三氧化二砷抑制小鼠B16黑色素瘤生长作用及其机制

目的　探讨三氧化二砷 (As2 O3 )对小鼠B16黑色素瘤的生长及其血管生成的抑制作用 ;同时观察其对B16细胞增殖活性、细胞形态、细胞周期及凋亡的影响。方法　选用小鼠黑色素瘤B16细胞接种C5 7BL/ 6J小鼠 ,观察腹腔注射As2 O3 对实体瘤的重量及成瘤率的影响 ;应用HE染色、Ⅷ RAg免疫组化染色观测瘤组织内新生血管密度 ;采用CellTiter 96AqueousOne试剂检测B16细胞增殖活力 ;Giem sa染色、Feulgen染色观察细胞形态学变化 ;流式细胞术分析细胞周期及细胞凋亡。结果　As2 O3 能显著抑制小鼠B16黑色素瘤的生长 ,治疗组成瘤率为 37 5 % ,抑瘤率达81 6 1% ,并能显著抑制瘤组织内血管生成 ;体外实验观察到As2 O3 能抑制B16细胞增殖 ,并存在浓度依赖效应 ,IC50 为32 99μmol·L-1;细胞形态学观察结果显示As2 O3 使B16细收稿日期 :2 0 0 4-0 2 -17,修回日期 :2 0 0 4-0 3 -2 8基金项目 :安徽省教育厅资助项目 ,No 2 0 0 4kJ2 79作者简介 :夏　俊 ( 1965 -) ,女 ,硕士 ,副教授 ,硕士生导师 ,研究方向 :肿瘤分子生物学 ,Tel:0 5 5 2 3 0 664 12 2 0 97,E mail:xia jun1965 @yahoo .com .cn崔秀云 ( 1941-) ,女 ,教授 ,博士生导师 ,研究方向 :癌基因与抑癌基因 ,Tel:0 411 472 0 64 8,E mail:cuixy @dlmedu .edu .     

卡介菌多糖核酸的抗炎和抗过敏作用

目的　研究卡介菌多糖核酸 (BCG PSN)的抗炎、抗过敏作用。方法　观察对磷酸组胺所致豚鼠皮肤瘙痒的影响 ;采用二甲苯所致小鼠耳廓肿胀及角叉菜胶所致大鼠足跖肿胀实验观察抗炎作用 ;以 2 ,4 二硝基氟苯所致小鼠皮肤迟发型变态反应、大鼠同种被动皮肤过敏反应及小鼠异种被动皮肤过敏反应 ,探讨抗过敏作用。结果　豚鼠隔日肌内注射BCG PSN(0 1,0 2 ,0 4mg·kg-1) 3wk ,对磷酸组胺所致皮肤瘙痒无明显影响。小鼠隔日肌内注射BCG PSN(0 15 ,0 30 ,0 6 0mg·kg-1) 3wk ,可剂量依赖性地抑制二甲苯所致耳廓肿胀和耳异种被动皮肤过敏反应 ,高剂量时也可显著抑制 2 ,4 二硝基氟苯诱导的迟发型变态反应。大鼠隔日肌内注射BCG PSN(0 1,0 2 ,0 4mg·kg-1) 3wk ,可剂量依赖性地抑制角叉菜胶所致足跖肿胀和同种被动皮肤过敏反应。收稿日期 :2 0 0 3 -12 -2 4,修回日期 :2 0 0 4-0 2 -12作者简介 :刘桂珍 ( 1965 -) ,女 ,主管实验师 ,研究方向 :心血管药理学。Tel:0 73 1 2 3 5 5 0 77;胡长平 ( 1969-) ,男 ,博士 ,副教授 ,通迅作者 ,研究方向 :心血管药理学 ,Tel:0 73 1 2 3 5 5 0 77,E mail:huchangping2 0 0 1@yahoo .com .cn结论　BCG PSN对急性炎症、速发型变态反应和迟发型变态反应具有抑制作用。     

