Antitumor‐active substances from mushrooms

Abstract

It has been known for many years that most fungi which have known effects against cancers of the stomach, esophagus, lungs, etc., belong to the Polyporacea. However, the components responsible for such action have not been clearly defined. In Japan, in 1968, it was reported that a hot water extract from some edible mushrooms belonging to the Polyporacea showed a marked host‐mediated antitumor activity. Since then, numerous researchers have isolated active materials and have identified them to be (1—3)‐ß‐D‐glucopyranans with a (1—6)‐ß‐glucosyl branch containing protein. Antitumor poly‐saccharides are considered to be biological response modifiers (BRM) or immunopotentiators because of their action mechanism. In Japan three different polysaccharide antitumor agents have been isolated from the fruiting body, mycelium, and cultured medium, from three mushroom species. As the result of screening for growth inhibition of cultured cancer cells, some terpenoids, steroids, and other compounds have been found to have antitumor activity. These compounds, lower molecular weight components, exhibit cytotoxicity and are being considered as chemotherapy agents.