鱼腥草不同溶剂提取物的抗病毒活性研究

目的 研究鱼腥草不同溶剂提取物体外抗手足口病毒（enterovirus type 71,EV71）、单纯疱疹病毒1型（herpes simplex virus type 1,HSV-1）、呼吸道合胞病毒（respiratory syncytial virus,RSV）、柯萨奇病毒B3型（coxsackie virus type B3,CV-B3）、柯萨奇病毒B5型（coxsackie virus type B5,CV-B5）的活性。方法 采用细胞体外培养技术,建立不同病毒感染模型,用鱼腥草不同溶剂提取物进行治疗,通过细胞融合病变观察法以及MTT比色法检测得到治疗指数（therapeutic index,TI）,以此判定其体外抗病毒活性。结果 体外抗病毒试验结果证明,鱼腥草不同溶剂提取物对HSV-1、EV71抗病毒作用较强,对RSV、CV-B3、CV-B5的效果甚微或无明显作用。鱼腥草醇提物中黄酮类成分含量较高,抗病毒活性相对较高;30%,50%,75%乙醇提取物以及水提醇沉处理沉淀物对HSV-1的TI值分别是81.68,67.23,41.91,32.61,均高于阳性对照阿昔洛韦TI值23.43,显示鱼腥草水醇提取物抗HSV-1的活性较强;75%,50%,30%乙醇提取物对EV71的TI值分别是19.58,20.13,18.84,效果较为显著。结论 研究证实鱼腥草提取物对HSV-1、EV71的抗病毒活性较高,可一定程度为临床应用鱼腥草治疗这2种病毒感染引发的疾病提供参考依据。     

东莞市7岁以下小儿常见呼吸道病毒感染的病原学研究

目的 了解广东省东莞市镇区7岁以下小儿常见呼吸道病毒感染的病原学特点及其影响因素.方法 收集2007年2-10月东莞市石碣医院儿科门诊及病房7岁以下小儿急性呼吸道感染病例的呼吸道分泌物标本340例,采用逆转录-聚合酶链反应法(RT-PCR)检测呼吸道合胞病毒A、B型(RSV-A、B型),流感病毒甲、乙型(FLU-A、B型),副流感病毒1、2、3型(PIV-1、2、3型)和人偏肺病毒(hMPV).结果 从340例呼吸道分泌物标本中检测出常见呼吸道病毒171例,阳性率为50.29%;其中RSV-A型69例(20.29%),FLU-A型39例(11.47%),hMPV 32例(9.41%),PIV3型22例(6.47%),RSV-B型9例(2.65%).在171例呼吸道病毒阳性病例中,有混合病毒感染16例,占所有病毒感染者9.36%;其中hMPV合并RSV-A感染者5例,RSV-A合并PIV-3者4例,hMPV合并FLU-A、PIV-3感染者各2例,FLU-A合并PIV-3者2例,RSV-A合并FLU-A者1例;但未见三重混合感染或多重感染.未榆测出FLU-B型及PIV-1,2型.结论 呼吸道病毒是东莞镇区7岁以下小儿急性呼吸道感染的重要病原体,RSV为最主要病原,其次为FLU-A和hMPV.     

白颖苔草提取物体外抗疱疹科病毒作用实验研究

目的探讨白颖苔草正丁醇提取物对疱疹科病毒的体外抑制作用。方法采用有机溶剂分步浸提得正丁醇提取物,以HSV-1-HEK293,HSV-2-HEK293,MCMV-3T3体外感染模型进行试验,通过显微镜观察细胞病变,分光光度计测定中性红染色A540值,计算治疗指数（TI）评价抗病毒效果。结果白颖苔草正丁醇提取物可抑制HSV-1,HSV-2,MCMV的细胞病变效应,TI分别为161．63,115．63,38．67。结论白颖苔草对疱疹科病毒具有抑制活性。     

The mechanism of action of the anti-herpes virus compound 2,3-dimethyl-6(2-dimethylaminoethyl)-6H-indolo-(2,3-b)quinoxaline.

The compound 2,3-dimethyl-6(2-dimethylaminoethyl)6H-indolo-(2,3-b)quinoxaline (B-220) has been shown to exhibit potent antiviral activity against herpes simplex virus type 1 (HSV-1), varicella-zoster virus (VZV) and cytomegalovirus (CMV). The mechanism of antiviral action of B-220 against HSV-1 has been studied; from the results it appears that B-220 binds by intercalation into the DNA helix and then disturbs steps that are vital for viral uncoating.     

