Search

Fragmentation of forest habitat has negative effects on arboreal mammals, compromising their natural dispersal and foraging movements. This paper describes an evolving series of mitigation measures aimed at creating cost-effective continuity pathways for arboreal mammals in Japan. The projects have focused on the endemic Japanese dormouse (Glirulus japonicus) a scarce, but popular and iconic species which provides an effective vehicle for environmental education and public engagement.

Among 920 strains of fungi tested only black koji-molds were found to be potent producers of 5′-phosphodiesterase. The enzyme from Aspergillus niger was partially purified from aqueous extract of the culture on wheat bran. The enzyme hydrolyzed 3′-hydroxyl-terminated 3′→5′ and 2′→5′ dinucleotides or 3′→5′ and 2′→5′ dinucleoside monophosphates without specificity toward bases or sugars. The enzyme also hydrolyzed p-nitrophenyl ester of nucleoside 5′-monophosphate, ADP, CDP-choline and UDPG to give nucleoside 5′-monophosphate. The enzyme was actually proved to split 2′→5′ dinucleotides in nuclease P1 digest of technical grade yeast RNA containing several per cent of 2′-5′ phosphodiester linkages in addition to 3′-5′ linkages.

Nuclease P1 was found to attack RNA and heat-denatured DNA in endo- and exonucleolytic manners. The evidence was as follows: (1) In the early stage of digestion both mononucleotides and oligonucleotides with various sizes were formed simultaneously with rapid fragmentation of polynucleotides. (2) The relative amount of the monomer was larger than that of any class of oligomers throughout the process of digestion. Nuclease P1 showed a preference for the linkages between 3′-hydroxyl group of adenosine or deoxyadenosine and the 5′-phosphoryl group of the adjacent nucleotides. p-Nitrophenyl ester of 3′-dTMP was hydrolyzed to thymidine and p-nitrophenyl phosphate, while p-nitrophenyl ester of 5′-dTMP was not attacked. It is concluded from these findings that the basic structure required for the substrate of nuclease P1 is a nucleoside 3′-phosphate-containing structure and the enzyme cleaves the diester bond between the phosphate and the 3′-hydroxyl group of the sugar.

1, 3-Dipolar cycloaddition of isoquinolinium cyano (methoxycarbonyl) methylide (V) and dimethyl acetylenedicarboxylate gave only one (VI) of the two possible primary adducts. Examination of the pyrolysis of this adduct revealed the structure of VI to have 10bhydrogen and 3-ester group in cis configuration. Heating of VI afforded 2, 3-dihydropyrroloisoquinoline (VIII), while its treatment with hydrogen chloride in benzene, followed by neutralization with potassium carbonate afforded the adduct (XIII) of two diastereoisomers (VIII and XIV). VIII was found to be unstable to acid and base, resulting in immediate hydrolysis of the ester group in its 3-position and decarboxylation to the diester (X). From the consideration of its reaction mechanism, the ester group in the 2- and 3-positions of VIII was determined to have a cis configuration and those in XIV, a trans configuration.

Tetramethyl 3, 10b-dihydropyrrolo [2, 1-α] isoquinoline-1, 2, 3, 3-tetracarboxylate (VI) was isolated for the first time as the primary addition product of a reaction between isoquinolinlium bis (methoxycarbonyl) methylide (V) and dimethyl acetylenedicarboxylate (IV). Treatment of VI with hydrogen chloride and then with potassium carbonate resulted in its isomerization into 2, 3-dihydropyrrolo [2, 1-α] isoquinoline derivative (VII). In the reaction of isoquinolinium dicyanomethylide (XI) with IV, the isomerized 2, 3-dihydro compound (XIII) and the eliminated product (XIV) were produced, instead of their primary adduct (XII). The relation between a substituent group in the 2, 3-dihydrotype compounds and their reactivity was examined. On the other hand, in the reaction of disubstituted pyridinium methylides with acetylenic compounds, only aromatized products were obtained.