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Isoflavones are a class of natural products that exhibit a wide range of interesting biological properties, including antioxidant, hepatoprotective, antimicrobial, and anti-inflammatory activities. Scandenone ( 1 ), osajin ( 2 ), and 6,8-diprenylgenistein ( 3 ) are natural prenylated isoflavones that share the same polyphenol framework. In this research, the key intermediate 15 was used for the synthesis of the natural isoflavones 1 - 3 , establishing a stereoselective synthetic method for both linear and angular pyran isoflavones. The antibacterial activities of 1 - 3 were also evaluated, and all of them displayed good antibacterial activity against Gram-positive bacteria. Among them, 2 was the most potent one against MRSA, with a MIC value of 2 μg/mL, and the SEM assay indicated that the bacterial cell membranes of both MRSA and E. faecalis could be disrupted by 2 . These findings suggest that this type of isoflavone could serve as a lead for the development of novel antibacterial agents for the treatment of Gram-positive bacterial infections.

Objectives: Hypoxia is a common pathological phenomenon, usually caused by insufficient oxygen supply or inability to use oxygen effectively. Hydroxylated and methoxylated flavonoids have significant anti-hypoxia activity. This study aims to explore the synthesis, antioxidant and anti-hypoxia activities of 6-hydroxygenistein (6-OHG) and its methoxylated derivatives., Methods: The 6-OHG and its methoxylated derivatives, including 4',6,7-trimethoxy-5-hydroxyisoflavone (compound 3), 4',5,6,7-tetramethoxyisoflavone (compound 4), 4',6-imethoxy-5,7-dihydroxyisoflavone (compound 6), and 4'-methoxy-5,6,7-trihydroxyisoflavone (compound 7), were synthesized by methylation, bromination, methoxylation, and demethylation using biochanin A as raw material. The structure of these products were characterized by 1 hydrogen-nuclear magnetic resonance spectroscopy ( 1 H-NMR) and mass spectrometry (MS). The purity of these compounds was detected by high pressure chromatography (HPLC). The antioxidant activity in vitro was investigated by 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) free radical scavenging assay. PC12 cells were divided into a normal group, a hypoxia model group, rutin (1×10 -9 -1×10 -5 mol/L) groups, and target compounds (1×10 -9 -1×10 -5 mol/L) groups under normal and hypoxic conditions. Cell viability was detected by cell counting kit-8 (CCK-8) assay, the target compounds with excellent anti-hypoxia activity and the drug concentration at the maximum anti-hypoxia activity were screened. PC12 cells were treated with the optimal concentration of the target compound or rutin with excellent anti-hypoxia activity, and the cell morphology was observed under light microscope. The apoptotic rate was determined by flow cytometry, and the expressions of hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) were detected by Western blotting., Results: The structure of 6-OHG and its 4 methylated derivatives were correct, and the purity was all more than 97%. When the concentration was 4 mmol/L, the DPPH free radical removal rates of chemical compounds 7 and 6-OHG were 81.16% and 86.94%, respectively, which were higher than those of rutin, the positive control. The removal rates of chemical compounds 3, 4, and 6 were all lower than 20%. Compared with the normal group, the cell viability of the hypoxia model group was significantly decreased ( P <0.01). Compared with the hypoxia model group, compounds 3, 4, and 6 had no significant effect on cell viability under hypoxic conditions. At all experimental concentrations, the cell viability of the 6-OHG group was significantly higher than that of the hypoxia model group (all P <0.05). The cell viability of compound 7 group at 1×10 -7 and 1×10 -6 mol/L was significantly higher than that of the hypoxia model group (both P <0.05). The anti-hypoxia activity of 6-OHG and compound 7 was excellent, and the optimal drug concentration was 1×10 -6 and 1×10 -7 mol/L. After PC12 cells was treated with 6-OHG (1×10 -6 mol/L) and compound 7 (1×10 -7 mol/L), the cell damage was reduced, the apoptotic rate was significantly decreased ( P <0.01), and the protein expression levels of HIF-1α and VEGF were significantly decreased in comparison with the hypoxia model group (both P <0.01)., Conclusions: The optimized synthesis route can increase the yield of 6-OHG and obtain 4 derivatives by methylation and selective demethylation. 6-OHG and compound 7 have excellent antioxidant and anti-hypoxia activities, which are related to the structure of the A-ring ortho-triphenol hydroxyl group in the molecule.

