Synthesis and monoamine transporter binding properties of 2beta-[3'-(substituted benzyl)isoxazol-5-yl]- and 2beta-[3'-methyl-4'-(substituted phenyl)isoxazol-5-yl]-3beta-(substituted phenyl)tropanes

A series of 2beta-[3'-(substituted benzyl)isoxazol-5-yl]- and 2beta-[3'-methyl-4'-(substituted phenyl)isoxazol-5-yl]-3beta-(substituted phenyl)tropanes were prepared and evaluated for affinities at dopamine, serotonin, and norepinephrine transporters using competitive radioligand binding assays. The 2beta-[3'-(substituted benzyl)isoxazol-5-yl]-3beta-(substituted phenyl)tropanes (3a-h) showed high binding affinities for the dopamine transporter (DAT). The IC(50) values ranged from 5.9 to 22nM. On the other hand, the 2beta-[3'-methyl-4'-(substituted phenyl)isoxazol-5-yl]-3beta-(substituted phenyl)tropanes (4a-h), with IC(50) values ranging from 65 to 173nM, were approximately 3- to 25-fold less potent than the corresponding 2beta-[3'-(substituted benzyl)isoxazol]tropanes. All tested compounds were selective for the DAT relative to the norepinephrine transporter (NET) and serotonin transporter (5-HTT). 3Beta-(4-Methylphenyl)-2beta-[3'-(4-fluorobenzyl)isoxazol-5-yl]tropane (3b) with IC(50) of 5.9nM at the DAT and K(i)s of 454 and 113nM at the NET and 5-HTT, respectively, was the most potent and DAT-selective analog. Molecular modeling studies suggested that the rigid conformation of the isoxazole side chain in 4a-h might play an important role on their low DAT binding affinities.     

Synthesis of acridinyl-thiazolino derivatives and their evaluation for anti-inflammatory, analgesic and kinase inhibition activities

Variety of N-(4-phenyl-3-(2',3',4'(un)substituted phenyl)thiazol-2(3H)-ylidene)-2,4(un)substituted acridin-9-amine (4a-o) and 1-[(2,4-(un)substituted acridin-9-yl)-3-(4-phenyl-3-(2',3',4'(un)substituted phenyl)thiazol-2(3H)-ylidene)]isothiourea (5a-h) derivatives have been synthesized by condensation of 4-phenyl-3-(2',3',4'(un)substituted phenyl)thiazol-2(3H)-imine (3a-g) with 9-chloro-2,4-(un)substituted acridine (1a-c) and 9-isothiocyanato-2,4-(un)substituted acridine (2a-d), respectively. All these compounds were characterized by correct 1H NMR, FT-IR, MS and elemental analyses. These compounds were screened for anti-inflammatory, analgesic and kinase (CDK1, CDK5 and GSK3) inhibition activities. Some compounds exhibited good anti-inflammatory (25-32%) and potent analgesic (50-75%) activities, at 50 mg/kg p.o. A compound, 4o (R1 = H, R2 = OCH3, R3 = CH3, R4 = CH3, R5 = H) exhibited moderate CDK1 (IC50 = 8.5 microM) inhibition activity.     

Structure-activity relationships of novel anti-malarial agents: part 5. N-(4-acylamino-3-benzoylphenyl)-[5-(4-nitrophenyl)-2-furyl]acrylic acid amides

We have developed the [5-(4-nitrophenyl)-2-furyl]acrylic acid substituted benzophenone 4g as a novel lead for anti-malarial agents. Here, we demonstrated that the acyl residue at the 2-amino group of the benzophenone core structure has to be a phenylacetic acid substructure substituted in its para-position with methyl or other substituents of similar size. The trifluoromethyl substituted derivative displayed an IC(50) of 47 nM against the multi-drug resistant Plasmodium falciparum strain Dd2.     

The effect of C2-fluoro group on the biological activity of DC-81 and its dimers

C2-Fluoro substituted pyrrolobenzodiazepines (PBDs) have been synthesized that exhibit potential anticancer activity in a number of human tumour cell lines. These C2-fluoro substituted PBDs also exhibit significant DNA-binding ability.     

