Maackia amurensis Rupr. et Maxim.: Supercritical CO2 Extraction and Mass Spectrometric Characterization of Chemical Constituents.

Three types of extraction were used to obtain biologically active substances from the heartwood of M. amurensis: supercritical CO2 extraction, maceration with EtOH, and maceration with MeOH. The supercritical extraction method proved to be the most effective type of extraction, giving the highest yield of biologically active substances. Several experimental conditions were investigated in the pressure range of 50-400 bar, with 2% of ethanol as co-solvent in the liquid phase at a temperature in the range of 31-70 °C. The most effective extraction conditions are: pressure of 100 bar and a temperature of 55 °C for M. amurensis heartwood. The heartwood of M. amurensis contains various polyphenolic compounds and compounds of other chemical groups with valuable biological activity. Tandem mass spectrometry (HPLC-ESI-ion trap) was applied to detect target analytes. High-accuracy mass spectrometric data were recorded on an ion trap equipped with an ESI source in the modes of negative and positive ions. The four-stage ion separation mode was implemented. Sixty-six different biologically active components have been identified in M. amurensis extracts. Twenty-two polyphenols were identified for the first time in the genus Maackia.

Neuroprotective and Antiherpetic Properties of Polyphenolic Compounds from Maackia amurensis Heartwood.

In this study, we isolated a new isoflavanostilbene maackiapicevestitol (1) as a mixture of two stable conformers 1a and 1b as well as five previously known dimeric and monomeric stilbens: piceatannol (2), maackin (3), scirpusin A (4), maackiasine (5), and maackolin (6) from M. amurensis heartwood, using column chromatography on polyamide, silicagel, and C-18. The structures of these compounds were elucidated by NMR, HR-MS, and CD techniques. Maksar® obtained from M. amurensis heartwood and polyphenolics 1-6 possessed moderate anti-HSV-1 activity in cytopathic effect (CPE) inhibition and RT-PCR assays. A model of PQ-induced neurotoxicity was used to study the neuroprotective potential of polyphenolic compounds from M. amurensis. Maksar® showed the highest neuroprotective activity and increased cell viability by 18% at a concentration of 10 µg/mL. Maackolin (6) also effectively increased the viability of PQ-treated Neuro-2a cells and the value of mitochondrial membrane potential at concentrations up to 10 µΜ. Maksar® and compounds 1-6 possessed higher FRAP and DPPH-scavenging effects than quercetin. However, only compounds 1 and 4 at concentrations of 10 µM as well as Maksar® (10 µg/mL) statistically significantly reduced the level of intracellular ROS in PQ-treated Neuro-2a cells.

Chemical constituents from Maackia amurensis and their anti-inflammatory and antioxidant activities.

A new flavonoid named (2S)-7,4'-dimethoxyl-6-(2″,3″-epoxy-3″-methylbutyl)flavanone (1), along with five known compounds (2-6), were isolated from the EtOAc-soluble extract of the stem bark of Maackia amurensis. Their structures were elucidated on the basis of spectroscopic methods. All compounds were evaluated for anti-inflammatory and antioxidant activities in vitro. Among them, compound 5 showed the highest inhibitory activity on NO production in RAW264.7 cells stimulated by LPS with IC50 value of 59.0 ± 1.5 µM. Meanwhile, compounds 1-6 exhibited varying antioxidant activities through DPPH, ABTS free radical-scavenging and FRAP assays.

Calycosin and 8-O-methylretusin isolated from Maackia amurensis as potent and selective reversible inhibitors of human monoamine oxidase-B.

Nineteen compounds were isolated from the stems of Maackia amurensis by activity-guided screening for new human monoamine oxidase-B (hMAO-B) inhibitors. Among the compounds isolated, flavonoids calycosin (5) and 8-O-methylretusin (6) were found to potently and selectively inhibit hMAO-B (IC50 = 0.24 and 0.23 µM, respectively) but not hMAO-A with high selectivity index (SI) values (SI = 293.8 and 81.3, respectively). In addition, 5 and 6 reversibly and competitively inhibited hMAO-B with Ki values of 0.057 and 0.054 µM, respectively. A pterocarpan (-)-medicarpin (18) was also observed to strongly inhibit hMAO-B (IC50 = 0.30 µM). Most of the compounds weakly inhibited AChE, except isolupalbigenin (13) (IC50 = 20.6 µM), which suggested 13 be considered a potential dual function inhibitor of MAO-B and AChE. Molecular docking simulation revealed that the binding affinities of 5 and 6 for hMAO-B (both -9.3 kcal/mol) were higher than those for hMAO-A (-7.4 and -7.2 kcal/mol, respectively). Compound 5 was found to interact by hydrogen bonding with hMAO-B at Cys172 residue (distance: 3.250 Å); no hydrogen bonding was predicted between 5 and hMAO-A. These findings suggest that compounds 5 and 6 be considered novel potent, selective, and reversible hMAO-B inhibitors and candidates for the treatment of neurological disorders.