This study aims to design and synthesize a series of novel formononetin (FMN) derivatives and explore their protective effects on oxygen glucose deprivation/relapse (OGD/R) damage to H9C2 cells, along with their molecular regulatory mechanisms. The OGD/R model was established to simulate myocardial ischemia-reperfusion injury. The protective effects of these novel compounds on H9C2 cells were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method, while the apoptosis rate, myocardial enzyme activity, and autophagy reaction post-compound treatment were assessed using kit-based methods. The formation of autophagosomes in H9C2 cells was observed via transmission electron microscopy, and the expression levels of autophagy-related proteins phosphatidylinositol 3-kinase (PI3K), Akt, Beclin-1, and P62 were determined using Western blotting. The experimental findings demonstrated that compounds 1-6 (C1-6) exhibited varying degrees of protective effects on damaged H9C2 cells, generally outperforming the parent compound FMN. Among these compounds, C4 demonstrated the most significant activity, even surpassing the positive control drug diltiazem. Further mechanistic investigations revealed that C4 could mitigate apoptosis rates, reduce the activity of myocardial enzyme (such as aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and CK), diminish the number of autophagic vesicles, and restore excessive autophagy. Additionally, C4 exerted its protective effects by downregulating the expression of autophagic proteins PI3K, Akt, Beclin-1, P62, LC3 and ATG12. These results indicated that C4 regulates autophagy through the PI3K/Akt/Beclin-1 signaling pathway, thereby exerting a protective effect on cardiomyocytes. Therefore, C4 emerges as a potential myocardial protective drug, offering a new research direction and strategy for the treatment of myocardial ischemia-reperfusion injury.

The side effects of kwao keur dietary supplements (obtained from the tuberous root of Pueraria mirifica) have recently been reported by the Ministry of Health, Labour and Welfare, Japan. To control the quality of kwao keur products, its ingredients need to be maintained by characteristic marker compounds, such as miroestrol, deoxymiroestrol, and kwakhurin (KWA). In this study, we described the facile synthesis of KWA, a marker compound of P. mirifica. Our revised synthetic method produced KWA with shorter steps and higher yield than the reported method. Furthermore, the absolute purity of KWA was determined by quantitative NMR analysis for standardization as a reagent, and its purity was 92.62 ± 0.12%.

In order to meet the increasing demand for environmentally benign chemical processes, we developed a Suzuki-Miyaura reaction protocol based on the combination of ohmic heating (ΩH) and supported ionic liquid phase catalysis (SILPC) in aqueous media. This methodology was applied to the synthesis of a series of flavonoid derivatives, including isoflavones, styrylisoflavones, and diarylalkenylisoflavones.

Daidzein is a common isoflavone, having multiple biological effects such as anti-inflammation, anti-allergy, and anti-aging. α-Tocopherol is the tocopherol isoform with the highest vitamin E activity including anti-allergic activity and anti-cancer activity. Hesperetin is a flavone, which shows potent anti-inflammatory effects. These compounds have shortcomings, i.e., water-insolubility and poor absorption after oral administration. The glycosylation of bioactive compounds can enhance their water-solubility, physicochemical stability, intestinal absorption, and biological half-life, and improve their bio- and pharmacological properties. They were transformed by cultured Nicotiana tabacum cells to 7-β-glucoside and 7-β-gentiobioside of daidzein, and 3'- and 7-β-glucosides, 3',7-β-diglucoside, and 7-β-gentiobioside of hesperetin. Daidzein and α-tocopherol were glycosylated by galactosylation with β-glucosidase to give 4'- and 7-β-galactosides of daidzein, which were new compounds, and α-tocopherol 6-β-galactoside. These nine glycosides showed higher anti-allergic activity, i.e., inhibitory activity toward histamine release from rat peritoneal mast cells, than their respective aglycones. In addition, these glycosides showed higher tyrosinase inhibitory activity than the corresponding aglycones. Glycosylation of daidzein, α-tocopherol, and hesperetin greatly improved their biological activities.

Neovascular eye diseases are a major cause of blindness. Excessive angiogenesis is a feature of several conditions, including wet age-related macular degeneration, proliferative diabetic retinopathy, and retinopathy of prematurity. Development of novel antiangiogenic small molecules for the treatment of neovascular eye disease is essential to provide new therapeutic leads for these diseases. We have previously reported the therapeutic potential of anti-angiogenic homoisoflavanone derivatives with efficacy in retinal and choroidal neovascularization models, although these are racemic compounds due to the C3-stereogenic center in the molecules. This work presents asymmetric synthesis and structural determination of anti-angiogenic homoisoflavanones and pharmacological characterization of the stereoisomers. We describe an enantioselective synthesis of homoisoflavanones by virtue of ruthenium-catalyzed asymmetric transfer hydrogenation accompanying dynamic kinetic resolution, providing a basis for the further development of these compounds into novel experimental therapeutics for neovascular eye diseases.

BACE-1 is considered to be one of the targets for prevention and treatment of Alzheimer's disease (AD). We here report a novel class of semi-synthetic derivatives of prenylated isoflavones, obtained from the derivatization of natural flavonoids from Maclura pomifera. In vitro anti-AD effect of the synthesized compounds were evaluated via human recombinant BACE-1 inhibition assay. Compound 7, 8 and 13 were found to be the most active candidates which demonstrates good correlation between the computational docking and pharmacokinetic predictions. Moreover, cytotoxic studies demonstrated that the compounds are not toxic against normal and cancer cell lines. Among these three compounds, compound 7 enhance the activity of P-glycoprotein (P-gp) on A549 cancer cells and increases the activity of P-gp ATPase with a possible role on the efflux of amyloid-β across the blood- brain barrier. In conclusion, the present findings may pave the way for the discovery of a novel class of compounds to prevent and/or treat AD., (Copyright © 2019 Elsevier Inc. All rights reserved.)