盐酸川芎嗪经腹腔注射在兔眼视网膜组织中的药代动力学

目的　测定腹腔注射盐酸川芎嗪后不同时间兔眼视网膜川芎嗪的浓度 ,计算其药动学参数 ,研究其药动学特点。方法　 4 4只家兔随机分为 11组 ,每只家兔腹腔注射盐酸川芎嗪 80mg·kg-1,在用药前 (0h)和用药后 0 2 5、0 5、0 75、1、1 5、2、3、5、8、12h取视网膜 ,采用反向高效液相色谱法 (RP HPLC)进行测定。 3P87软件拟合药动学参数。结果　腹腔注射盐酸川芎嗪后 ,其浓度在正常家兔眼视网膜呈开放型二室模型。理论值高峰浓度 (Cmax)为 1 6 3mg·g-1,达收稿日期 :2 0 0 4-0 1-3 1,修回日期 :2 0 0 4-0 2 -2 8基金资助 :广东省自然科学基金 (张清炯 0 10 765 )、国家自然科学基金(杨锦南 3 0 3 0 0 467)和广东省中医药管理局科学基金 (邓新国 10 40 0 64 )资助项目作者简介 :邓新国 ( 1961-) ,男 ,博士 ,研究方向 :眼科药物的开发、药理、药效和药代动力学研究 ;胡世兴 ( 195 2 -) ,男 ,博士 ,美国波士顿哈佛医学院眼科及免疫学博士后研究员 ,教授 ,博士生导师 ,通讯作者 ,Tel:0 2 0 873 3 0 2 89,E mail:Markhu @2 63 .net峰时间 (Tmax)为 0 32h ,半衰期T1/ 2α为 0 35h ,T1/ 2 β为 2 5 0h ,清除率 (CL)为 7 89g·h-1。实测值 15min为 (1 36± 0 16 )mg·g-1,30min达高峰为 (2 5 9± 0 19)mg·     

盐酸埃他卡林对[~3H]格列本脲与动脉平滑肌K_(ATP)结合和解离动力学过程的影响以及与核苷酸的交互作用

目的　研究盐酸埃他卡林 (Iptakalimhydrochloride,Ipt)对 [3 H]格列本脲 (glibenclamide,Gli)与大鼠血管平滑肌ATP敏感性钾通道 (ATP sensitivepotassiumchannel,KATP)的硫脲受体(Sulfonylureareceptor,SUR2B)结合和解离动力学过程的影响 ,并比较其作用特点与核苷酸类物质的异同点及它们之间的交互效应。方法　KATP拮抗剂 [3 H]Gli与大鼠去内皮主动脉平滑肌特异性结合与解离的动力学试验。结果　 (1 )在浓度为 1 0pmol·L-1 ～ 0 5mmol·L-1 范围内 ,Ipt不能取代SUR2B与 [3 H]Gli2 0 0 3 0 616收稿 ,2 0 0 3 112 5修回 国家新药研究与发展重点项目 ,No 9690 10 10 1;国家“863”计划重大专项 ,No 2 0 0 2AA2Z3 13 7作者简介 :何华美 ,男 ,3 6岁 ,博士 ,副教授。研究方向 :心血管药理学。E mail:longchaoliang @sohu .com ;汪　海 ,男 ,40岁 ,研究员 ,博士生导师。研究方向 :心血管药理和新药。通讯作者。Tel :86 10 6693 2 65 1,Fax:86 10 682 1165 6,E mail:wh @nic.bmi.ac .cn之间的特异性结合。Ipt 1 0 0 μmol·L-1 调节 [3 H]Gli与SUR2B特异性结合的动力学过程的特征为抑制其结合动力学过程 ,使其结合速率减慢 ,结合幅度降低 ;促进其解离动力学过程 ,使其解离速率加快 ,解离幅度增加。 (2 )ATP     

丙基硫氧嘧啶对甲状腺NADH-细胞色素b_5还原酶活性影响

目的　探讨丙基硫氧嘧啶 (PTU)抗甲状腺作用新的药理机制。方法　以高铁氰化钾和二氯酚靛酚为底物测定NADH 细胞色素b5还原酶 (b5R)活性 ,应用高香草酸荧光分析技术对H2 O2 浓度进行测定 ,观察PTU对甲状腺b5R活性和H2 O2 浓度影响。结果　PTU可抑制b5R活性 ,且呈浓度依赖性 ,0 0 5mmol·L-1PTU即对b5R活性有抑制作用 ,以后随PTU浓度增加 ,b5R活性逐渐降低 ;H2 O2 浓度则随b5R活性降低而下降。NADH有拮抗PTU对b5R的抑制作用。结论　PTU对甲状腺b5R活性有抑制作用 ,抑制b5R活性从而抑制H2 O2 的生成可能为PTU抗甲状腺作用另一重要药理机制     

