Bioactive phenolics and polar compounds from Melilotus messanensis

The methanolic extract from sweetclover, Melilotus messanensis, afforded th e new coumestan melimessanol A, the 3-arylcoumarin melimessanol B and the 2 -arylbenzofuran melimessanol C, which where identified on the basis of spec troscopic methods. The known isoflavones formononetin and cyclosin; the iso flavanone vestitone; the flavanone liquiritigenin; the pterocarpans (3R,4R) -medicarpin, 3-hydroxymedicarpin and melilotocarpane B; the coumestans coum estrol, 4'-O-methylcoumestrol and 7-hydroxy-4',5'-dimethoxycoumestan; the 3 -arylcoumarin 3-(4'-methoxy-2'-hydroxyphenyl)-7-hydroxycoumarin; the lignan pinoresinol; 3-hydroxycoumarin and the simple phenolics p-coumaric acid, v anillic acid, p-hydroxybenzoic acid, a diterpene, two loliolides, a cyclito l and two saponins have been also isolated and spectroscopically identified . Cyclosin, vestitone, 4'-O-methylcoumestrol, 7-hydroxy-4',5'-dimethoxycoum estan, 3-(4'-methoxy-2'-hydroxyphenyl)-7-hydroxycoumarin and 3-hydroxycouma rin are first reported in the genus Melilotus. The effects of a series of a queous solutions from 10(-4)-10(-9) M of twelve phenolics, two loliolides, a diterpene and a cyclitol on germination and growth of the dicotyledons La ctuca sativa cvs. Roman and Nigra and Lycopersicum esculentum and the monoc otyledons Allium cepa and Hordeum vulgare, have been studied. The isoflavon es formononetin and cyclosin and the pterocarpan medicarpin have been found to inhibit principally A. cepa germination. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.