Page 22 - FPGEE Medicinal and Organic Chemistry Q&A Book

Krisman

Pneumocystis pneumonia. It is a member of the 250. (b) Undecylenic / undecenoic acid is an
8-aminoquinoline group of drugs. organic unsaturated fatty acid derived from
natural castor oil. It is the common name of the
10-undecenoic acid (CH CH(CH ) COOH). It
2 2 8
is used in the manufacture of pharmaceuticals,
N cosmetics and perfumery including anti-dan-
N druff shampoos, and anti-microbial powders.
Quinoline Isoquinoline Undecylenic acid is produced by the cracking
of Castor oil under pressure. Undecylenic acid
248. (b) I and II only. Thiabendazole (Mintezol) is a natural fungicide and is FDA approved in
is classified as anthelmintic drug. It is indicated over-the-counter medications for skin disorders
for the treatment of helminth infections. There or problems. It is the active ingredient in medi-
are two heterocyclic organic compounds present cations for skin infections and relieves itching,
in Thiabendazole: benzimidazole and thiazole. burning, and irritation. For example, it is used
against fungal skin infections such as athlete’s
N N foot, ringworm and candida albicans. It is also
used in the treatment of psoriasis.
N S
251. (c) Pyrazinamide (PZA) is a drug used to
H
treat tuberculosis in afflicted patients. The drug
Benzimidazole Thiazole
is largely bacteriostatic, but can be bacteriocidal
N on actively replicating tuberculosis bacteria. It
S is only used in combination with other drugs

such as isoniazid and rifampicin in the treat-
Isothiazole ment of Mycobacterium tuberculosis. It
metabolizes to pyrazinoic acid and then subse-
249. (c) Flucytosine (Ancobon), a pro-drug, is quently to 5-hydroxypyrazinoic acid.
converted by fungal cytosine deaminase to 5-
fluorouracil. This reaction does not occur in N COOH
N CO-NH 2 N COOH
mammalian cells. The 5-fluorouracil is then
converted to cytotoxic agent, 5-
fluorodeoxyuridine monophosphate. Human
O H
cells do not contain cytosine deaminase and N N N
therefore do not convert flucytosine to 5-
fluorouracil. It is indicated only in the treatment Pyrazinamide Pyrzinoic acid 5-hydroxypyrazinoic acid
of serious infections caused by susceptible
strains of Candida and/or Cryptococcus. 252. (b) Ethambutol (Myambutol) is a bacte-
riostatic anti-mycobacterial drug prescribed to
O
treat tuberculosis (Mycobacterium tuberculo-
H F sis). It is usually given in combination with other
N
tuberculosis drugs, such as isoniazid,
pyrazinamide and rifampicin. It may reduce vi-
O N
sual acuity, including irreversible blindness,
H which appears to be due to optic neuritis. Optic
5-fluorouracil neuropathy, including optic neuritis or retrob-

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