEC-LLS), LLS, and viscometry in 0.2 M aqueous NaCl and in dimethyl sulfoxide (DMSO) containing 0.25 M LiCl at 25 degrees C respectively. The Mw values of the O-sulfonated derivatives were much lower than those of the native alpha-D-glucans. The experimental results indicate that the O-sulfonated derivatives are water-soluble and exist as an expanded flexible chain in aqueous solution owing to intramolecular hydrogen bonding or interaction between charge groups. The in vivo and in vitro antitumor activities of the native alpha-D-glucans and their O-sulfonated derivatives against solid tumor Sarcoma 180 cells were evaluated and compared. Interestingly, all of the O-sulfonated derivatives exhibited higher antitumor activities than those of the native glucans. The results reveal that the effect of O-sulfonation of the alpha-D-glucan on the improvement of their antitumor activities was considerable.     

Synthesis,antibacterial and antifungal activities of 3-(1,2,4-triazol-3-yl)-4-thiazolidinones

A new series of 3-(1,2,4-triazol-3-yl)-4-thiazolidinone derivatives has been synthesized by the reaction of Schiff bases of 3-amino-1,2,4-triazoles with mercaptoacetic acid and 2-mercaptopropionic acid. Their antibacterial and antifungal activities were evaluated against S. aureus, S. epidermidis, C. albicans and C. glabrata     

Synthesis of N-aryl-3-(indol-3-yl)propanamides and their immunosuppressive activities

N-Aryl-3-(indol-3-yl)propanamides were synthesized and their immunosuppressive activities were evaluated. This study highlighted the promising potency of 3-[1-(4-chlorobenzyl)-1H-indol-3-yl]-N-(4-nitrophenyl)propanamide 15 which exhibited a significant inhibitory activity on murine splenocytes proliferation assay in vitro and on mice delayed-type hypersensitivity (DTH) assay in vivo.     

Cytokinins: Synthesis of 2-, 8-, and 2,8-substituted 6-(3-methyl-2-butenylamino)purines and their relative activities in promoting cell growth

We have synthesized 2- and 8-monosubstituted and 2,8-disubstituted derivatives of the cytokinin 6-(3-methyl-2-butenylamino)purine (N⁶-isopentenyladenine) and have shown the dependence of growth-promoting activity in the tobacco bioassay upon the position, number, and type of substituent. The representative substituent groups were MeS, Me, MeSO₂, C₆H₅CH₂S, HS and Cl. The 8-methyl derivative was exceptional in being more active than the unsubstituted parent compound. In general, substitution in the 8-position decreases activity less than substitution in the 2-position, with the exception of the electron-attracting methylsulfonyl. Substitution in both the 2- and 8-positions lowers the activity more than substitution at either single position on the adenine nucleus, with the exception of the 2,8-dimethyl derivative. The chloro and methylthio derivatives show activity in the same range as the methyl derivatives, and the mercapto compounds, which exist mainly as CS tautomers, show somewhat less activity than the corresponding methylthio compounds. Bulky (C₆H₅CH₂S and MeSO₂) and strongly electron-attracting (MeSO₂) substituents cause relatively great reduction in cytokinin activity.     

Synthesis and biological activities of octyl 2,3,4-tri-O-sulfo-alpha-L-fucopyranosyl-(1-->3)-2,4-di-O-sulfo-alpha-L-fucopyranosyl-(1-->3)-2,4-di-O-sulfo-alpha-L-fucopyranosyl-(1-->3)-2,4-di-O-sulfo-beta-L-fucopyranoside

An efficient method for the regioselective 3-O-silylation of beta-thiofucopyranoside was disclosed. Based on this discovery, we described a high-yielding strategy for the synthesis of the natural core structure of L-fucan and its fully sulfated derivative. The bioassay suggested that octyl 2,3,4-tri-O-sulfo-alpha-L-fucopyranosyl-(1-->3)-2,4-di-O-sulfo-alpha-L-fucopyranosyl-(1-->3)-2,4-di-O-sulfo-alpha-L-fucopyranosyl-(1-->3)-2,4-di-O-sulfo-beta-L-fucopyranoside presented better antitumor activities than that of the free tetramer based on Sarcoma 180 cells and Lewis lung carcinoma model studies.     

