547.636+547.972 V. A. Denisenko, and S. A. FedoreevThe rare α,4,2′,4′-tetrahydroxydihydrochalcone, flavanones liquiritigenin and naringenin, isoflavones calycosin and 5-methoxydaidzein, and reduced stilbene dihydroresveratrol were isolated for the first time from Maackia amurensis wood. The structures of the pure compounds were established using 2D NMR COSY, NOE, HMBC, and HSQC experiments. Maackia amurensis is the single woody representative of the Fabaceae family in the Russian Far East. The polyphenol complex obtained from its wood possesses strong antioxidant properties. The hepatoprotective preparation Maksar based on it has greater activity than the known hepatoprotectors Carsil and Legalon [1]. Therefore, the chemical composition of M. amurensis is interesting not only for scientific curiosity but also for complete characterization of the preparation.Herein we report on minor components of the M. amurensis wood polyphenol complex. Six known compounds were isolated and characterized: α,4,2′,4′-tetrahydroxydihydrochalcone (1) [2], liquiritigenin (2) [3], naringenin (3) [4], calycosin (4) [5], 5-methoxydaidzein (5) [6], and dihydroresveratrol (6) [7]. We observed in the heartwood and characterized earlier isoflavonoids, stilbenes, dimeric stilbenes, stilbenolignan, and isoflavostilbene [8]. The rare dihydrochalcone that was hydroxylated in the α-position and flavanones were observed for the first time in M. amurensis wood. About ten α-hydroxydihydrochalcones have been isolated and characterized until now. These are luonogenin [9], nubigenol [10], α,2′-dihydroxy-4,4′-dimethoxydihydrochalcone [11], α,2′,4,4′-tetrahydroxydihydrochalcone [2], coatlines A and B [12], α-hydroxy-2′,4,4′-trimethoxydihydrochalcone [13], and kanzonol Y [14].Mass spectra of the isolated compounds showed that 4 and 5 had the same mass, 284 amu. The presence in the PMR spectra of these compounds of a 1H singlet at 8.05-8.34 ppm indicated that they were isoflavonoids. Compounds 4 and 5 were structural isomers. Their separation on KSK silica gel and Sephadex LH-20 was unsatisfactory. Therefore, they were chromatographed over a column (210 × 30 mm) packed with Toypearl HW-50F sorbent equilibrated with alcohol:water (1:9)