A new tridentate fluorescent-colorimetric chemosensor for copper(II) ion

A new tri-imidazolium salt, tris(4-(3-(2-((8-hydroxy-9,10-dioxo-9′,10′-dihydroanthracen-1-yl)oxy)ethyl)-1H-imidazole-3′-ium-1′-yl)phenyl)amine hexafluorophosphate was prepared and characterized. Particularly, the recognition performance of the tri-imidazolium salt for cations was investigated through fluorescence and ultraviolet titrations, MS, IR spectra and ¹H NMR titrations. The results indicated that the tri-imidazolium salt can distinguish effectively copper(II) ion from other cations by the changes of spectroscopy and colour (from yellow to orange under sunlight). Furthermore, the tri-imidazolium salt was also used in detecting Cu²⁺ through employing smartphone with the computed detection limit down to 0.51 μM.     

New benzimidazole derivatives: Design,synthesis, docking,and biological evaluation

The aim of this study was to synthesize novel enaminonitrile derivatives starting from 2-aminobenzimidazole and utilize this derivative for the preparation of novel heterocyclic compounds and assess their function for biological activity screening. The key precursor N-(1H-benzo[d]imidazol-2-yl)carbonohydrazonoyl dicyanide (2) was prepared in pyridine by coupling of diazotized 2-aminobenzimidazole (1) with malononitrile. Compound 2 was subjected to react with various secondary amines such as piperidine, morpholine, piperazine, diphenylamine, N-methylglucamine, and diethanolamine in boiling ethanol to give the acrylonitriles (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-(piperidin-1-yl)acrylonitrile (3), (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-morpholinoacrylonitrile (4), (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-(piperazin-1-yl)acrylonitrile (5), (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-(diphenylamino)acrylonitrile (6), (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-(methyl((2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl)amino)acrylonitrile (7), and (2Z)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-3-amino-3-(bis(2-hydroxyethyl)amino)acrylonitrile (8), respectively. It has been found that the behaviour of nitrile derivative 2 towards hydrazine hydrate to the creation of 4-((1H-benzo[d]imidazol-2-yl)diazenyl)-1H-pyrazole-3,5-diamine (9). The reaction of malononitrile with compound 2 in an ethanolic solution catalyzed with sodium ethoxide afforded 4-amino-1-(1H-benzo[d]imidazol-2-yl)-6-imino-1,6-dihydropyridazine-3,5-dicarbonitrile (11). Moreover, malononitrile reacted with 7 in a boiling ethanolic sodium ethoxide solution to give 2-(5-((1H-benzo[d]imidazol-2-yl)diazenyl)-4-amino-6-(methyl((2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl)amino)pyrimidin-2-yl)acetonitrile (14). Heating 7 in boiling acetic anhydride and pyridine afforded (2R,3R,4R,5S)-6-(((1E)-2-((1-acetyl-1H-benzo[d]imidazol-2-yl)diazenyl)-1-(N-acetylacetamido)-2-cyanovinyl)(methyl)amino)hexane-1,2,3,4,5-pentayl pentaacetate (15). When compound 15 is heated for a long time in refluxing DMF including a catalytic of TEA, cyclization occurs to give the corresponding (2R,3R,4R,5S)-6-((1-acetyl-3-((1-acetyl-1H-benzo[d]imidazol-2-yl)diazenyl)-4-amino-6-oxo-1,6-dihydropyridin-2-yl)(methyl)amino)hexane-1,2,3,4,5-pentayl pentaacetate (16). In addition, triethyl orthoformate was reacted with compound 7 in the presence of acetic anhydride to afford the corresponding ethoxymethyleneamino derivative (2R,3R,4R,5S)-6-(((1E)-2-((1-acetyl-1H-benzo[d]imidazol-2-yl)diazenyl)-2-cyano-1-(((E) ethoxymethylene)amino)vinyl)(methyl)amino)hexane-1,2,3,4,5-pentayl pentaacetate (17). Also, it has been found that heating a mixture of 7 with DMF/DMA in anhydrous xylene yielded compound (1E)-N'-((1E)-2-((1H-benzo[d]imidazol-2-yl)diazenyl)-2-cyano-1-(methyl((2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl)amino)vinyl)-N,N-dimethylformimidamide (18). In addition, compound 7, when reacted with several acid anhydrides, allowed the matching phthalimide derivatives 19–26. The results showed that compound 14 has significantly higher ABTS and antitumor activities than the other compounds. Molecular modelling was also studied for compounds 22 and 24. The viability of four many cell lines—the African green monkey kidney epithelial cells (VERO), human breast adenocarcinoma cell line (MCF-7), human lung fibroblast cell line (WI-38), and human hepatocellular liver carcinoma cell line (HepG2) was examined to determine the antitumor activities of the newly synthesized compounds. Also, it was found that compounds 9, 11, 15, 16, 22, 23, 24 and 25 are strong against HepG2 cell lines, while 16, 22, and 25 are strong against WI-38 cell lines. Moreover, it was also found that compounds 16 and 22 are strong against VERO cell lines. On the other hand, compounds 7, 14, 15, 16, and 22 are strong while the rest of the other compounds are moderate against the MCF-7 cell line. The result of docking showed that compound 24 got stabilized inside the pocket with a very promising binding score of ? 8.12 through hydrogen bonds with Arg184 and Lys179, respectively.     

