Synthesis and biological activities of novel ethers of quinolinone linked with coumarins

Abstract  

A series of new ethers of quinolinone linked with different substituted coumarins and benzofurans were synthesized from 4-(bromomethyl)quinolinones. All newly synthesized compounds were screened for their in vitro antibacterial and antifungal activities. Most of the compounds with chloro substitution at the C-6 or C-7 position in quinolinone showed potent antibacterial and antifungal activities. In pharmacological evaluations, some of these chloroquinolinones also showed 70–77% inhibition of inflammation after 8 h, whereas the other compounds showed 51–55% inhibition. Most of the compounds showed potent analgesic activity compared to the standard and control. The structures of all newly synthesized compounds were characterized by elemental analysis, IR, ¹H NMR, ¹³C NMR, and EI-MS.     

Synthesis and optical characterization of novel enantiopure BODIPY linked azacrown ethers as potential fluorescent chemosensors

Two novel enantiopure BODIPY linked azacrown ether chemosensors were prepared by reacting 3-chloro-5-methoxyBODIPY with new enantiopure monoaza-18-crown-6 ether ligands bearing two methyl and isobutyl groups on their chiral centres, respectively. The latter compounds were synthesized starting from optically active tetraethylene glycols in six steps. The operation of chemosensors is based on the intramolecular charge transfer (ICT) process. They exhibit pronounced off-on type fluorescent responses to some metal ions and chiral primary aralkyl ammonium ions, in particular to Ca²⁺ and Pb²⁺. Even in the case of 1:1 ratio of Ca²⁺ and Pb²⁺ ions to the ionophores, the fluorescence intensities and quantum yield values increased more than 10-fold, as well as both the absorption and emission bands were blue-shifted by about 20-30 nm (hipsochromic effect) in acetonitrile. The formation of relatively stable complexes allowed the determination of log K_s values by the mole-ratio method.     

Synthesis and biological studies of some new acrylic acid ethyl esters of quinolinone

Abstract  

A series of new acrylic acid ethyl esters of quinolinones were synthesized from 4-(bromomethyl)quinolinones and screened for in vitro antimicrobial and in vivo analgesic and anti-inflammatory activities. Most of the compounds with chloro substitution at the C-6 or C-7 position in the quinolinone moiety and a methoxy group in the aryloxy moiety showed potent antibacterial and antifungal activities when compared with non-halogenated quinolinones and the quinolinones bearing a CH₃ at the C-8 position. In a pharmacological evaluation, the halogen substitution at the C-6 or C-7 position in quinolinones was found to enhance both analgesic and anti-inflammatory activities of the molecule when compared with a simple unsubstituted (non-halogenated) quinolinone. The structures of all newly synthesized compounds were characterized by elemental analysis, IR, ¹H NMR, ¹³C NMR, and FAB-MS.     

Synthesis of novel spin-labeled crown ethers

Diazonium salts obtained from aminophenyl-substituted crown ethers react with paramagnetic imidazolinium salt to yield arylazoenamines, containing spin-labeled crown ethers. An alternative approach to the synthesis of related compounds, spin-labeled ureas, consists of the reaction of aminophenyl-substituted crown ethers with paramagnetic isocyanates.     

Synthesis of novel thio(seleno) phosphate-phosphonates and their biological activities

In order to search for novel herbicides with high activity and selectivity, a series of thio(seleno) phosphate-phosphonate derivatives were synthesized in good yields by a one-pot procedure using tris(diethylamino)phosphine activated by iodine as the phosphorylating reagent. The structures of all compounds prepared were confirmed by spectroscopic methods and microanalyses. Preliminary bioassays indicated that some of the products possess potent and selective herbicidal activities and antiphytoviral activities against the tobacco mosaic virus (TMV). In addition, some of them exhibit significant fungicidal activities against R. Solani and P. Piricola. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:369–375, 1998     

Synthesis and biological activities of novel triazole compounds containing 1,3-dioxolane rings

Thirteen new triazoles containing 1,3-dioxolane rings were synthesized and their identities confirmed by means of IR, NMR, MS, elemental analysis and X-ray crystallography. The results of preliminary biological tests show that all of these compounds possess some fungicidal and plant growth regulant activities.     

Synthesis and biological activities of novel bis‐heterocyclic pyrrodiazole derivatives

Novel structures of bis‐heterocyclic pyrrodiazole derivatives containing pyrazole were designed and synthesized. The title compounds were characterized by ¹H NMR, IR, MS, and elemental analysis. Biological activities of three intermediate compounds and 25 pyrrodiazole derivatives were tested in vivo and in vitro. Some of the title compounds exhibited certain herbicidal activities against barnyardgrass and rape. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:21–27, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20369     

Synthesis and biological activities of flavolipids

Syntheses of the bacterial surfactants 6S,6S-, 9S,9S-, and 9U,9U-flavolipids confirmed the structures proposed for them from spectroscopic analysis of a flavolipid mixture and made pure flavolipids available for the first time. All three synthetic flavolipids and a straight chain analogue were found to be weakly cytotoxic and to inhibit metastatic cancer cell migration, with 9U,9U-flavolipid (the most abundant natural flavolipid) having the most activity. Biosynthetic routes to the branched side-chains of the flavolipids are suggested, and it is proposed that branched chains are employed to hinder biodegradation.     

Synthesis of novel disulfide-bridged dilactam crown ethers

The novel macrocyclic dilactams with redox-switched disulfide linkage were synthesized.These compounds were obtained from 2,2'-dithiodibenzoyl chloride in the macrocyclization step by fast addition method in moderate yields.     

Synthesis and biological activities of novel quinazolinone derivatives containing a 1,2,4-triazolylthioether moiety

A series of novel quinazolinone derivatives containing a 1,2,4-triazolylthioether moiety were synthesised and their antimicrobial activities were evaluated. All the target compounds were characterised by ¹H NMR, ¹³C NMR, ESI-MS, IR and elemental analyses. The single crystal structure of 3-((5-((2-fluorobenzyl)thio)-4-phenyl-4H-1,2,4-triazol-3-yl)methyl)quinazolin-4(3H)-one (VIIi) was also determined. The preliminary bioassays indicated that some of the target compounds possessed good antimicrobial activities. For example, 3-((4-phenyl-5-((4-(trifluoromethyl)benzyl)thio)-4H-1,2,4-triazol-3-yl)methyl)quinazolin-4(3H)-one (VIIs) exhibited the best inhibitory effect against Xanthomonas oryzae pv. oryzae and Xanthomonas axonopodis pv. citri with the half-effective concentration (EC₅₀) values of 47.6 μg mL^?1 and 22.1 μg mL^?1, respectively, which were superior to the commercial bactericide, bismerthiazol. Meanwhile, 3-((5-((4-chlorobenzyl)thio)-4-phenyl-4H-1,2,4-triazol-3-yl)methyl)quinazolin-4(3H)-one (VIIh) exhibited better fungicidal activities against Pellicularia sasakii and Colletotrichum capsici at the concentration of 50 μg mL^?1, in comparison with the commercial fungicide, hymexazol.     

Synthesis of novel pyrano fused quinolones,coumarins, and pyridones

Dedicated to Professor Dr. Hans Junek, Graz, on the occasion of his 70th birthday A novel efficient synthesis of pyrano fused heterocycles namely, pyrano[3,2-c]quinoline-2,5(6H)-diones 3a-e, 7b-d , pyrano[3,2-c]benzopyran-2,5(6H)-dione ( 7f ), and pyrano[3,2-c]pyridine-2,5(6H)-diones 10, 11 was achieved by the condensation of 4-hydroxy-2-(1H)-quinolones 1a-e , 4-hydroxycoumarin ( 1f ), or 4-hydroxy-2(1H)-pyridone ( 9 ) with α-acetyl-γ-butyrolactone ( 2 ) or the sodium salt of α-formyl-γ-butyrol-actone ( 6 ), respectively, in the presence of ammonium acetate.     

