No abstract

No abstract

Isoflavonoids, an interesting and restricted group of secondary metabolites of legumes, exhibit estrogenic, antiangiogenic, and anticancer activities and are now popular as dietary supplements. Plant cell cultures that possess an increased ability to synthesize these metabolites were examined. During the investigation, cell cultures of the Far Eastern relict tree Maackia amurensis (Leguminosae) were established. A selection of seed-derived cell aggregates yielded the callus line designated A-18. This culture produces 20 isoflavonoids, namely, the isoflavones genistein, daidzein, formononetin, calycosin, derrone, and pseudobaptigenin and their glycosylated conjugates genistin, 6''-O-malonylgenistin, ononin, 6''-O-malonylononin, daidzin, 3'-methoxydaidzin, 4'-O-beta-D-glucopyranosyldaidzin, 4'-O-beta-D-glucopyranosylgenistin, and 7-O-beta-D-glucopyranosylcalycosin; the pterocarpans maackiain and medicarpin and their glycosylated conjugates 6'-O-malonyl-3-O-beta-D-glucopyranosylmaackiain and 6'-O-malonyl-3-O-beta-D-glucopyranosylmedicarpin; and the new pterocarpan glucoside 6'-O-malonyl-3-O-beta-D-glucopyranosyl-6,6a-dehydromaackiain. These isoflavonoids, possessing a hepatoprotective activity, were stably produced by the A-18 calli for prolonged periods of observation.

Rabdosiin and related caffeic acid metabolites have been proposed as active pharmacological agents demonstrating potent anti-HIV and antiallergic activities. We transformed Eritrichium sericeum and Lithospermum erythrorhizon seedlings by the rolC gene, which has been recently described as an activator of plant secondary metabolism. Surprisingly, the rolC-transformed cell cultures of both plants yielded two- to threefold less levels of rabdosiin and rosmarinic acid (RA) than respective control cultures. This result establishes an interesting precedent when the secondary metabolites are differently regulated by a single gene. We show that the rolC gene affects production of rabdosiin and RA irrespective of the methyl jasmonate (MeJA)-mediated and the Ca(2+)-dependent NADPH oxidase pathways. Cantharidin, an inhibitor of serine/threonine phosphatases, partly diminishes the rolC-gene inhibitory effect that indicates involvement of the rolC-gene-mediated signal in plant regulatory controls, mediated by protein phosphatases. We also show that the control MeJA-stimulated E. sericeum root culture produces (-)-rabdosiin up to 3.41% dry weight, representing the highest level of this substance for plant cell cultures reported so far.

No abstract

No abstract

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)

No abstract