The responses of the Queensland fruit fly to food-based lures were studied, with particular emphasis on the importance of ammonia as an attractant or repellent. Certain solutions of ammonium bicarbonate were found to be highly effective attractants for the Queensland fruit fly, provided they were tested in traps in which the retention of the flies did not depend on their contacting the bait solution. The attractancies of such solutions were found to be strongly dependent on concentration and pH, and mean attractancies more than five times that of the commercial protein hydrolysate used as a standard were obtained. Highest attractancies were associated with ammonia evolution rates in the region 5-25 �l ammonia (s.t.p.) h-1 100 ml-1 of solution; rates above 400 �1 ammonia (s.t.p.) h-1 100 ml-1 appeared to be repellent. The addition of a mixture of amino acids to the ammonium bicarbonate solutions under these trap conditions had no significant effect on their attractancy; but the addition of the standard protein hydrolysate to a 0.001 M solution of ammonium bicarbonate, with pH adjusted to 8.5, produced an outstandingly effective lure, with a mean attractancy almost nine times as great as the standard hydrolysate alone at its normal pH of 4.8. Subsequent experiments showed that simply raising the pH of the standard protein hydrolysate to 8.5 caused a similar high attractancy, which could be due in part to the marked rise in ammonia production from endogenous sources. Protein hydrolysate solutions showed pronounced increases in both ammonia production and fruit fly attractancy when microorganisms were allowed to flourish. No such increases occurred when the microorganisms were inhibited with a preservative. Evidence is also presented which indicates that carbon dioxide is mildly repellent to the Queensland fruit fly.

The chemical characteristics of protein attractants for the Queensland fruit fly, Dacus tvyoni, have been investigated.Highly effective commercial fruit fly attractants were found to contain a large proportion of high molecular weight material. Lists are provided of the amino acids present in free and bound form in these hydrolysates. The products found by gas liquid chromatography-mass spectrometry analysis of methylene chloride extracts and head-space volatiles were mainly the primary and secondary products of amino acid degradation, including a number of aldehydes and significant amounts of ethylene. None of these aldehydes nor any of a number of others that may have been present in smaller quantities was found to be active when tested individually for attractancy. Nor did ethylene show any evidence of attractancy under the conditions of these tests. Strecker reagents (such as isatin), which stimulate the formation of amino acid degradation products, caused a temporary and relatively small elevation in attractancy of the commercial hydrolysates.Three enzymatic hydrolysates of a relatively pure protein (bovine serum albumin) were prepared and studied; one, a tryptic digest, was exceptionally attractive to the fruit fly. Analysis of methylene chloride extracts and head-space of these 'model' preparations revealed a number of significant differences between them, but the most important difference in relation to attractancy was found to be the presence of ammonium salts in the trypsin hydrolysate.Subsequent experiments showed that high attractancies could be attained by combinations of amino acid mixtures and ammonium bicarbonate, even though neither had high attractancy (under the particular conditions of these experiments) when tested independently. This apparent synergism was probably due to the attractancy of the ammonia coupled with a feeding stimulus provided by the amino acids.

The known triterpenes ursonic acid, oleanonic acid, ursolic acid, oleanolic acid and 24-hydroxy-3-oxoolean-12-en-28-oic acid occur in Lantana tiliaefolia Cham., together with a new triterpene,24-hydroxy-3-oxours-12-en-28-oic acid. A detailed 13C n.m.r. study has been made of a number of olean-12-enes and urs-12-enes, and the 1H n.m.r. signals from the secondary methyl groups in urs-12-enes have been investigated. N.m.r. evidence shows significant conformational differences in ring A between a number of 3-oxo derivatives that differ in their ring A substituents. Methyl ursonate and methyl oleanonate have been separated on columns of Spherosorb A5Y alumina.

22β-[(S)-2-Methylbutanoyloxy]-3-oxoolean-12-en-28-oic acid, a new constituent of Lantanu camara L. is closely related to lantadene A and lantadene B. Although hydrolysis gives 2-methylbutanoic acid as a partial racemate, it has been shown by n.m.r. spectroscopy that the natural ester is theoptically pure (S)-isomer. Catalytic hydrogenation of lantadene A gives a mixture of diastereoisomeric esters in which the (S)-2-methylbutanoate predominates, and a 1 : 1 mixture of the (R)- and(S)-esters was obtained by esterification with (RS)-2-methylbutanoyl chloride of 22β-hydroxy-3-oxoolean-12-en-28-oic acid protected as the diphenylmethyl ester.

When porphyrins or related pigments are reduced by HI-AcOH, their meso-substituents (R = H or alkyl) appear as a-CH2R groups in the resulting pyrroles. The identification of the pyrroles, as by g.l.p.c., defines and orders the meso-substituents flanking each pair of peripheral substituents in the porphyrin. If one meso-substituent differs from the others, all the substituents about the two adjacent pyrrole nuclei are then ordered.The pyrroles can be reductively alkylated in situ, and symmetry then reduces their number when the aldehyde used (R.CH0) corresponds to a bridge and its meso-substituent. This may simplify the pyrrole mixtures, identify meso-substituents, or make pyrroles distinguishable by g.1.p.c.The critical pyrrole -propionic acids are separable as methyl esters by g.1.p.c. Desoxophylloerythrin and pyrophaeophorbides (the latter first reduced with potassium borohydride) are reduced to cyclopenteno-pyrroles which reveal the isocyclic rings and the 5-substituents. The r.r.t.3 of relevant pyrroles are reported.La reduction des porphyrines et des pigments du mCme genre par HI-AcOH fait que les substituants mtso (R = H OLI alkyle) apparaissent sous forme de groupements CH2R en cc des pyrroles resultants. L'identification des pyrroles par c.p.l.g., par exemple, definit et classe les substituants meso qui se trouvent a cBte de chaque paire de substituants peripheriques dans la porphyrine. Si un des substituants meso differe des autres, tous les substituants autour des deux noyaux pyrroles adjacents sont alors clasds.L'alkylation reductive irz situ des pyrroles peut riduire par symitrie le nombre de pyrroles lorsque l'aldehyde utilise (R.CH0) correspond au pont et au substituant meso de la porphyrine initiale. Ceci peut simplifier le melange des pyrroles, identifier les substituant meso et differentier les pyrroles par c.p.1.g.Les acides critiques pyrrole -propioniques sont separables de leurs esters methyliques par c.p.1.g. La dCsoxophylloerythrine et les pyrophaephorbides (ces dernieres d'abord reduites par le borohydrure de potassium) sont reduites en cyclopenteno-pyrroles, ce qui revele les noyaux isocycliques et les substituants en 5. Les donnees t.r.r, des pyrroles correspondants sont rapportkes.