Direct drug metabolism monitoring in a live single hepatic cell by video mass spectrometry

The metabolism of anti-breast cancer drug, tamoxifen, in a single human hepatocellular carcinoma cell, HepG2, was directly monitored by a video-mass spectroscope. The cytoplasm, a vacuole or nucleus of the cell was directly sucked by a nano-spray tip under a video-microscope, and then was introduced into a mass spectrometer. Unchanged drug molecules were found in cytoplasm and a vacuole, but the metabolites were only found in the cytoplasm. This direct detection of drug metabolites in a live single cell is useful for speedy drug metabolism monitoring.     

Distance Between Qubit States with Initial System-Environment Correlation

The time-evolution of the trace distance between two qubit states in the presence of an initial correlation with an environment is investigated by means of the exactly solvable model of qubit and environmental system, where there is at most one excitation in the whole system, It is found that the trace distance can exceed its initial value during the time-evolution under certain conditions if the qubit is initially entangled with the environment. Furthermore the Bures distance between two qubit states is investigated. It is seen that the time-evolution of the Bures distance is quite different from that of the trace distance.     

Preparation of (Z)-1-fluoro-1-alkenyl carboxylates,carbonates and carbamates through chromium mediated transformation of dibromofluoromethylcarbinyl esters and the reactivity as double acyl group donors

CrCl₂/Mn-mediated transformation of various dibromofluoromethylcarbinyl esters including carboxylates, carbonates and carbamates provided 1-fluoro-1-alkenyl esters via [2,3]-sigmatropic rearrangement of ester group. Reaction proceeded by using CrCl₂/Mn system under mild conditions (in THF at room temperature) to give 1-fluoro-1-alkenyl esters in good yield with an excellent Z selective manner. 1-Fluoro-1-alkenyl ester thus obtained acts as a double acyl donor in the reaction with necleophiles such as amine, thiol, alcohol as well as bifunctional necleophiles such as ethylene diamine derivative.     

A novel disaccharide,wilforibiose from cynanchum wilfordi h(=emsl)

The structure of a novel disaccharide, wilforibiose, isolated from the root of $\text{Cynanchum wilfordi}$ H(=emsl), has been established by spectral data.     

(+)-4-Hydroxysarcocapnine: Structure and stereochemical considerations

(+)-4-Hydroxysarcocapnine obtained from Sarcocapnos enneaphylla (L.) DC. has been shown by spectral studies and synthesis to possess the new 4-hydroxyisocularine structure (1a). Straightforward assignment of the configuration of a 4-hydroxycularine by NMR is also-discussed.     

Molecular Structure of the Silver(I) Triflate Complex with N,N′,N″,N‴-tetrakis(3′,5′-difluorobenzyl)-1,4,8,11-tetraazacyclotetradecane

The structure of the silver(I) triflate complex with N,N′,N″,N?-tetrakis-(3′,5′-difluorobenzyl)-1,4,8,11-tetraazacyclotetradecane is reported. The Ag⁺–π interaction between the Ag⁺ ion incorporated in the cyclam moiety and the aromatic side-arm was observed in solid and solution by X-ray crystallography and UV–VIS titration experiments, respectively. It is also revealed that the Ag⁺ complex is stable in gas phase from the FAB-MS. The energy of the Ag⁺–π interaction was estimated as about 30 kJ/mol by Hartree–Fock/3-21G^(*) and DFT (B3LYP/3-21G^(*)) calculations. The NBO analysis indicated that s donation is the main contribution to the Ag⁺–aromatic ring interaction.     

Total Synthesis and Biological Evaluation of Siladenoserinol A and its Analogues

The total synthesis of siladenoserinol A, an inhibitor of the p53–Hdm2 interaction, has been achieved. AuCl₃‐catalyzed hydroalkoxylation of an alkynoate derivative smoothly and regioselectively proceeded to afford a bicycloketal in excellent yield. A glycerophosphocholine moiety was successfully introduced through the Horner–Wadsworth–Emmons reaction using an originally developed phosphonoacetate derivative. Finally, removal of the acid‐labile protecting groups, followed by regioselective sulfamate formation of the serinol moiety afforded the desired siladenoserinol A, and benzoyl and desulfamated analogues were also successfully synthesized. Biological evaluation showed that the sulfamate is essential for biological activity, and modification of the acyl group on the bicycloketal can improve the inhibitory activity against the p53–Hdm2 interaction.     

Ultrafast photoinduced intramolecular charge separation and recombination processes in the oligothiophene-substituted benzene dyads with an amide spacer

Photoinduced intramolecular charge separation (CS) and recombination (CR) processes of the tetrathiophene-substituted benzene dyads with an amide spacer (4T-PhR, R = 4-H (1), 4-CN (2), 3,4-(CN)2 (3), 4-NO2 (4), 3,5-(NO2)2 (5)) in solvents of different polarities were investigated using various fast spectroscopies. It was revealed that the CS rates depend on the ability of the acceptor and solvent polarity. Ultrafast CS with the rate of 5 x 10(12) s(-1) was revealed for 5 in PhCN and MeCN. The ultrafast CS can be attributed to the large electronic coupling matrix element between the donor and the acceptor despite the relative long donor-acceptor distance. The existence of the state with large electron density on the spacer between 14T*-PhR and LUMO should facilitate the CS process in the present dyad system. It was also revealed that the CR rates in these dyads were rather fast because of the enhanced superexchange interaction through the amide spacer.     

Synthesis of chiral nonracemic 1-(2-pyridinyl)ethylamines: stereospecific introduction of amino function onto the 2-pyridinylmethyl carbon center

Stereospecific substitutions of optically pure 1-(pyridinyl)ethyl methanesulfonates with various amines are described. The reaction of (R)- or (S)-1-(2-pyridinyl)ethyl methanesulfonate with primary amines, including amino acid esters, gives N-substituted (S)- or (R)-1-(2-pyridinyl)ethylamines (4) with inversion of the configuration. Secondary cyclic amines are also reacted with (R)-2 to give the corresponding substituted amines (5) in excellent yields. Optically pure and meso triamine ligands having two pyridine rings, (S,S)-4f and meso-4f, (S,S)-9e, (S,R)-9e, and (S,S)-9f, have been prepared in stereochemically pure form by this method. Not only the substitution reaction of optically active 2 but also that of 1-(4-pyridinyl)ethyl and 1-(3-pyridinyl)ethyl methanesulfonates 11 and 14 take place stereospecifcally with inversion of the chiral center.     

Stereocontrolled synthesis of steroid side chain; stereoselective syntheses of cholesterol and 25-hydroxycholesterol

Novel stereoselective method to introduce side chain onto 17-oxosteroids has been deviced, and using the method cholesterol and 25-hydroxycholesterol are synthesized.