In this study, three hybrids of podophyllotoxin and formononetin were synthesized and evaluated for anticancer efficacy. Some of the derivatives exhibited potent cytotoxicity against a panel of human and mouse cancer cell lines, with IC 50 values in the low micromolar to submicromolar range. Evaluation against A549 lung tumor cell line identified that the IC 50 value of compound 10a was 0.753 μM, indicating that 10a was 2.568-fold more efficacious than parent podophyllotoxin. Mechanistic studies revealed that 10a induced A549 cell apoptosis mainly via caspase pathway, as well as disrupted the microtubule organization by occupying the colchicine binding site of the tubulin. Moreover, wound healing assay and transwell invasion assay indicated that 10a displayed potent inhibitory effects on invasion and migration in A549 cancer cells. In additiona, a decrease in vimentin immunostaining was also observed in A549 cells after treatment with 10a. Overall, hybrid 10a might be a promising candidate for the potential treatment of human lung carcinoma., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Histamine H 3 receptor (H 3 R), a kind of G-protein coupled receptor (GPCR), is expressed mainly in the central nervous system (CNS) and plays a vital role in homoeostatic control. This study describes the design and synthesis of a series of novel H 3 R antagonists based on the iso-flavone scaffold. The results of the bioactivity evaluation show that four compounds (1c, 2c, 2h, and 2o) possess significant H 3 R inhibitory activities. Molecular docking indicates that a salt bridge, π-π T-shape interactions, and hydrophobic interaction all contribute to the interaction between compound 2h and H 3 R.

A novel β -glucosidase gene ( Bgl3B ) of glycoside hydrolase (GH) family 3 was cloned from the thermophilic fungus Talaromyce leycettanus JM12802 and successfully expressed in Pichia pastoris . The deduced Bgl3B contains 860 amino acid residues with a calculated molecular mass of 91.2 kDa. The purified recombinant Bgl3B exhibited maximum activities at pH 4.5 and 65°C and remained stable at temperatures up to 60°C and pH 3.0-9.0, respectively. The enzyme exhibited broad substrate specificities, showing β -glucosidase, glucanase, cellobiase, xylanase, and isoflavone glycoside hydrolase activities, and its activities were stimulated by short-chain alcohols. The catalytic efficiencies of Bgl3B were 693 and 104/mM/s towards p NPG and cellobiose, respectively. Moreover, Bgl3B was highly effective in converting isoflavone glycosides to aglycones at 37°C within 10 min, with the hydrolysis rates of 95.1%, 76.0%, and 75.3% for daidzin, genistin, and glycitin, respectively. These superior properties make Bgl3B potential for applications in the food, animal feed, and biofuel industries.

AChE and BuChE are druggable targets for the discovery of anti-Alzheimer's disease drugs, while dual-inhibition of these two targets seems to be more effective. In this study, we synthesised a series of novel isoflavone derivatives based on our hit compound G from in silico high-throughput screening and then tested their activities by in vitro AChE and BuChE bioassays. Most of the isoflavone derivatives displayed moderate inhibition against both AChE and BuChE. Among them, compound 16 was identified as a potent AChE/BuChE dual-targeted inhibitor (IC 50 : 4.60 μM for AChE; 5.92 μM for BuChE). Molecular modelling study indicated compound 16 may possess better pharmacokinetic properties, e.g. absorption, blood-brain barrier penetration and CYP2D6 binding. Taken together, our study has identified compound 16 as an excellent lead compound for the treatment of Alzheimer's disease.

Crotadihydrofuran C (CC) from the herbs of Crotalaria albida is able to inhibit adipocyte differentiation and lipid accumulation. However, the effects of CC on obesity and metabolic disorders have not yet been elucidated. In our study, the first enantioselective synthesis of the 2-isopropenyl dihydrofuran isoflavone skeleton (CC) is described. The convenient and efficient synthetic protocols developed skilfully solve the problems of the ortho-para directing group and Suzuki coupling reaction using a boronic acid pinacol ester that was more stable and easy to obtain. Furthermore, CC treatment of high-fat diet (HFD)-fed obese mice remarkably reduced their body weight, fat mass, and lipid level as well as improved insulin resistance and non-alcoholic fatty liver disease (NAFLD). A TR-FRET assay showed that CC was specifically bound to PPARγ LBD, which was further confirmed by the molecular docking study. These results suggest that CC could be a useful and potential natural product for treating metabolic diseases, including obesity, hyperlipidemia insulin resistance and NAFLD, without toxic side-effects.

Naturally occurring homoisoflavonoids containing either 5,7-dihydroxy-6-methoxy or 7-hydroxy-5,6-dimethoxy groups such as the antiangiogenic homoisoflavanone, cremastranone, were synthesized via three or four linear steps from the known 4-chromenone. This facile synthesis includes chemoselective 1,4-reduction of 4-chromenone and selective deprotection of 3-benzylidene-4-chromanone a containing C7-benzyloxy group.