Rhenium tricarbonyl core complexes of thymidine and uridine derivatives

Thymidine and uridine were modified at the C2' and C5' ribose positions to form amine analogues of the nucleosides (1 and 4). Direct amination with NaBH(OAc)3 in DCE with the appropriate aldehydes yielded 1-{5-[(bis(pyridin-2-ylmethyl)amino)methyl]-4-hydroxytetrahydrofuran-2-yl}-5-methyl-1H-pyrimidine-2,4-dione (L1), 1-{5-[(bis(quinolin-2-ylmethyl)amino)methyl]-4-hydroxytetrahydrofuran-2-yl}-5-methyl-1H-pyrimidine-2,4-dione (L2), and 1-[3-(bis(pyridin-2-ylmethyl)amino)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-2-yl]-1H-pyrimidine-2,4-dione (L5), while standard coupling procedures of 1 and 4 with 5-(bis(pyridin-2-ylmethyl)amino)pentanoic acid (2) and 5-(bis(quinolin-2-ylmethyl)amino)pentanoic acid (3) in the presence of HOBT-EDCI in DMF provided a second novel series of bifunctional chelators: 5-(bis(pyridin-2-ylmethyl)amino)pentanoic acid [(3-hydroxy-5-(5-methyl-4-oxo-3,4-dihydro-2H-pyrimidin-1-yl)tetrahydrofuran-2-yl)methyl] amide (L3), 5-(bis(quinolin-2-ylmethyl)amino)pentanoic acid [(3-hydroxy-5-(5-methyl-4-oxo-3,4-dihydro-2H-pyrimidin-1-yl)tetrahydrofuran-2-yl)methyl] amide (L4), 5-(bis(pyridin-2-ylmethyl)amino)pentanoic acid [2-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl] amide (L6), and 5-(bis(quinolin-2-ylmethyl)amino)pentanoic acid [2-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl] amide (L7). The rhenium tricarbonyl complexes of L1-L4, L6, and L7, [Re(CO)3(LX)]Br (X=1-4, 6, 7: compounds 5-10, respectively), have been prepared by reacting the appropriate ligand with [NEt4][Re(CO)3Br3] in methanol. The ligands and their rhenium complexes were obtained in good yields and characterized by common spectroscopic techniques including 1D and 2D NMR, HRMS, IR, cyclic voltammetry, UV, and luminescence spectroscopy and X-ray crystallography. The crystal structure of complex 6.0.5NaPF6 displays a facial geometry of the carbonyl ligands. The nitrogen donors of the tridentate ligand complete the distorted octahedral spheres of the complex. Crystal data: monoclinic, C2, a = 24.618(3) A, b = 11.4787(11) A, c = 15.5902(15) A, beta = 112.422(4) degrees , Z = 4, D(calc) = 1.562 g/cm3.     

