HIV-1 reverse transcriptase(RT) inhibitors are major components of HAART(highly active antiviral therapy). The S-DABOs(dihydro-alkylthio-benzyl-oxopyrimidines) series and their similar skeletons have exhibited p...HIV-1 reverse transcriptase(RT) inhibitors are major components of HAART(highly active antiviral therapy). The S-DABOs(dihydro-alkylthio-benzyl-oxopyrimidines) series and their similar skeletons have exhibited preferable activities to inhibit HIV-1 RT. In the present study, we generated field-based QSAR models using common structure alignment, which was characterized by Gaussian steric, electrostatic, hydrophobic, hydrogen bond donor, hydrogen bond acceptor and aromatic ring fields(R2 = 0.8421, RCV2 = 0.5949 for the training set, Q2 = 0.5486, Pearson-r = 0.7460 for the test set). Docking, pocket surface and contour map analyses were carried out. Key pharmacophore features were investigated, including(i) π-π interaction with residue Tyr181, Tyr188 and Trp229, σ-π interaction with His236,(ii) hydrogen bond with residue Lys101 and halogen bond with residue Tyr188. The docking analysis and field-based QSAR models could provide reasonable guidance in the rational design of potent HIV-1 RT inhibitors.展开更多
N-1-alkyl-5-halogeno-6-alkylamino uracils,which are novel 1-[(2-hydroxyethoxy) methyl]-6-(phenylthio) thymine (HEPT) analogues,were synthesized as the selective and potent non-nucleoside human immunodeficiency virus(H...N-1-alkyl-5-halogeno-6-alkylamino uracils,which are novel 1-[(2-hydroxyethoxy) methyl]-6-(phenylthio) thymine (HEPT) analogues,were synthesized as the selective and potent non-nucleoside human immunodeficiency virus(HIV)-1 reverse transcriptase inhibitors.Some of the compounds showed potent inhibitory activity against HIV-1 reverse transcriptase.For instance,compounds 1d,1m and 1n exhibited potent anti-HTV-1 activity with the IC_(50) values of 13.3,11.7 and 3.15μM,respectively, which are comparable to that of nevirapine(IC_(50) 8.38μM).展开更多
A series of novel dihydro-alkylthio-benzyl-oxopyrimidines (S-DABOs) 7a-f have been designed and synthesized with an efficient method. Biological evaluation of their HIV-1 reverse transcriptase inhibitory activities ...A series of novel dihydro-alkylthio-benzyl-oxopyrimidines (S-DABOs) 7a-f have been designed and synthesized with an efficient method. Biological evaluation of their HIV-1 reverse transcriptase inhibitory activities was performed using Nevirapine (NVP) as a reference compound. Among the series, compound 7d shows the highest reverse transcriptase inhibitory activity, which is better than Nevirapine.展开更多
1-Alkyl-5-amino-6-phenylethyluracils (1a, 1b) were synthesized as potential non-nucleoside HIV-1RT inhibitors. A convenient synthetic procedure was developed for the preparation of 1-alkyl-5-amino or 5-aminosubstitu...1-Alkyl-5-amino-6-phenylethyluracils (1a, 1b) were synthesized as potential non-nucleoside HIV-1RT inhibitors. A convenient synthetic procedure was developed for the preparation of 1-alkyl-5-amino or 5-aminosubstituted-6-phenylethyluracils, which were synthesized in three or four steps from 6-methyluracil in good yield. The development of a one-pot reaction that simultaneously removed the benzyl protection group and reduced the nitro group greatly improved the yield of the synthesis. Compounds 1a and 1b are analogs of MKC-442, which is an efficient inhibitor of HIV-1 reverse transcriptase, 1a and 1b were tested for their inhibition of HIV-1RT, and moderate activity was found for 1a.展开更多
