Serendipity in anticancer drug discovery

Table 4 List of drugs discovered with the aid of serendipity in the laboratory, the number of identified derivatives and their therapeutic notation

Drugs	Ref.	Derivatives	Notation
Acetanilide	[3,4]	1	Antipyretic
Acetohexamide	[1,3,4]	8	Diabetes II
Captopril	[1,3]	8	Cardiovascular
Cisplatin	[1-4]	2	Cancer
Diethylstilbestrol	[3,4]	1	Hormonal
Digoxin	[1,3]	4	Cardiovascular
Ergotamine	[1-3]	6	Cardiovascular
Ephedrine	[3]	9	CNS
Griseofulvin	[3,4]	0	Antifungal
Heparin	[2-4]	4	Cardiovascular
Isoniazid	[3,4]	0	Antibiotic
Lidocaine	[3]	6	CNS
Lithium	[1-4]	0	CNS
Marinol	[3]	1	CNS
Mechlorethamine	[1-4]	5	Cancer
Mecillinam	[3]	1	Antibiotic
Methotrexate	[1,3]	1	Cancer
Nalidixic acid	[1,3]	8	Antibiotic
Nitroglycerine	[1,3,4]	2	Cardiovascular
Penicillin	[1-4]	21	Antibiotic
Pentamidine	[3]	0	Antiprotozoal
Physostigmine	[3]	0	Ocular
Quinine	[3]	1	Antiprotozoal
Sorafenib	[1]	0	Cancer
Streptomycin	[1,2]	7	Antibiotic
Sulfanilamide	[1-3]	13	Antibiotic
Valproic acid	[3,4]	1	CNS
Vinblastine	[1-3]	3	Cancer
Dicoumarol	[2-4]	0	Cardiovascular
Warfarin	[2-4]	3	Cardiovascular
Zinc sulfate	[3]	0	Wilson’s disease

CNS: Central nervous system.