Penicillium moulds

Semisynthetic. In 1959, scientists at Beecham Researeh Laboratories sueceeded in isolating the penicillin nucleus, 6-aminopenicillanie aeid (6-APA Fig. 5.1 A R represents H). During the commercial production of benzylpenicillin, phenylacetic (phenylethanoic) acid (C6H5.CH2.COOH) is added to the medium in whieh the Penicillium mould is growing (see Chapter 7). This substance is a precursor of the side... 

Thiamin levels in milk products (Appendix 6A) are generally 0.02-0.05 mg per 100 g. As a result of the growth of the Penicillium mould, the rind of Brie and Camembert cheese is relatively rich in thiamin (0.5 and 0.4 mg per 100 g, respectively). 

This compound was made because it was needed in a synthesis of multicolanic acid, a metabolite of a penicillium mould. It is easy to see which atoms of the natural product were provided by the compound we have just made in a single easy step. 

Benzylpenicillin (1942) is produced by growing one of the penicillium moulds in deep tanks. In 1957 the penicillin nucleus (6-amino-penicillanic acid) was synthesised and it became possible to add various side-chains and so to make semisynthetic penicillins with different properties. It is important to recognise that not all penicillins have the same antibacterial spectrum and that it is necessary to choose between a number of penicillins just as it is between antimicrobials of different structural groups, as is shown below. 

He initially thought that the mould was a potent strain of Penicillium rubrum, although it was subsequently shown to be Penicillium notatum. He screened a number of other Penicillium moulds from contaminated foodstuffs, old books, paintings, etc., but none except one provided by the hospital mycologist had the potency of the first mould. This confirmed his suspicion that he was dealing with a very unusual strain. 

Nearly sixty years have now passed since Sir Alexander Fleming observed antibiosis between a Penicillium mould and bacterial cultures and gave the name penicillin to the active principle (Fleming, 1929). Although it was proposed in 1943 that penicillin contained a p-lactam ring [1] (Abraham et al 1943), this was not generally accepted until an X-ray crystallographic determination of the structure had been completed (Crowfoot et al., 1949). 

Methyl 6-methylsalicylate is the trail pheromone of some ants, it is also found in carabid beetle, 6-methylsalicylaldehyde in the defensive secretion of a cerambycid beetle, and 6-methylsalicylic acid is made by some Penicillium moulds. Orsellinic acid and 6-methylsalicylic acid are... 

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