HIV-1 reverse transcriptase (RT) RNase H (HIV-RH) is a key target of anti-AIDS drugs. Metal-chelating compounds are an important class of chemicals in pharmacological drug discovery, especially in relation to HIV-RT a...HIV-1 reverse transcriptase (RT) RNase H (HIV-RH) is a key target of anti-AIDS drugs. Metal-chelating compounds are an important class of chemicals in pharmacological drug discovery, especially in relation to HIV-RT and the highly-related HIV-integrase. The correlation between the metal-chelating properties and enzyme activities of the metal chelators is always of high scientific interest, as an understanding of this may accelerate the rational optimization of this class of inhibitors. Our NMR data show that Mg2+ and Ca2+ bind specifically to the active site of the RNase H domain and two Mg2+ ions sequentially bind one molecule of RNase H. We also demonstrate here, using saturated and unsaturated tricyclic N-hydroxypyridones designed to block the active site, that the primary binding sites and affinities of divalent metal ions are correlated with the structures of the chelating motifs. Chemical shift perturbation studies of protein/metal-ion/compound ternary complexes also indicate that divalent metal ions play important roles for the specific interaction of the compounds with the RNase H active site.展开更多
We have synthesized the novel compounds 1a-1i,which are a series of hybrid analogues to 6-benzyl-1-(benzyloxymethyl)- 5-iodouracil,a compound showing strong activity against HIV-1.We also evaluated the activity of t...We have synthesized the novel compounds 1a-1i,which are a series of hybrid analogues to 6-benzyl-1-(benzyloxymethyl)- 5-iodouracil,a compound showing strong activity against HIV-1.We also evaluated the activity of these compounds as the inhibitors of HIV-1 reverse transcriptase(HIV-1 RT),and they have demonstrated moderate activity.展开更多
With our continuous endeavors in seeking potent anti-HIV-1 agents,we reported here the discovery,biological characterization,and druggability evaluation of a class of nonnucleoside reverse transcriptase inhibitors.To ...With our continuous endeavors in seeking potent anti-HIV-1 agents,we reported here the discovery,biological characterization,and druggability evaluation of a class of nonnucleoside reverse transcriptase inhibitors.To fully explore the chemical space of the NNRTI-binding pocket,novel series of dihydrothiopyrano[3,2-d]pyrimidines were developed by employing the structure-based design strategy.Most of the derivatives were endowed with prominent antiviral activities against HIV-1 wild-type and resistant strains at nanomolar levels.Among them,compound 23h featuring the aminopiperidine moiety was identified as the most potent inhibitor,with EC50values ranging from 3.43 to 21.4 nmol/L.Especially,for the challenging double-mutants F227L+V106A and K103N+Y181C,23h exhibited 2.3-to 14.5-fold more potent activity than the first-line drugs efavirenz and etravirine.Besides,the resistance profiles of 23h achieved remarkable improvement compared to efavirenz and etravirine.The binding target of 23h was further confirmed to be HIV-1 reverse transcriptase.Molecular modeling studies were also performed to elucidate the biological evaluation results and give guidance for the optimization campaign.Furthermore,no apparent inhibition of the major CYP450 enzymes and hERG channel was observed for 23h.Most importantly,23h was characterized by good pharmacokinetic properties and excellent safety in vivo.Collectively,23h holds great promise as a potential candidate for its effective antiviral efficacy and favorable drug-like profiles.展开更多
N-l-alkyl-5-halogeno-6-alkylamino uracils, which are novel l-[(2-hydroxyethoxy) methyl]-6-(phenylthio) thymine (HEPT) analogues, were synthesized as the selective and potent non-nucleoside human immunodeficiency...N-l-alkyl-5-halogeno-6-alkylamino uracils, which are novel l-[(2-hydroxyethoxy) methyl]-6-(phenylthio) thymine (HEPT) analogues, were synthesized as the selective and potent non-nucleoside human immunodeficiency virus (HIV)-I reverse transcriptase inhibitors. Some of the compounds showed potent inhibitory activity against HIV-1 reverse transcriptase. For instance, compounds ld, lm and In exhibited potent anti-HIV-1 activity with the ICso values of 13.3, 11.7 and 3.15 μM, respectively, which are comparable to that of nevirapine (IC50 8.38 μM).展开更多
