Structure elucidation of some insect pheromones : a contribution to the development of selective pest control agents

The use of pheromones is one of the methods currently being investigated intensively as an alternative method of insect control. The various ways in which pheromones might be used in insect control programmes are briefly discussed in Chapter 1.Chapter 2 gives a detailed description of the isolation and identification of the sex pheromone of the American cockroach, Periplaneta americana. The various techniques that have been used for the structure elucidation are described.The sex pheromone of P. americana contains two major components (periplanone-A and periplanone-B), as well as minute amounts of another four.Periplanone-B could be identified as (1 Z, 5 E)-1,10(14)-diepoxy- 4(15), 5-germacradiene-9-one. Periplanone-A proved to be very unstable, isomerizing to a biologically inactive compound. The instability of the compound rendered a complete structure elucidation impossible.The four minor compounds could not be collected in sufficient amounts to carry out a complete structure elucidation.Of the compounds reported to mimic the natural pheromone, only germacrene-D was found to do so. However, its threshold is very much higher than that of the natural pheromone. The same holds for the other reported mimics, even they do elicit electroantennogram responses. Regardless of concentration, none of the mimics elicit responses as marked as the natural pheromone.Apart from causing sexual excitation, periplanone-B also can attract males of P. americana.The isolation, identification and field evaluation of the sex pheromone of the leafroller moth, Archips podana, is described in Chapter 3. The pheromone consists of a mixture of equal amounts of cis -11-tetradecenyl acetate and trans -11-tetradecenyl acetate. Although the individual compounds are not attractive in field experiments, a 1:1 mixture of the two is capable of attracting many males of this species.Investigation of the sex pheromone of the false codling moth, Cryptophlebia leucotreta (Chapters 4 and 5) revealed that the pheromone is a mixture of equal amounts of cis -8-dodecenyl acetate and trans -8-dodecenyl acetate. This finding contradicts other reports which state that the pheromone of this insect is trans -7-dodecenyl acetate. Mixtures of cis -8- and trans -8-dodecenyl acetate in various ratios proved to be very attractive to males of this species.In Chapter 6 the isolation, identification and field evaluation of the sex pheromone of the potato tuberworm moth, Phthorimaea operculella, is described. The sex pheromone of this moth is a mixture of about equal amounts of trans -4, cis -7-tridecadienyl acetate and trans -4, cis -7, cis -10-tridecatrienyl acetate. These findings were confirmed by synthesis and by trapping experiments in the field

Recent development in insect pheromone research, in particular in the Netherlands

A review is given of recent pheromone work carried out in the Netherlands on Lepidoptera, cockroaches, pharaoh's ants and termites, special emphasis being given to isolation and identification aspects. The sex pheromones of three leaf roller moths (Tortricidae) have been isolated, identified and field tested, viz. those of Adoxophyes orana (cis-9-tetradecenyl acetate (tda) and cis-I1-tda in the ratio 9:1), Clepsis spectrana (cis-9-tda:cis-11-tda, 1:3) and Archipspodana (cis-11-tda:trans-l1-tda, about 1:1). For ?ponomeuta, data have been obtained indicating a correlation between taxonomic groups and pheromone structure. Two sex pheromones (periplanone A and B) of the American cockroach, Periplaneta americana, have been isolated and partially identified. Their elementary formulas, C. 15H. 20O. 2 and C. 15H. 20O. 3, respectively, suggest that they are sesquiterpenoids, spectral data of periplanone B indicating that it has the germacrane skeleton. The aggregation pheromone of the German cockroach, Blattella germanica appears to be a complex mixture in which certain free acids play an important role. Three heterocyclic compounds have been isolated from Pharaoh's ants, Monomorium pharaonis. Monomorine I, C. 13H. 25N, is the first indolizine derivative found in the animal kingdom. Monomorine II, C. 13H. 27N, and monomorine III, C. 15H. 29N, are pyrrolidine derivatives. The three compounds are constituents of the odour trail and are present in excretions collected from the insect's sting. These excretions have a function in trail-following as well as in defense. In choice tests monomorine I and III act as attractants. Cis-3, cis-6, trans-8-dodecatrienol, initially identified as a trail pheromone of the termite Reticulitermes virginicus, was found to be a trail pheromone also for Reticulitermes santonensis. Eight dodecatrienol isomers were tested for activity towards this termite. In their ability to evoke trail-following behaviour as well as their attractancy in choice tests, they resemble each other qualitatively, but quantitatively, they show considerable differences. From fungus-infected wood a compound was isolated which effectively induces trail-following behaviour, and moreover, is a potent attractant. Its elementary formula, C. 15H. 24O, and the presence of acorane among its hydrogenation products, show that it is a sesquiterpenoid. Two other potent attractants for R. santonensis were found in wood oils: tricycloekasantalal, C. 12H. 13O in East-Indian sandalwood oil and dihydroagarofuran, C. 15H. 20O in West-Indian sandalwood oil. © 1974 BRILL

Microorganisms in the aetiology of atherosclerosis.

Recent publications have suggested that infective pathogens might play an important role in the pathogenesis of atherosclerosis. This review focuses on these microorganisms in the process of atherosclerosis. The results of in vitro studies, animal studies, tissue studies, and serological studies will be summarised, followed by an overall conclusion concerning the strength of the association of the microorganism with the pathogenesis of atherosclerosis. The role of the bacteria Chlamydia pneumoniae and Helicobacter pylori, and the viruses human immunodeficiency virus, coxsackie B virus, cytomegalovirus, Epstein-Barr virus, herpes simplex virus, and measles virus will be discusse