Synthesis of novel pyrimidine derivatives with (pyridin-3-ylmethyl)thio and phenylamino moieties and evaluation of their antifungal activity

A series of novel pyrimidine derivatives with (pyridin-3-ylmethyl)thio and phenylamino moieties were synthesized from ethyl acetoacetate, thiourea, 3-pyridinylmethyl chloride hydrochloride, and substituted anilines by multi-step reactions. The structures of the target compounds were characterized by IR, ¹H NMR, ¹³C NMR and elemental analysis. The in vitro antifungal activities against Botrytis cinerea and Sclerotinia sclerotiorum were evaluated. The result showed that N-phenyl-6-methyl-2- ((pyridin-3-ylmethyl)thio) pyrimidin-4-amine (4a) displayed high inhibition activity against Botrytis cinerea with 87.5%inhibition at 100 µg/mL; 4a, and N-(4-isopropylphenyl)-6-methyl-2-((pyridin-3-ylmethyl)thio)pyrimidin-4-amine (4c), N-(4-methoxyphenyl)-6-methyl-2-((pyridin-3-ylmethyl)thio)pyrimidin-4-amine (4d) and N-(2-hydroxy-5-chloro)-6-methyl-2-((pyridin-3-ylmethyl)thio)pyrimidin- 4-amine (4h) exhibited sufficient activities against Sclerotinia sclerotiorum with 86.6% –93.7% inhibitions at the same concentration.     

Synthesis of 5,8-Diamino-Substituted Pyrano[4″,3″:4′,5′]pyrido[3′,2′:4,5]thieno[3,2-<Emphasis Type="Italic">d</Emphasis>]pyrimidines and Pyrimido[4′,5′:4,5]thieno[2,3-<Emphasis Type="Italic">c</Emphasis>]isoquinolines

Ethyl 1-amino-8,8-dimethyl-5-(piperidin-1-yl)-8,9-dihydro-6H-pyrano[4,3-d]thieno[2,3-b]pyridine-2-carboxylate and ethyl 1-amino-5-(piperidin-1-yl)-6,7,8,9-tetrahydrothieno[2,3-c]isoquinoline-2-carboxylate reacted with benzoyl isothiocyanate to give the corresponding 1-thioureido derivatives which underwent cyclization to 2,2-dimethyl-5-(piperidin-1-yl)-10-thioxo-1,4,10,11-tetrahydro-2H-pyrano[4″,3″:4′,5′]pyrido-[3′,2′:4,5]thieno[3,2-d]pyrimidin-8(9H)-one and 5-(piperidin-1-yl)-10-thioxo-1,2,3,4,10,11-hexahydropyrimido-[4′,5′:4,5]thieno[2,3-c]isoquinolin-8(9H)-one. The cyclization products were converted into 8-chloro derivatives, and the chlorine atom therein was replaced by various amines.     

New Monoterpene-Substituted Dihydrochalcones from Piper aduncum

Five New unusual monoterpene-substituted dihydrochalcones, the adunctins A–E (1″S)-1-{2′-hydroxy-4′-methoxy-6′-[4″-methyl-1″-(1?-methylethyl)cyclohex-3″ -en-1″ -yloxy]phenyl}-3-phenylpropan-1-one ( 1 ), (5aR*,8R*,9aR*)-3-phenyl-1-[5′,8′,9′,9′a-tetrahydro-3′-hydroxy-1′-methoxy-8′-(1″-methylethyl)-5′-a-methyldibenzo-[b,d]furan-4′-yl]propan-1-one ( 2 ), (2′R*,4″S*)-1-{6′-hydroxy-4′-methoxy-4″-(1?-methylethyl)spiro[benzo[b]-furan-2′(3′H),1″ -cyclohex-2″ -en]-7′-yl}-3-phenylpropan-1-one ( 3 ), (2′R*,4″R*)-1-{6′-hydroxy-4′-methylethyl-4″-(1?-methylethyl)spiro[benzo[b]furan-2′(3′H),1″-cyclohex-2″-en]-7′-yl}-3-phenypropan-1-one ( 4 ), and (5′aR*,6′S*, 9′R*,9′aS*)-1-[5′a,6′,7′,8′,9′a-hexahydro-3′,6′-methoxy-6′-methyl-9′-(1″-methylethyl)dibenzo[b,d]-furan-4′-yl]-3-phenylpropan-1-one ( 5 ) were isolated from the leaves of Piper aduncum (Piperaceae) by preparative liquid chromatography. In addition, (?)-methyllindaretin ( 6 ), trans-phytol, and α-tocopherol ( = vitamin E) were also isolated and identified. The structures were elucidated by spectroscopic methods, including 1D- and 2D-NMR spectroscopy as well as single-crystal X-ray diffraction analysis. The antibacterial and cytotoxic potentials of the isolates were also investigated.     

Synthesis and properties of tetraanthraquinonyl- and tetraanthraquinonyloxy-substituted copper and cobalt phthalocyanines

Cobalt and copper tetra-[4-(9,10-dioxo-9,10-dihydroanthraceny-2-yl)]- and tetra-{4-[(9,10-dioxo-9,10-dihydroanthracen-2-yl)oxy]}phthalocyanines have been prepared; their spectral properties have been studied.     

Three new flavonol C-glycosides from Sida cordifolia Linn

Three new flavonol C-glycosides: 3′-(3″,7″-dimethyl-2″,6″-octadiene)-8-C-β-D-glucosyl-kaempferol 3-O-β-D-glucoside (1), 3′-(3″,7″-dimethyl-2″,6″-octadiene)-8-C-β-D-glucosyl-kaempferol 3-O-β-D-glucosyl [1→4]-α-D-glucoside (2) and 6-(3″-methyl-2″-butene)-3′-methoxyl-8-C-β-D-glucosyl-kaempferol 3-O-β-D-glucosyl [1→4]-β-D-glucoside (3) have been isolated from 80% ethanolic extract of the aerial parts of Sida cordifolia Linn followed by partitioning with ethyl acetate. Structures were established by chemical and spectroscopic methods.     

Building libraries of skeletally diverse scaffolds from novel heterocyclic active methylene compound through multi-component reactions

Libraries of skeletally diverse potential bioactive polycyclic/spirocyclic heterocyclic compounds; 2-amino-7,9-dimethyl-5-oxo-4-aryl-4,5,6,7-tetrahydropyrano[2,3-d]pyrazolo[3,4-b]pyridine-3-carbonitrile, 2′-amino-7′,9′-dimethyl-2,5′-dioxo-6′,7′-dihydro-5′H-spiro[indoline-3,4′-pyrano[2,3-d]pyrazolo[3,4-b]pyridine]-3′-carbonitrile, and 5,5′-(arylmethylene)bis(4-hydroxy-1,3-dimethyl-1H-pyrazolo[3,4-b]pyridin-6(7H)-one) have been synthesized through a multi-component reaction using novel heterocyclic active methylene compound 4-hydroxy-1,3-dimethyl-1H-pyrazolo[3,4-b]pyridine-6(7H)-one as one of the building blocks. This protocol can be considered to be an efficient and eco-friendly strategy for diversity oriented synthesis.     

