Reactions of allylic compounds such as allyl alcohols,allyl ethers,and allylamines using trans-Mo(N2)2(Ph2PCH2CH2PPh2)2

Double-bond migration of allylic alcohols and allylic alkyl ethers was catalytically effected with trans-Mo(N₂)₂(dpe)₂(dpe = Ph₂PCH₂CH₂PPh₂). Decarbonylation occurred simultaneously in the case of allyl alcohol. Diallyl ether and allyl phenol ether gave the fragmentation products presumably through initial oxidative addition of the allylO bond. Allylamine was converted to N-propylideneallylamine and NH₃. N,N-Dimethylallylamine was isomerized to N-trans-propenyldimethylamine, which was further transformed into 4-dimethylamino-1,3-hexadiene and dimethylamine on addition of oxygen. The catalytic allylation of methyl acetoacetate with allylic ethers and amines was achieved by use of trans-Mo(N₂)₂(dpe)₂.     

Facile conversion of 23-hydroxyspirosolane into pregnane

Two novel reactions with regard to steroidal alkaloid sapogenols obtained from ripe tomato have been found. These reactions have been attained by simple facile method in only refluxing with pyridine and water. One is isomerization of a spirosolane derivative, isoesculeogenin A (2), into a rare solanocapsine derivative, esculeogenin B (3), disclosing a chemical correlation between isoesculeogenin A and esculeogenin B. Another is conversion of a 23-hydroxyspirosolane derivative, esculeogenin A (1), into a pregnane derivative (4), presenting an epoch-making method for derivation of steroidal hormone material.     

Gastrointestinal absorption of chlorothiazide: evaluation of a method using salicylazosulfapyridine and acetaminophen as the marker compounds for determination of the gastrointestinal transit time in the dog

Gastrointestinal absorption properties of chlorothiazide was investigated in dogs by a double-marker method using acetaminophen and salicylazosulfapyridine as the markers. The mean absorption time of acetaminophen (MATAAP) and the time for first appearance of sulfapyridine in plasma (TFASP) were used for the assessment of gastric emptying and oro-colonic transit times, respectively. Chlorothiazide absorption efficiency was increased by pretreatment with atropine sulfate. There was a good correlation between MATAAP and the extent of bioavailability of chlorothiazide, however, there was no correlation between TFASP and the extent of bioavailability of the drug. These results indicate that chlorothiazide absorption takes place primarily in a limited segment of the upper small intestine, supporting the assumption reported previously. This double-marker method seems to be a useful tool for the investigation of the relationship between drug absorption and its gastrointestinal transit.     

Synthesis and thermal properties of poly(cycloalkyl methacrylate)s bearing bridged- and fused-ring structures

Radical polymerizations of some cycloalkyl methacrylates bearing bridged- and fused-ring structures, i.e., bornyl methacrylate (BoMA), isobornyl methacrylate (IBoMA), 2-decahydronaphthyl methacrylate (DNMA), and 3-tetracyclo [4.4.0^2,5.1^7,10] dodecyl methacrylate (TCDMA), were carried out. The radical polymerization reactivities of these monomers depended on the structure of the cycloalkyl ester groups in the following order: TCDMA > BoMA > DNMA > CHMA > IBoMA > MMA, where CHMA and MMA are cyclohexyl and methyl methacrylates, respectively. The propagation and termination rate constants of these monomers were evaluated from the polymer radical concentration determined by electron spin resonance spectroscopy. The solubilities and microstructures of the resulting polymers were examined. Thermal properties, i.e., glass transition temperatures and decomposition behaviors, of the polymers were also investigated and related to the structures of the polymer side chain. © 1993 John Wiley & Sons, Inc.     

