Chitin inhibitors

Pelsue, F.W. 1985. Histopathological effects of two insect chitin inhibitors in the alimentary canal of chirono-mid midges (diptera chironomidae). Bull. Soc. Vector Ecol. 10 72-79. 

Nikkomycins. The nikkomycins (141—159), isolated from S. tendae are nucleoside-peptide antibiotics (1,4,244,245) as shown in Table 8. Nikkomycins X and Z are stmcturaHy identical to neopolyoxins A and C, respectively. Compound (141) is a competitive inhibitor of chitin synthetase. Two new nikkomycins, nikkomycin pseudo-Z and pseudo-J (158, 159), contain a C-glycosidic bond between C-5 of uracil and C-1 of... 

Since diflubenzuron toxicity seems to be similar in both insects and crustaceans, extreme care must be taken when this compound and other chitin synthesis inhibitors are used for insect control in areas where aquatic crustaceans occur. Otherwise, ecological instability may result, with consequences... 

El-Gazzar, L.M., R.S. Patterson, and P.G. Koehler. 1988. Activity of chitin synthesis inhibitors on the cat flea, Ctenocephalides felis Bouche. Jour. Agricul. Entomol. 5 117-120. 

Ho, C.M., T.R. Hsu, J.Y. Wu, and C.H. Wang. 1987. Effect of dimilin, a chitin synthesis inhibitor, on the growth and development of larvae of Aedes albopictus Skuse. Chinese Jour. Entomol. 7 131-141. 

Marx, J.L. 1977. Chitin synthesis inhibitors new class of insecticides. Science 197 1170-1172. 

Muzzarelli, R. 1986. Chitin synthesis inhibitors effects on insects and on nontarget organisms. CRC Crit. Rev. Environ. Control 16 141-146. 

Chitin is an abundant biopolymer, especially in Perth where the thriving Western rock lobster industry produces tonnes of waste, a good proportion of which is exoskeleton and rich in chitin. It has been our aim for some years to put this waste chitin to some good use and so, initially, we have set out to prepare epoxyalkyl glycosides based on W-acetyl-D-glucosamine and its oligomers, for example 60 and 61. It is hoped that molecules such as 60 and 61 will prove to be efficient inhibitors of chitinases, ubiquitous enzymes involved in many biological processes [42]. 

Fermentation procedures for preparing uridine 5 -(2-acetamido-2-deoxy-a-D-glucopyranosyl pyrophosphate) have also been reported. One of them255 involves the cultivation of Helminthosporium sativum in the presence of 2-amino-2-deoxy-D-glucose and the antibiotic polyoxin the latter is an inhibitor of chitin biosynthesis. The other256 utilized the incubation of yeast cells with uridine 5 -phosphate in the presence of an excess of 2-amino-2-deoxy-D-glucose and inorganic phosphate.257... 

Both compounds (Figure 4.7) are non-competitive inhibitors of chitin synthase and also interfere with the Bremner-Greenberg methylation pathway.6 Their activity is dependent upon the oxidation of the phosphorous - sulfur linkage, a feature that is the basis of resistance development, which is common sensitive strains of P. oryzae metabolise the compounds more rapidly than resistant strains. 

Polyoxins are inhibitors of chitin biosynthesis. Chitin is a component of fungal cell walls except in Phycomycete fungi these contain cellulose as their major cell wall constituent, hence polyoxins are inactive against Plasmopara, Pythium and Phytophthora. 

Chitin Synthesis Inhibitors. These are insect growth regulators that prevent the formation of the insect chitinous exoskeleton and thus produce a critical biochemical lesion during hatching, ecdysis, or pupation (44). These complex biochemical and physiological processes are unique to arthropods therefore, the benzoyl phenyl ureas are highly specific insecticides (44). 

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