Highly sensitive and selective determination of Hg2+ by using 3-((2-(1H-benzo[d]imidazol-2-yl)phenylimino)methyl)benzene-1,2-diol as fluorescent chemosensor and its application in real water sample

A new receptor 3-((2-(1H-benzo[d]imidazol-2-yl)phenylimino)methyl)benzene-1,2-diol (1) was synthesised and developed as a highly selective fluorescent chemosensor for the detection of Hg²⁺ in semi-aqueous media. The fluorescence of receptor 1 was dramatically and selectively quenched on complexation with Hg²⁺ ion with the detection limit down to 0.20 μM. The developed sensor was successfully applied for the determination of Hg²⁺ content in water samples. Density Functional Theory (DFT) calculations were performed to study the mechanistic behaviour behind the binding of Hg²⁺ with receptor 1.     

One-Pot Synthesis of Novel Spiro Pyrano[2,3-d][1,3]thiazolo[3,2-a]pyrimidine Derivatives

In a one-pot synthesis, 1′-methyl-2,3″-dioxo-5″-aryl-1,2,5a″,7″,8″,9a″-hexahydro-5″H,6″H-dispiro[indole-3,2′-pyrrolidine-3′,2″-pyrano[2,3-d][1,3]thiazolo[3,2-a]pyrimidine]-4′-carboxylic acid methyl ester was prepared via the sequential reaction of 4-aryl-octahydro-pyrano[2,3-d]pyrimidine-2-thione, dimethyl acetylenedicarboxylate (DMAD), and a mixture of isatin and sarcosine. All the novel spiro compounds, in moderate yields, were characterized thoroughly by infrared, NMR, mass spectromentry, and elemental analysis together with x-ray crystallographic analysis.     

Synthesis and Ni(0)-catalyzed oligomerization of isomeric 4,4‴-dichloroquaterphenyls

4,4?-Dichloro-1,1′ : 2′,1″ : 2″,1?-quaterphenyl ( 9 ), 4,4?-dichloro-1,1′ : 3′,1″ : 3″,1?-quaterphenyl ( 10 ), and 4,4?-dichloro-1,1′ : 4′,1″ : 4″,1?-quaterphenyl ( 11 ) were synthesized by Pd (0) catalyzed cross-coupling reaction of 4-chlorobenzeneboronic acid with 2,2′-, 3,3′-, and 4,4′-bis (trifluoromethanesulfonyloxy)biphenyl respectively. 4,4?-Dichloro-1,1′ : 2′,1″ : 2″,1?-quaterphenyl ( 9 ) and 4,4?-dichloro-1,1′ : 3′,1″ : 3″,1?-quaterphenyl ( 10 ) were oligomerized by Ni(0) catalyzed homocoupling reaction to yield white and soluble oligophenylenes. © 1993 John Wiley & Sons, Inc.     

Synthesis of linear and cyclic compounds containing the 3,4-bis(furazan-3-yl)furoxan fragment

Some chemical transformations of 3,4-bis(4-aminofurazan-3-yl)furoxan (1) and 3,4-bis-(4-nitrofurazan-3-yl)furoxan (2) were considered. Compounds 1 and 2 are valuable synthons for the preparation of linear and cyclic compounds containing the 3,4-bis(furazan-3-yl)furoxan fragment. The reaction of compound 2 with a series of N- and O-nucleophiles afforded novel heterocyclic systems: 7-R-7H-difurazano[3,4-b:3′,4′-f]furoxano[3″,4″-d]azepine and difurazano[3,4-b:3′,4′-f]furoxano[3″,4″-d]oxepin.     

A NOVEL SYNTHESIS OF 2-SUBSTITUTED-4H-THIENO [2,3-d][1,3] OXAZIN-4-ONE AND 2,3-DISUBSTITUTED THIENO [2,3-d]PYRIMIDIN-4(3H)-ONE DERIVATIVES

