Structure-activity study of brassinin derivatives as indoleamine 2,3-dioxygenase inhibitors.
A screen of indole-based structures revealed the natural product brassinin to be a moderate inhibitor of indoleamine 2,3-dioxygenase (IDO), a new cancer immunosuppression target. A structure-activity study was undertaken to determine which elements of the brassinin structure could be modified to enhance potency. Three important discoveries have been made, which will impact future IDO inhibitor development: (i) The dithiocarbamate portion of the brassinin lead is a crucial moiety, which may be binding to the heme iron of IDO; (ii) an indole ring is not necessary for IDO inhibition; and (iii) substitution of the S-methyl group of brassinin with large aromatic groups provides inhibitors that are three times more potent in vitro than the most commonly used IDO inhibitor, 1-methyl-tryptophan.
Gaspari
Paul
P
Department of Chemistry, Bryn Mawr College, Pennsylvania 19010-2899, USA.
Banerjee
Tinku
T
Malachowski
William P
WP
Muller
Alexander J
AJ
Prendergast
George C
GC
DuHadaway
James
J
Bennett
Shauna
S
Donovan
Ashley M
AM
D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000037:antagonists & inhibitors* / Q000737:chemistry; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D013329:Structure-Activity Relationship; D013859:Thiocarbamates / Q000138:chemical synthesis* / Q000737:chemistry; D000094162:Phytoalexins
D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D007211:Indoles; D013859:Thiocarbamates; C089020:brassinin; D000094162:Phytoalexins