AIM: To study the relationship between interleukin-lbeta (IL-1β) up-regulating tissue inhibitor of matrix metalloproteinase-1 (TIMMP-1) mRNA expression and phosphorylation of both c-jun N-terminal kinase (INK)...AIM: To study the relationship between interleukin-lbeta (IL-1β) up-regulating tissue inhibitor of matrix metalloproteinase-1 (TIMMP-1) mRNA expression and phosphorylation of both c-jun N-terminal kinase (INK) and p38 in rat heffatic stellate cells (HSC). METHODS: RT-PCR was performed to measure the expression of TIMMP-1 mRNA in rat HSC. Western blot was performed to measure IL-1β-induced JNK and p38 activities in rat HSC. RESULTS: TIMMP-1 mRNA expression (1.191± 0.079) was much higher after treatment with IL-1β (10 ng/mL) for 24 h than in control group (0.545±0.091) (P〈0.01). IL-1β activated INK and p38 in a time-dependent manner. After stimulation with IL-1β for 0, 5, 15, 30, 60 and 120 min, the INK activity was 0.982±0.299, 1.501±0.720, 2.133±0.882, 3.360±0.452, 2.181±0.789, and 1.385 ± 0.368, respectively. There was a significant difference in JNK activity at 15 min (P〈 0.01), 30 min (P〈 0.01) and 60 min (P〈0.01) in comparison to that at 0 min. The p38 activity was 1.061±0.310, 2.050±0.863, 2.380±0.573, 2.973±0.953, 2.421±0.793, and 1.755 ± 0.433 at the 6 time points (0, 5, 15, 30, 60 and 120 min) respectively. There was a significant difference in p38 activity at 5 min (P〈0.05), 15 min (P〈0.01), 30 min (P〈0.01) and 60 min (P〈0.01) compared to that at 0 min. TIMMP-1 mRNA expression trended to decrease in 3 groups pretreated with different concentrations of SP600125 (10 μmol/L, 1.022±0.113; 20 μmol/L, 0.869±0.070; 40 μmol/L, 0.666±0.123). Their decreases were all significant (P〈0.05, P〈0.01, P〈0.01) in comparison to control group (without SP600125 treatment, 1.163±0.107). In the other 3 groups pretreated with different concentrations of SB203580 (10 μmol/L, 1.507±0.099; 20 μmol/L, 1.698±0.107; 40 μmol/L, 1.857±0.054), the expression of TIMMP-1 mRNA increased. Their levels were higher than those in the control group (without SB203580 treatment, 1.027 ± 0.061) with a significant statistical significance (P〈 0.01). CONCLUSION: IL-1β has a direct action on hepatic fibrosis by up-regulating TIMMP-1 mRNA expression in ratessionin in rate HSC.JNK and p38 mitogen-activated protein kinases (MAPKs) are involved in IL-1β-induced TIMMP-1 gene expression, and play a distinct role in this process, indicating that p38 and .INK pathways cooperatively mediate TIMP-1 mRNA expression in rat HSC.展开更多
Among the structurally diverse NNRTIs, pyridinone scaffolds demonstrate high potency against HIV-1 wild type and drug-resistant strains. During the optimization of our pyridinone compound 1(LAM-trans), we found that...Among the structurally diverse NNRTIs, pyridinone scaffolds demonstrate high potency against HIV-1 wild type and drug-resistant strains. During the optimization of our pyridinone compound 1(LAM-trans), we found that the introduction of the N atoms in the C-4 position could dramatically improve the water solubility(7b), whereas protonation of the piperidine N atom resulted in a decrease in its hydrophobic interaction with the binding pocket. In particular, protonation altered the orientation of the alicyclic rings in the hydrophobic pocket, thus impeding the formation of key halogen bond and eventually leading to a huge change in anti-HIV-1 RT activity. These results provided theoretical and experimental basis for the subsequent structural modification of pyridinone compounds.展开更多