Abstract

The synthesis of acetic 2-{[1-methyl-2-(4-oxo-5,6,7,8-tetrahydro-4H-benzo [4,5]-thieno [2,3-d] [1,3-oxazin-2-yl)ethylidene]amino}-4,5,6,7-tetrahydrohenzo[b]thiophene ?3-carboxylic acid anhydride 5 and 2-(oxopropyl)-5,6,7,8-tetrahydro-4H-benzo-[4,5] thieno[2,3-d][1,3]oxazin-4-one 7, has been achieved in three steps from ethyl 2-amino-4,5,6,7-tetrahydrobenzo(b]thiophene-3-carboxlate 1 via the reaction with ethyl acetoacetate followed by hydrolysis and acetic anhydride-induced cyclization. The 2-substituent in compound 5 has two functional groups i.e. active methylene and acid anhydride which are suitably located for intramolecular transformation. Thermal and/or base catalyzed intramolecular cyclization of 5 afforded 2-(4-acetoxy-(hydroxyl)-2-methyl-5,6,7,8-tetrahydrobenzo[4,5] thieno[2,3-b]pyridin-3-yl)-5,6,7,8- tetrahydro-4H-benzo[4,5]thieno[2,3-d] [1,3]oxazin-4-one 10 and 9 respectively. Treatment of 5 with hydrazine hydrate, aromatic and/or heterocyclic amines induced the same intramolecular cyclization with a concomitant oxazine-pyrimidine interconversion to give 3-amino(aryl or heteryl)-2-(4-hydroxy-5,6,7,8-tetrdhydrobenzo-[4,5]thieno[2,3-b]pyridin-3-yl)-3,4,5,6,7,8-hexahydrobenzo[4,5] thieno[2,3-d] pyrimid in-4-one 11–14 respectively.     

Midrange affinity fluorescent Zn(II) sensors of the Zinpyr family: syntheses, characterization, and biological imaging applications

The syntheses and photophysical characterization of ZP9, 2-{2-chloro-6-hydroxy-3-oxo-5-[(2-{[pyridin-2-ylmethyl-(1H-pyrrol-2-ylmethyl)amino]methyl}phenylamino)methyl]-3H-xanthen-9-yl}benzoic acid, and ZP10, 2-{2-chloro-6-hydroxy-5-[(2-{[(1-methyl-1H-pyrrol-2-ylmethyl)pyridin-2-ylmethylamino]methyl}phenylamino)methyl]-3-oxo-3H-xanthen-9-yl}benzoic acid, two asymmetrically derivatized fluorescein-based dyes, are described. These sensors each contain an aniline-based ligand moiety functionalized with a pyridyl-amine-pyrrole group and have dissociation constants for Zn(II) in the sub-micromolar (ZP9) and low-micromolar (ZP10) range, which we define as "midrange". They give approximately 12- (ZP9) and approximately 7-fold (ZP10) fluorescence turn-on immediately following Zn(II) addition at neutral pH and exhibit improved selectivity for Zn(II) compared to the di-(2-picolyl)amine-based Zinpyr (ZP) sensors. Confocal microscopy studies indicate that such asymmetrical fluorescein-based probes are cell permeable and Zn(II) responsive in vivo.     

Specificity of the cyclization of 1-alkyl(aryl)sulfonylamino-9,10-anthraquinones into naphtho[1,2,3-cd]indol-6(2H)-ones

Cyclization of N-(9,10-dioxo-9,10-dihydroanthracen-1-yl)methanesulfonamides to 2,6-dihydronaphtho[1,2,3-cd]indol-6-ones in DMSO-KOH involves intermediate formation of 2,3-dihydroanthra[1,9-cd]-[1λ⁶,2]thiazin-7-one 2,2-dioxides, whereas heterocyclization of N-(9,10-dioxo-9,10-dihydroanthracen-1-yl)-ethane- and -arenesulfonamides under analogous conditions occurs with participation of methylsulfonylmethanide.     

