title: Relaxant activity of 4-amido-3,4-dihydro-2H-1-benzopyran-3-ols and 4-amido-2H-1-benzopyrans on guinea pig isolated trachealis.
abstract: A series of 4-amido-3,4-dihydro-2H-1-benzopyran-3-ols and 4-amido-2H-1-benzopyrans related to the potassium channel activator cromakalim have been prepared and evaluated for their relaxant activity in guinea pig isolated tracheal spirals. Several analogues show enhanced relaxant activity relative to cromakalim in this preparation and the rank order of potency for those substituents investigated at C-6 was CF3 greater than CN greater than C2H5 greater than aza greater than or equal to CH3. One compound, trans-3,4-dihydro-2,2-dimethyl-4-(2-oxopiperidin-1-yl)-7-(trifluor omethyl)-2H- 1-benzopyran-3-ol (24), was resolved into its two enantiomers and the activity was shown to reside essentially in the (+)-isomer, adding further support to the suggestion that the smooth muscle receptor for these potassium channel activators is stereoselective.
authors.affiliation: SmithKline Beecham Pharmaceuticals, Biosciences Research Centre, Epsom, Surrey, England.
authors.forename: D R
authors.initials: DR
authors.lastname: Buckle
authors.forename: J R
authors.initials: JR
authors.lastname: Arch
authors.forename: A E
authors.initials: AE
authors.lastname: Fenwick
authors.forename: C S
authors.initials: CS
authors.lastname: Houge-Frydrych
authors.forename: I L
authors.initials: IL
authors.lastname: Pinto
authors.forename: D G
authors.initials: DG
authors.lastname: Smith
authors.forename: S G
authors.initials: SG
authors.lastname: Taylor
authors.forename: J M
authors.initials: JM
authors.lastname: Tedder
mesh_terms: D000577:Amides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D001578:Benzopyrans / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D001993:Bronchodilator Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D055598:Chemical Phenomena; D002621:Chemistry; D019806:Cromakalim; D006168:Guinea Pigs; D015394:Molecular Structure; D009126:Muscle Relaxation / Q000187:drug effects*; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology; D011758:Pyrroles / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D014132:Trachea / Q000502:physiology*
chemical_list: D000577:Amides; D001578:Benzopyrans; D001993:Bronchodilator Agents; D015221:Potassium Channels; D011758:Pyrroles; D019806:Cromakalim