Inhibitory effects of flavonoids on human immunodeficiency virus type-I integrase

One hundred and eighty-three flavonoids were screened for their inhibitory effects on HIV-l integrase (IN) using a multiplate integration assay (MIA). Of the tested flavonoids, 6-hydroxyluteolin, scutellarein, pedalitin, scutellarin, baicalein dimer, hypolaetin, 7-O-benzyl-6-hydroxyluteolin and baicalein showed appreciable inhibition with IC_ values of 0.4, 0.6, 1.3, 1.7, 2.0, 2.1, 3.0 and 3.6 μM, respectively. The potent inhibition was observed with flavonoids having at least one pair of vicinal hydroxyl groups and the activity was highly dependent on the number of vicinal hydroxyl groups. On the other hand, the inhibitory activity tended to be decreased by replacing a hydroxyl group with one of methoxyl, acetoxyl, isopropoxyl, isopentenyl, benzyloxyl, glucuronyl and glycosyl groups. No flavanones, flavanonols and chalcones examined in this experiment showed any significant inhibitory activity. マルチプレートインテグレーション法を用いて183種のフラボノイド類のHIV-1インテグラーゼ阻害効果を検討した。これらのうち6-hydroxyluteolin, scutellarein, pedalitin, scutellarin, baicalein二量体,hypolaetin,7-O-benzyl-6-hydroxyluteolinおよびbaicaleinは強い阻害を示し,それらの50%阻害濃度はそれぞれ0.4, 0.6, 1.3, 1.7, 2.0 ,2.1 ,3.0および3.6μMであった。フラボノイド類による阻害には少なくとも一対の隣接したヒドロキシル基が必要であった。また,隣接したヒドロキシル基の数が増加するに従い,HIV-1インテダラーゼ阻害活性も上昇した。他方,ヒドロキシル基がmethoxyl基, acetoxyl基, isopropoxyl基, isopentenyl基, benzyloxyl基, glucuronyl基 及びglycosyl基に置換されると阻害活性は減少あるいは消失した。試験したフラバノン,フラバノール,カルコン類には顕著な阻害活性は認められなかった

Assignment of the 31P and 1H resonances in oligonucleotides by two-dimensional NMR spectroscopy

AbstractThe use of new 1H-detected heteronuclear 1H-31P shift correlation experiments is demonstrated for oligonucleotides of 12 and 40 base pairs. The methods give unambiguous assignments of the 31P resonances and also permit identification of the C4′ and C5′ sugar protons. Use of the new methods enables one to make sequence-specific resonance assignments without reference to a known or assumed conformation of the DNA fragment