朱砂莲提取物(A_(1015))对D-氨基半乳糖胺肝损伤模型小鼠DNA合成作用的影响

目的　研究朱砂莲提取物 (A10 15)对D 氨基半乳糖胺(D Gl)肝损伤模型小鼠DNA合成作用的影响。方法　采用D Gl造模 ,3 H TdR参入法测定小鼠肝细胞DNA合成 ,并与肝细胞再生因子进行比较。观察了A10 15的剂量曲线和时间曲线。结果和结论　朱砂莲提取物 (A10 15)抵抗D Gl造成的肝组织坏死和促进肝脏细胞DNA合成作用的最适剂量为 2 5mg·kg-1体重。试验还提示A10 15的抗肝中毒作用2 0 0 1-12 -2 6收稿 ,2 0 0 2 -0 3 -0 6修回1 华西医科大学基础部药理学教研室 ,成都　 610 0 41作者简介 :刘碧崇 ,女 ,3 7岁 ,副研究员 ,博士。研究方向 :微生物药物与中药研究。Tel:0 2 8 43 780 40 ,Fax :0 2 8 43 3 3 2 18,E mail:huanggen @mail sc cninfo net;王浴生 ,男 ,81岁 ,教授 ,博士生导师。研究方向 :抗生素与中药药理不强于肝细胞再生因子     

替米沙坦在中国健康志愿者体内的药代动力学特征

目的　通过对健康志愿者口服不同剂量替米沙坦片后的药代动力学研究 ,探讨替米沙坦在国人体内的药代动力学特征。方法　 9名中国健康男性志愿者按拉丁方设计分别口服三种单剂量替米沙坦片 (4 0、80、12 0mg) ,用高效液相色谱荧光检测法测定血浆替米沙坦浓度 ,采用 3P97软件拟合药代动力学参数。结果　受试者血药浓度随其单剂量给药量的增加呈现非比例的升高趋势 ,计算所得的药动学参数显示 ,口服 4 0、80、12 0mg替米沙坦片的AUC0～ 96分别为(895 0 3± 36 4 5 3)、(30 30 34± 14 5 4 80 )和 (135 70 4 4±35 5 1 5 4 ) μg·h-1·L-1;Cmax 分别为 (6 0 71± 2 8 10 )、(2 14 0 5± 74 14 )和 (978 32± 2 34 89) μg·L-1,不同剂量组的AUC0 t/dose、Cmax/Dose比值间差异有显著性 (P <收稿日期 :2 0 0 4-0 4-2 6,修回日期 :2 0 0 4-0 5 -2 9作者简介 :熊玉卿 ( 195 7-) ,女 ,博士 ,教授 ,研究方向 :药物代谢及药代动力学 ,Tel:0 791 63 60 65 4,E mail:xyq112 6@yahoo .com .cn0 0 1)。结论　替米沙坦在中国人体内过程 (剂量范围为 4 0～ 12 0mg)显示非线性药代动力学特征     

来曲唑在子宫内膜异位症治疗中的作用

目的通过观察芳香化酶抑制剂-来曲唑作用于体外培养的子宫内膜异位症患者在位内膜细胞(Ectopic endometrial cells of women with endometriosis,EE)后芳香化酶及芳香化酶转录刺激因子-类固醇源性因子(SF-1)的表达情况,探讨来曲唑作为芳香化酶抑制剂对子宫内膜异位症(内异症)的作用。方法以0、0.1、1、10、100 nmol/L浓度的来曲唑对体外培养的子宫内膜异位症者的在位内膜细胞(EE)分别进行刺激。72 h后采用RT-PCR法从核酸水平检测Aromatase和SF-1的mRNA表达情况。结果不同浓度的来曲唑均可明显抑制细胞内Aromatasem RNA及SF-1mRNA表达,与空白组比较有显著性差异(P<0.05);且抑制作用呈浓度依赖性。结论芳香化酶抑制剂-来曲唑对内异症在位内膜细胞具有明显抑制EE细胞内芳香化酶及其转录调节因子SF-1的与mRNA表达。     