Synthesis and anti-rheumatoid arthritis activities of 3-(4-aminophenyl)-coumarin derivatives

Rheumatoid arthritis is a chronic systemic disease characterised by an unknown aetiology of inflammatory synovitis. A large number of studies have shown that synoviocytes show tumour-like dysplasia in the pathological process of RA, and the changes in the expression of related cytokines are closely related to the pathogenesis of RA. In this thesis, a series of novel 3-(4-aminophenyl) coumarins containing different substituents were synthesised to find new coumarin anti-inflammatory drugs for the treatment of rheumatoid arthritis. The results of preliminary activity screening showed that compound 5e had the strongest inhibitory activity on the proliferation of fibroid synovial cells, and it also had inhibitory effect on RA-related cytokines IL-1, IL-6, and TNF-α. The preliminary mechanism study showed that compound 5e could inhibit the activation of NF-κB and MAPKs signal pathway. The anti-inflammatory activity of compound 5e in vivo was further determined in the rat joint inflammation model.     

Preparation of alkyl (R)-(-)-3-hydroxybutyrate by acidic alcoholysis of poly-(R)-(-)-3-hydroxybutyrate

An efficient method for the preparation of optically active alkyl (R)-(-)-3-hydroxybutyrates by chemical depolymerization of biopolymer, poly-(R)-(-)-(3-hydroxybutyrate), was established. This method consists of simple recovery of poly-(R)-(-)-(3-hydroxybutyrate) from bacterial cells followed by acidic alcoholysis. When poly-(R)-(-)-(3-hydroxybutyrate) was purified by a simple digestion method that used 0.2 N sodium hydroxide, alkyl (R)-(-)-hydroxybutyrates were most efficiently produced by alcoholysis with anhydrous hydrochloric acid.     

Optimization of antimalarial,and anticancer activities of (E)-methyl 2-(7-chloroquinolin-4-ylthio)-3-(4-hydroxyphenyl) acrylate

Chemically modified versions of bioactive substances, are particularly useful in overcoming barriers associated with drug formulation, drug delivery and poor pharmacokinetic properties. In this study, a series of fourteen (E)-methyl 2-(7-chloroquinolin-4-ylthio)-3-(4-hydroxyphenyl) acrylate (2–15) were prepared by using a one step synthesis from 1 previously described by us as potential antimalarial and antitumor agent. Molecules were evaluated as inhibitors of β-hematin formation, where most of them showed a significant inhibition value (%?>?70). The best inhibitors were tested in vivo as potential antimalarials in mice infected with P. berghei ANKA, chloroquine susceptible strain. Three of them (5, 6, and 15) displayed antimalarial activity comparable to that of chloroquine. Also, molecules were evaluated for their cytotoxic activity against two human cancer cell lines (Jurkat E6.1 and HL60) and primary culture of human lymphocytes. Most of the synthesized compounds, except for analogs 2–6, 8, and 10–12, displayed cytotoxicity against cancer cell lines without affecting normal cells. The potency of the compounds was 15???1, and 14?>?7, 9, and 13. Flow cytometry analysis demonstrated an increase in apoptotic cell death after 24?h. The compounds may affect tumor cell autophagy and consequently increase cell apoptosis.     

Antimycobacterial activities of 5-alkyl (or halo)-3'-substituted pyrimidine nucleoside analogs

Several 5-alkyl (or halo)-3'-azido (amino or halo) analogs of pyrimidine nucleosides have been synthesized and evaluated against Mycobacterium bovis, Mycobacterium tuberculosis and Mycobacterium avium. Among these compounds, 3'-azido-5-ethyl-2',3'-dideoxyuridine (3) was found to have significant antimycobacterial activities against M. bovis (MIC(50)=1μg/mL), M. tuberculosis (MIC(50)=10μg/mL) and M. avium (MIC(50)=10μg/mL).     

Synthesis of 3-(3-pyridyl)- and 3-(3-benzo[b]thienyl)-D-alanine

The DL-arylamino acid ethyl ester derivatives of beta-(3-pyridyl)-DL-alanine, and beta-(3-benzo[b]thienyl)-DL-alanine were synthesized by diethyl acetamidomalonate condensation with the respective arylmethyl halides followed by partial hydrolysis to the monoethyl ester and decarboxylation. Each derivative was enzymatically resolved to a separable mixture of the corresponding N-acetyl-L-amino acid and the unchanged D amino acid derivative. Acidic hydrolysis of the latter gave the corresponding D-amino acid, the optical purity of which was established by HPLC analysis of the 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl isothiocyanate (GITC) derivative. The free D amino acids were converted to D-BOC derivatives by reaction with di-tert-butyldicarbonate in tert-butyl alcohol, water and sodium hydroxide.     

硬毛粗盖孔菌子实体提取物抑制H_(22)荷瘤小鼠肿瘤活性研究

本文对硬毛粗盖孔菌子实体不同提取物的抗肿瘤活性进行筛选。通过建立H_(22)荷瘤小鼠肿瘤移植模型,研究硬毛粗盖孔菌子实体的石油醚提取物、二氯甲烷提取物、乙酸乙酯提取物、甲醇提取物以及水提取物等5种提取物的高、中、低剂量组对H_(22)荷瘤小鼠的抑瘤作用,并对其H_(22)荷瘤小鼠的抑瘤率、体质量、胸腺指数、脾脏指数、肝脏指数、肾脏指数进行了考察。对小鼠肿瘤、脾脏、肾脏进行了组织病理学检查,对血清中的细胞因子IL‐2、IL‐4、IFN‐γ及TNF‐α的含量进行测定。结果表明:各组分均有抑瘤效果,其中乙酸乙酯提取物中剂量组(1 000mg/kg)抑瘤效果最佳,与阴性对照组比较有极显著差异(P0.01),并且这组的H_(22)荷瘤小鼠血清中白介素‐2的含量显著增加,同时肿瘤细胞通过HE染色后,可观察到出现坏死面积增大,与抑制肿瘤活性具有相关性。     

Novel substituted (Z)-2-(N-benzylindol-3-ylmethylene)quinuclidin-3-one and (Z)-(+/-)-2-(N-benzylindol-3-ylmethylene)quinuclidin-3-ol derivatives as potent thermal sensitizing agents

Use of ionizing radiation is essential for the management of many human cancers, and therapeutic hyperthermia has been identified as a potent radiosensitizer. Radiation therapy combined with adjuvant hyperthermia represents a potential tool to provide outstanding local-regional control for refractory disease. (Z)-(±)-2-(N-Benzylindol-3-ylmethylene)quinuclidin-3-ol (2) and (Z)-(±)-2-(N-benzenesulfonylindol-3-ylmethylene)quinuclidin-3-ol (4) were initially identified as potent thermal sensitizers that could lower the threshold needed for thermal sensitivity to radiation treatment. To define the structural requirements of the molecule that are essential for thermal sensitization, we have synthesized and evaluated a series of (Z)-2-(N-benzylindol-3-ylmethylene)quinuclidin-3-one (9), and (Z)-(±)-2-(N-benzylindol-3-ylmethylene)quinuclidin-3-ol (10) analogs that incorporate a variety of substituents in both the indole and N-benzyl moieties. These systematic structure–activity relationship (SAR) studies were designed to further the development and optimization of potential clinically useful thermal sensitizing agents. The most potent analog was compound 10 (R¹ = H, R² = 4-Cl), which potently inhibited (93% inhibition at 50 μM) the growth of HT-29 cells after a 41 °C/2 h exposure.     

Synthesis of 2-(3-(3,5-bis(trifluoromethyl)phenyl)thioureido)-3-((dimethylamino)methyl)camphor organocatalysts

In a stereo-divergent synthesis, three novel camphor-derived bifunctional thiourea organocatalysts 7-9 have been prepared in five steps starting from (+)-camphor. In addition, borneol-derived bifunctional thiourea organocatalysts 19/19' have been prepared in three steps from (1S)-(+)-camphorquinone. Novel organocatalysts 7-9, 19/19' have been evaluated in a model reaction of Michael addition of dimethyl malonate to trans-β-nitrostyrene with low to moderate enantioselectivities (20%-60% ee). Configuration of all novel compounds has been meticulously determined using nuclear magnetic resonance (NMR) techniques.     

Design, synthesis and anticonvulsant activities of novel 1-(substituted/unsubstituted benzylidene)-4-(4-(6,8-dibromo-2-(methyl/phenyl)-4-oxoquinazolin-3(4H)-yl)phenyl) semicarbazide derivatives

Novel quinazolinone derivatives 5a-5n were designed, synthesized and screened for antiepileptic activity using MES and scPTZ seizures tests. Neurotoxicity study was performed by rotorod test. Compounds 5c, 5d, 5g, 5j and 5k were found active in the preliminary screening in MES model and/or scPTZ model. Further all these five compounds were administered to rats, 5c and 5d showed better activity than Phenytoin in oral route. Among all the title compounds tested, the most active one was 5c that revealed protection in MES at a dose of 30 mg/kg (ip) after 0.5 and 4h. This molecule also provided protection in the scPTZ at a dose of 100mg/kg (0.5h) and 300 mg/kg (4h).     