Inhibition of diacylglycerol acyltransferase by prenylated flavonoids isolated from the stem bark of Maackia amurensis.

A new prenylated flavanone, erythraddison Z (1), together with eight known flavonoids (2-9), was isolated from the stem bark of Maackia amurensis. Their structures were elucidated on the basis of spectroscopic methods, including 1D and 2D NMR (COSY, HMQC, and HMBC) techniques. All the isolates, with the exception of 3, 6 and 7, strongly inhibited diacylglycerol acyltransferase activity in an in vitro assay with IC50 values ranging from 96.5 ± 0.6 to 135.1 ± 1.4 µM.

[Hepatoprotective properties of isoflavonoids from roots of Maackia amurensis on experimental carbon tetrachloride-induced hepatic damage].

Hepatoprotective properties of ethanol extract from the roots of Maackia amurensis Ruper et Maxim have been studied on the model of toxic hepatitis induced by carbon tetrachloride damage. It is established that the extract contains daidzein, 7-O-gentobiosides of isoflavonoids genistein, formononetin, pseudobabtige-nin, and 5-O-methylgenistein, and 3-O-gentobiosides of pterocarpans (6aR, 11aR)-maakiain and (6aR, 11aR)-medicarpin. The administration of extract facilitates the restoration of antioxidant protection enzymes activity and reduced glutathione level, decreases the formation of toxic peroxidation products, produces normalizing impact on liver phospholipid pattern, and improves the erythrocyte tolerance to hemolytic agents. The action of isoflavonoids from Maackia amurensis in restoration of metabolic pathways of the liver and removal of toxic stress was more effective as compared to that of the reference hepatoprotector legalon.

Tectoridin from Maackia amurensis modulates both estrogen and thyroid receptors.

AIM: The stem bark of Maackia amurensis has been used as folk medicine for the treatment of cancer, cholecystitis, arthritis, and hyperthyroidism in females. In this study we examined the effects of the ethyl acetate fraction obtained from the 70% ethanol extract of M. amurensis and tectoridin, an active constituent isolated from the ethyl acetate fraction on thyroid and estrogen hormone activity. METHODS: The effect of the ethanolic extract of M. amurensis stem bark on thyroid hormone activity was evaluated using thyroid hormone responsive-luciferase assay. We isolated tectoridin from the ethyl acetate fraction using a recrystallization method. T-screen assays were used to confirm thyroid hormone activity. The estrogenic activity of the ethyl acetate fraction of M. amurensis and tectoridin was evaluated by estrogen responsive-luciferase assay and estrogen receptor alpha regulation as compared to 17ß-estradiol. RESULTS: Both the ethyl acetate fraction and tectoridin activated thyroid-responsive reporters and increased thyroid hormone-dependent proliferation of rat pituitary GH3 cells, indicating modulation of thyroid hormone receptors. In parallel, the estrogenic activity of the fraction and tectoridin were characterized in a transient transfection system using estrogen-responsive luciferase plasmids in MCF-7 cells. The ethyl acetate fraction and tectoridin activated reporter gene expression and decreased the estrogen receptor protein level. CONCLUSIONS: These data indicate that tectoridin acts as a weak phytoestrogen as well as a thyroid hormone-like agent by activating both estrogen and thyroid hormone receptors.

A new cytisine-type alkaloid from the stem bark of Maackia amurensis.

One new cytisine-type alkaloid, [(3-hydroxy-6-pyridinyl)-methyl]-cytisine (1), was isolated from the stem bark of Maackia amurensis, together with five known alkaloids: cytisine, N-formylcytisine, N-(3-oxobutyl)cytisine, (-)-epibaptifoline and N-methylcytisine. The structure of 1 was elucidated based on spectral methods (IR, CD, 1D and 2D NMR, HR-ESI-MS and EI-MS).

Tyrosinase inhibitory constituents from the stems of Maackia fauriei.

Bioassay-guided investigation of the stems of Maackia fauriei led to the isolation of seven flavonoid constituents, formononetin (1), genistein (2), daidzein (3), texasin (4), tectorigenin (5), odoratin (6) and mirkoin (7). Their structures were elucidated on the basis of spectral studies as well as by comparison with literature data. Tyrosinase inhibition activities were carried out on the isolated compounds. Among these, mirkoin (7) was identified as a potent tyrosinase inhibitor. It inhibited mushroom tyrosinase with an IC(50) value of 0.005 mm, which is ten times more active than kojic acid (IC(50) = 0.045 mm). The inhibition kinetics, analysed by Lineweaver-Burk plots, indicated mirkoin (7) to be a competitive inhibitor of tyrosinase when L-tyrosinase was used as a substrate. The results suggest that hydroxyl groups at C-4' in the B ring of flavonoids play an important role in the tyrosinase inhibition activities. Interestingly, compounds 4-7 were isolated for the first time from this plant.