大鼠心肌多胺代谢限速酶ODC、SSAT活性分析

目的建立大鼠心肌多胺代谢限速酶鸟氨酸脱羧酶(ODC)及精脒/精胺乙酰转移酶(SSAT)活性分析方法。方法以Langendorff离体灌流心肌为实验材料,制备心肌组织匀浆;分别以dl[114C]Ornithine及[114C]acetylCoenzymeA为底物,以液体闪烁计数仪记录生成的14CO2及[14C]acetylspermidine的放射活度,并以其代表ODC,SSAT的活性;计算大鼠心肌ODC、SSAT的酶促反应动力学参数,筛选出适宜的底物浓度;同时观察一氧化氮(NO)供体硝普钠(SNP)对酶活性的影响。结果①大鼠心肌ODC、SSAT基础活性分别为:(9.67±3.09)nmol·mg-1Pro·h-1;(3.59±0.91)nmol·mg-1Pro·min-1。②ODC催化LOrnithine的酶促反应动力学参数Km=(54.95±8.14)μmol·L-1;Vmax=(2.364±0.37)nmol·mg-1·h-1;SSAT催化AcetylCoenzymeA的酶促反应动力学参数Km=(12.87±1.88)μmol·L-1;Vmax=(0.50±0.07)nmol·mg-1·min-1。③大鼠心肌ODC、SSAT活性检测的底物浓度分别为:90μmol·L-1(18.5kBq)DL[114C]Ornithine及36μmol·L-1(2.96kBq)[114C]acetylCoA。④SNP呈浓度依赖性地抑制ODC的活性、诱导SSAT的活性。结论建立了大鼠心肌多胺代谢限速酶鸟氨酸脱羧酶(ODC)及精脒/精胺乙酰转移酶(SSAT)活性的分析方法,该方法简便易行;根据Km值确定测定大鼠心肌ODC及SSAT?     

二恶英对内膜组织中细胞色素芳香化酶P450表达的影响

目的建立小鼠模型并探讨二恶英对小鼠内膜组织中细胞色素芳香化酶P450表达的影响。方法建立小鼠模型,采用二恶英0、3、10μg/kg对小鼠进行宫内、外暴露或宫内宫外联合暴露,从而将小鼠模型分为五组:0-0组、3-0组、0-3组、3-3组和3-10组,各有24只小鼠。采用免疫组织化学法检测小鼠模型中子宫内膜组织中细胞色素芳香化酶P450的表达水平。结果细胞色素芳香化酶P450在小鼠暴露组的表达高于对照组(P<0.05),并随二恶英暴露剂量的增加而升高(P<0.05)。结论二恶英可以促进子宫内膜中细胞色素芳香化酶P450的表达。     

A novel method for measuring aromatase activity in tissue samples by determining estradiol concentrations

Increasing scrutiny of endocrine disrupters has led to changes to European pesticide and biocide legislation and to the introduction of the Endocrine Disrupter Screening Program by the US EPA. One element of endocrine disrupter identification is to determine its effects on aromatase, but most available assays are limited as they depend on tritiated water production to indicate enzyme activity. Whilst acceptable for determining aromatase effects using a cell-free approach, this method is unreliable for cell or tissue-based investigations as other cytochrome P-450 isoenzyme activities can similarly produce tritiated water and consequently confound interpretation of the aromatase data. To address this lack of specificity an assay directly measuring the final estrogen product by incubating rat tissue protein with testosterone and measuring the resultant estradiol concentration was developed. Using this approach we demonstrated marked increases in enzyme activity in pregnant rat ovary samples and dose-related inhibitions when incubating non-pregnant rat ovary samples with known aromatase inhibitors. Hepatic aromatase activity was investigated using our method and by tritiated water production with microsomes from rats dosed with the antiandrogen 1,1-dichloro-2,2-bis(4 chlorophenyl)ethane. Additional cytochrome P-450s were also measured. Treatment-related increased tritiated water production and general hepatic enzyme activity were recorded but estradiol was not increased, indicating that the increased tritiated water was due to general enzyme activity and not aromatase activity. A simple and specific method has been developed that can detect aromatase inhibition and induction, which when applied to tissue samples, provides a means of generating relevant animal data concerning chemical effects on the aromatase enzyme.     

大脑皮层~3H-三环哌酯结合位点的药理学特征

目的研究大脑皮层３Ｈ－三环哌酯（３Ｈ－ＴＣＰＮ）结合位点的药理学特征。方法在大鼠大脑皮层匀浆标本上，测定３Ｈ－ＴＣＰＮ的特异性结合位点以及药物对它的影响。结果３Ｈ－ＴＣＰＮ与大鼠大脑皮层膜标本具有特异性结合，其饱和性结合的参数与３Ｈ－ＱＮＢ的饱和性结合参数相似，其中，Ｋｄ值为０．４０ｎｍｏｌ·Ｌ－１，Ｂｍａｘ值为１２５８ｐｍｏｌ·ｇ－１。３Ｈ－ＴＣＰＮ特异性结合位点中，被阿托品取代的Ｍ受体部分占７０％，不被阿托品取代的称Ｘ位点部分占３０％；Ｘ结合位点既不为Ｎ受体激动剂烟碱和非竞争拮抗剂美加明所占据，也不为ＧＡＢＡ受体拮抗剂苦味毒素，甘氨酸受体拮抗剂士的宁和胆碱酯酶抑制剂毒扁豆碱所占据。结论大鼠大脑皮层３Ｈ－ＴＣＰＮ特异性结合位点中，７０％为Ｍ受体，其它位点的药理学性质有待进一步研究     

