Research Abstract |
(1)The screening experiments were carried out on sleeping-time- elongation effect in mice of 16 kinds of crude drugs, 12 out of which showed the significant activities in one or more fractionation products obtained from each of the crude drugs at the dose of 2-5 g/kg (p. o.). The activities were rarely found in fractionation product soluble solely in water. (2) We investigated on chemical components of Sappan Lignum responsible for the sedative effect. Brazilin( <I> ), brazilein( <II> ), sappanchalcone( <III> ), protosappanins A( <IV> ), B( <V> ), C( <VI> ) and E-1( <VII> , unknown structure) were isolated from Sappan Lignum. <III> is a new chalcone represented by 2'-methoxy-3,4, 4'-trihydroxychalcone and seems to be the biosynthetic precursor of <I> and <II> . <IV> - <VI> belong to a new class of natural products, and afforded sappanin on alkali fusion. Their structures were established as 7,8-dihydro-3,10,11-trihydroxy-6H-dibenz[b,d]oxocin-7-one( <IV> ), (7S)-7,8-dihydro-3,7,10,11-tetrahydroxy-7(6H)-dibenz[b,d]oxocinmethanol( <V> ) and (7R)-7,8-dihydro-3,7,10,11-tetra-hydroxy-7(6H)-dibenz[b,d]oxocincarbaldehyde( <VI> ). <III> ( at the dose of 142 mg/kg, i. p.), <IV> (43 mg/kg, i. p.), <V> (157 mg/kg, i. p.) and <VI> (150 mg/kg, i. p.) elongated the sleeping-time in mice of the control (30 minutes) induced by hexobarbital (80 mg/kg, i. p.) by 41, 48, 75 and 8 %, respectively.
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