Antiviral activity of Plantago major extracts and related compounds in vitro

Plantago major L., a popular traditional Chinese medicine, has long been used for treating various diseases varying from cold to viral hepatitis. The aim of present study was to examine the antiviral activity of aqueous extract and pure compounds of P. major. Studies were conducted on a series of viruses, namely herpesviruses (HSV-1, HSV-2) and adenoviruses (ADV-3, ADV-8, ADV-11). The antiviral activity of EC50 was defined as the concentration achieved 50% cyto-protection against virus infection and the selectivity index (SI) was determined by the ratio of CC50 (concentration of 50% cellular cytotoxicity) to EC50. Results showed that aqueous extract of P. major possessed only a slight anti-herpes virus activity. In contrast, certain pure compounds belonging to the five different classes of chemicals found in extracts of this plant exhibited potent antiviral activity. Among them, caffeic acid exhibited the strongest activity against HSV-1 (EC50=15.3 microg/ml, SI=671), HSV-2 (EC50=87.3 microg/ml, SI=118) and ADV-3 (EC50=14.2 microg/ml, SI=727), whereas chlorogenic acid possessed the strongest anti-ADV-11 (EC50=13.3 microg/ml, SI=301) activity. The present study concludes that pure compounds of P. major, which possess antiviral activities are mainly derived from the phenolic compounds, especially caffeic acid. Its mode of action against HSV-2 and ADV-3 was found to be at multiplication stages (postinfection of HSV-1: 0-12 h; ADV-3: 0-2 h), and with SI values greater than 400, suggesting the potential use of this compound for treatment of the infection by these two viruses.     

金银花多糖的提取纯化及抗病毒活性研究

目的：提取纯化金银花多糖,并研究金银花多糖的体外抗病毒活性。方法：采用醇沉法提取多糖并用酶法纯化多糖,运用细胞培养技术,对纯化后的多糖进行体外抗病毒实验,以MTT染色法检测细胞活性,结合CPE法研究金银花多糖对单纯疱疹病毒（HSV-1）、柯萨奇病毒B5（COX-B5）、柯萨奇病毒B3（COX-B3）和肠道病毒71型（EV71）的抑制作用。结果：多糖纯化后含量为54.04%,金银花多糖对COX-B5、EV71、COX-B3、HSV-1的治疗指数分别为4.84,63.85,4.77,51.25。结论：金银花多糖具有体外抗HSV-1、EV71、COX-B5、COX-B3的活性,为临床治疗提供理论依据。     

板蓝根抗病毒有效部位筛选

目的:对板蓝根药材中提取的10个化学部位进行体外抗单纯疱疹病毒(HSV)活性研究,确定板蓝根抗病毒的有效部位。方法:利用溶剂法和色谱法从板蓝根中提取分离出10个粗提和精制部位,用MTT法检测这10个部位体外对HSV-Ⅰ及HSV-Ⅱ型病毒的抑制作用,以病毒抑制率和治疗指数(TI)为评价指标,比较各化学部位体外抗病毒的效果。结果:水提大孔树脂吸附的10%、50%醇洗部位(Ⅷ、Ⅹ)作用最强,对HSV-Ⅰ型病毒的抑制率为分别为53.21%、56.28%,接近阳性对照药阿昔洛韦(62.55%),其TI分别为4.61、18.62。结论:板蓝根不同化学部位的抗病毒作用强度有较大差异。     

注射用银黄体外抗呼吸道合胞病毒

目的:研究注射用银黄对呼吸道合胞病毒的体外抑制作用。方法:采用细胞培养技术,通过银黄直接抗病毒,病毒感染细胞同时使用银黄,先使用银黄再感染病毒3种给药方法,利用生物显微镜观察人喉癌细胞(Hep-2)和人宫颈癌细胞(Hela)发生病变的情况及观察实验组与病毒对照组病毒感染的滴度。结果:注射用银黄在Hep-2和Hela细胞上对呼吸道合胞病毒均有明显的抗病毒作用,注射用银黄对病毒的最小有效浓度(M IC)为0.016 g.L-1,而且毒性低,最大无毒浓度(TDO)为1.6 g.L-1,治疗指数(TI)为100。结论:体外实验注射用银黄对呼吸道合胞病毒具有抑制和直接杀灭的特异性。     

