CONDENSATION PRODUCTS OF 7H-BENZO[DE]NAPHTHACENE-7-ONE

Condensation reaction of 7H-benzo[de]naphthacene-7-one (1 Kohno, Y., Kohno, M., Saito, Y. and Inokuchi, H. 1975. Crystal Structure of Tetrabenzo[a,cd,j,lm]perylene. Acta Cryst., B31: 2076–2080.  [Google Scholar]) was conducted in fused salt using zinc dust at 275°C for 2 h. The reaction products were isolated by column chromatography and then purified by recrystallization, yielding crystals of orange-yellow needles as the main product. This compound with an absorption maximum at 450 nm was identified as trinaphtho[2,3-c; 2′,1′,8′-fgh; 2″,1″,8″-uva]-pentaphene by one-dimensional and two-dimensional ¹H NMR spectroscopy, which was one of expected condensation products. We are now trying to isolate the other expected condensation products, benzo[vwx]dinaphtho[2,1-a; 8′,1′,2′-cde]hexaphene and benzo[cd]naphtho[2,3-f]anthra[3,2,1-lm]perylene, from the byproducts.     

Economic Analysis of a High-volume Flexible Manufacturing System by High-speed Processing

Agility in manufacturing requires a quick response to the changes in quantity of products without losing productivity. A high-volume flexible manufacturing system (HV-FMS) attains the high flexibility as well as the high volume production. We consider in this paper the energy-saving effect of HV-FMS from the viewpoint of consumed electric power. We take a production system of cylinder heads for automobile engines as a subject in this study, and draw a comparison of the energy-saving effect between HV-FMS and flexible transfer line to verify the effectiveness of HV-FMS. Moreover, we discuss the economic effect of high-speed processing at HV-FMS. We measure the energy-saving effect by high-speed processing and give the permissible level for additional tooling cost.     

Context aware messaging service: A dynamical messaging delivery using location information and schedule information

This paper describes a context-based dynamic messaging system. It uses schedule information and location information of the message addressee. According to the addressee's communication context (schedule, location, and available media), the system selects the most suitable telephone number or e-mail address, and redirects each incoming message dynamically. It also writes the schedule and location information of users into an HTML file which users can share on the WWW. It will work as mobile groupware for mobile workers. Evaluating the system during a two-month experiment in Tokyo, we found that our system produced smooth communication and a greater feeling of teamwork.     

Serotonin/5-HT1A Signaling in the Neurovascular Unit Regulates Endothelial CLDN5 Expression

We previously reported that site-selective claudin-5 (CLDN5) breakdown and protein kinase A (PKA) activation are observed in brain microvessels of schizophrenia, but the underlying molecular basis remains unknown. The 5-HT1 receptors decline the intracellular cAMP levels and inactivate the major downstream PKA, and the 5-HT1A receptor is a promising target for schizophrenia. Therefore, we elucidated the involvement of serotonin/5-HT1A signaling in the endothelial CLDN5 expression. We demonstrate, by immunohistochemistry using post-mortem human brain tissue, that the 5-HT1A receptor is expressed in brain microvascular endothelial cells (BMVECs) and mural cells of the normal prefrontal cortex (PFC) gray matter. We also show that PKA is aberrantly activated not only in BMVECs but also in mural cells of the schizophrenic PFC. We subsequently revealed that the endothelial cell–pericyte tube-like structure was formed in a novel two-dimensional co-culture of human primary BMVECs and a human brain-derived pericyte cell line, in both of which the 5-HT1A receptor was expressed. Furthermore, we disclose that the serotonin/5-HT1A signaling enhances endothelial CLDN5 expression in BMVECs under two-dimensional co-culture conditions. Our findings provide novel insights into the physiological and pathological significance of serotonin/5-HT1A signaling in the region-specific regulation of the blood-brain barrier.     

ANALYSIS OF THE METABOLIC TRANSFORMATION OF MUTAGENIC NITROBENZOBENZANTHRONES BY MOLECULAR ORBITAL CALCULATIONS

The mutagenic activity of three nitrobenzobenzanthrones (NBBAs) and two dinitrobenzobenzanthrones (DNBBAs) was found to depend largely on the position and the number of the nitro groups as well as that of nitrobenzanthrones (NBAs). Two NBBAs exhibit the activity approximately two and a half times as large as that of 3-NBA, whereas the other less than one-hundredth. The activity of the DNBBAs is smaller than that of structurally corresponding NBBAs. To elucidate these differences in the mutagenicity, we postulated a metabolic activation pathway of NBAs and NBBAs and calculated physicochemical properties of the parent molecules, metabolites, and ultimate mutagens by the semi-empirical molecular orbital method. Correlation of the results with the mutagenic activity revealed that important factors determining the activity are the LUMO energies of the parent molecules and nitroso-metabolites and the HOMO energies of the hydroxylamino metabolites, which almost the same as those obtained in the case of NBAs and DNBAs.     

