ABSTRACT
We have newly synthesized the non-symmetrical "phthalimidoyl active ester" bi-dentate cross-linking reagents having an acid chloride, 2-benzothiazole, or 1-benzotriazole group (i.e., 9, 15, and 16) on the basis of the reactivity study of the "active ester" model compounds, 11-14, toward the various nucleophiles and examined their reaction selectivity towards the same nucleophiles. Then, we applied for the modification of cholesterol at the more reactive site of the bi-dentate linkers to give 3ß-cholesteryl 4-(phthalimidoyloxycarbonyl)butyrate (39), and the subsequent reaction of 39 with several amines, such as benzylamine, 4-chlorobenzylamine, 2-phenylethylamine, L-phenylalanine methyl ester, or diphenylalanine benzyl ester as a protein model of the cholesterol antigen.
Subject(s)
Acids/chemistry , Benzothiazoles/chemistry , Chlorides/chemistry , Cross-Linking Reagents/chemistry , Esters/chemistry , Crystallography, X-Ray , Molecular Structure , StereoisomerismABSTRACT
In the course of our study of the development of a synthetic methodology for the aziridination of fullerenes, we recently reported the photochemical [2+1] cycloaddition reaction of nitrene onto C(60) generated from sulfilimine. Sulfilimines with an electron-donating group on the N atom are well known to undergo Michael-type reactions, followed by concomitant elimination of sulfide to afford the corresponding aziridines. In these reactions, sulfilimines act as a nucleophile to the electrophilic olefins. Furthermore, C(60) has characteristic features of a low LUMO level and electron-accepting properties. Therefore, it can be an electrophilic olefin. In this context, sulfilimines might react with C(60) to afford the corresponding aziridinofullerenes. We have studied the thermal reaction of (S,S)-diphenylsulfilimines with C(60) and regioselectively synthesized bis- and tris-aziridinated fullerenes. These structures were determined through spectroscopic analyses. Among these, the structure of bis-aziridinated[60]fullerene, C(60)(NCH(3))(2), was determined using single-crystal X-ray analysis. Results show that the multi-aziridination occurs exclusively at the same six-membered ring of C(60) to afford one isomer of the bis-adduct and tris-adduct.
ABSTRACT
The reaction of 'active ester' bidentate cross-linking reagents, phthalimido 4-chloroformylbutanoate (1) and phthalimido 4-(2-benzothiazolyloxycarbonyl)butanoate (2) with several protected D-glucose derivatives is described. These reactions are used to introduce the reactive group into cellulose (filter paper) with the aim of linking proteins and cellulose.
Subject(s)
Benzothiazoles/chemistry , Cellulose/metabolism , Chlorides/chemistry , Glucosides/chemistry , Phthalimides/chemistry , Phthalimides/metabolismABSTRACT
We studied the continuous flow photocatalytic treatment integrated with separation/reuse of titanium dioxide on the removal of phenol (20 mg l(-1)) in electrolytes containing tap water. A circulative flow tubular photoreactor and a separation tank were used, where inflow of phenol continuously flowed into a mixing tank (for titanium dioxide suspension) and treated water overflowed from the separation tank. Black light and sunlight were used by turns as the light source on the photocatalytic treatment. Photocatalytic removal of phenol was maximum at the circulative flow rate of 600 ml min(-1) and the transmittance of 0.3%. Integration of circulative photocatalytic treatment and titanium dioxide separation and continuous use of titanium dioxide could be performed effectively at low inflow of 10 ml min(-1). The titanium dioxide slurry sedimented spontaneously by standing was continuously used for at least 72 h without decreasing the efficiency of the photocatalytic treatment. The used titanium dioxide can be replaced with a fresh one by draw and fill method without interrupting the treatment.
Subject(s)
Phenol/isolation & purification , Titanium/chemistry , Water Pollutants, Chemical/isolation & purification , Water Purification/methods , Catalysis , Equipment Design , Light , Phenol/chemistry , Phenols/chemistry , Photochemical Processes , Photochemistry/methods , Sunlight , Time Factors , Waste Disposal, Fluid/methods , Water/chemistry , Water Pollutants, Chemical/chemistryABSTRACT
To evaluate the ability of dibenzothiophene N-substituted sulfilimines as photochemical nitrene sources, their photolyses in the presence of several trapping reagents, such as sulfides, olefins, and phosphorus compounds, were performed. In the reactions, the corresponding imino-transfer compounds, namely sulfilimines, aziridines, and iminophosphoranes, were formed in good yields, indicating dibenzothiophene N-tosyl and N-acylsulfilimines have a potent nature as nitrogen sources.