Nonresolving inflammation is one of the consistent features of the tumor microenvironment in the intestine and plays a critical role in the initiation and development of colon cancer. Here we reported the inhibitory effects of GEN-27, a new derivative of genistein, on the inflammation-related colon cancer cell proliferation and delineated the mechanism of its action. The results indicated that GEN-27 inhibited the proliferation of human colon tumor HCT116 cells stimulated by culture supernatants of LPS-induced human monocytes THP-1 cells and significantly decreased LPS-induced secretion of proinflammatory cytokines interleukin-6 and interleukin-1β in THP-1 cells. The HCT116 cell proliferation elicited by THP-1-conditioned medium could be blocked by the interleukin-1 receptor antagonist (IL-1RA). Further mechanistic study revealed that GEN-27 remarkably inhibited the nuclear translocation of NF-κB and phosphorylation of IκB and IKKα/β in both HCT116 and THP-1 cells. In addition, GEN-27 markedly suppressed the HCT116 cell proliferation stimulated by IL-1β treatment, which was dependent on the inhibition of NF-κB/p65 nuclear localization, as verified by p65 overexpression and BAY 11-7082, an NF-κB inhibitor. Taken together, our findings established that GEN-27 modulated NF-κB signaling pathway involved in inflammation-induced cancer cells proliferation and therefore could be a potential chemopreventive agent against inflammation-associated colon cancer.

When cerebral ischemia-reperfusion injury happened in patients, multiple pathological processes occur, such as leukocyte infiltration, platelet, and complement activation, which would result in cognitive dysfunction and inflammation. Puerarin has shown protective effect on injury of neural cell. In order to enhance this protective effect of puerarin, puerarin derivatives with different log⁡ P values were designed and synthesized. The original phenolic hydroxyl in the puerarin molecules was substituted in order to change the blood-brain barrier permeability and thus enhance the efficacy for preventing cerebral ischemia/reperfusion injury. And the structure of the newly synthesized molecules was confirmed by 1H NMR spectroscopy and mass spectrometry. The mouse model of cerebral artery ischemia/reperfusion injury was established to test the anticerebral ischemia-reperfusion injury activity of the puerarin derivatives. The assays of the water maze, Y maze, brain cortex Ca 2+ -Mg 2+ -ATP enzyme, and iNOS enzyme activity were performed in this mouse model. The results showed that puerarin derivative P1-EA and P2-EA were resulting in an increased lipophilicity that enabled the derivatives to pass more efficiently through the blood-brain barrier, thus, improving the protective effects against cerebral ischemia/reperfusion injury. Therefore, derivatives of puerarin may serve as promising approach to improve neuron function in ischemia-reperfusion brain injury-related disorders.

A series of 3-benzylidene-4-chromanone derivatives (3-20) were synthesized and the structure-activity relationships for antioxidant and α-glucosidase inhibitory activities were evaluated. Among synthesized compounds, compounds 5, 13, 18, which contain catechol moiety, showed the potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity (5: EC50 13 µM; 13: EC50 14 µM; 18: EC50 13 µM). The compounds 12, 14, 18 showed higher α-glucosidase inhibitory activity (12: IC50 15 µM; 14: IC50 25 µM; 18: IC50 28 µM). The compound 18 showed both of potent DPPH radical scavenging and α-glucosidase inhibitory activities. These data suggest that 3-benzylidene-4-chromanone derivatives, such as compound 18, may serve as the lead compound for the development of novel α-glucosidase inhibitors with antioxidant activity.

A set of novel isoflavone derivatives from chickpea were synthesized. The structures of derivatives were identified by proton nuclear magnetic resonance (¹H-NMR), carbon-13 ((13)C)-NMR and mass spectrometry (MS) spectral analyses. Their anti-diabetic activities were evaluated using an insulin-resistant (IR) HepG2 cell model. Additionally, the structure-activity relationships of these derivatives were briefly discussed. Compounds 1c, 2h, 3b, and 5 and genistein exhibited significant glucose consumption-enhancing effects in IR-HepG2 cells. In addition, the combinations of genistein, 2h, and 3b (combination 6) and of 3b, genistein, and 1c (combination 10) exhibited better anti-diabetic activity than the individual compounds. At the same dosage, there was no difference in effect between the combination 10 and the positive control (p > 0.05). Aditionally, we found the differences between the combination 10 and combination 6 for the protective effect of HUVEC (human umbilical vein endothelial cells) under high glucose concentration. The protective effects of combination 10 was stronger than combination 6, which suggested that combination 10 may have a better hypoglycemic activity in future studies. This study provides useful clues for the further design and discovery of anti-diabetic agents.