Photooxidation of Benzo[ de ]naphtho[2,1,8,7- stuv ]anthra[2,1,9,8- hijkl ]pentacene

This article describes the photooxidation of benzo[ de ]naphtho-[2,1,8,7- stuv ]anthra[2,1,9,8- hijkl ]pentacene (BNAP) synthesized by the condensation of naphthanthrone with zinc dust. When an o -dichlorobenzene solution of BNAP was irradiated with light of its maximum absorption wavelength (535 nm), the original absorption band was reduced and a new band appeared at longer wavelengths showing a peak at 606 nm. Excitation of the photobleached sample with 600 nm gave rise to fluorescence on the red side of that of BNAP by about 90 nm. The new fluorescence spectrum showed a vibrational progression of about 1,600 cm m 1 , which corresponds to the stretching of a carbonyl group. No spectral changes occurred in degassed solution. These findings suggest that BNAP reacts with singlet oxygen to form a ketone. Molecular orbital calculations revealed that the carbonyl group of the product is located at the C-18 position and that a hydroxy group is also present at the C-2 position; therefore the product is predicted as 2,18-dihydrobenzo[ de ]-naphtho[2,1,8,7- stuv ]anthra[2,1,9,8- hijkl ]pentacen-18-one.     

Nitration of Condensed Polycyclic Aromatic Ketones

Nitration of three isomeric dibenzanthrones, 13H-dibenzo[a,de]-anthracene-13-one(3), 7H-benzo[hi]chrysene-7-one(4), and 7H-dibenzo[a,kl]anthracene-7-one(5), with concentrated nitric acid was studied under various conditions. The nitration of (3) at 15 °C in 1,1,2,2-tetrachloroethane gave the 5-nitro derivative. The nitration of (4) in boiling acetic acid produced the 9-nitro derivative. The nitration of (5) at 70 °C in acetic acid gave the 5-nitro derivative. These nitro compounds are very useful in synthesizing undecacyclic aromatic hydrocarbons.     

Concentrated colloids of silica-encapsulated gold nanoparticles: colloidal stability, cytotoxicity, and X-ray absorption

As an effort to develop a new, effective, nontoxic X-ray contrast agent, the concentrated colloids of silica-encapsulated gold nanoparticles (Au@SiO2 NPs) were fabricated and their colloidal stability, cytotoxicity, and X-ray absorption were investigated. The concentrated colloidal NPs were manufactured by forming a 4 nm-thick silica shell on the surface of each Au NP with 15 nm diameter, followed by enrichment to [Au] = 100 mM. They were very stable in water: the NPs were well separated each other without forming agglomerates and their optical property was very similar to that before enrichment. The colloidal stability of the NPs in biological environment was strongly dependent on their previous morphology in water. The NPs with minor shell damage were stable in phosphate buffered saline (PBS) solution: both in water and in PBS solution, they showed very similar morphology and optical property. However, the NPs with profound shell damage formed big agglomerates in PBS solution, resulting in the red-shift and broadening of the Au surface plasmon resonance peak. Cell viability and proliferation assessments revealed the biocompatibility of the Au@SiO2 NPs: no apparent cytotoxicity was observed even at 100 ppm NPs. The concentrated colloidal NPs showed very strong X-ray absorption. Their relative X-ray transmittance to water was comparable to that of a commercial agent. Considering these, the concentrated colloids of the Au@SiO2 NPs are suitable for an X-ray contrast agent.     

Blood compatibility and tissue responsiveness on simple and durable methylsiloxane coating

This study was conducted to evaluate the blood compatibility and tissue responsiveness of methylsiloxane (MS)-coated inorganic (glass and metal) substrates both in vitro and in vivo. MS was prepared from methyltriethoxysilane (MTES) through hydrolysis of a sol–gel solution at 80 °C. The adhesive strength of the MS coating was evaluated by using a tear-off test, revealing that the MS strongly adhered to the surface of the inorganic substrates. Blood compatibility was evaluated by assessing platelet adhesion and blood plasma coagulation time. The platelet aggregation ratio of the MS-coated glass tube was reduced to 10%, which was much smaller than that of the coating-free glass tubes (99%) and conventional blood-compatible polystyrene (PS) tubes (18%). Coagulation time was measured by active partial thromboplastin time (APTT) test, which showed that MS coating is as inert as PS in activating blood coagulation factor XII. Tissue responsiveness to the bulk MS sample, evaluated by animal test, showed a desirable compatibility comparable to that of the control titanium sample. This study indicated that MS coating is readily available to convert inorganic materials to useful biomaterials that have suitable mechanical strength and are compatible with blood and tissue.     

Condensation of 7 H -Benzo[ de ]naphthacene-7-one (9,10-Dibenzanthrone)

We have synthesized undecacyclic aromatic hydrocarbons using condensation of dibenzoanthrones. For example, dibenzo[ a,o ]dinaphtho[3,2,1- cd ;1,2,3- lm ]perylene, diphenanthra[1,2,3- cd ; 3,2,1- lm ]perylene and diphenanthra[2,3,4- cd ;4,3,2- lm ]perylene were produced from 5,6-, 8,9- and 10,11-dibenzoanthrones, respectively. In the present study, we have extended our work and aimed to synthesize new undecacyclic aromatic hydrocarbons by the use of 9,10-dibenzoanthrone (7 H -benzo[ de ]naphthacene-7-one) as a starting material. 9,10-Dibenzoanthrone was prepared by the cyclization of 1,2'-dinaphthylketone in aluminum chloride anhydride and sodium chloride, and the structure was confirmed by NMR measurements. It dissolves into ethanol and crystallizes in pale yellow needles; its melting point is 198.2-199.3°. The condensation of 9,10-dibenzoanthrone should give undecacyclic aromatic hydrocarbons such as benzo[ vwx ]naphtha[12,1,2- cde ] hexaphene.