Antithrombogenic and antiplatelet activities of extract from Maackia amyrensis wood.

Antithrombogenic and antiplatelet effects of a new drug, containing isoflavonoids (extract from the wood of Maackia amyrensis, a Far Eastern plant), were studied. A course (200 mg/kg intragastrically during 14 days) of Maackia amyrensis extract prevented intravascular clotting, initiated by application of 10% iron chloride solution on the vessel. The drug increased antiaggregant activity of the vascular wall and potentiated endothelium-dependent vasodilatation in ovariectomied rats. The reference drug ethinylestradiol (25 mug/kg intragastrically during 14 days) potentiated the antiaggregant effect of the endothelium, but was inferior to Maackia amyrensis extract in the capacity to induce endothelium-dependent vasodilatation in ovariectomied rats.

[Isoflavone glycosides from the bark of Maackia amurensis].

To study the chemical constituents of the Maackia amurensis, the constituents were isolated by various chromatographies and the structures were elucidated on the basis of chemical and spectroscopic data (ESI-MS, 1D and 2D NMR). Thirteen isoflavone glycosides were isolated from the n-BuOH-soluble fraction of the 70% ethanol extract and identified as 7-hydroxy-4',6-dimethoxyisoflavone-7-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (1), dalsympathetin (2), ononin (3), glycitin (4), genestin (5), saikoisoflavonoside A (6), afrormosin-7-O-beta-D-glucopyranoside (7), gehuain (8), kushenol O (9), 7-hydroxy-4',6-dimethoxyisoflavone-7-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside (10), tectoridin (11), biochanin A 7-O-beta-D-gentiobioside (12) and 7-hydroxy-4'-methoxyisoflavone-7-O-beta-D-apiofuranosy l-(1-->6)-beta-D-glucopyranoside (13). Compound 1 is a new isoflavone glycoside, named as maackiaisoflavonoside, compounds 2, 8, 9, 10, 12 and 13 were isolated from this genus for the first time.

Isoflavone glycosides from the bark of Maackia amurensis / 药学学报

To study the chemical constituents of the Maackia amurensis, the constituents were isolated by various chromatographies and the structures were elucidated on the basis of chemical and spectroscopic data (ESI-MS, 1D and 2D NMR). Thirteen isoflavone glycosides were isolated from the n-BuOH-soluble fraction of the 70% ethanol extract and identified as 7-hydroxy-4',6-dimethoxyisoflavone-7-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (1), dalsympathetin (2), ononin (3), glycitin (4), genestin (5), saikoisoflavonoside A (6), afrormosin-7-O-beta-D-glucopyranoside (7), gehuain (8), kushenol O (9), 7-hydroxy-4',6-dimethoxyisoflavone-7-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside (10), tectoridin (11), biochanin A 7-O-beta-D-gentiobioside (12) and 7-hydroxy-4'-methoxyisoflavone-7-O-beta-D-apiofuranosy l-(1-->6)-beta-D-glucopyranoside (13). Compound 1 is a new isoflavone glycoside, named as maackiaisoflavonoside, compounds 2, 8, 9, 10, 12 and 13 were isolated from this genus for the first time.

[Effects of Maackia amurensis extract on the lipid spectrum and lipid peroxidation in erythrocyte membranes of ovariectomized rats].

Ovariectomy in rats induces the activation of lipid peroxidation processes, reduces total lipid content, and decreases the accumulation of lysophospholipids in erythrocyte membranes. The administration of Maackia amurensis extract (200 mg/kg, p.o., during 14 days) reduces the level of lipid peroxidation, prevents a decrease in the total lipid content, normalizes the proportion of lipids and proteins, and eliminates the accumulation of lysophospholipids in erythrocyte membranes in ovariectomized rats.

[Hepatoprotector properties of polyphenolic complexes from wood and cell culture of Maackia amurensis].