金仓鼠脑内的 kappa 受体

目的：研究〔３Ｈ〕依托啡与金仓鼠脑内ｋａｐｐａ受体结合及其在脑内分布的特性。方法：用受体结合和药物的竞争抑制试验研究〔３Ｈ〕依托啡与金仓鼠脑匀浆中ｋａｐｐａ受体结合。结果：〔３Ｈ〕依托啡与金仓鼠脑匀浆中ｋａｐｐａ受体结合的Ｋｄ值和Ｂｍａｘ值分别为０．５２ｎｍｏｌ·Ｌ－１和３４．０ｐｍｏｌ·ｇ－１蛋白。５μｍｏｌ·Ｌ－１（Ｄ－Ａｌａ２，Ｄ－Ｌｅｕ５）脑啡肽可完全阻断〔３Ｈ〕依托啡与ｋａｐｐａ受体的结合。该结合易被苯吗啡烷类及奥列巴文类药物取代，而不易被强啡肽Ａ（１－１３）取代。金仓鼠脑内ｋａｐｐａ受体存在不同的局部分布，纹状体和中脑的密度较高（Ｋｄ和Ｂｍａｘ值为０．４８±０．０２１ｎｍｏｌ·Ｌ－１和２６．６±２．１ｐｍｏｌ·ｇ－１蛋白；０．４１±０．０１５ｎｍｏｌ·Ｌ－１和２４．９±０．３６ｐｍｏｌ·ｇ－１蛋白），大脑皮层的密度较低（Ｋｄ和Ｂｍａｘ值为０．４２±０．０２ｎｍｏｌ·Ｌ－１和１０．５±０．８５ｐｍｏｌ·ｇ－１蛋白）。结论：金仓鼠脑内有优势的ｋａｐｐａ受体，它不同于经典的ｋａｐｐａ受体，可能属于ｋａｐ－ｐａ２受体。纹状体和中脑的ｋａｐｐａ受体分布密度最高。     

Atrazine-induced changes in aromatase activity in estrogen sensitive target tissues

Atrazine (ATR) is a pesticide used widely throughout North America. Although not directly estrogenic, ATR treatment has been shown to increase aromatase activity in tumor cell lines. Thus, it is suggested that ATR can increase local tissue estrogen levels in estrogen sensitive target tissues through increased aromatase activity. Therefore the effect of ATR on aromatase activity was measured in human granulosa-lutein cell cultures, cells that abundantly express aromatase, and endometrial stromal cell (ESC) cultures, cells that do not express aromatase. Aromatase activity was quantified by the tritiated water method and the specificity of the assay was confirmed by co-incubation with 4-hydroxyandrostenedione, an irreversible inhibitor of the catalytic activity of aromatase. Aromatase activity in ATR treated (1-10 microm) granulosa-lutein cells was increased more than 2-fold compared with control cultures. There were no treatment related changes in cellular protein and thus it is suggested that the ATR-induced change in aromatase activity was not due to an increase in cell number. ATR-treatment had no effect on ESC aromatase activity at any concentration tested. Similarly, there was no effect of ATR treatment on human recombinant aromatase activity in our cell-free test system. Therefore it is concluded that microm concentrations of ATR can increase aromatase activity of human granulosa cells but not ESC and this effect is not elicited at the enzyme level.     

甘草次酸与大鼠肝膜血管紧张素Ⅱ受体相结合

目的从中药成份中筛选血管紧张素Ⅱ（ＡⅡ）受体的拮抗剂。方法采用大鼠肝细胞膜为材料的受体放射配基结合分析。结果大鼠肝细胞膜ＡⅡ受体的ＫＤ值为０５１８ｎｍｏｌ·Ｌ－１，Ｂｍａｘ为０１１９ｐｍｏｌ·Ｌ－１，是属于高和性的单位点结合。膜制剂在－７０℃保存３０～６０ｄ，结合率基本不受影响。从２１种中药有效成分选出甘草次酸对血管紧张素Ⅱ受体有较好结合作用，其ＩＣ５０为７５０μｍｏｌ·Ｌ－１。结论甘草次酸有望成为ＡⅡ受体非肽拮抗剂的先导化合物     

