Orally active purine-based inhibitors of the heat shock protein 90.
Orally active Hsp90 inhibitors are of interest as potential chemotherapeutic agents. Recently, fully synthetic 8-benzyladenines and 8-sulfanyladenines such as 4 were disclosed as Hsp90 inhibitors, but these compounds are not water soluble and consequently have unacceptably low oral bioavailabilities. We now report that water-solubility can be achieved by inserting an amino functionality in the N(9) side chain. This results in compounds that are potent, soluble in aqueous media, and orally bioavailable. In an HER-2 degradation assay, the highest potency was achieved with the neopentylamine 42 (HER-2 IC(50) = 90 nM). In a murine tumor xenograft model (using the gastric cancer cell line N87), the H(3)PO(4) salts of the amines 38, 39, and 42 induced tumor growth inhibition when administered orally at 200 mg/kg/day. The amines 38, 39, and 42 are the first Hsp90 inhibitors shown to inhibit tumor growth upon oral dosage.
Biamonte
Marco A
MA
Department of Medicinal Chemistry, Conforma Therapeutics Corporation, San Diego, California 92121, USA. mbiamonte@conformacorp.com
Shi
Jiandong
J
Hong
Kevin
K
Hurst
David C
DC
Zhang
Lin
L
Fan
Junhua
J
Busch
David J
DJ
Karjian
Patricia L
PL
Maldonado
Angelica A
AA
Sensintaffar
John L
JL
Yang
Yong-Ching
YC
Kamal
Adeela
A
Lough
Rachel E
RE
Lundgren
Karen
K
Burrows
Francis J
FJ
Timony
Gregg A
GA
Boehm
Marcus F
MF
Kasibhatla
Srinivas R
SR
D000225:Adenine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D000284:Administration, Oral; D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D001682:Biological Availability; D005260:Female; D018841:HSP90 Heat-Shock Proteins / Q000037:antagonists & inhibitors*; D051379:Mice; D008819:Mice, Nude; D011687:Purines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D012995:Solubility; D013329:Structure-Activity Relationship; D023041:Xenograft Model Antitumor Assays
C508809:8-(2-iodo-5-methoxyphenylsulfanyl)-9-(3-isopropylaminiopropyl)-9H-purin-6-ylamine; C508810:9-(2-(2,2-dimethylpropylamino)ethyl)-8-(2-iodo-5-methoxyphenylsulfanyl)-9H-purin-6-ylamine; C508808:9-(3-sec-butylaminopropyl)-8-(2-iodo-5-methoxyphenylsulfanyl)-9H-purin-6-ylamine; D000970:Antineoplastic Agents; D018841:HSP90 Heat-Shock Proteins; D011687:Purines; D000225:Adenine