- Synthesis of novel 3,7-dihydro-purine-2,6-Dione derivatives
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Forty-six novel 3,7-dihydro-purine-2,6-dione derivatives (substituted xanthines) with great structural diversity were synthesized for biological activity screening. Three series of substituted xanthine analogs have been prepared in moderate to excellent y
- Liu, Gang,Reddy, P.S. Murali,Barber, Jack R.,Ng, Shi Chung,Zhou, Yuefen
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experimental part
p. 1418 - 1436
(2010/07/06)
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- Xanthines, optionally incorporated in liposomes, for promoting skin or hair pigmentation
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A method of treating skin or hair for promoting pigmentation wherein a xanthine component, in an amount effective to promote pigmentation, is incorporated in liposomes or hydrated lipidic lamellar phases.
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- Effects of Alkyl Substitutions of Xanthine Skeleton on Bronchodilation
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Structure-activity relationships in a series of 1,3,7-trialkyl-xanthine were studied with guinea pigs.Relaxant actions in the tracheal muscle were increased with alkyl chain length at the 1- and 3-positions of the xanthine skeleton, but decreased by alkylation at the 7-position.Positive chronotropic actions in the right atrium were potentiated with 3-alkyl chain length but tended to decrease with 1-alkylation and diminish by 7-substitution.Consequently, while the 1- and 3-substitutions were equally important for the tracheal smooth muscle relaxation, the substitution at the 1-position was more important than the 3-substitution for bronchoselectivity.The 7-alkylation may be significant to cancel heart stimulation.There were good correlations between the smooth muscle relexant action and the cyclic AMP-PDE inhibitory activity in 3-substituents and the affinity for adenosine (A1)receptors in 1-,3-, and 7-substituents.This suggests that not only the cyclic AMP-PDE inhibitory activity but also the adenosine antagonistic activity is important in the bronchodilatory effects of alkylxanthines.Among these xanthine derivatives, 1-butyl-3-propylxanthine and its 7-methylated derivative showed high bronchoselectivity in the in vitro and in vivo experiments compared to theophylline and enprofylline and may be new candidates for bronchodilator.
- Sakai, Ryosuke,Konno, Kayo,Yamamoto, Yasunori,Sanae, Fujiko,Takagi, Kenzo,et al.
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p. 4039 - 4044
(2007/10/02)
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- Analogue of Coffeine and Theophylline: Effect of Structural Alterations on Affinity at Adenosine Receptors
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A variety of analogues of caffeine and theophylline in which the 1-, 3-, and 7-methyl substituents have been replaced with n-propyl, allyl, propargyl, and isobutyl and, in few cases with chloroethyl, hydroxyethyl, or benzyl were assessed for potency and s
- Daly, J. W.,Padgett, W. L.,Shamim, M. T.
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p. 1305 - 1308
(2007/10/02)
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