Novel tetrahydroisoquinoline derivatives with inhibitory activities against acyl-CoA: cholesterol acyltransferase and lipid peroxidation.
To find a novel acyl-CoA: cholesterol acyltransferase (ACAT) inhibitor with anti-lipid peroxidative activity, a series of tetrahydroisoquinoline derivatives were synthesized and evaluated. A compound with a N-(4-hydroxy-2,3,5-trimethylphenyl)carbamoyl moiety at the 3-position and an octanoyl moiety at the 2-position (7) was demonstrated to show anti-foam cell formation activity stronger than and anti-lipid peroxidative activity comparable to those of Pactimibe, while it was hardly absorbed orally. To increase its bioavailability, the acyl chain at the 2-position was shortened and various polar or basic moieties were introduced at the 7-position of 7. Among the synthesized derivatives, (S)-7-dimethylamino-N-(4-hydroxy-2,3,5-trimethylphenyl)-2-isobutyryl-1,2,3,4-tetrahydroisoquinoline-3-carboxamide hydrochloride (21) showed about 16-fold stronger anti-foam cell formation activity, 3-fold stronger hepatic ACAT inhibitory activity, similar anti-low density lipoprotein (LDL) oxidative activity and 2-fold more potent protective activity against macrophage cell death by oxidative stress in comparison with Pactimibe. Compound 21 was efficiently absorbed after oral administration at 10 mg/kg in rats and dogs and its C(max) values were higher than its IC(50) values for in vitro activities. In conclusion, a tetrahydroisoquinoline structure is a useful scaffold for designing a phenolic anti-oxidative ACAT inhibitor, and compound 21 is expected to effectively prevent atherosclerosis.
Ohta
Masaru
M
Research Laboratories, Kyoto Pharmaceutical Industries, Ltd., 38 Nishinokyo Tsukinowa-cho, Nakagyo-ku, Kyoto, Japan.
Takahashi
Kenji
K
Kasai
Masayasu
M
Shoji
Yoshimichi
Y
Kunishiro
Kazuyoshi
K
Miike
Tomohiro
T
Kanda
Mamoru
M
Mukai
Chisato
C
Shirahase
Hiroaki
H
D000818:Animals; D000975:Antioxidants / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D016923:Cell Death / Q000187:drug effects; D002784:Cholesterol / Q000378:metabolism; D004285:Dogs; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D004951:Esterification; D015227:Lipid Peroxidation / Q000187:drug effects*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D008297:Male; D015394:Molecular Structure; D018384:Oxidative Stress / Q000187:drug effects; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D013237:Stereoisomerism; D002785:Sterol O-Acyltransferase / Q000037:antagonists & inhibitors*; D013329:Structure-Activity Relationship; D044005:Tetrahydroisoquinolines / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*
D000975:Antioxidants; D004791:Enzyme Inhibitors; D044005:Tetrahydroisoquinolines; D002784:Cholesterol; D002785:Sterol O-Acyltransferase