PC group-bearing

A decisive breakthrough to a T range above 230°C was achieved with a polycarbonate based on spitobisiudan (SBI-PC, (8)) (203) or 3,3,5-trimethyl cyclohexane (TMC-PC, (7) whereia the cyclohexane ring bears three methyl groups) (204). 

Normal and tumor tissues of PC-3 tumor-bearing Balb/c nu/nu mice are excised in various treatment groups within 6-12 h after the last treatment. 

FIGURE 6.2 Phosphatidylcholine (PC) synthesis by the CDP-ethanolamine pathway. Structures of ethanolamine and choline. The nucleotide moiety S-adenosyl methionine (SAM) is requiivct to transfer the methyl group of methionine to phosphatidylethanolamine (J E) to form PC. In the process, SAM is converted to S-adenosyl homocysteine (SAH). The nitrogen atom of PC has four covalent bonds and is called a quaternary amine. It bears a positive charge that is not influenced by changes in the pH of the suitoimding fluids. The PE methyltran.sferase pathway of I C synthesis occurs only in the liver. 

In the present study, we have shown that basic solids do catalyse the transcarbonation of 4,4 -dinitro into PNP and recyclable PC. This is a remarkable advantage compared with homogeneous systems, where a stoichiometric amount of consumed base is required [5]. Best performances are obtained by using inorganic salts of cesium, such as fluorides and carbonates, or organic resins bearing weak basic functional groups, such as N,N-dimethylbenzylamine. 

The water-soluble silicon Pc bearing two PEG at the axial position on the central Si ion was also prepared by displacement of the chloro groups of the bis(chloro-propyldimethylsiloxy) SiPc (SiPcClPr) by the methoxypoly(ethylene glycol) amine (Brasseur, et al., unpublished results). In vitro, SiPcPEG2 and SiPcClPr formulated, respectively, in PBS and in Cremophor emulsion were much more active than... 

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