鸢尾黄素衍生物的制备及抗其病毒活性研究

摘要：目的 通过对单体化合物鸢尾黄素的结构改造,寻找高效、低毒的新型抗病毒候选药物。方法 以鸢尾黄素为先 导化合物合成了3个化合物,并以鸢尾黄素和利巴韦林为对照,考察化合物体外抗病毒的活性,观察的主要指标为半数毒性浓 度(TC50)、半数抑制浓度(IC50)、抗病毒指数(TI),为研发新抗病毒药物提供依据。结果 化学试验分别通过磺化反应合成化合 物1,乙基化反应合成化合物2,乙基化、磺化反应两步合成化合物3,并根据红外、紫外、质谱和核磁等数据确定各化合物的 结构,分别是鸢尾黄素-5'-磺酸钠、4',7-二乙基鸢尾黄素、4',7-二乙基鸢尾黄素-5'-磺酸钠;抗病毒研究表明各化合物组在不同 剂量时对H3N2、ADV3、RSV、CVB3等病毒毒株均有不同程度的抑制作用,且明显强于同等剂量的鸢尾黄素组。化合物1对 H3N2和RSV有明显的抑制作用,抗H3N2病毒指数为29.57,强于利巴韦林(15.87);抗RSV病毒指数为28.39,略强于利巴韦林 (27.29);化合物2对CVB3有明显的抑制作用,抗CVB3病毒指数为31.60,略强于利巴韦林(29.00);化合物3对H3N2和RSV有 明显的抑制作用,抗RSV病毒指数为34.24,略强于利巴韦林(27.29);抗H3N2病毒指数为35.56,远强于利巴韦林(15.87)。结 论 化合物3具有高效、低毒的抗病毒活性,可作为潜在的抗H3N2病毒新药研发。     

Synthesis and antiviral activity of 9-alkoxypurines. 2. 9-(2,3-Dihydroxypropoxy)-, 9-(3,4-dihydroxybutoxy)-, and 9-(1,4-dihydroxybut-2-oxy)purines.

Reaction of alkenoxyamines (3,5) or (R,S)-, (R)-, and (S)-hydroxy-protected derivatives of hydroxyalkoxyamines (20a,b, 37a-c) with 4,6-dichloro-2,5-diformamidopyrimidine (4) and cyclization of the resultant 6-[(alkenoxy)amino]-and 6-(alkoxyamino)pyrimidines (6,7,21a,b, 38a,b,c) by heating with diethoxymethyl acetate afforded 9-alkenoxy- and 9-alkoxy-6-chloropurines (9,10,22a,b, 39a-c, 40a). These were subsequently converted to 9-(2,3-dihydroxypropoxy), 9-(3,4-dihydroxybutoxy), and 9-(1,4-dihydroxybut-2-oxy) derivatives of guanine and 2-aminopurine (13-16, 25-28, 41a-c, 42a). A 2-amino-6-methoxypurine derivative (17) was also prepared. The racemic guanine derivative 13 showed potent and selective activity against herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), but was less active against varicella zoster virus (VZV). Its antiviral activity is attributable to the S isomer (28), which was found to be more active than acyclovir against HSV-1 and HSV-2 and about 4 times less active than acyclovir against VZV. The S enantiomer of 9-(1,4-dihydroxybut-2-oxy)guanine (41c) also showed noteworthy antiviral activity in cell culture. Although this acyclonucleoside (41c) is only weakly active against HSV-1 and inactive against HSV-2, it is about twice as active as acyclovir against VZV.     

Antiviral activity of phosphonylmethoxyalkyl derivatives of purine and pyrimidines