In order to clarify, the mechanism of inhibition of human neutrophil peptide-1 ( HNP-1 ) on hu- man immunodeficiency vires type 1 (HIV-1 ), CD4^ + cells were used as the target cells for acute infection with HIV-...In order to clarify, the mechanism of inhibition of human neutrophil peptide-1 ( HNP-1 ) on hu- man immunodeficiency vires type 1 (HIV-1 ), CD4^ + cells were used as the target cells for acute infection with HIV-1, and experiments were peffomed separately with the interaction of different concentrations of HNP-1 with free vires particles, un-infected and infected CD4^+ cells. The activity of reverse transcriptase (RT) in the supematant of cell cultures of different lots of experiments were then assayed accordingly, and the toxicity effect on human lymphocytic cells MT4 was measured by MTT assay. The experimental results showed that pre-incubation of HNP-1 with the concentrated stock of vires could block the binding of vires to target cells with EC50 of 2.49 μg/ml, while pre-treatment of CD4^+ cells with HNP- 1 prior to inoculation could reduce the ability of cells to bind vires with EC50 of 20.7 μg/ml. In addition, When culturing the infected CD4^+ cells in the continuous presence of various concentrations of HNP-1 added immediately after infection, HNP-1 exhibited modest inhibitory effect on viral replication with reduced RT activities in comparison with those of the control group ( P 〈 0.05 at 100 μg/ml of the highest concentration) . No cytotoxieity effect of HNP-1 was observed as demonstrated by MTT assay. These results indicate that HNP-1 exerts anti-HIV activity by at least two levels: direct inactivation of vires particles and effect on the ability of target cells to bind with viruses. The evaluation of two parameters, inhibitoty effect and the cytotoxicity renders HNP-1 an available candidate for anti-HIV therapeutic agent.展开更多
基金National Natural Science Foundation of China(Grant No.21172014,20972011,21042009,21272017 and 81172917)Grants from the Ministry of Science and Technology of China(Grant No.2009ZX09301-010)
文摘HIV-1 reverse transcriptase(RT) inhibitors are major components of HAART(highly active antiviral therapy). The S-DABOs(dihydro-alkylthio-benzyl-oxopyrimidines) series and their similar skeletons have exhibited preferable activities to inhibit HIV-1 RT. In the present study, we generated field-based QSAR models using common structure alignment, which was characterized by Gaussian steric, electrostatic, hydrophobic, hydrogen bond donor, hydrogen bond acceptor and aromatic ring fields(R2 = 0.8421, RCV2 = 0.5949 for the training set, Q2 = 0.5486, Pearson-r = 0.7460 for the test set). Docking, pocket surface and contour map analyses were carried out. Key pharmacophore features were investigated, including(i) π-π interaction with residue Tyr181, Tyr188 and Trp229, σ-π interaction with His236,(ii) hydrogen bond with residue Lys101 and halogen bond with residue Tyr188. The docking analysis and field-based QSAR models could provide reasonable guidance in the rational design of potent HIV-1 RT inhibitors.
基金National Natural Science Foundation of China (Grant No.20672008 and 20972011).
文摘N-1-alkyl-5-halogeno-6-alkylamino uracils,which are novel 1-[(2-hydroxyethoxy) methyl]-6-(phenylthio) thymine (HEPT) analogues,were synthesized as the selective and potent non-nucleoside human immunodeficiency virus(HIV)-1 reverse transcriptase inhibitors.Some of the compounds showed potent inhibitory activity against HIV-1 reverse transcriptase.For instance,compounds 1d,1m and 1n exhibited potent anti-HTV-1 activity with the IC_(50) values of 13.3,11.7 and 3.15μM,respectively, which are comparable to that of nevirapine(IC_(50) 8.38μM).
基金National Natural Science Foundation of China (GrantNo.20972011,21042009)
文摘A series of novel dihydro-alkylthio-benzyl-oxopyrimidines (S-DABOs) 7a-f have been designed and synthesized with an efficient method. Biological evaluation of their HIV-1 reverse transcriptase inhibitory activities was performed using Nevirapine (NVP) as a reference compound. Among the series, compound 7d shows the highest reverse transcriptase inhibitory activity, which is better than Nevirapine.
基金National Science Foundation of China (Grant No.20672)the Doctoral grant of the Ministry of Education of China(Grant No.2007000174).
