BONE ABSORPTION INHIBITOR AND NAPHTHALENE DERIVATIVE

摘要

PURPOSE:To obtain a naphthalene derivative useful as a preventive and a treating agent for osteoporosis, directly acting on bone and showing inhibitory action on bone absorption. CONSTITUTION:A partially new naphthalene derivative shown by formula I (ring A and ring B may contain substituent group; R is H or alkoxy which may be substituted with OH; part containing broken line shows carbon-carbon single bond or double bond) or Justicia procumbens L. var. leucantha Honda containing the compound or an extract of the plant is used as a bone absorption inhibitor. Among the above-mentioned compound, a compound shown by formula II (R' is substituted with hydrocarbon residue wherein ring A is halogen or may be replaced and includes a case wherein bifunctional hydrocarbon residue may form ring), especially juticidin G shown by formula III and juticidin H shown by formula IV are new substances and obtained by extracting and purifying stems and leaves or while plants of Justicia procumbens L. var. leucantha Honda.