Various 3-hydroxy-2-phosphonylmethoxypropyl (HPMP) and 2-phosphonylmethoxyethyl (PME) derivatives of purine [adenine (A), guanine (G), 2,6-diaminopurine (DAP), 2-monoaminopurine (MAP), hypoxanthine (HX)] and pyrimidine [cytosine (C), uracil (U), thymine (T)] have been evaluated for their antiviral properties. PMEDAP, (S)-HPMPA [and the cyclic phosphonate thereof, (S)-cHPMPA)], (S)-HPMPC, PMEG, PMEA, HPMPG and HPMPDAP proved to be effective inhibitors of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). (S)-HPMPA and (S)-cHPMPA were the most effective inhibitors of varicella-zoster virus (VZV), and (S)-HPMPC was the most effective inhibitor of cytomegalovirus (CMV). Against adenovirus (types 2, 3 and 4) and vaccinia virus again (S)-HPMPA and (S)-cHPMPA showed the greatest inhibitory activity. As a rule, the PME derivates were much less inhibitory to VZV, CMV, vaccinia and adenovirus than the HPMP derivatives. However, PMEA, PMEDAP and PMEMAP showed marked and selective activity against the human immunodeficiency virus (HIV). (S)-HPMPA was selected for further evaluation in animal model infections. It proved efficacious in the topical treatment of HSV-1 keratitis in rabbits and cutaneous HSV-1 infection in hairless mice, and in the systemic treatment of both HSV-1 and vaccinia virus infections in mice.     

朱砂七总蒽醌体外抗单纯疱疹病毒的研究

目的研究朱砂七总蒽醌(ZSQ)体外对单纯疱疹病毒的抑制作用。方法运用单纯疱疹病毒I型(HSV-Ⅰ)和Ⅱ型(HSV-Ⅱ),以非洲绿猴肾细胞(Vero细胞)为宿主细胞,通过观察感染病毒后的细胞变性反应(CPE)和MTI比色法,检测ZSQ对单纯疱疹病毒的抑制作用。结果与病毒对照组相比,朱砂七总蒽醌各质量浓度组均能有效地保护感染HSV-I和HSV-Ⅱ病毒的Vero细胞,抑制单纯疱疹病毒的复制,使病毒导致的细胞病变减弱。ZSQ抗HSV-I病毒作用IC50为0.004 7g.L-1,抗病毒有效率达90.83%,治疗指数(TI)为16.62;总蒽醌抗HSV-Ⅱ病毒作用IC50为0.006 7g.L-1,抗病毒有效率达90.06%,治疗指数(TI)为11.66。结论 ZSQ在体外显示出明显的保护宿主细胞、抵抗单纯疱疹病毒感染的活性。     

Antiviral effect of aqueous extracts from species of the Lamiaceae family against Herpes simplex virus type 1 and type 2 in vitro

Aqueous extracts from species of the Lamiaceae family were examined for their antiviral activity against Herpes simplex virus (HSV). Extracts from lemon balm (Melissa officinalis), peppermint (Mentha x piperita), prunella (Prunella vulgaris), rosemary (Rosmarinus officinalis), sage (Salvia officinalis) and thyme (Thymus vulgaris) were screened. Their inhibitory activity against Herpes simplex virus type 1 (HSV-1), type 2 (HSV-2) and an acyclovir-resistant strain of HSV-1 (ACV (res)) was tested in vitro on RC-37 cells in a plaque reduction assay. The 50% inhibitory concentrations (IC (50)) of the extracts for HSV plaque formation were determined in dose-response studies. All test compounds showed a high antiviral activity against HSV-1, HSV-2 and ACV (res). In order to identify the mode of antiviral action, the extracts were added to the cells or viruses at different stages of infection. Both types of Herpes virus including ACV (res) were considerably neutralized after treatment with the extracts prior to infection. At maximum non-cytotoxic concentrations of the extracts, plaque formation was significantly reduced by > 90% for HSV-1 and HSV-2 and > 85% for ACV (res). In time-response studies over a period of 2 hours, a clearly time-dependent activity was demonstrated. These results indicate that the extracts affect HSV before adsorption, but have no effect on the intracellular virus replication. Therefore, the extracts exert their antiviral effect on free HSV and offer a chance to use them for topical therapeutic application against recurrent HERPES infections.     

