Chemistry Reference
In-Depth Information
3.10
IMMUNOSUPPRESSANTS
The induction of immunosuppression is generally used to prevent the body from
rejecting an organ transplant or for the treatment of autoimmune diseases such as
rheumatoid arthritis or Crohn's disease. Several microbial compounds have been
discovered that can suppress the immune response.
3.10.1 Immunosuppressive Peptides
Cyclosporine A (
85
) is a cyclic undecapeptide produced by the mold
Tolypocla-
dium nivenum
. Mechanistically, it suppresses the immune system by interrupting
calcium-mediated activating events (calcineurin) through complex formation with
cyclophilins and by impairing cytoplasmic and nuclear responses of lymphocytes
to alloantigens (57). With regard to its structure, the amino acid (4R)-4-[(E)-2-
butenyl]-4-methyl-L-threonine (Bmt or C-9 amino acid) seems to be essential for
immunosuppression.
3.10.2 Terpenoids with Immunosuppressive Activity
Mycophenolic acid can be produced by
Penicillium brevicompactum
(58) and
Penicillium echinulatum
. Its chemical structure (
86
) consists of a single pheno-
lic hydroxyl, one CH
3
O group, a lactone group, and a double bond (58, 59).
Mycophenolic acid has been used in the treatment of psoriasis and other inflam-
matory dermatoses. It was never commercialized as an antibiotic because of its
85
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