On the Physiology of Rhizopus Species

Part. V. The preliminary research on the occurrence of zymase and carboxylase in Rhizopus species.

Part. VI. The verification of the occurrence of zymase in Rhizopus species.

Part. VII. On the formation of ethyl alcohol from acetic acid by acetone-Rhizopus (Rhizopus treated by acetone.)

Part. VIII. On the formation of ethyl alcohol from malic acid by Rhizopus species.

Part. IX. On the formation of ethyl alcohol from malic acid by ace’one-Rhizopus.     

Studies on the biology of some freshwater fishes Part VI. Mystus cavasius (Ham.)

Summary The biology of a freshwater fish, M. cavasius with particular reference to its length frequency, breeding and food has been described. length frequency distribution gave an indication of 4 modes during the quarter, July–September.Both the sexes attain maturity when they are approximately 10 cm long. Females grow larger than the males and are more abundant in the population. The spawning of this fish seems to take place during August and September. Maturing ovaries of females show only one batch of eggs which is probably shed in a single spawning act. The condition factor of the fish has no correlation either with the seasonal changes in maturity or with the feeding rhythm. The fish has an omnivorous habit and consumes all types of food available in the habitat. The feeding is high during the monsoon and winter months and low during the summer months.This work was carried out in the Department of Zoology, Aligarh Muslim University, Aligarh, U.P. India in continuation of the series I–III by Qasim & Qasim (1964) and IV–V published elsewhere by the present author (1970–71).     

Studies on reactions of nucleoside H-phosphonates with bifunctional reagents. Part VI. Reaction with diols

Reactions of nucleoside H-phosphonates with various diols using different types of condensing agents have been studied. Depending on the coupling procedure and the length of a polymethylene chain of the diol, acyclic H-phosphonate diesters or cyclic phosphite triesters were formed. The course of oxidation with iodine to produce cyclic nucleoside alkyl phosphotriesters or hydroxyalkyl nucleoside phosphodiesters can be controlled by the amount of water present in the reaction medium.     

Studies on Reactions of Nucleoside H-Phosphonates with Bifunctional Reagents. Part VI. Reaction with Diols

Abstract

Reactions of nucleoside H-phosphonates with various diols using different types of condensing agents have been studied. Depending on the coupling procedure and the length of a polymethylene chain of the diol, acyclic H-phosphonate diesters or cyclic phosphite triesters were formed. The course of oxidation with iodine to produce cyclic nucleoside alkyl phosphotriesters or hydroxyalkyl nucleoside phosphodiesters can be controlled by the amount of water present in the reaction medium.     

Studies on Amino Acids. IX.

The synthetic procedures for the preparation of α-keto acid analogue of methionine, α-keto-γ-methylmercaptobutyric acid, were investigated. As a result, the procedure consisting of the ester condensation between methyl β-methylmercaptopropionate and methyl oxalate, and subsequent hydrolysis and decarboxylation was found to be a satisfactory route     

Studies on Amino Acids. XI.

As a part of the studies intending to clarify biological significance of the presence of acylase, enzymatic activity which hydrolyzes acyl amino acids, its activity in yeast was investigated. As a results, the occurrence in yeast of acylase activity was confirmed for the first time.

In order to study the enzymatic properties of this acylase activity, experiments were carried out with the enzyme preparation from brewer’s yeast. As a result of the investigation, yeast acylase was found to be able to hydrolyze a number of acyl amino acids, of these chloroacetyl derivatives especially readily, as in the case of previously studied acylase activity in other sources such as mold acylase. Several observations on the influence of metal ions and inhibitors, optical specificity and others were also presented.     

Studies on Amino Acids. II

The enzymatic procedures for the resolution of dl-lysine such as asymmetric synthesis of acyl l-lysinc anilide and acyl dl-lysines have been studied. As a result, the procedure consisting in the enzymatic asymmetric hydrolysis of ε-benzoyl-α-acctyl-dl-lysine was found to be the most advantageous for the resolution of dl-lysine.     

Studies on Biologically Active Substances Formed by Bacilli

The products of several Bacillus strains were investigated on rabbit serum calcium decreasing, oxytocic and toad heart function promoting activities. These products were obtained from the clear supernatant fluid of the culture medium after the cells were removed by centrifugation.

For the production of rabbit serum calcium decreasing substance, Bacillus subtilis K and Bacillus natto No. 8 were found to be usefull, Bacillus megaterium KM, Bacillus cereus var. mycoides and Bacillus subtilis K produced oxytocic principle. Bacillus subtilis K, Bacillus brevis and Bacillus megaterium KM also produced toad heart function promoting factor.

A procedure was developed to obtain the electrophoretically homogenous rabbit serum calcium decreasing substance from culture filtrate of Bacillus subtilis K. The crude substance was obtained as isoelectric precipitate by adjusting the culture filtrate to pH 3.0. The crude substance was purified by gel filtration on a Sephadex G-75 column, isoelectric fractionation and chromatography on DEAE-cellulose column. The purified preparation was shown to be homogenous by Tiselius electrophoresis but was separated into two bands by polyacrylamide electrophoresis. The chemical analysis of this biologically active substance indicated this substance to be a lipoprotein. The substance decreased rabbit serum calcium level about 12% at 6~8hr after intravenous injection (dose; 0.5 mg/kg body weight).     

Studies on Amino Acids XII.

Although acylase activities in animal tissues, molds, bacteria and yeast have been clarified, nothing has been reported on the acylase activity in plants. Therefore, as a part of a series of studies intending to elucidate the biological significance of the presence of acylase activity, activity in plants was investigated.

As a result, the occurrence of acylase activity in plants such as vegetables, potatoes, pulses, cereals and fruits, has been confirmed for the first time. Besides the above higher plants a relatively higher acylase activity was also found in mushroom.