文摘1-Alkyl-5-amino-6-phenylethyluracils (1a, 1b) were synthesized as potential non-nucleoside HIV-1RT inhibitors. A convenient synthetic procedure was developed for the preparation of 1-alkyl-5-amino or 5-aminosubstituted-6-phenylethyluracils, which were synthesized in three or four steps from 6-methyluracil in good yield. The development of a one-pot reaction that simultaneously removed the benzyl protection group and reduced the nitro group greatly improved the yield of the synthesis. Compounds 1a and 1b are analogs of MKC-442, which is an efficient inhibitor of HIV-1 reverse transcriptase, 1a and 1b were tested for their inhibition of HIV-1RT, and moderate activity was found for 1a.
文摘HIV-1 reverse transcriptase (RT) RNase H (HIV-RH) is a key target of anti-AIDS drugs. Metal-chelating compounds are an important class of chemicals in pharmacological drug discovery, especially in relation to HIV-RT and the highly-related HIV-integrase. The correlation between the metal-chelating properties and enzyme activities of the metal chelators is always of high scientific interest, as an understanding of this may accelerate the rational optimization of this class of inhibitors. Our NMR data show that Mg2+ and Ca2+ bind specifically to the active site of the RNase H domain and two Mg2+ ions sequentially bind one molecule of RNase H. We also demonstrate here, using saturated and unsaturated tricyclic N-hydroxypyridones designed to block the active site, that the primary binding sites and affinities of divalent metal ions are correlated with the structures of the chelating motifs. Chemical shift perturbation studies of protein/metal-ion/compound ternary complexes also indicate that divalent metal ions play important roles for the specific interaction of the compounds with the RNase H active site.
基金National Natural Science Foundation of China (Grant No.20672008,and 20972011)
文摘We have synthesized the novel compounds 1a-1i,which are a series of hybrid analogues to 6-benzyl-1-(benzyloxymethyl)- 5-iodouracil,a compound showing strong activity against HIV-1.We also evaluated the activity of these compounds as the inhibitors of HIV-1 reverse transcriptase(HIV-1 RT),and they have demonstrated moderate activity.
基金financial support from the National Natural Science Foundation of China(NSFC nos.81973181 and 81903453)Science Foundation for Outstanding Young Scholars of Shandong Province(ZR2020JQ31,China)+6 种基金Science Foundation for Excellent Young Scholars of Shandong Province(ZR2020YQ61,China)Foreign Cultural and Educational Experts Project(GXL20200015001,China)China Postdoctoral Science Foundation(2022M721948)Shandong Province Natural Science Foundation for Youths(ZR2023QH217,China)Natural Science Foundation of Jiangsu Province(BK20230252,China)Qilu Young Scholars Program of Shandong UniversityTaishan Scholar Program at Shandong Province。
文摘With our continuous endeavors in seeking potent anti-HIV-1 agents,we reported here the discovery,biological characterization,and druggability evaluation of a class of nonnucleoside reverse transcriptase inhibitors.To fully explore the chemical space of the NNRTI-binding pocket,novel series of dihydrothiopyrano[3,2-d]pyrimidines were developed by employing the structure-based design strategy.Most of the derivatives were endowed with prominent antiviral activities against HIV-1 wild-type and resistant strains at nanomolar levels.Among them,compound 23h featuring the aminopiperidine moiety was identified as the most potent inhibitor,with EC50values ranging from 3.43 to 21.4 nmol/L.Especially,for the challenging double-mutants F227L+V106A and K103N+Y181C,23h exhibited 2.3-to 14.5-fold more potent activity than the first-line drugs efavirenz and etravirine.Besides,the resistance profiles of 23h achieved remarkable improvement compared to efavirenz and etravirine.The binding target of 23h was further confirmed to be HIV-1 reverse transcriptase.Molecular modeling studies were also performed to elucidate the biological evaluation results and give guidance for the optimization campaign.Furthermore,no apparent inhibition of the major CYP450 enzymes and hERG channel was observed for 23h.Most importantly,23h was characterized by good pharmacokinetic properties and excellent safety in vivo.Collectively,23h holds great promise as a potential candidate for its effective antiviral efficacy and favorable drug-like profiles.
基金Foundation items: National Natural Science Foundation of China (Grant No. 20672008 and 20972011).