Background: Homoisoflavonoids are naturally occurring compounds belong to flavonoid classes possessing various biological properties such as cytotoxicity. In this work, an efficient strategy for the synthesis of novel homoisoflavonoids, [1,3]dioxolo[4,5-g]chromen-8-ones, was developed and all compounds were evaluated for their cytotoxic activities on three breast cancer cell lines., Methods: Our synthetic route started from benzo[d][1,3]dioxol-5-ol which was reacted with 3-bromopropanoic acid followed by the reaction of oxalyl chloride to afford 6,7-dihydro-8H-[1,3]dioxolo[4,5-g]chromen-8-one. The aldol condensation of the later compound with aromatic aldehydes led to the formation of the title compounds. Five novel derivatives 4a-e were tested for their cytotoxic activity against three human breast cancer cell lines including MCF-7, T47D, and MDA-MB-231 using the MTT assay., Results: Among the synthesized compounds, 7-benzylidene-6,7-dihydro-8H-[1,3]dioxolo[4,5-g]chromen-8-one (4a) exhibited the highest activity against three cell lines. Also the analysis of acridine orange/ethidium bromide staining results revealed that 7-benzylidene-6,7-dihydro-8H-[1,3]dioxolo[4,5-g]chromen-8-one (4a) and 7-(2-methoxybenzylidene)-6,7-dihydro-8H-[1,3]dioxolo[4,5-g]chromen-8-one (4b) induced apoptosis in T47D cell line., Conclusion: Finally, the effect of methoxy group on the cytotoxicity of compounds 4b-4d was investigated in and it was revealed that it did not improve the activity of [1,3]dioxolo[4,5-g]chromen-8-ones against MCF-7, T47D, and MDA-MB-231.

Preventing pathological ocular angiogenesis is key to treating retinopathy of prematurity, diabetic retinopathy and age-related macular degeneration. At present there is no small molecule drug on the market to target this process and hence there is a pressing need for developing novel small molecules that can replace or complement the present surgical and biologic therapies for these neovascular eye diseases. Previously, an antiangiogenic homoisoflavanone was isolated from the bulb of a medicinal orchid, Cremastra appendiculata. In this study, we present the synthesis of a novel homoisoflavanone isomer of this compound. Our compound, SH-11052, has antiproliferative activity against human umbilical vein endothelial cells, and also against more ocular disease-relevant human retinal microvascular endothelial cells (HRECs). Tube formation and cell cycle progression of HRECs were inhibited by SH-11052, but the compound did not induce apoptosis at effective concentrations. SH-11052 also decreased TNF-α induced p38 MAPK phosphorylation in these cells. Intriguingly, SH-11052 blocked TNF-α induced IκB-α degradation, and therefore decreased NF-κB nuclear translocation. It decreased the expression of NF-κB target genes and the pro-angiogenic or pro-inflammatory markers VCAM-1, CCL2, IL8, and PTGS2. In addition SH-11052 inhibited VEGF induced activation of Akt but not VEGF receptor autophosphorylation. Based on these results we propose that SH-11052 inhibits inflammation induced angiogenesis by blocking both TNF-α and VEGF mediated pathways, two major pathways involved in pathological angiogenesis. Synthesis of this novel homoisoflavanone opens the door to structure-activity relationship studies of this class of compound and further evaluation of its mechanism and potential to complement existing antiangiogenic drugs.

Background and the Purpose of the Study: There has been increscent interest in the field of cancer chemotherapy by discovery and development of novel agents with high efficacy, low toxicity, and minimum side effects. In order to find new anticancer agents, we replaced the pyrazolone part of well-known cytotoxic agent SJ-172550 with 7-methoxychroman-4-one. Thus, a novel series of 3-benzylidene-4-chromanones were synthesized and tested in vitro against human cancer cell lines., Methods: The title compounds were prepared by condensation of 7-methoxychroman-4-one with suitable aldehydes in appropriate alcohol in the presence of gaseous HCl. The antiproliferative activity of target compounds were evaluated against MDA-MB-231 (breast cancer), KB (nasopharyngeal epidermoid carcinoma) and SK-N-MC (human neuroblastoma) cell lines using MTT assay., Results: Although the direct analog of SJ-172550 (compound 5d) did not show any cytotoxic activity against tested cell lines, but 2-(2-chloro-6-methoxyphenoxy)acetic acid methyl ester analog 5c showed some activity against MDA-MB-231 and SK-N-MC cells. Further modification of compound 5c resulted in the 3-chloro-4,5-dimethoxybenzylidene derivative 5b which demonstrated better cytotoxic profile against all tested cell lines (IC50 values = 7.56-25.04 μg/ml)., Conclusion: The results demonstrated that the cytotoxic activity of compound 5b against MDA-MB-231 and SK-N-MC cells is more than etoposide. Therefore, compound 5b prototype could be considered as novel cytotoxic agent for further developing new anticancer chemotherapeutics.