Synthesis and activity of polyacetylene substituted 2-hydroxy acids,esters, and amides against microbes of clinical importance

A series of novel polyacetylene substituted 2-hydroxy acids and derivatives were prepared and characterized. Alkylation of butane-2,3-diacetal (BDA) protected glycolic acid with iodoalkyl substituted polyacetylene compounds gave the corresponding diacetal protected polyacetylene substituted 2-hydroxy acids. Diacetal deprotection through acid mediated hydrolysis, transesterification or aminolysis afforded the 2-hydroxy-polyacetylenic acid, ester or amide derivatives. Twenty one of these novel compounds were tested against 10 microbes of clinical importance and several of them showed good antimicrobial activity, in particular against Pseudomonas aeruginosa.     

Lipolysis and reesterification: effects of some inhibitors of adenosine 3',5'-cyclic monophosphate phosphodiesterase

Theophylline and three lipolytic agents, 2,5-bis(2-chloroethylsulfonyl)-pyrrole-3,4-dicarbonitrile (substituted pyrrole), 2,4-diamino-6-butoxy-s-triazine (substituted triazine), and 2,3-dihydro-5,6-dimethyl-3-oxo-4-pyridazinecarbonitrile (substituted pyridazine), stimulate basal lipolysis in adipose tissue in vitro. They also cause an increased release of free fatty acids, but not glycerol, from adipose tissue in which lipolysis is already maximally stimulated by epinephrine. The four compounds also inhibit cyclic AMP phosphodiesterase and the conversion of [1-(14)C]glucose to (14)CO(2). Evidence is presented that free fatty acids accumulate as the result of inhibited reesterification. The substituted pyridazine and triazine, but not the pyrrole, elevate plasma free fatty acids after oral or intraperitoneal administration in rats.     

Characterization of some O-acetylated saponins from Quillaja saponaria Molina

Sixteen saponins were identified from a bark extract of Quillaja saponaria Molina. The compounds were characterized, using NMR spectroscopy, mass spectrometry and monosaccharide analysis, as quillaic acid substituted at C-3 with oligosaccharides consisting of a disaccharide, beta-D-Galp-(1-->2)-beta-D-GlcpA substituted with either D-xylose or L-rhamnose and at C-28 with complex oligosaccharide structures consisting of a disaccharide, alpha-L-Rhap-(1-->2)-4-O-acetyl-beta-D-Fucp, substituted with various amount of D-xylose. D-glucose, D-apiose, and L-rhamnose.     

Cellular effect of styrene substituted biscoumarin caused cellular apoptosis and cell cycle arrest in human breast cancer cells

BackgroundCoumarins occurs naturally across plant kingdoms exhibits significant pharmacological properties and pharmacokinetic activity. The conventional, therapeutic agents are often associated with poor stability, absorption and increased side effects. Therefore, identification of a drug that has little or no-side effect on humans is consequential. Here, we investigated the antiproliferative activity of styrene substituted biscoumarin against various human breast cancer cell lines, such as MCF-7, (ER-) MDA-MB-231 and (AR+) MDA-MB-453. Styrene substituted biscoumarin induced cell death by apoptosis in MDA-MB-231 cell line was analyzed.MethodsAntiproliferative activity of Styrene substituted biscoumarin was performed by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Styrene substituted biscoumarin induced apoptosis was assessed by Hoechst staining, Annexin V-fluorescein isothiocyanate/propidium iodide (Annexin V-FITC/PI) staining and flow cytometric analysis. Migratory and proliferating characteristic of breast cancer cell line MDA-MB-231 was also analyzed by wound healing and colony formation assay. Furthermore, mRNA expression of BAX and BCL-2 were quantified using qRT-PCR and protein expression level analyzed by Western blot.ResultsThe inhibition concentration (IC₅₀) of styrene substituted biscoumarin was assayed against three breast cancer cell lines. The inhibition concentration (IC₅₀) value of styrene substituted biscoumarin toward MDA-MB-231, MDA-MB-453 and MCF-7 cell lines was 5.63, 7.30 and 10.84 μg/ml respectively. Styrene substituted biscoumarin induced apoptosis was detected by Hoechst staining, DAPI/PI analysis and flow-cytometric analysis. The migration and proliferative efficiency of MDA-MB-231 cells were completely arrested upon styrene substituted biscoumarin treatment. Also, mRNA gene expression and protein expression of pro-apoptotic (BAX) and anti-apoptotic (BCL-2) genes were analyzed by qRT-PCR and western blot analysis upon styrene substituted biscoumarin treatment to MDA-MB-231 cells. Our results showed that styrene substituted biscoumarin downregulated BCL-2 gene expression and upregulated BAX gene expression to trigger apoptotic process.ConclusionStyrene substituted biscoumarin could induce apoptosis through intrinsic mitochondrial pathway in breast cancer cell lines, particularly in MDA-MB-231. Our data suggest that styrene substituted biscoumarin may act as a potential chemotherapeutic agent against breast cancer.     