Subject(s)
Imines/radiation effects , Thiophenes/chemistry , Thiophenes/radiation effects , Ultraviolet Rays , Aziridines/chemical synthesis , Aziridines/chemistry , Aziridines/radiation effects , Imines/chemical synthesis , Imines/chemistry , Molecular Structure , Phosphoranes/chemical synthesis , Phosphoranes/chemistry , Phosphoranes/radiation effects , Photochemistry , Photolysis , StereoisomerismABSTRACT
A new type of lambda6-sulfanenitrile with an SN triple bond at both ends, Ph2S(=N-(Ph2)S[triple bond]N)2 (5), was prepared in excellent yield from the one-pot synthesis of diphenylsulfimide (Ph2SNH) with fluoro(diphenyl)-lambda6-sulfanenitrile (Ph2FSN) in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene. Its molecular structure was determined by X-ray crystallographic analysis. Compound 5 reacted further with methyl triflate and trifluoromethanesulfonic anhydride to afford the corresponding bis-N-methylated and -N-sulfonated compounds.
Subject(s)
Blood Cell Count , Blood Chemical Analysis , Dioxins/blood , Food Contamination , Oryza/poisoning , Plant Oils/poisoning , Polychlorinated Biphenyls/poisoning , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Creatine Kinase/metabolism , Electrolytes/blood , Female , Hematopoiesis , Humans , Infant , Kidney Function Tests , Male , Middle Aged , Poisoning/blood , Poisoning/physiopathology , Polychlorinated Biphenyls/blood , Proteins/metabolismABSTRACT
Diphenyl 1-amino-2-phenylethylphosphonate was introduced to poly(ethylene glycol)s (PEGs) with average molecular masses of 300, 400, and 600 to prepare water-insoluble PEG-inhibitor conjugates. Interestingly, only the conjugate from PEG with an average molecular weight of 600 formed a precipitate with chymotrypsin but not with trypsin. The results demonstrated that the PEG-inhibitor conjugate is useful for separation of chymotrypsin.
Subject(s)
Chymotrypsin/isolation & purification , Organophosphonates/chemistry , Polyethylene Glycols/chemistry , Protease Inhibitors/chemistry , Chemical Precipitation , Methods , Molecular Weight , Serine Endopeptidases/isolation & purification , TrypsinABSTRACT
A diphenyl alpha-aminoalkylphosphonate derivative, which is an irreversible inhibitor of chymotrypsin-like serine proteases, was immobilized on cyanogen bromide-activated Sepharose, and the selective binding of chymotrypsin to the obtained inhibitor-gel was evaluated using batch and column methods. Complete removal of chymotrypsin in an aqueous solution was done using the column method, while partial removal was done using the batch method.
Subject(s)
Chymotrypsin/isolation & purification , Organophosphonates/chemistry , Sepharose/chemistry , Chymotrypsin/chemistryABSTRACT
Previously we reported the novel thioaldehydes generation via thermolyses of phenacyl sulfoxides bearing some heteroaromatics. Thermolysis of sulfoxides (1a,b and 2a-4a) bearing other heterocycles such as thiadiazole, triazole, and tetrazole in the presence of 2,3-dimethyl-1,3-butadiene in dioxane at 100 degrees C led to the unexpected products 6-substituted-5,6-dihydro-3,4-dimethyl-2H-thiapyran 1-oxide (5a,b). These products were considered to be formed by the Diels-Alder reaction of the diene with the sulfines formed initially by the thermal decomposition of the sulfoxides. The rate acceleration and the improvement of the yield by addition of 1.5 equiv of triethylamine, especially in the case of ethoxycabonylmethyl sulfoxide 1c, was observed. The cis-trans selectivity for sulfine cycloadducts was also studied by NMR spectrometry. The reactions of alpha-substituted phenacyl sulfoxides 1d-f bearing a phenyl-substituted tetrazolyl group in the presence of the same diene were also studied.