Inhibition of herpes simplex virus type 1 and adenovirus type 5 by heterocyclic Schiff bases of aminohydroxyguanidine tosylate

Eleven heterocyclic Schiff bases of aminohydroxyguanidine tosylate (SB-AHGs), compounds I-XI, were tested for antiviral activity against herpes simplex virus type 1 (HSV-1) and adenovirus type 5 (Ad 5) via plaque reduction and virus yield reduction assays. This work was undertaken to test the hypothesis that low molecular weight SB-AHGs (MW < 235 for the free SB) make better antiviral agents than high MW SB-AHGs (MW > 300). The plaque reduction assay method demonstrated that three compounds, I, VII and IX, had moderate activity against HSV-1, with 50% inhibitory concentration (IC50) values of 38.0, 23.5 and 52.1 microM, respectively. Against Ad 5, compounds I, VIII and XI exhibited moderate activity, with IC50 values of 52.7, 19.3 and 5.1 microM, respectively. Among the compounds screened, compound I (1-[(3'-hydroxy-6'-methyl-2'-pyridyl)methylene]amino-3-hydroxyguanidi ne tosylate) was the most promising antiviral candidate, with selectivity indices (SI) of 10.2 (HSV-1) and 7.6 (Ad 5), respectively. Virus yield reduction assays indicated that compound I had less antiviral potency against HSV-1 than against Ad 5. The antiviral effects of compound I at a high input virus multiplicity of infection (MOI > 5) indicated that compound I had effective anti-adenoviral activity at 24 h post infection. This work demonstrated that some of SB-AHGs only have moderate antiviral activities against Ad 5 and HSV-1 viruses. In general, low MW SB-AHGs have low cytotoxicities to the host cells.     

Antiviral activity of Spirulina maxima against herpes simplex virus type 2

Spirulina has been used in a variety of practical applications in biotechnology and medical sciences. This paper presents the antiviral activity found in a hot water extract (HWE) of a commercial preparation of Spirulina maxima, studied by a microplate inhibition assay, using several viruses. The HWE inhibited the infection for: herpes simplex virus type 2 (HSV-2), pseudorabies virus (PRV), human cytomegalovirus (HCMV), and HSV-1, and the 50% effective inhibition doses (ED(50)) were 0.069, 0.103, 0.142, and 0.333 mg/ml for each virus, respectively. For adenovirus the inhibition was less than 20%, and no inhibition was found for measles virus, subacute sclerosing panencephalitis virus (SSPE), vesicular stomatitis virus (VSV), poliovirus 1 and rotavirus SA-11, at concentrations of 2 mg/ml of the HWE. The highest antiviral activity was for HSV-2, with a selectivity index of 128. The antiviral activity was not due to a virucidal effect. Herpesvirus infection was inhibited at the initial events (adsorption and penetration) of the viral cycle. To initiate the isolation and identification of the compound that exhibits the antiviral activity of S. maxima, some extracts made by using several solvents with different polarity were evaluated by microplate inhibition assay using HSV-2. The highest antiviral activity was detected in the methanol-water 3:1, which suggests that the antiviral activity is probably due to highly polar compounds.     

Antiviral activity of the marine alga Symphyocladia latiuscula against herpes simplex virus (HSV-1) in vitro and its therapeutic efficacy against HSV-1 infection in mice

The antiviral activities of extracts from 5 species of marine algae collected at Haeundae (Pusan, Korea), were examined using plaque reduction assays. Although the activity of a methanol (MeOH) extract of Sargassum ringoldianum (Sargassaceae) was the most potent against several types of viruses, it was also cytotoxic. A MeOH extract of Symphyocladia latiuscula (Rhodomelaceae) and its fractions exhibited antiviral activities against acyclovir (ACV) and phosphonoacetic acid (PAA)-resistant (AP(r)) herpes simplex type 1 (HSV-1), thymidine kinase (TK(-)) deficient HSV-1 and wild type HSV-1 in vitro without cytotoxicity. The major component, 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (TDB) of a CH(2)Cl(2)-soluble fraction was active against wild type HSV-1, as well as AP(r) HSV-1 and TK(-) HSV-1 (IC(50) values of 5.48, 4.81 and 23.3 microg/ml, respectively). The therapeutic effectiveness of the MeOH extract and TDB from S. latiuscula was further examined in BALB/c mice that were cutaneously infected with HSV-1 strain 7401H. Three daily oral administrations of the MeOH extract and TDB significantly delayed the appearance of score 2 skin lesions (local vesicles) and limited the development of further score 6 (mild zosteriform) lesions in infected mice without toxicity compared with controls. In addition, TDB suppressed virus yields in the brain and skin. Therefore TDB should be a promising anti HSV agent.     