Background: Increased consumption of plant-based diets has been linked to the presence of certain phytochemicals, including polyphenols such as flavonoids. Several of these compounds exert their protective effect via inhibition of tumor angiogenesis. Identification of additional phytochemicals with potential antiangiogenic activity is important not only for understanding the mechanism of the preventive effect, but also for developing novel therapeutic interventions., Results: In an attempt to identify phytochemicals contributing to the well-documented preventive effect of plant-based diets on cancer incidence and mortality, we have screened a set of hitherto untested phytoestrogen metabolites concerning their anti-angiogenic effect, using endothelial cell proliferation as an end point. Here, we show that a novel phytoestrogen, 6-methoxyequol (6-ME), inhibited VEGF-induced proliferation of human umbilical vein endothelial cells (HUVE) cells, whereas VEGF-induced migration and survival of HUVE cells remained unaffected. In addition, 6-ME inhibited FGF-2-induced proliferation of bovine brain capillary endothelial (BBCE) cells. In line with its role in cell proliferation, 6-ME inhibited VEGF-induced phosphorylation of ERK1/2 MAPK, the key cascade responsible for VEGF-induced proliferation of endothelial cells. In this context, 6-ME inhibited in a dose dependent manner the phosphorylation of MEK1/2, the only known upstream activator of ERK1/2. 6-ME did not alter VEGF-induced phosphorylation of p38 MAPK or AKT, compatible with the lack of effect on VEGF-induced migration and survival of endothelial cells. Peri-tumor injection of 6-ME in A-431 xenograft tumors resulted in reduced tumor growth with suppressed neovasularization compared to vehicle controls (P < 0.01)., Conclusions: 6-ME inhibits VEGF- and FGF2-induced proliferation of ECs by targeting the phosphorylation of MEK1/2 and it downstream substrate ERK1/2, both key components of the mitogenic MAPK pathway. Injection of 6-ME in mouse A-431 xenograft tumors results to tumors with decreased neovascularization and reduced tumor volume suggesting that 6-ME may be developed to a novel anti-angiogenic agent in cancer treatment.

We report a novel molecular dyad as an antioxidant, retinylisoflavonoid, with a retinal analogue C(22)-aldehyde and the isoflavonoid daidzein covalently linked. Its physicochemical properties, pK(a) (pK(a1) = 8.45, pK(a2) = 11.42), oxidation potential (1.03 V vs NHE), and Log(10) partition (Log P = 1.96), as well as the Trolox equivalent antioxidant capacity (TEAC = 0.4), have been characterized. Spectroscopic and quantum chemical investigations have revealed the following unique structural characters: (i) Either free in solution or included in liposomal membranes, the C(22)-aldehyde moiety of retinylisoflavonoid is coplanar with the B-ring of daidzein owing to the strong intramolecular hydrogen bonding C(14')=O···HO-B4'. Accordingly, the C(22)-aldehyde moiety extends its π-conjugation significantly to the B-ring. (ii) The inherent amphiphilicity of retinylisoflavonoid allows the C(22)-aldehyde moiety embedded in the lipid phase of the liposomes, whereas the daidzein counterpart stays at the membrane surface, in effect facilitating interior-to-surface radical communication. As the result, the antilipooxidation activity of retinylisoflavonoid is improved significantly in protecting membrane lipids compared to the parent compounds alone or in combination, and importantly, the performance is more prominent under higher-level oxidative stress. This work provides an advanced case study of new antioxidant development based on optimized electronic and molecular structures.

The production of beta-maltooligosaccharides of glycitein and daidzein using Lactobacillus delbrueckii and cyclodextrin glucanotransferase (CGTase) as biocatalysts was investigated. The cells of L. delbrueckii glucosylated glycitein and daidzein to give their corresponding 4'- and 7-O-beta-glucosides. The beta-glucosides of glycitein and daidzein were converted into the corresponding beta-maltooligosides by CGTase. The 7-O-beta-glucosides of glycitein and daidzein and 7-O-beta-maltoside of glycitein showed inhibitory effects on IgE antibody production. On the other hand, beta-glucosides of glycitein and daidzein exerted 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging activity and supeoxide-radical scavenging activity.

One new homoisoflavonoid, (3E)-2,3-dihydro-6,7-dimethoxy-3[(3-hydroxy-4-methoxyphenyl)methylene]-4H-1-benzopyran-4-one and four naturally new analogues, (3E)-3-(1,3-benzodioxol-5-ylmethylene)-2,3-dihydro-7-hydroxy-4H-1-benzopyran-4-one, (3E)-3-(1,3-benzodioxol-5-ylmethylene)-2,3-dihydro-7-methoxy-4H-1-benzopyran-4-one, (3E)-2,3-dihydro-7-hydroxy-3-[(3-hydroxy-4-methoxyphenyl)methylene]-4H-1-benzopyran-4-one and (3E)-2,3-dihydro-3-[(3,4-dimethoxyphenyl)methylene]-7-methoxy-4H-1-benzopyran-4-one, along with four known homoisoflavonoids, bonducellin, sappanone A, 2'-methoxybonducellin and 7-O-methylbonducellin were isolated from aerial parts of Caesalpinia pulcherrima. The structures of the new compounds were elucidated by interpretation of their 1D and 2D NMR spectra. Syntheses of the naturally new compounds and the known compounds have also been accomplished. The antibacterial and antifungal activities of the isolated homoisoflavonoids were studied.

Forty-eight kinds of isoflavones (8), thirty-one isoflavanes (9), and forty-seven biphenyl-ketones (10, 10') were synthesized from eleven kinds of substituted phenols (11) and six phenylacetic acids (12). Among them, seventy-five compounds are new. The radical scavenging activities of these compounds were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) at pH 6.0. We found that thirty-nine out of forty-three compounds having a catechol moiety on either the A- or the B-ring exhibited a high activity (ED(50)=12-54 microM) similar to that of catechin. In these cases, the remaining part of their structure seemed to have little effect on their activity. Many 6- or 8-hydroxyisoflavanes (9E-I) and their biphenyl-ketone derivatives (10E-H) also showed a high activity (ED(50)=or<50 microM), while all of their corresponding isoflavones (8E-I) were not active at all. The 7-hydroxyisoflavanes having either an additional hydroxyl group at the C5-position (9D) or a methoxy group at the C6-position (9J) presented a high activity (ED(50)=26-32 microM). This study suggests that natural isoflavones have the possibilities of exhibiting antioxidant activities through the hydroxylation at the C6-, C8-, or C3'-position or the formation of the isoflavanes (9) and/or the biphenyl-ketone derivatives (10') by metabolism or biotransformation.

Recently, we reported that the natural product derrubone exhibits Hsp90 inhibitory activity. Due to its unique architectural scaffold and proposed rapid assembly, the synthesis of this natural product was pursued with the aim of identifying structure--activity relationships. Synthesis of the natural product was accomplished in eight highly convergent steps, which led to a facile method for the construction of related compounds. Biological evaluation of derrubone and its analogues identified several compounds that exhibit low micromolar inhibitory activity against breast and colon cancer cell lines.

A facile five-step synthesis of naturally occurring 1,3,7-trihydroxyxanthone has been described starting from 1,3,5-trimethoxybenzene via NBS-induced nuclear bromination, lithiation followed by an in situ benzoylation with methyl 2,5-dibenzyloxybenzoate, selective deprotection of the two benzyl groups, base-catalyzed intramolecular cyclization, and demethylations pathway with 62% overall yield. The regioselective coupling reactions of 1,3,7-trihydroxyxanthone with prenal in the presence of calcium hydroxide at room temperature and under thermal conditions at 140-150 degrees C have been demonstrated to exclusively obtain the natural products osajaxanthone in 75% yield and nigrolineaxanthone F in 98% yield, respectively.

Biotransformation of the 5,7,4'-trimethoxyisoflavone (1), 6,7,4'-trimethoxyisoflavone (2), and 7,4'-dimethoxyisoflavone (3) by insects, Spodoptera litura was investigated. Compound 1 was transformed to 5-hydroxy-7,4'-dimethoxyisoflavone (4), 7-hydroxy-5,4'-dimethoxyisoflavone (5) and 4'-hydroxy-5,7-dimethoxyisoflavone (6) by S. litura. Compounds 2 and 3 were hardly metabolized by S. litura. This suggested that compound 1 was converted to compounds 4, 5 and 6 by demethylation at the C-5, C-7 and C-4' position, respectively.

The palladium-catalyzed coupling reaction of 6-iodoisoflavone, prepared from 3'-iodoacetophenone derivative, with 2-methyl-3-butyn-2-ol gave 6-alkynylisoflavone derivative, which was hydrogenated to give 6-alkylhydroxyisoflavone (luteone hydrate) (2). Dehydration of 2 gave 2',4',5,7-tetrahydroxy-6-prenylisoflavone (luteone) (1). Wighteone hydrate (3) was also synthesized from 6-iodotris(benzyloxy)isoflavone in a similar manner. 6-Alkyl-4'5,7-trihydroxy-coumaronochromone (4) was synthesized by oxidative cyclization of 2 with o-chloranil.

Although deoxybenzoins are intermediates in the synthesis of isoflavones, their estrogenic activity has not been investigated. Eleven deoxybenzoins were synthesized and their estrogenicity was evaluated. While their affinities for estrogen receptors (ER) ERalpha and ERbeta were found grossly comparable to those of daidzein, some exhibited considerable selectivity and transcriptional bias toward ERbeta, which appeared to allow for enhancement of ER-mediated transcription via deoxybenzoin binding of ERbeta. Their activity to stimulate the proliferation of ER-positive breast cancer cells and regulate the expression of endogenous and stably transfected reporter genes differed considerably, with some inhibiting cell proliferation while effectively inducing gene expression at the same time. Molecular modeling confirmed that deoxybenzoins fit well in the ligand binding pocket of ERbeta, albeit with different orientations. Our data support the view that deoxybenzoins constitute a promising new class of ERbeta-biased phytoestrogens.

The reaction of a chromene with BH(3) followed by treatment with benzoquinone and air is the key step in a direct entry to O-methyl claussequinone.

Phytoestrogens have been shown to inhibit platelet activation by blocking platelet calcium channels. This study examined the effect of several synthetic derivatives of trans-resveratrol, genistein, and daidzein on platelet free intracellular calcium ([Ca2+]i) elevation in thrombin-activated platelets and the possible mechanisms of this inhibitory effect. Studies were conducted on fresh human platelets from healthy volunteers. The fluorescent dye fura-2 was used to monitor [Ca2+]i in platelets. At 10 microM-resveratrol, triacetyl-trans-resveratrol, and trimethoxy-trans-resveratrol produced, respectively, 57 +/- 4%, 40 +/- 4%, and 21 +/- 1% inhibition; genistein, acetylgenistein, and dihydrogenistein produced 51 +/- 10%, 26 +/- 7%, and 16 +/- 2% inhibition, respectively; daidzein and diacetyldaidzein produced 56 +/- 5% and 45 +/- 10% inhibition of thrombin-induced [Ca2+]i elevation. The inhibitory effect was immediate and appeared to directly affect the calcium influx channels. Phytoestrogen action on [Ca2+]i did not cause alteration in nitric oxide signaling. Tyrosine phosphorylation was not involved in the inhibition of [Ca2+]i elevation by phytoestrogens, because the percent inhibition produced by the tyrosine kinase inhibitor genistein and its inactive analogue daidzein on thrombin-induced and thapsigargin-induced [Ca2+]i elevation was not significantly different for either compound at any concentration tested. Structure-activity relationship studies on this limited set of compounds reveal the requirements for the stilbene pharmacophore for the calcium-blocking activity.

The asymmetric Weitz-Scheffer epoxidation of the isoflavones 3, mediated by the cinchonine- and cinchonidine-derived phase-transfer catalysts (PTCs) 1, affords the enantiomerically enriched isoflavone epoxides 4 with ee values of up to 98% in nearly quantitative yields. With the appropriately configured PTC 1, both enantiomers of the isoflavone epoxides may be obtained by using the commercially available cumyl hydroperoxide 2b as oxidant. Methylation of the hydroxy functionality in the most effective PTC (1b) reduces significantly the enantioselectivity of the isoflavone epoxidation as illustrated for the substrate 3c. This fact indicates the pivotal role of the hydroxy group for enantioselective control, which is rationalized in terms of a hydrogen-bonded aggregate between the ether-oxygen atom of isoflavone 3 and the phase-transfer catalyst 1. The present attractive and convenient method should be useful for the preparation of optically active epoxides of the biologically relevant isoflavone structure.

In a continuation of our search for novel anti-platelet agents, isoflavone quinone and isoflavanquinone were selected as lead compounds and the synthesis of their methoxy derivatives was carried out. Among them, the 4'- and 7-methoxy derivatives were successfully prepared, whereas the attempt to obtain 3'-methoxy derivatives resulted in their isomers, 3'-methoxyflavone quinone and 3'-methoxyflavanquinone, instead. After screening for their anti-platelet, anti-inflammatory and anti-allergic activities, a preliminary structure-activity relationship was established. Compounds 6c, 7a-c, 8c and 9a-c were found to exhibit significant activities. In particular, compound 7c demonstrated very potent anti-platelet, anti-inflammatory and anti-allergic activities and was then recommended for further pharmacological investigation.

Three new 6-O-acylated isoflavone glycosides were isolated from soybeans fermented with Bacillus subtilis (natto) and identified as daidzein 7-O-beta-(6''-O-succinyl)-D-glucoside (1), genistein 7-O-beta-(6''-O-succinyl)-D-glucoside (2), and glycitein 7-O-beta-(6''-O-succinyl)-D-glucoside (3) on the basis of spectral data and chemical transformations. During fermentation, the content of the isoflavone glycosides first decreased and then increased, whereas the corresponding 6''-O-succinyl derivatives first accumulated and then decreased, in either soybeans or soybean cooking solution. These changes suggest that enzymatic interconversion of isoflavone glycosides and the corresponding 6''-O-succinylated derivatives occurs in these media during fermentation. The 6-O-succinylated isoflavone glycosides 1, 2 and 3 accounted for 4.8, 7.2 and 0.6%, respectively, of the total isoflavones in commercial fermented soybeans (Japanese natto). Oral administration of 1 or 2 alone for 4 weeks at a dose of 50 mg/kg/d prevented bone loss in ovariectomized (ovx) rats fed a calcium-deficient diet, being as effective as the positive controls, daidzin and genistin, respectively. Compound 1 seems to be proestrogenic, like daidzin, which suppresses bone resorption to prevent bone loss after ovariectomy by directly acting on bone sites, while 2 appears to have a different mechanism of action, like that of genistin.

Nineteen isoflavones were synthesized and their attracting activity to Aphanomyces euteiches zoospore were investigated. Isoflavones (1, 2, 4, 16 and 19) with an unsubstituted B ring were synthesized by the oxidation of corresponding 2'-hydroxychalcones with thallium (III) nitrate trihydrate in methanolic perchloric acid. A hydroxyl group at the C-5 position in isoflavones was necessary for strong attraction to A. euteiches zoospore. The introduction of an additional hydroxyl group at the C-7 or C-4' position strengthened the attracting activity. Moreover, the methylation of the C-7 hydroxyl group strengthened the attracting activity, but the methylation of the C-4' hydroxyl group slightly weakened it. The naturally occurring isoflavones (9 and 10), which were reported to possess estrogen activity, showed moderate attracting activity.