一种含载流子传输基的铱配合物:合成及深黄色电致磷光器件

合成了一种含有载流子传输基新的铱配合物(BPPBI)2Ir(ECTFBD)[HBPPBI:1-苯基-2-(4-联苯基)苯并咪唑,HECTFBD:1-(9-乙基-3-咔唑基)-4,4,4-三氟-1,3-丁二酮],其结构和组成经核磁共振氢谱和元素分析所证实。研究了这种铱配合物二氯甲烷溶液的光物理和电化学性质。制作了基于这种铱配合物的电致磷光器件。器件结构是ITO/MoO3(10 nm)/NPB(80 nm)/CBP:x%(BPPBI)2Ir(ECTFBD)(20 nm)/TPBi(45 nm)/LiF/Al[x%:质量百分比为4%和7%的掺杂浓度;NPB:N4,N4′-二(1-萘基)-N4,N4′-二苯基-4,4′-联苯二胺,CBP:4,4′-二(9-咔唑基)联苯,TPBi:1,3,5-三(2-(1-苯基)苯并咪唑基)苯]。这些器件显示出深黄色的发射。对于7%掺杂浓度器件,最大的电流效率和最大发光亮度分别是5.2 cd.A-1和8 690 cd.m-2。     

Herpetetradione,nouveau lignoide tetramere isole d'Herpetospermum caudigerum wall.

The title compound, a new tetramer of coniferyl alcohol, has been isolated from seeds of $\text{Herpetospermum caudigerum}$ Wall. (Cucurbitaceae). Its structure was elucidated by spectroscopic means as $\text{rel}$-(7′S, 8′S, 7″S, 8″)-4,9,4′,4″,4″′,9″′-hexahydroxy-5,5′5″,5″′-tetramethoxy-7,7″′-dioxo-8.3′, 7′.0.9″,8′.8″,9′.0.7″,3″.8″′ -lignoïd.     

Enhanced activity and modified substrate-favoritism of Burkholderia cepacia lipase by the treatment with a pyridinium alkyl-PEG sulfate ionic liquid

Three types of pyridinium salts, i.e., 1-ethylpyridin-1-ium cetyl-PEG₁₀ sulfate (PY_ET), 1-butylpyridin-1-ium cetyl-PEG₁₀ sulfate (PY_BU), and 1-(3-methoxypropyl)pyridin-1-ium cetyl-PEG₁₀ sulfate (PY_MP), have been prepared and evaluated for their activation property of Burkholderia cepacia lipase by comparison to the control IL-coated enzymes, 1-butyl-2,3-dimethylimidazolium cetyl-PEG₁₀ sulfate-coated lipase PS (IL1-PS). Among the tested pyridinium salt-coated lipases, the PY_ET-coated lipase PS (PY_ET-PS) exhibited the best results; the transesterification of 1-(pyridin-2-yl)ethanol, 1-(pyridin-3-yl)ethanol, 1-(pyridin-4-yl)ethanol, or 4-phenylbut-3-en-2-ol proceeded faster than those of the IL1-PS-catalyzed reaction while maintaining an excellent enantioselectivity (E?>?200). This improved efficiency was found to be dependent on the increased K_cat value.     

Synthesis and pharmacological evaluation of 5-[2′-(1H-tetrazol-5-yl)-biphenyl-4-ylmethyl]-4,5,6,7-tetrahydro-thieno[3,2-c]pyridine derivatives as platelet aggregation inhibitors

One pot synthesis and characterization of new 5-[2′-(1H-tetrazol-5-yl)-biphenyl-4-ylmethyl]-4,5,6,7-tetrahydro-thieno[3,2-c]pyridines (3a–k) using amides (2a–k) were reported. The prepared 5-[2′-(1H-tetrazol-5-yl)-biphenyl-4-ylmethyl]-4,5,6,7-tetrahydro-thieno[3,2-c]pyridine (3a) is a bioisostere of 4′-(6,7-dihydro-4H-thieno [3,2-c]pyridin-5-ylmethyl)-biphenyl-2-carboxylic acid (1), having good in vivo antithrombotic activity compared with Clopidogrel. The new tetrazole derivatives (3a–k) were screened for their in vitro activity as platelet aggregation inhibitors.