(+)-3-(3-hydroxyphenyl)-N-(1-propyl)piperidine [(+)-3-PPP] but not (-)-3-PPP produces (+)-N-allylnormetazocine-like (SKF 10,047) discriminative stimuli

In rats trained to discriminate the prototypic sigma receptor agonist, (+)-N-Allylnormetazocine [(+)-N-Allylnormetazocine [(+)-NANM/SKF 10,047], from saline, the (+)- but not the (-)-isomer of 3-(3-hydroxyphenyl)-N-(1-propyl)piperidine (3-PPP) produced (+)-NANM-like discriminative stimuli. (+)-3-PPP binds stereo selectively to the (+)-NANM binding site, but not to the phencyclidine binding site. Additionally, phencyclidine was found to produce (+)-NANM-like discriminative stimuli. Although the 3-PPP isomers were shown to produce changes in central dopaminergic activity (Hjorth et al. Life Sci 37, 673, 1985), the discriminative stimulus properties of (+)-3-PPP are apparently not mediated via the dopaminergic system. This hypothesis is supported by the fact that apomorphine did not produce (+)-NANM-like discriminative stimuli. These stimuli are thus non-dopaminergic and may be due to the (+)-3-PPP actions at the sigma binding site. However, it is possible that (+)-NANM, PCP, and (+)-3-PPP may have common non-sigma pharmacologic properties that account for the similar discriminative stimulus properties of these compounds.     

BACE1 inhibitory activities of enantiomerically pure, variously substituted N-(3-(4-benzhydrylpiperazin-1-yl)-2-hydroxypropyl) arylsulfonamides

β-Secretase (BACE1) has been widely recognized as one of the possible therapeutic targets for the treatment of Alzheimer's disease. In this paper, we report the synthesis and the BACE1 inhibitory activity of new, variously substituted N-(3-(4-benzhydrylpiperazin-1-yl)-2-hydroxypropyl) arylsulfonamides. Each enantiomeric form was separately evaluated in BACE1 inhibition assays and IC(50) values were obtained in the low micromolar range. According to our biological results and docking studies, it can be asserted that the stereochemistry around the OH group in the central hydroxyethylamino linker does not significantly influence the BACE1 inhibitory activity of this type of molecules.     

Synthesis and biological activities of octyl 2,3-di-O-sulfo-alpha-L-fucopyranosyl-(1-->3)-2-O-sulfo-alpha-L-fucopyranosyl-(1-->4)-2,3-di-O-sulfo-alpha-L-fucopyranosyl-(1-->3)-2-O-sulfo-alpha-L-fucopyranosyl-(1-->4)-2,3-di-O-sulfo-beta-L-fucopyranoside

Octyl 2,3-di-O-sulfo-alpha-L-fucopyranosyl-(1-->3)-2-O-sulfo-alpha-L-fucopyranosyl-(1-->4)-2,3-di-O-sulfo-alpha-L-fucopyranosyl-(1-->3)-2-O-sulfo-alpha-L-fucopyranosyl-(1-->4)-2,3-di-O-sulfo-beta-L-fucopyranoside, a fucosyl pentasaccharide with a regular structure resembling the repeating unit of a natural sulfated fucan, was chemically synthesized using a convergent '2+3' strategy. Regioselective 3-O-silylation of beta-thiofucopyranoside and AgOTf-catalyzed glycosylation of the protected glycosyl trichloroacetimidate facilitated a one-pot trisaccharide synthesis. The synthesized target compound showed good antitumor activity in vivo, and promising anticoagulant activity in vitro.     

Synthesis and antibacterial activity of 3-O-acyl-6-O-carbamoyl erythromycin A derivatives

A series of 3-O-acyl-6-O-carbamoyl erythromycin A derivatives has been synthesized. Several functional groups were identified as the optimal C3-substituents, and the best compounds in this series possess potent in vitro antibacterial activity against erythromycin-susceptible and erythromycin-resistant bacteria.