Synthesis and Anticancer Activity of Functionalized Thieno[2,3-d]pyrimidine Compounds and Their Triazinyl and Tetrazinyl Derivatives

Russian Journal of Bioorganic Chemistry - New thienopyrimidine derivatives substituted with amino and hydrazinyl side chains were synthesized starting with 2-hydrazinyl substituted thienopyrimidine...     

Conversion of substituted naphthalenesulfonates by Pseudomonas sp. BN6

The range of substituted naphthalenesulfonates which are metabolized by Pseudomonas sp. BN6 were investigated. Resting cells from strain BN6 oxidized 1- and 2-naphthalenesulfonate, 1-hydroxynaphthalene-2-sulfonate, 2,6-naphthalenedisulfonate and all monosulfonated naphthalene-2-sulfonates which carry one or two substitutents in the positions 4-, 5-, 6-, 7- or 8- of the naphthalene ring-system. With the exception of (substituted) 4- or 5-amino- and 4-hydroxynaphthalene-2-sulfonates these compounds were converted to the corresponding salicylates. Strain BN6 did not oxidize substituted naphthalene-1-sulfonates, 3-substituted naphthalenesulfonates and substituted naphthalenedisulfonates. Turnover of 4-amino- or 4-hydroxynaphthalene-2-sulfonates resulted in the accumulation of the corresponding naphthoquinones in the culture medium. Thus, degradation of 4-amino- and 4-hydroxynaphthalenesulfonates was restricted by the rapid autoxidation of the substituted 1,2-dihydroxynaphthalenes formed as metabolites. Catabolic activities of strain BN6 for naphthalenesulfonates were induced by salicylate, 3- or 6-hydroxysalicylate, and 3-, 4- or 5-aminosalicylate but not by 4- and 5-hydroxysalicylate. All naphthalenesulfonates that were not converted into the corresponding salicylates, were found to be inefficient as effectors. It was therefore concluded that (substituted) salicylates are the inducers of the relevant enzymes. The degradation of 2-naphthalene-sulfonate by a pure culture of strain BN6 was prevented by the toxicity of the dead-end product salicylate. Substituted salicylates were less toxic and allowed growth of strain BN6 in axenic culture with various substituted naphthalenesulfonates.Abbreviations AB aminobenzoate - ANS aminonaphthalenesulfonate - DHN dihydroxynaphthalene - DHNC dihydroxynaphthalene-carboxylate - DHNDO 1,2-dihydroxynaphthalene dioxygenase - HBPA 2-hydroxybenzalpyruvate aldolase - HNS hydroxynaphthalenesulfonate - HS hydroxysalicylate - Ind-C indolecarboxylate - Ind-S indolesulfonate - MANS N-methylaminonaphthalenesulfonate - NC naphthalenecarboxylate - NDS naphthalenedisulfonate - NQ naphthoquinone - NS naphthalenesulfonate - NSDO naphthalenesulfonate dioxygenase - R_t retention time - SADH salicylaldehyde dehydrogenase - THN trihydroxynaphthalene (hydroxy-1,2-dihydroxynaphthalene)     

Synthesis and biological evaluation of 2-aminothiazole derivatives as antimycobacterial and antiplasmodial agents

A series of compounds derived from the 2-amino-4-(2-pyridyl) thiazole scaffold was synthesized and tested for in vitro antimycobacterial activity against the Mycobacterium tuberculosis H37Rv strain, antiplasmodial activity against the chloroquine sensitive NF54 Plasmodium falciparum strain and cytotoxicity on a mammalian cell line. Optimal antimycobacterial activity was found with compounds with a 2-pyridyl ring at position 4 of the thiazole scaffold, a substituted phenyl ring at the 2-amino position, and an amide linker between the scaffold and the substituted phenyl. The antiplasmodial activity was best with compounds that had the phenyl ring substituted with hydrophobic electron withdrawing groups.     

