Question

Salvarsan is a drug which was first used for the treatment of _______.
A- Syphilis
B- Typhoid
C- Meningitis
D- Dysentery

Answer 1

Hint: Salvarsan is also known as Arsphenamine. It was first prepared in 1907 but named as salvarsan in 1910. Salvarsan is used for the treatment of disease caused by bacterium treponema pallidum, a spirochete.

Complete answer:
 We know that salvarsan is an organic compound containing arsenic element as a substituent. Arsphenamine can exist as a dimer, trimer, and pentamer. Arsphenamine consists of an amine group and arsenic on phenol. Arsphenamine dimer has As-As double bond. The structure of Arsphenamine is

Arsenical organic compounds are used for the treatment of many diseases. Salvarsan is toxic to the bacterium treponema pallidum, which is syphilis causing bacteria. Salvarsan has a great improvement over other drugs made of inorganic mercury compounds which were used previously for the treatment of syphilis. In the trimer of Arsphenamine, there will be a cyclic ring between three arsenic atoms of 3 molecules. In the pentamer of Arsphenamine, there will be a cyclic ring between five arsenic atoms of 5 molecules.
Since the results of using salvarsan for the treatment of syphilis were appreciative it was used as first for the treatment of syphilis. Therefore, option A is correct.

Note: Typhoid, Meningitis, and Dysentry were not treated by salvarsan. Dysentery was caused by parasites and tinidazole was used for treatment. Typhoid was treated by ciprofloxacin. Meningitis was treated by taking antibiotics, no other drug was used.