Polyphenolic complexes (PPCs) extracted from core wood and cell culture of Maackia amurensis decrease the acute toxicity of tetrachloromethane, suppress the necrosis of hepatocytes and the cellular infiltration in liver parenchyma, prevent the development of fatty and protein dystrophy in the liver, normalize the activity of aminotransferases and gamma-glutamyltransferase in the blood, restore the protein and lipid content, and stimulate the conjugation of bilirubin. The therapeutic effect was more pronounced for the PPC obtained from the cell culture. The hepatoprotector effect of the PPCs is due to the presence of isoflavonoids, including daidzein, retusin, genistein, afromosin, formononetin, orobol, tektorigenin, maakiain, and medicarpin. Ther PPC from the cell culture of Maackia amurensis does not affect the blood cholesterol level, which is probably explained by the absence of mono- and dimeric stilbenes in this cell culture.

[Callus formation and its isoflavonoid accumulation in Maackia amurensis].

OBJECTIVE: To obtain Maackia amurensis callus and investigate some factors influencing total isoflavonoid production in callus. METHOD: Different media were used for callus induction from cotyledonary and hypocotyl explants. Total isoflavonoid content was determined by UV spectrophotometer. RESULT: Medium types and hormone combinations influenced both callus formation and their developmental states. MS medium supplemented with NAA/BA or containing 2,4-D was suitable for callus induction from cotyledonary explants. Among the basal media tested, MS, N6 and B5 were suitable for cotyledonary callus formation and SH for hypocotyl callus formation. The formed callus could synthesize isoflavones. Media containing NAA were suitable for isoflavonoid production in cotyledonary callus and media containing 2,4-D/BA were suitable for hypocotyl callus, but 2,4-D/KT at high concentration inhibited the isoflavonoid accumulation in hypocotyl and coytledonary calli. According to the developmentally morphological characters, the formed callus could be classified into four types. II-type callus with yellow in color and friability in texture showed the highest accumulation of isoflavones. CONCLUSION: The influences of medium type and hormone combinations on Maackia amurensis callus formation are reflected in both developmentally morphological characters and isoflavonoid accumulation of calli. Yellow, friable callus induced from cotyledonary and hypocotyl explants in MS or N6 medium supplemented with 2,4-D and BA exhibit the optimum growth and isoflavonoid production.

[Preclinical study of maxar safety]. / Doklinicheskoe izuchenie bezopasnosti maksara.

The results of preclinical safety evaluation of the new hepatoprotector maxar showed that this drug can be classified as a low-toxicity substance with respect to acute toxicity. No significant functional and structural changes in the systems and organs of experimental animals were observed after a 6-month administration in rats (in a dose of 300, 600, and 1200 mg/kg) and in dogs (500 mg/kg). Maxar exhibited no mutagen and allergen properties, produced no immunotoxicant action, and did not adversely affect the reproduction function.

Callus formation and its isoflavonoid accumulation in Maackia amurensis / 中国中药杂志

<p><b>OBJECTIVE</b>To obtain Maackia amurensis callus and investigate some factors influencing total isoflavonoid production in callus.</p><p><b>METHOD</b>Different media were used for callus induction from cotyledonary and hypocotyl explants. Total isoflavonoid content was determined by UV spectrophotometer.</p><p><b>RESULT</b>Medium types and hormone combinations influenced both callus formation and their developmental states. MS medium supplemented with NAA/BA or containing 2,4-D was suitable for callus induction from cotyledonary explants. Among the basal media tested, MS, N6 and B5 were suitable for cotyledonary callus formation and SH for hypocotyl callus formation. The formed callus could synthesize isoflavones. Media containing NAA were suitable for isoflavonoid production in cotyledonary callus and media containing 2,4-D/BA were suitable for hypocotyl callus, but 2,4-D/KT at high concentration inhibited the isoflavonoid accumulation in hypocotyl and coytledonary calli. According to the developmentally morphological characters, the formed callus could be classified into four types. II-type callus with yellow in color and friability in texture showed the highest accumulation of isoflavones.</p><p><b>CONCLUSION</b>The influences of medium type and hormone combinations on Maackia amurensis callus formation are reflected in both developmentally morphological characters and isoflavonoid accumulation of calli. Yellow, friable callus induced from cotyledonary and hypocotyl explants in MS or N6 medium supplemented with 2,4-D and BA exhibit the optimum growth and isoflavonoid production.</p>

[Studies on chemical constituents of Maackia amurensis Rupr. et. Maxim].

OBJECTIVE: To study the chemical constituents of EtOH extract from heartwood of Maackia amurensis. METHOD: Silica gel column chromatography and Sephadex LH-20 were employed to separate, and the compounds obtainedere elucidated by means of UV, IR, MS, 1H NMR, 13C NMR. RESULT: 4', 8-dihydroxyl-7-methoxylisoflavone (I), tectorigenin(II), glycitein(III) and resveratrol (IV) were isolated and identified. CONCLUSION: Among them, Compound I was a new isoflavone and compound III was obtained from M. amurensis for the first time.