Chitin Biosynthesis Inhibition

Chitin is the microfibrillar component of some fungal cell walls and is equivalent to cellulose microfibrils in plants. It is a characteristic feature of the Ascomycetes, Deuteromycetes and Basidiomycetes but is absent in the Phycomycetes, which contain cellulose as their major cell wall constituent. 

Chitin synthase is localised in the plasma membrane at the apex of 

Polyoxins are used in the control of several pathogens, notably sheath blight of rice (Rhizoctonia solani). Polyoxin is specific to Alternaria, Botrytis, and powdery mildew. Differences in activity between members of the polyoxin group probably reflect dissimilar uptake characteristics, which are governed by specific peptides. Different peptides may limit polyoxin activity at the level of the uptake mechanism and may also determine their resistance traits. 

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Another group of fungicides interferes with cell wall formation. Two examples of this group include 1) the polyoxines, which prevent chitin formation by competitively inhibiting chitin-synthase, the final enzyme involved in chitin biosynthesis, and 2) melanine biosynthesis inhibitors, especially in Pyricularia oryzae. Examples of... 

Nikkomycins Z 94 and X 95, isolated as nucleoside antibiotics from Streptomyces tendae 221 inhibit chitin biosynthesis and have fungicidal and insecticidal properties. 

Insect cuticle Benzolphenylureas, buprofezin, etoxazole, flufenoxuron Cyromazine Boric acid, silica aerogels Pesticidal soaps Inhibition of chitin biosynthesis Molting disruption Abrasion of cuticle Disruption of cuticle and breakdown of cell membranes... 

The growth of insects can be controlled by the disruption of the molting process by inhibiting chitin biosynthesis [23, 24]. Since the mid-1970s several fluorinated... 

Kakiki et ai. (1969) reported that EBP inhibited the incorporation of glucosamine-into the cell wall of Piricularia orysae. This suggested that a mode of action of this compound might be the inhibition of chitin biosynthesis. According to the experiments of Akatsuka et al. (1977) and of Kodama et al. (1979) the specific inhibition of conversion from phosphatidylethanolamine to phos-phatidylcholin by the transmethylation of S-adenosylmethionine might be one of the modes of action of IBP. 

A group of aminoacylamino- nucleoside antibiotics (more than 25 components) from cultures of Streptomyces tendae, see also polyoxins. The N. exhibit acar-icidal, insecticidal, and antifungal activities. The activity is based on an inhibition of chitin biosynthesis as a result of the structural analogy to UDP-Al-acetyl-... 

Over the past three decades, the N-benzoyl-N -phenyl ureas (BPUs) have been developed and used as commercial IGRs acting by inhibiting chitin biosynthesis... 

Pyrimidine peptide antifungal agents, produced by Streptomyces cacaoi, that inhibit cell wall chitin biosynthesis used to inhibit agriculrurally signiftcam fungi. 

The production of canned crab and shrimp meat as well as the production of citric acid from Aspergillus niger originates very large amounts of chitinous wastes, which not only represent a worry from the ecological standpoint, but also a destruction of renewable polysaccharidic resources 10, Moreover, insects destroy a substantial aliquot of our crops thus, since insects possess a chitinous exoskeleton and their larvae are protected by a chitinous membrane, H an important approach to the crop protection and insect control is the inhibition of chitin biosynthesis 12-15 also interested in protecting... 

Chitin synthesis in wing pads of 1-day-old fifth-instar larvae of Locusta is stimulated in vitro by 20-hydroxyecdysone and makisterone A 88), This chitin biosynthesis system requires integrity of the microtubular system and the chitin-synthetase complex. Chitin synthesis can be inhibited in this test system by azadirachtin as well as by colcemid, a microtubular poison, or by diflubenzuron, a chitin synthetase inhibitor. It is also of interest to note that RH5849 stimulates chitin synthesis in wing discs of Plodia interpunctella 89). 

Some anti-frmgal agents such as tricyclazole produce a weakening of cell walls by inhibiting melanin biosynthesis. More recently, several compounds that target the p-(l,3)-D-glucan and chitin synthases have been developed. 

Microscopic examination suggests that 15G256Yacts by inhibiting cell wall biosynthesis. However, the target, which does not seem to be glucan or chitin synthase, remains to be identified. 

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