摘要:

AbstractSynthetic work leading to the commercial preparation of allethrin (the ester of (±)‐cis‐trans‐3‐isobutenyl‐2 : 2‐dimethylcyclopropane‐1‐carboxylic acid [(±)‐cis‐trans‐chrys‐anthemic acid] with (±)‐2‐allyl‐3‐methylcyclopent‐2‐en‐4‐ol‐1‐one [(±)‐allethrolone]} is reviewed briefly. The relative insecticidal activity and abundance of the eight isomeric esters present in allethrin are deduced and the most effective is shown to be (+)‐allethronyl (+)‐trans‐chrysanthemate. The effect of various changes in the molecule of allethrin on insecticidal activity is described. The biological action of allethrin appears to be of a similar nature to that of the natural pyrethrins, and is associated with the particular stereochemical conformation in which the various parts of the molecule are held with respect to each other and with the chemical and physical properties of the groups so positioned. Although allethrin is inferior to the natural pyrethrins against most species of insects and by most methods of application, it is highly biologically active and, unlike many modern synthetic in

ISSN:0022-5142    

DOI:10.1002/jsfa.2740051102

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY

摘要:

AbstractThe total non‐protein nitrogenous (NPN) fraction of oven‐dried grassland herbage has been examined. The NPN was obtained by extraction of dried herbage with boiling water and it was fractionated as follows : (1) precipitation of part of the peptide‐nitrogen with 75% alcohol, followed by (2) precipitation of purines with silver sulphate (this treatment also precipitated some peptides), followed by (3) passage through a cation‐exchange resin, which gave three main fractions : (a) non‐adsorbed nitrogen compounds, including nitrate, pyrimidines and unidentified substances, (b) adsorbed compounds which were eluted with sodium hydroxide—amino‐acids, amides, ammonia, betaines, peptides or ‘bound’amino‐acids, and unidentified substances and (c) basic compounds, including choline, and strongly adsorbed compounds that could not be eluted from the column with strong acid, probably mainly peptides and possibly including nucleotides.Two grasses, a clover and a lucerne sample were used and the proportion of their total nitrogen present as NPN varied from 23 to 30%. An analysis including amino‐nitrogen after hydrolysis, amide‐nitrogen, ammonia‐nitrogen, nitrate‐nitrogen, purine‐nitrogen, betaine‐nitrogen and choline‐nitrogen accounted for 77‐88% of the NPN. The fractionation gave higher recoveries when assumptions were made on the probable peptide content and it indicated where uni

ISSN:0022-5142    

DOI:10.1002/jsfa.2740051103

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY

摘要:

AbstractVictoria plums from a number of sources, and including samples from trees on different rootstocks, have been examined with a view to identifying their major and minor constituents. The red pigment common to all samples is cyanidin‐3‐monoglucoside, and obvious differences in colour appear to be due to variations in the amounts of green or brown pigments. The present paper concerns the essentially qualitative preliminary examination of the fruits, which is to be followed by quantitative analyses continued over several ye

ISSN:0022-5142    

DOI:10.1002/jsfa.2740051104

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY

摘要:

AbstractThe chrysanthemic acids are catalytically hydrogenated to the stereoisomeric dihydro‐chrysanthemic acids. These acids are characterized, and esterified with allylrethrolone and propylrethrolone to give a series of esters for insecticidal testin

ISSN:0022-5142    

DOI:10.1002/jsfa.2740051105

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY

摘要:

AbstractThe large seeds ofOmphalea queenslandiae, a member of the Euphorbiaceae, contain 28% of an edible, semi‐drying oil. Its component glycerides consist almost entirely of those of the four common fatty acids, which in one sample were present in the proportions : palmitic 12.7, stearic 8.1, oleic 47.0 and linoleic 31.7%. The composition of the oil is variabl

ISSN:0022-5142    

DOI:10.1002/jsfa.2740051106

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY

摘要:

AbstractPrevious accounts of the damage to wheat and wheat products caused by carbon disulphide fumigation are partly contradictory, and rarely describe accurate chemical measurements of sorption or the moisture content of the sorbent. The sorption is found to be critically dependent on moisture content, with a minimum sorption at about 14% of water. The sorption of carbon disulphide is even lower than that of methyl bromide, and seems to be mainly physical in origin. Most of the sorbed fumigant is recoverable, the remainder is held chiefly in the bran and endosperm. At high moisture contents, the seed‐coat no longer inhibits sorption, which tends to the same limit as that exhibited by wholemeal flou

ISSN:0022-5142    

DOI:10.1002/jsfa.2740051107

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY

摘要:

AbstractIn a series of trials, weanling pigs were fed all‐vegetable diets and diets containing fish meal, with and without procaine penicillin, under bothad libitumfeeding and restricted feeding systems. The responses to the various treatments, as indicated by live‐weight gains, suggest that factors that tend to promote keenness of appetite, such as antibiotics or fish meal, are favoured byad libitumfeeding, but do not exert their full effect with restricted feeding. These trials, and further trials with older pigs, confirm that responses to procaine penicillin are small after the 100‐lb. live‐weight stage, whether the supplement is first introduced then or has been fed continuously from an earlier period. The addition, of a cyanocobalamin (vitamin B12) supplement was found to enhance the growth‐promoting effect of procaine penicillin on weanling pigs. Discontinuing the feeding of an antibiotic, after an initial response had been obtained, resulted in some degree of retardation.The results for carcass conformation indicate no significant differences due to antibiotic treatments, and afford no evidence that such treatments result in commercially inferior

ISSN:0022-5142    

DOI:10.1002/jsfa.2740051108

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY

摘要:

AbstractThe autoxidation of sulphurous acid has been investigated with the aim of finding suitable conditions under which the acid might be used, either alone or in the presence of strong mineral acids, for the hydrolysis of proteins.Sulphurous acid alone was used to hydrolyse casein, lactalbumin, ovalbumin and fibrin to 34‐37% of complete hydrolysis. Losses of tryptophan ranged from o to 3% of the total. Use ofN‐sulphuric acid with the sulphurous acid gave 65‐70% hydrolysis with losses of tryptophan ranging from 2 to 10% of the total. Amounts of 10 g. of sulphur dioxide per 100 ml. ofN‐sulphuric acid and 15 g. of sulphur dioxide per 100 ml. ofN‐hydrochloric acid were required to give effective tryptophan preservation.Preliminary rat‐feeding tests indicated that a sulphurous acid‐sulphuric acid casein‐hydrolysate would support growth and that it was no

ISSN:0022-5142    

DOI:10.1002/jsfa.2740051109

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY

ISSN:0022-5142    

DOI:10.1002/jsfa.2740051101

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY