异黄酮衍生物的设计、合成与抗肿瘤活性

为了提高大豆苷元的生物利用度以改善其抗肿瘤活性,利用前药原理对大豆苷元进行修饰。本文根据前药原理成功设计合成了5个新型大豆苷元磺酸酯衍生物（3～7）,所有化合物的结构均经IR、MS、元素分析和。HNMR确证。体外细胞初步活性筛选试验结果表明,部分标题化合物也具有一定的抗肿瘤活性。     

Expression profiling of the estrogen responsive genes in response to phytoestrogens using a customized DNA microarray

Here, we examined phytoestrogens, isoflavones (genistein, daidzein, glycitein, biochanin A and ipriflavone), flavones (chrysin, luteolin and apigenin), flavonols (kaempferol and quercetin), and a coumestan, a flavanone and a chalcone (coumestrol, naringenin and phloretin, respectively) by means of a DNA microarray assay. A total of 172 estrogen responsive genes were monitored with a customized DNA microarray and their expression profiles for the above phytoestrogens were compared with that for 17beta-estradiol (E2) using correlation coefficients, or R values, after a correlation analysis by linear regression. While R values indicate the similarity of the response by the genes, we also examined the genes by cluster analysis and by their specificity to phytoestrogens (specific to genistein, daidzein or glycitein) or gene functions. Several genes were selected from p53-related genes (CDKN1A, TP53I11 and CDC14), Akt2-related genes (PRKCD, BRCA1, TRIB3 and APPL), mitogen-activated protein kinase-related genes (RSK and SH3BP5), Ras superfamily genes (RAP1GA1, RHOC and ARHGDIA) and AP-1 family and related genes (RIP140, FOS, ATF3, JUN and FRA2). We further examined the extracts from two local crops of soy beans (Kuro-daizu or Mochi-daizu) by comparing the gene expression profiles with those of E2 or phytoestrogens as a first step in utilizing the expression profiles for various applications.     

Quercetin and daidzein β-apo-14’-carotenoic acid esters as membrane antioxidants

Abstract

Esterification by β-apo-14’-carotenoic acid was found to have opposite effects on antioxidant activity of quercetin (at B4’, B3’ hydroxyl) as of daidzein (at A7 hydroxyl) in phosphatidylcholine liposomes. The daidzein ester had increased activity, while quercetin had a significant decreased activity. Quantum mechanical calculations using density function theory (DFT) indicate a modest decrease in bond dissociation enthalpy, BDE, for (weakest) hydrogen–oxygen phenolic bond in daidzein from 368.4 kJ·mol^{? 1} to 367.7 kJ·mol^{? 1} compared to a significant increase in quercetin from 329.5 kJ·mol^{? 1} to 356.6 kJ·mol^{? 1} upon derivatization. These opposite changes in tendency for hydrogen atom transfer from phenolic groups to lipid radicals combined with an increase in A-to-B dihedral angle from 0.0° to 36.4° and in dipole moment from 0.40 D to 6.01 D for quercetin upon derivatization, while less significant for daidzein (36.4°–36.7° and 3.26 D–7.87 D, respectively), together provide a rationale for the opposite effect of esterification on antioxidation.     

Dynamics of appetite-mediated gene expression in daidzein-fed female rats in the meal-feeding method

We previously found that daidzein decreased food intake in female rats. The present study aimed to elucidate the relationship between dynamics of appetite-mediated neuropeptides and the anorectic effect of daidzein. We examined appetite-mediated gene expression in the hypothalamus and small intestine during the 3 meals per day feeding method. Daidzein had an anorectic effect specifically at the second feeding. Neuropeptide-Y (NPY) and galanin mRNA levels in the hypothalamus were significantly higher after feeding in the control but not in the daidzein group, suggesting that daidzein attenuated the postprandial increase in NPY and galanin expression. The daidzein group had higher corticotrophin-releasing hormone (CRH) mRNA levels in the hypothalamus after feeding, and increased cholelcystokinin (CCK) mRNA levels in the small intestine, suggesting that CCK is involved in the hypothalamic regulation of this　anorectic effect. Therefore, daidzein may induce anorexia by suppressing expression of NPY and galanin and increasing expression of CRH in the hypothalamus.     

Genistein and daidzein induce neurotoxicity at high concentrations in primary rat neuronal cultures

Summary It is known that estrogen can protect neurons from excitotoxicity. Since isoflavones possess estrogen-like activity, it is of interest to determine whether isoflavones can also protect neurons from glutamate-induced neuronal injury. Morphological observation and lactate dehydrogenase (LDH) release assay were used to estimate the cellular damage. It is surprising that, contrary to estrogen, isoflavones, specifically genistein and daidzein, are toxic to primary neuronal culture at high concentration. Treatment of neurons with 50 μM genistein and daidzein for 24 h increased LDH release by 90% and 67%, respectively, indicating a significant cellular damage. Under the same conditions, estrogen such as 17β-estradiol did not show any effect on primary culture of brain cells. At 100 μM, both genistein and daidzein increased LDH release by 2.6- and 3-fold, respectively with a 30-min incubation. Furthermore, both genistein and daidzein at 50 μM increased the intracellular calcium level, [Ca²⁺]_i, significantly. To determine their mode of action, genistein and daidzein were tested on glutamate and GABA_A receptor binding. Both genistein and daidzein were found to have little effect on glutamate receptor binding, while the binding of [³H]muscimol to GABA_A receptors was markedly inhibited. However, 17β-estradiol did not affect GABA_A receptor binding suggesting that the toxic effect of genistein and daidzein could be due to their inhibition of the GABA_A receptor resulting in further enhancement of excitation by glutamate and leading to cellular damage. Ying Jin, Heng Wu contributed equally to this article.     

A novel chemiluminescence system for the determination of daidzein and its hydroxyl radical-scavenging capacity

A novel chemiluminescence (CL) system was established for the determinations of daidzein in pharmaceutical preparations and to assess its ability to scavenge hydroxyl radicals. It was shown that a strong CL signal generated when eosin Y was mixed with Fenton reagent was decreased significantly when daidzein was added to the reaction system due to partial scavenging of the hydroxyl radicals in the solution. The extent of decrease in the CL intensity had a good stoichiometric relationship with the daidzein concentration. Based on this, we developed a new method for the determination of daidzein, using a flow‐injection chemiluminescence (FI–CL) technique. Under the optimal conditions, the linear range of daidzein concentration was 8.0 × 10^–8–3.0 × 10^–6 mol/L (R = 0.9982), with a detection limit of 9.0 × 10^–9 mol/L (S:N = 3), and the RSD was 5.8% for 1.0 × 10^–6 mol/L daidzein (n = 11). This method was successfully used in the determination of daidzein in tablets and for evaluation of the hydroxyl radical‐scavenging capacity of daidzein. The possible reaction mechanism of the CL system is discussed. Copyright © 2011 John Wiley & Sons, Ltd.     

Isoflavones in the Rutaceae family: twenty selected representatives of the genera Citrus, Fortunella, Poncirus, Ruta and Severinia

Enzyme-linked immunosorbent assays in combination with semi-preparative high-performance liquid chromatography (HPLC) and analytical HPLC with mass spectroscopy in the selective ion monitoring mode were used for the determination of selected isoflavones, daidzein, genistein, biochanin A and their homologues, in 20 representatives of the Rutaceae family. Species belonging to five genera were studied, namely Citrus, Fortunella, Poncirus, Ruta and Severinia. The enzyme immunoassays used were based on polyclonal antibodies raised against isoflavonoid conjugates with bovine serum albumin (BSA), namely biochanin A-7-BSA, daidzein-7-BSA, daidzein-4'-BSA, genistein-7-BSA and genistein-4'-BSA. Aglycones as well as glycosides were detected, and methoxyisoflavones appeared to be more abundant than hydoxyisoflavones. The content of individual isoflavonoids ranged from 0 to 2.6 mg/kg (dry weight); the sum of all measured substances reached up to 5.9 mg.     

Daidzein but not other phytoestrogens preserves bone architecture in ovariectomized female rats in vivo

Ovariectomy of immature female rats, results in significant decrease of trabecular bone volume and in cortical bone thickness. Previously, we found that estradiol-17beta (E(2)) restored bone structure of ovariectomized (Ovx) female rats to values obtained in intact sham-operated female rats. E(2) also selectively stimulated creatine kinase (CK) specific activity a hormonal-genomic activity marker. In the present study, we compared the effects of E(2) and the phytoestrogens: daidzein (D), biochainin A (BA), genistein (G), carboxy-derivative of BA (cBA), and the SERM raloxifene (Ral) in Ovx, on both histological changes of bones and CK, when administered in multiple daily injections for 2.5 months. Bone from Ovx rats, showed significant disrupted architecture of the growth plate, with fewer proliferative cells and less chondroblasts. The metaphysis underneath the growth plate, contained less trabeculae but a significant increased number of adipocytes in the bone marrow. D like E(2) and Ral but not G, BA, or cBA, restored the morphology of the tibiae, similar to that of control sham-operated animals; the bony trabeculeae observed in the primary spongiosa was thicker, with almost no adipocytes in bone marrow. Ovariectomy resulted also in reduced CK, which in both epiphysis and diaphysis was stimulated by all estrogenic compounds tested. In summary, only D stimulated skeletal tissues growth and differentiation as effectively as E(2) or Ral, suggesting that under our experimental conditions, D is more effective in reversing menopausal changes than any of the other isolated phytoestrogens which cannot be considered as one entity.     

Riboflavin as an independent and accurate biomarker for adherence in a randomized double-blind and placebo-controlled clinical trial

Background: Medication adherence is critical for success of clinical trials.

Objective: To assess oral riboflavin is an adherence marker.

Methods: Riboflavin was incorporated into active treatment and placebo pills for a clinical trial lasting for 2 years.

Results: The accuracy (area under the receiver operating curve) of urinary riboflavin was 0.91 as a binary classifier of adherence, and was similar or better than for two active study ingredients daidzein (0.92) and genistein (0.87) (all p?<?0.0001). Decreased adherence over time was similar in the two study groups.

Conclusion: Riboflavin is an accurate and useful biomarker for study pill ingestion.