Imidazole antimycotics: inhibitors of steroid aromatase

Miconazole and clotrimazole, members of a class of imidazole agents which have broad spectrum antimycotic activity, were shown to be potent inhibitors of steroid aromatase activity of human placental microsomes. The I50 values for the inhibition of aromatase activity by miconazole, clotrimazole, ketoconazole, and aminoglutethimide were 0.6, 1.8, 60 and 44 microM respectively. The most effective compound, miconazole, exhibited competitive kinetics with respect to androstenedione, the aromatase substrate. The apparent inhibitory constant (Ki) was 55 nM, under assay conditions where the apparent Km for androstenedione was 220 nM. The inhibition of aromatase activity by miconazole was shown to be reversible by dilution. Miconazole was a relatively poor inhibitor of the cholesterol side chain cleavage activity of a placental mitochondria-enriched fraction, while both clotrimazole and ketoconazole markedly inhibited this mitochondrial monooxygenase activity. Spectrophotometric studies revealed that miconazole bound to the cytochrome P-450 component of the placental microsomal aromatase complex and had negligible effect on NADPH-cytochrome c (P-450) reductase activity. These results strongly support direct interaction of miconazole with microsomal cytochrome P-450 in human placental microsomes with high affinity resulting in the inhibition of aromatase activity.     

BN3C对大鼠心肌细胞膜二氢吡啶受体的作用

目的研究ＢＮ３Ｃ对大鼠心肌细胞膜二氢吡啶受体的作用。方法放射性配基结合实验。结果［３Ｈ］ＰＮ２００－１１０在０．１～３．２ｎｍｏｌ·Ｌ－１范围与大鼠心肌细胞膜的特异性结合是可饱和的,其ＫＤ和Ｂｍａｘ值分别为０．８２ｎｍｏｌ·Ｌ－１和１０９．７２ｐｍｏｌ·ｇ－１Ｐｒｏ－１。当有１×１０－９ｍｏｌ·Ｌ－１ＢＮ３Ｃ存在时,其ＫＤ和Ｂｍａｘ值分别为２．０１ｎｍｏｌ·Ｌ－１和１１５．３１ｐｍｏｌ·ｇ－１Ｐｒｏ－１。ＢＮ３Ｃ、拉西地平、硝苯吡啶竞争性抑制［３Ｈ］ＰＮ２００－１１０与大鼠心肌细胞膜结合的ＩＣ５０分别为２．４×１０－９,１．５×１０－８,１．９×１０－８ｎｍｏｌ·Ｌ－１;ＫＩ值分别为１．４９,９．２２和１１．６４ｎｍｏｌ·Ｌ－１。结论ＢＮ３Ｃ可特异性地作用于［３Ｈ］ＰＮ２００－１１０的结合部位,竞争性地抑制［３Ｈ］ＰＮ２００－１１０与大鼠心肌细胞膜的结合;ＢＮ３Ｃ与受体的亲和力强于拉西地平和硝苯吡啶。     

Synthesis and Aromatase Inhibitory Activity of Flavanones

Purpose. Aromatase inhibitors are known to prevent the conversion of androgens to estrogens and play a significant role in the treatment of estrogen dependent diseases such as breast cancer. Some flavonoids have been reported as potent aromatase inhibitors; therefore, in an effort to develop novel anti breast cancer agents, B ring substituted flavanones with a 7-methoxy group on A ring were synthesized and tested to assess their ability to inhibit aromatase activity and to determine the optimal B ring substitution pattern. Methods. A series of flavanones was prepared by cyclisation of 2'-hydroxychalcones previously obtained by Claisen-Schmidt condensation and the aromatase inhibitory activity of these compounds was investigated using human placental microsomes and radiolabeled [1,2,6,7-³H]-androstenedione as substrate. Results. Almost all flavanones exhibited inhibitory effect on the aromatase activity but their potency was dependent on their B ring substitution pattern. Hydroxylation at position 3 and/or 4' enhanced the anti-aromatase activity; thus, 3,4'-dihydroxy-7-methoxyflavanone was found to be twice more potent than aminoglutethimide, the first aromatase inhibitor clinically used. Conclusions. These results indicated that these flavanones could be considered as potential anti breast cancer agents through the inhibition of aromatase activity and allowed us to select some of these compounds as skeleton for the development of flavonoid structurally-related aromatase inhibitors.