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We investigated electrical properties of titanyl-phthalocyanine ͑TiOPc͒ films under ultrahigh vacuum ͑UHV͒ conditions to avoid the influence of gas adsorption. The field-effect measurement revealed that TiOPc films exhibited an n-type semiconducting behavior in UHV. The electron mobility at room temperature was 9ϫ10 Ϫ6 cm 2 V Ϫ1 s Ϫ1 with activation energy of 0.20 eV. The conductivity and carrier density were 9ϫ10 Ϫ8 S cm Ϫ1 and 6ϫ10 16 cm Ϫ3 , respectively. A clear conversion from n-type to p-type behavior was observed when the film was exposed to oxygen. Strict control of atmosphere made it possible to obtain a quasi-intrinsic state where both p-and n-type conductions appeared simultaneously.

We studied the electronic structure of cobalt-phthalocyanine (CoPc) molecules on Au(111) and Cu(100) surfaces by scanning tunneling microscopy and spectroscopy at 5 K. In the differential conductance (dI=dV) spectra, there were some peaks related to the highest occupied molecular orbital (HOMO), the lowest unoccupied MO (LUMO) and the d-orbitals of the Co atom. CoPc molecules on the Cu(100) surface had new electronic states between the peaks related to HOMO and LUMO, while those on the Au(111) surface did not show additional peaks. A dI=dV image indicated that the new states were generated by the hybridization between the LUMO of molecules and the electronic states of the Cu(100) surface.

Aculeacin A, a new antifungal antibiotic was isolated from the mycelial cake of Aspergillus aculeatus M-4214. The antibiotic is a white amorphous powder soluble in lower alcohols and hardly soluble in other organic solvents or water. Aculeacin A gave palmitic acid and five ninhydrin-positive products including threonine, hydroxyproline upon acid hydrolysis. The antibiotic showed a potent activity against molds and yeasts, but exhibited no antibacterial activity.

BTQBT (bis-(1, 2, 5-thiadiazolo)-p-quinobis(1, 3-dithiole)) films have been prepared as active semiconducting layers of organic field effect transistors (FETs). BTQBT films showed a p-type semiconducting behavior. The hole mobility and on/off ratio of BTQBT films under ultrahigh vacuum conditions reached to 0.2 cm 2 /V·s and 10 8 , respectively, by optimization of the growth conditions. These values are in the same order as those of pentacene thin films, which indicates that BTQBT molecules have a great potential for active layers of organic electronic devices.

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The fraction of substrate metabolized (f ) can be used to estimate drug interactions and can be determined by comparison of the intrinsic clearances (CL ) of victim drugs obtained from inhibited and uninhibited hepatic enzymes Commercially available human liver microsomes were recently developed in which one cytochrome P450 (P450) isoform is selectively inactivated. These inactivated liver microsomes were used to evaluate the roles of P450 2C isoforms in the depletion and oxidation of probe substrates. Determination of CL with sets of control and P450 2C9-inactivated liver microsomes yielded f values of 0.69-1.0 for celecoxib, diclofenac and warfarin. Apparent minor contributions of P450 1A2/2C8/3A4 were seen in depletion assays, yielding ~1 for the sum of the f values. Selectively inactivated liver microsomes were thereby shown to be potentially useful for determining the in vitro f values for major P450 2C9 contributions to substrate oxidations. Metabolite formations from diclofenac and warfarin were suppressed by 62-84% by the replacement of control liver microsomes with P450 2C9-inactivated liver microsomes. R-, S- and racemic omeprazole and troglitazone oxidation activities by liver microsomes at multiple substrate concentrations were suppressed by 26-36% and 22-50%, respectively, when P450 2C19- and 2C8-inactivated liver microsomes were used in place of control liver microsomes. This study provides important information to help elucidate the different roles of P450 isoforms in metabolite formation at different substrate concentrations. The data obtained allow the fractions metabolized to be calculated for victim drugs.