Bacteria macrocyclic lactones from

Spinosad Insecticide Compound from bacteria Macrocyclic lactone... 

They contain 12-, 14-, or 16-membered macrocyclic lactone rings attached to amino acids and/or a neutral sugar moiety attached via glycoside bonds. Beyond this, their individual chemical structures and sizes as reflected by molecular weight are dramatically different. Thus, despite exerting similar mechanisms on bacteria, they are very chemically different from each other. 

Macrolide-producing organisms are classified as shown in Table 11. Actino-mycetes produce the largest number of macrolides (more than 800). Myxobacte-ria produce about 100 macrolides, and the other bacteria produce about only 40 macrolides. A rather large number of macrolides have been isolated from fungi (about 200). Lichens produce only three compounds. About 70 macrolides have been isolated from algae. Though plants produce about 700 macrocyclic lactone compounds, most of them are tannins or alkaloids such as pyrrolizidines. So they... 

Lactonization. The disulfide 1 (7, 141) was used instead of 2,2 -dipyridyl disulfide by Corey and Bhattacharyya in a total synthesis of macrocyclic lactone enterobactin (2) involved in the transport of iron in certain bacteria. The lactone ring was constructed from three L-serine units, with protection of the amino group as the CBZ group and of the hydroxyl group as the THP ether. The three serine units were condensed in steps using 1 and triphenylphosphine to give the... 

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