Question

Isopenicillin N is produced by the fungi Penicillium chrysogenum. This compound may be

converted by the enzyme penicillin transacetylase to Penicillin G (Benzylpenicillin) by the

same microorganism if the growth medium is supplied with phenylacetic acid. The net

reaction is:

Isopenicillin N + Phenylacetic acid → Penicillin G + Aminoadipic Acid

12.0 g phenylacetic acid is added to a broth containing 15.0 g of Isopenicillin N.

What percentage of the phenylacetic acid added ends up incorporated in benzylpenicillin?

Answer 1

Answer:

Isopenicillin N + Phenylacetic acid → Penicillin G + Aminoadipic Acid

359.39 136.15 334.4 g/mol Molar masses of the compounds

15g 12g

For 15 g of Isopencillin N required phenyl acetic acid:

Isopenicillin N + Phenylacetic acid → Penicillin G + Aminoadipic Acid

359.39 136.15

15g ?

= (15 x 136.15) / 359.39

= 5.682 g

12 g of the phenyl acetic acid is added but 5.682 g is required.

For the 15g of the Isopenicillin N, The 100% yield of the Penicillin G:

Isopenicillin N + Phenylacetic acid → Penicillin G + Aminoadipic Acid

359.39 334.4 g/mol Molar masses of the compounds

15g ?

= (15 x 334.4) / 359.39

= 5016 / 359.39

= 13.956 g

But the question is percentage of phenyl acetic acid added ends up incorporated in Benzylpenicillin:

13.956g of the penicillin G producing by the involment of 5.682 g of phenyl acetic acid

Then the percentage of phenyl acetic acid is as fallows

13.956 g ....................... 100

5.682 g ......................... ?

= (5.682 x 100) / 13.956

= 568.2 / 13.956

= 40.713

Hence the percentage of the phenyl acetic acid is 40.713