Synthesis and biological activities of thio-triazole derivatives as novel potential antibacterial and antifungal agents

A series of novel thio-triazole derivatives including thiols, thioethers and thiones as well as some corresponding triazolium compounds were conveniently and efficiently synthesized from commercially available halobenzyl halides and thiosemicarbazide. All the new compounds were characterized by 1 H NMR, 13 C NMR, FTIR, MS and HRMS spectra. Their antibacterial and antifungal activities in vitro were evaluated against four Gram-positive bacteria, four Gram-negative bacteria and two fungi by two-fold serial dilution technique. The preliminary bioassay indicated that some prepared triazoles exhibited effective antibacterial and antifungal activities. Especially, 3,4-dichlorobenzyl triazolethione and its triazolium derivatives displayed the most potent activities against all the tested strains.     

Synthesis and biological activities of novel 2-amino-1,3-thiazole-4-carboxylic acid derivatives

A series of novel 2-amino-1, 3-thiazole-4-carboxylic acid derivatives were designed and synthesized. Their structures were confirmed by melting points, IR, ¹H NMR, ¹³C NMR, and HRMS or elemental analysis. Biological activities of all title compounds including fungicidal activity and antivirus activity were evaluated systematically. Preliminary bioassays indicated that these compounds exhibited good fungicidal activity at 50 μg/mL, compounds 4b and 4i exhibited over 50% activity against six fungi tested. Most compounds showed good activity against TMV with different models in vivo at 100 μg/mL. Compounds 4c and 4e stood out with high effects against TMV in vivo in all models tested, including protective, inactivative, curative, and inductive activities. These data demonstrate a new strategy for fungi and virus control.     

Synthesis, structure investigation, spectral characteristics and biological activities of some novel azodyes

Four novel azo compounds were synthesized; o-phenylazo- (C(14)H(13)N(3)O(2)) (I), p-bromo-o-phenylazo- (C(14)H(13)BrN(3)O(2)) (II), p-methoxy-o-phenaylazo- (C(15)H(16)N(3)O(3)) (III) and p-nitro-o-phenylazo-p-acetamidophenol (C(14)H(13)N(4)O(4)) (IV). These compounds were carefully investigated using elemental analyses, UV-vis, FT-IR, (1)H NMR and mass spectra. Also, the effects of p-substituents such as bromo, methoxy and nitro groups on the mass fragmentation pathways of these dyes were studied using Hammet's effects. This research aimed chiefly to threw lights on the structures-stability relationship of four novel newly prepared azo derivatives of p-acetoamidophenol. The data obtained referred to the variation of mass fragmentation pathways with the variation of p-substituent of these dyes which can be used in industry for various dyeing purposes. This variation is also correlated and verified by molecular orbital calculations which were done on ionic forms of these dyes using semi empirical PM3 program. The biological activities of these dyes were also investigated and its structure relationship was correlated.     

Synthesis of novel macrocyclic crown ethers from D-glucose

A simple and efficient synthetic protocol for an easy access of carbohydrate-linked crown ethers from cheap and readily available D-glucose in good yields has been devised. The base-mediated cyclization of sugar-linked bis-iodo podands in CH₃CN with amines, including ethylamine and furfurylamine afforded the novel chiral monoaza-15-crown-5-type macrocyclic crown ethers anellated to 3-O-benzyl-1,2-O-isopropylidene-α-D-glucofuranose and 3-O-benzyl-1,2-O-isopropylidene-α-D-allofuranose. The glucose-based crown ethers have been characterized by spectroscopy techniques including IR, ¹H NMR, and ¹³C NMR.     

Syntheses and biological activities of novel triazole compounds

Fifteen novel compounds bearing the triazole moiety were synthesized and structurally characterized. The title compounds showed some antimycotic and plant growth regulating activities, especially in the case of 4d and 4c . The latter compound affected also the liver cancer 7402 cell viability.     

Synthesis and characterization of novel ionophores of double-armed penta-crown ethers

Unique structures of novel ionophores of double-armed penta-crown ethers were successfully synthesized. Diaza 18-crown-6 was designed as the parent crown ring. The penta-crown ethers were prepared by the reaction of trimethylolpropane triacrylate (TMPTA) with diaza 18-crown-6 and further with 1-aza crown ethers through the Michael reaction. The newly synthesized penta-crown ethers were characterized by ¹H NMR, ¹³C NMR, FAB mass spectrum, IR and elemental analyses, respectively.