Purification and mode of action of two different arabinoxylan arabinofuranohydrolases from Bifidobacterium adolescentis DSM 20083

Two novel arabinofuranohydrolases (AXH-d3 and AXH-m23) were purified from Bifidobacterium adolescentis DSM 20083. Both enzymes were induced upon growth of Bi. adolescentis on xylose and arabinoxylan-derived oligosaccharides. They were only active with arabinoxylans and therefore denoted as arabinoxylan arabinofuranohydrolases. Their optimal activity was at pH 6 and 30–40 °C. They were very specific in their mode of action and were clearly different from AXH-m from Aspergillus awamori. AXH-m23 released only arabinosyl groups, which were linked to the C-2 or C-3 position of singly substituted xylose residues in arabinoxylan oligomers. AXH-d3 hydrolysed C-3-linked arabinofuranosyl residues of doubly substituted xylopyranosyl residues of arabinoxylans and arab- inoxylan-derived oligosaccharides. No activity was observed with C-2-linked arabinofuranosyl residues of these doubly substituted xylopyranosyl residues, or against C-2- and C-3-linked arabinofuranosyl residues of singly substituted xylopyranosyl residues. The combination of AXH-d3 and AXH-m showed low debranching activity with highly substituted glucurono-arabinoxylans. However, arabinoxylan from wheat flour was debranched almost completely. Received: 12 January 1999 / Accepted: 17 January 1999     

Synthesis and biological evaluation of pyridine-modified analogues of 3-(2-aminoethoxy)pyridine as novel nicotinic receptor ligands

Analogues of the potent nicotinic receptor agonist 3-(2-aminoethoxy)pyridine substituted at the 5' and 6'-positions of the pyridine ring were synthesized and tested in vitro for nicotinic receptor binding activity (displacement of [(3)H](-)cytisine from whole rat brain synaptic membranes). The substituted analogues exhibited K(i) values ranging from 0.076 to 319 nM compared to a K(i) value of 26 nM for compound 1. Among the compounds tested, 5'-vinyl-6'-chloro substituted 1 was the most potent.     

Interaction of the hemin 2 and 4 substituents with apo horseradish peroxidase

2-formyl, 4-vinyl deuterohemin (1) and 2-vinyl, 4-formyl deuterohemin (2) substituted horseradish peroxidases have been prepared from apoperoxidase and the respective hemins. The two hemins bind at different rates to the apoprotein and the resultant substituted peroxidases possess different visible spectra and activities. These results indicate that the hemin 2 and 4 substituents interact with apoperoxidase and are not exposed to the solvent.     

取代短链脂肪酸对秀丽隐杆线虫的抗氧化作用

短链脂肪酸(short chain fatty acids, SCFAs)是碳原子数为1～6的有机脂肪酸,不但可以作为生物体内能源物质,而且还具有抗炎、影响肠道菌群代谢和预防早发1型糖尿病等重要作用。然而,目前多数是对传统短链脂肪酸的生物学作用进行研究,对取代短链脂肪酸(short branched-chain fatty acids, SBCFAs)的相关研究甚少。本研究以秀丽隐杆线虫为模式动物,系统探究SBCFAs的抗氧化生物活性作用。采用胡桃醌氧化应激模型,在体内评价SBCFAs对秀丽隐杆线虫生存能力的影响,并通过体外抗氧化及H_2DCFDA荧光染色实验,进一步评价SBCFAs清除活性氧自由基(reactive oxygen species,ROS)的能力。本研究证实,在氧化应激研究中,传统脂肪酸不能延长秀丽隐杆线虫的存活时间,而2′-甲基取代短链脂肪酸(n=4-6)具有显著的抗氧化作用。体外抗氧化实验表明,2′-甲基取代短链脂肪酸(n=4-6)不具有体外直接清除ROS的能力,但是H_2DCFDA荧光染色实验显示2′-甲基丁酸能够显著降低线虫体内的ROS水平,表明2′-甲基丁酸通过降低体内ROS水平,从而增强秀丽隐杆线虫的抗氧化应激能力。本研究提示,传统短链脂肪酸不具有抗氧化作用;2′-甲基取代短链脂肪酸(n=4-6)能显著增强秀丽隐杆线虫的抗氧化能力;甲基取代位置和取代烷基长度对短支链脂肪酸的抗氧化作用至关重要,其作用机制需进一步研究。     

Simultaneous determination of enantiomerization and hydrolysis kinetic parameters of chiral N‐alkylbenzothiadiazine derivatives

On‐column stopped flow multidimensional HPLC (sfMDHPLC) and dynamic high‐performance liquid chromatography were applied to investigate the influence of alkyl substituents at the sulfonamidic and amino moieties of benzothiadiazine 1,1‐dioxide derivatives on hydrolysis and enantiomerization rate constants. The data obtained indicate the presence of pyrrolo substituent at the 3,4 positions on benzothiadiazine rings inhibits the hydrolysis, whereas the enantiomerization occurs in acidic medium. Hydrolysis rates are quite similar for the two benzothiadiazines methyl substituted to nitrogen at 2‐ and 4‐positions. Conversely, enantiomerization rate of 4‐N‐methyl substituted is significantly higher than 2‐N‐methyl substituted. Chirality 2010. © 2009 Wiley‐Liss, Inc.     

