Question: When was the first chemotherapeutic agent discovered?
About the article "Chemotherapy", section "The term "chemotherapy"".

Candidate passages:
Arsphenamine, also known as Salvarsan and compound 606, is a drug that was introduced at the beginning of the 1910s as the first effective treatment for syphilis, and was also used to treat trypanosomiasis.
It is an organoarsenic molecule, and was the first modern chemotherapeutic agent. 
Chemotherapy is described in one dictionary entry as "the treatment of disease by the use of chemical substances, especially the treatment of cancer by cytotoxic and other drugs."
The word "chemotherapy" without a modifier usually refers to cancer treatment, but its historical meaning is broader.
The term was historically used for non-oncological references, such as the use of antibiotics ("antibacterial chemotherapy").
The first modern chemotherapeutic agent was arsphenamine, an arsenic compound discovered in 1909 and used to treat syphilis.
This was later followed by sulfonamides (sulfa drugs) and penicillin.
Other uses that have been termed chemotherapy are the treatment of autoimmune diseases such as multiple sclerosis, dermatomyositis, polymyositis, lupus, and rheumatoid arthritis.
Vinblastine was first isolated by Robert Noble and Charles Thomas Beer at the University of Western Ontario from the Madagascar periwinkle plant.
Vinblastine's utility as a chemotherapeutic agent was first suggested by its effect on the body when an extract of the plant was injected in rabbits to study the plant's supposed anti-diabetic effect.
(A tea made from the plant was a folk-remedy for diabetes.)
The rabbits succumbed to a bacterial infection, due to a decreased number of white blood cells, so it was hypothesized that vinblastine might be effective against cancers of the white blood cells such as lymphoma. 
Despite, or possibly because of, its long-known toxicity, arsenic-containing potions and drugs have a history in medicine and quackery that continues into the 21st century.
Starting in the early 19th century and continuing into the 20th century, Fowler's solution, a toxic concoction of sodium arsenite, was sold.
The organoarsenic compound Salvarsan was the first synthetic chemotherapeutic agent, discovered by Paul Ehrlich.
The treatment, however, led to many problems, causing long lasting health complications.
Around 1943 it was finally superseded by penicillin.
"In vitro" studies suggest that arsenic trioxide (As2O3) inhibits the proliferation of myeloma cells via cell cycle arrest as well as triggering cell death.
These results suggest that arsenic trioxide may be a clinically useful treatment in patients with multiple myeloma or leukemia. 
  1961 developed patents for synthesis of vitamin A   1995 acute promyelocytic sphere of drug treatment leukemia Vesanoid was released.
1996 anti-viral chemotherapeutic agent Hivid released (HIV reverse transcriptase inhibitor)   1997 HIV protease inhibitor Invirase released   1999 immunosuppressive agent Cellcept released   2000 Release of an antiemetic drug Kytril developed to combat the side effects of chemotherapy  2001 Produced an anti-influenza virus Tamiflu (Roche)   2001 Discovered a malignant lymphoma target molecule Rituxan   2001 Released Herceptin, a novel breast cancer therapeutic