Comparative pharmacokinetics of sulpiride and N-[(1-butyl-2-pyrrolidinyl)methyl]-2-methyl-5-sulfamoyl-2,3- dihydrobenzofuran-7-carboxamide hydrochloride, a new lipophilic substituted benzamide in rats

The pharmacokinetics of a new lipophilic substituted benzamide N-[(1-butyl-2-pyrrolidinyl)methyl]-2-methyl-5-sulfamoyl-2,3- dihydrobenzofuran-7-carboxamide hydrochloride (1) and sulpiride in both plasma and brain were investigated in rats. The octanol-water partition coefficients of the base of 1(2) and sulpiride were 6.3 and 0.2, respectively. The eliminations of 2 from plasma and brain were similar to those of sulpiride. The systemic bioavailabilities of 1 and sulpiride after oral administration of 200 mg/kg were 60.9 +/- 10.9 and 18.2 +/- 6.4%, respectively. The brain concentrations of 2 were about 2-3 times higher than those of sulpiride until 4 h after oral administration of 100 mg/kg. The brain/plasma ratios of 2 were about 2 times higher than those of sulpiride. These results indicate that the penetration of 2 through the gastrointestinal membrane and/or the blood-brain barrier are higher than those of sulpiride.     

Catalytic alkynylation of ketones and aldehydes using quaternary ammonium hydroxide base

Catalytic alkynylation of diverse ketones and aldehydes using nonmetallic benzyltrimethylammonium hydroxide or a basic resin of the hydroxide type in DMSO is described. Aliphatic or alicyclic carbonyl partners gave satisfactory results, whereas aromatic ones afforded products with low yields. When aromatic aldehydes were reacted with phenylacetylene, enones such as chalcone derivatives were obtained in place of ynols. These organobase-catalyzed systems provide a practical nonmetallic protocol for C[bond]C formation.     

Use of ferrocene scaffolds as pendant groups in hairpin-type pyrrole-imidazole polyamide molecules showing sequence-selective binding to DNA duplexes

[reaction: see text] The synthesis and properties of new conjugate molecules, Fc-PIA, composed of ferrocene (Fc) and pyrrole-imidazole polyamides (PIA) are reported. As a PIA sequence, we chose Im-Py-Im/Py-Im-Py considering its future application to the SNPs detection of genes having a GCG/CGC sequence. Two types of Fc-containing linkers, i.e., ferrocene-1,1'-dicarboxamide and ferrocenecarboxamide, were designed, and several Fc-PIPA molecules having these linkers were synthesized. Titration studies by use of circular dichroism revealed that the carboxamide-type Fc-PIA could bind to the target DNA with an association constant of 10(7) M(-1). In contrast, ferrocene dicarboxamide-type compounds have slightly weaker affinity for the target DNA. However, the affinity could be recovered by replacing one of the pyrrole residues with beta-alanine. We carried out the CV measurement and observed quasi-irreversible oxidation of the ferrocene moieties in the Fc-PIA compounds. These properties of Fc-PIA indicate the potential usefulness of these molecules in electrochemical detection of genes.     

PRESUMED PHOTORECEPTOR PROTEIN AND ULTRASTRUCI'URE OF THE PHOTORECEPTOR ORGANELLE IN THE CILIATED PROTOZOAN, Blepharisma

Abstract-The red pigment granule of Belpharisma japonicum is believed to be a photoreceptor organelle mediating photodispersal. Freeze-fracture and thin section electron microscopy revealed that the pigment granules contained a honeycomb-like structure constructed of folded membranes. In the fracture face of the honeycomb-like structure, small membrane particles were observed, which might correspond to pigment—protein complexes. The pigment granules were isolated and detergent-solubilized. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that the pigment granules mainly contained a 200 kDa membrane protein. The complex of red pigment and 200 kDa protein was isolated by gel-filtration chromatography of the detergent-solubilized components, and the protein was subjected to SDS-PAGE and amino acid analysis. The 200 kDa protein could not be dissociated into subunits by 2-mercaptoethanol, indicating that the protein is composed of a single polypeptide chain. Hydrophobic amino acids contained in the 200 kDa protein were not dominant, suggesting that only partial domains may extend across the membrane of the honeycomb-like structure.