Abstract
Previously N-methyl-5, 6, 7, 8-tetrahydrodibenz [c, e] azocine (DA-VIII-Me) and N-methyl-10, 11-methylenedioxy-5, 6, 7, 8-tetrahydrodibenz [c, e] azocine (DA-VIII-M-Me) were found to have strong α-adrenolytic activities ; the pAs values were 8.76 and 7.71, respectively. N-Benzyl-N-methyl-β-phenethylamine (BMPA) and N-benzyl-N-methyl-3, 4-methylenedioxy-β-phenethylamine (BMPA-MO) which resemble DA-VIII-Me and DA-VIII-M-Me in structure but with the azocine ring opened at the biphenyl bond, were synthesized. It was found that the α-adrenolytic activities of these compounds on rat aortic strips were much less than those of DA-VIII-Me and DA-VIII-M-Me ; the pA2 values for BMPA and BMPA-MO were 6.79 and 5.78, respectively. Thus it was concluded that the dibenz [c, e] azocine structure of the latter compounds was important for their α-adrenolytic activities. It was also found that BMPA and BMPA-MO had a dual action, producing a moderately strong long-lasting contraction and inhibiting the contractile responses to various stimulants of isolated smooth muscles.