Enhancement of non-specific resistance to viral infection by muramyldipeptide and its analogs

Antiviral activity of muramyldipeptide (MDP) and its lipophilic derivatives, B30-MDP and MDP-Lys(L18), was investigated in mice infected with vaccinia virus (VV) and herpes simplex virus type 2 (HSV-2). Mice administered these compounds subcutaneously or orally were protected against VV in tail lesion tests and against HSV-2 in skin lesion tests, respectively. Since in vitro antiviral activity was not demonstrated with these compounds in cultured mammalian cells infected with either VV or HSV-2, host-mediated defense mechanisms may play a role in the activity of the compounds. As for serum interferon (IFN) induction, MDP and its analogs showed no activity in mice, suggesting that IFN does not participate in the antiviral mechanisms against VV and HSV-2. An extrinsic antiviral activity was demonstrated when peritoneal macrophages from the mice administered these compounds were cocultivated with VV-infected 3T3 cells. The results indicate that macrophage activation by MDP and its analogs plays a role in the defense mechanisms against viral infection. This activity was not virus-specific. We also demonstrate that the introduction of lipophilic residue(s) into MDP enhances the antiviral activity of mice against VV and HSV-2.     

Inhibition of bovine viral diarrhea virus in vitro by xanthohumol: Comparisons with ribavirin and interferon-α and implications for the development of anti-hepatitis C virus agents

Xanthohumol (XN) is a natural compound with potential antiviral activity. In this study, the ability of XN to inhibit bovine viral diarrhea virus (BVDV), a surrogate model of hepatitis C virus (HCV), was investigated. The antiviral activity of XN was compared with that of ribavirin (RBV) and interferon (IFN)-α. The results showed that XN could inhibit BVDV induced cytopathic effects (CPE). At 1000 TCID₅₀ and 100 TCID₅₀, the values of 50% effective concentration (EC₅₀) were 3.24 ± 0.02 mg/l and 2.77 ± 0.19 mg/l, respectively, and the therapeutic indices were >7.72 and >9.03, respectively. XN inhibited BVDV E2 expression and viral RNA levels in a dose-dependent manner. At 6.25 mg/l, XN decreased the viral RNA from released virus by 3.83 log 10 at 1000 TCID₅₀ and to an undetectable level at 100 TCID₅₀, and decreased the viral RNA level in whole cell culture by 3.36 log 10 and 2.88 log 10 at 1000 TCID₅₀ and 100 TCID₅₀, respectively. The inhibitory activity of XN on CPE, BVDV E2 expression and viral RNA levels was stronger than that of RBV and weaker than that of IFN-α. These results indicate the need to investigate the anti-HCV potential of XN.     

Antiviral amentoflavone from Selaginella sinensis

Amentoflavone and three other flavonoids were isolated from the ethanol extract of Selaginella sinensis. Amentoflavone showed potent antiviral activity against respiratory syncytial virus (RSV), with an IC50 of 5.5 microg/ml. The contents of amentoflavone in nine species of Selaginella were determined by reversed-phase HPLC. S. sinensis showed a higher content of 1.13%.     

Antiviral activity of cyclosaligenyl prodrugs of the nucleoside analogue bromovinyldeoxyuridine against herpes viruses

A series of 42 lipophilic bromovinyldeoxyuridine monophosphates (BVDUMPs) are presented as potential prodrugs of the antiviral agent (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU). The 5'-cycloSal-masking group technique has been applied to this cyclic nucleoside analogue to achieve delivery of the monophosphate of BVDU inside the target cells. The new substances have been tested for their antiviral activity against herpes simplex virus types 1 and 2 (HSV-1 and -2), thymidine kinase-deficient (TK(-)) HSV-1, varicella-zoster virus (VZV), human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV). The XTT-based tetrazolium reduction assay EZ4U (for HSV), the plaque inhibition test (for VZV and HCMV) and a DNA hybridisation assay (for EBV) were used to assess antiviral activity. The results indicate that cycloSal-BVDUMP triesters proved to be potent and selective inhibitors of HSV-1 comparable with aciclovir. VZV replication was inhibited by very low concentrations, and two substances had a slightly better anti-VZV activity than the parent compound BVDU. No antiviral effect could be demonstrated against TK(-)-HSV-1, HSV-2 and HCMV, most likely owing to the lack of phosphorylation to BVDU diphosphate. Most remarkably, several cycloSal-BVDUMP triesters yielded promising anti-EBV activity whereas the parent compound BVDU was entirely inactive.