Biosynthesis of morindone and alizarin in intact plants and cell suspension cultures of Morinda citrifolia

Chrysophanol (1,8-dihydroxy-3-methylanthraquinone) is an acetate-derived anthraquinone which is substituted in both benzenoid rings. Morindone (1,5,6-trihydroxy-2-methylanthraquinone) is also substituted in both rings but is shown to be derived from shikimic acid via o-succinoylbenzoic acid.     

Synthesis and Functional Characterization of Substituted Isoquinolinones as MT2-Selective Melatoninergic Ligands

A series of substituted isoquinolinones were synthesized and their binding affinities and functional activities towards human melatonin MT₁ and MT₂ receptors were evaluated. Structure-activity relationship analysis revealed that substituted isoquinolinones bearing a 3-methoxybenzyloxyl group at C5, C6 or C7 position respectively (C5>C6>C7 in terms of their potency) conferred effective binding and selectivity toward the MT₂ receptor, with 15b as the most potent compound. Most of the tested compounds were MT₂-selective agonists as revealed in receptor-mediated cAMP inhibition, intracellular Ca²⁺ mobilization and phosphorylation of extracellular signal-regulated protein kinases. Intriguingly, compounds 7e and 7f bearing a 4-methoxybenzyloxyl group or 4-methylbenzyloxyl at C6 behaved as weak MT₂-selective antagonists. These results suggest that substituted isoquinolinones represent a novel family of MT₂-selective melatonin ligands. The position of the substituted benzyloxyl group, and the substituents on the benzyl ring appeared to dictate the functional characteristics of these compounds.     

Structural studies on water-soluble arabinoxylans in rye grain using enzymatic hydrolysis

The major water-soluble arabinoxylan fraction from rye grain, containing 4-linked β- -xylopyranosyl residues of which about 43% were substituted solely at O-3 and 7% at both O-2 and O-3 with terminal - -arabinofuranosyl units, was hydrolysed to different extents using semi-purified xylanase from Trichoderma reesei. Products were fractionated on Biogel P-2 and structurally elucidated by sugar, methylation and high-field ¹H-NMR analysis. Moderate hydrolysis released arabinose, xylose, xylobiose, xylotriose and xylotetraose together with xylo-oligosaccharides (DP ≥ 4) in which one or more of the residues were substituted at O-3 with a terminal arabinose unit. The xylose residues substituted with arabinose units at both O-2 and O-3 became enriched in the remaining polymeric fraction. Extensive hydrolysis with the enzyme released arabinose, xylose and xylobiose as major products together with small amounts of two oligosaccharides and a polymeric fraction. One of the oligosaccharides was identified as xylotriose in which the non-reducing end was substituted at O-2 and O-3 with terminal arabinose units and the other as xylotetraose in which one of the interjacent residues was substituted with arabinose units in the same way. The polymeric fraction contained a main chain of 4-linked xylose residues in which 60–70% of the residues were substituted at both O-2 and O-3 with arabinose units.

The semi-purified enzyme contained xylanase and arabinosidase activities which rapidly degraded un- and mono-substituted xylose residues while the degradation of double-substituted xylose residues was much slower. The results show that the mono- and double-substituted xylose residues were present in different polymers or different regions of the same polymer.     

Xyloglucan from the leaves of Hymenaea courbaril

A fucosylated xyloglucan was isolated from the leaves of Hymenaea courbaril by alkaline extraction, followed by ethanol precipitation and ion-exchange chromatography. The isolated polysaccharide showed Glc:Xyl:Gal:Fuc in molar ratio of 8:5:2.5:1 and (D)(25) +40.5 degrees. Composition and linkage analyses, supported by NMR spectroscopic measurements, showed that the polysaccharide has a glucan backbone which is highly substituted at O-6 with D-xylopyranose residues, about a half of which are substituted at O-2 by D-galactopyranosyl units. Some of the galactose residues are further substituted by L-fucopyranose at O-2. The M(r), as determined by HPSEC, was 49,500.