文摘N-l-alkyl-5-halogeno-6-alkylamino uracils, which are novel l-[(2-hydroxyethoxy) methyl]-6-(phenylthio) thymine (HEPT) analogues, were synthesized as the selective and potent non-nucleoside human immunodeficiency virus (HIV)-I reverse transcriptase inhibitors. Some of the compounds showed potent inhibitory activity against HIV-1 reverse transcriptase. For instance, compounds ld, lm and In exhibited potent anti-HIV-1 activity with the ICso values of 13.3, 11.7 and 3.15 μM, respectively, which are comparable to that of nevirapine (IC50 8.38 μM).
文摘AIM: To study the relationship between interleukin-lbeta (IL-1β) up-regulating tissue inhibitor of matrix metalloproteinase-1 (TIMMP-1) mRNA expression and phosphorylation of both c-jun N-terminal kinase (INK) and p38 in rat heffatic stellate cells (HSC). METHODS: RT-PCR was performed to measure the expression of TIMMP-1 mRNA in rat HSC. Western blot was performed to measure IL-1β-induced JNK and p38 activities in rat HSC. RESULTS: TIMMP-1 mRNA expression (1.191± 0.079) was much higher after treatment with IL-1β (10 ng/mL) for 24 h than in control group (0.545±0.091) (P〈0.01). IL-1β activated INK and p38 in a time-dependent manner. After stimulation with IL-1β for 0, 5, 15, 30, 60 and 120 min, the INK activity was 0.982±0.299, 1.501±0.720, 2.133±0.882, 3.360±0.452, 2.181±0.789, and 1.385 ± 0.368, respectively. There was a significant difference in JNK activity at 15 min (P〈 0.01), 30 min (P〈 0.01) and 60 min (P〈0.01) in comparison to that at 0 min. The p38 activity was 1.061±0.310, 2.050±0.863, 2.380±0.573, 2.973±0.953, 2.421±0.793, and 1.755 ± 0.433 at the 6 time points (0, 5, 15, 30, 60 and 120 min) respectively. There was a significant difference in p38 activity at 5 min (P〈0.05), 15 min (P〈0.01), 30 min (P〈0.01) and 60 min (P〈0.01) compared to that at 0 min. TIMMP-1 mRNA expression trended to decrease in 3 groups pretreated with different concentrations of SP600125 (10 μmol/L, 1.022±0.113; 20 μmol/L, 0.869±0.070; 40 μmol/L, 0.666±0.123). Their decreases were all significant (P〈0.05, P〈0.01, P〈0.01) in comparison to control group (without SP600125 treatment, 1.163±0.107). In the other 3 groups pretreated with different concentrations of SB203580 (10 μmol/L, 1.507±0.099; 20 μmol/L, 1.698±0.107; 40 μmol/L, 1.857±0.054), the expression of TIMMP-1 mRNA increased. Their levels were higher than those in the control group (without SB203580 treatment, 1.027 ± 0.061) with a significant statistical significance (P〈 0.01). CONCLUSION: IL-1β has a direct action on hepatic fibrosis by up-regulating TIMMP-1 mRNA expression in ratessionin in rate HSC.JNK and p38 mitogen-activated protein kinases (MAPKs) are involved in IL-1β-induced TIMMP-1 gene expression, and play a distinct role in this process, indicating that p38 and .INK pathways cooperatively mediate TIMP-1 mRNA expression in rat HSC.
基金The National Natural Science Foundation of China(Grant No.21172014,20972011 and 21042009)
文摘Among the structurally diverse NNRTIs, pyridinone scaffolds demonstrate high potency against HIV-1 wild type and drug-resistant strains. During the optimization of our pyridinone compound 1(LAM-trans), we found that the introduction of the N atoms in the C-4 position could dramatically improve the water solubility(7b), whereas protonation of the piperidine N atom resulted in a decrease in its hydrophobic interaction with the binding pocket. In particular, protonation altered the orientation of the alicyclic rings in the hydrophobic pocket, thus impeding the formation of key halogen bond and eventually leading to a huge change in anti-HIV-1 RT activity. These results provided theoretical and experimental basis for the subsequent structural modification of pyridinone compounds.
文摘In order to clarify, the mechanism of inhibition of human neutrophil peptide-1 ( HNP-1 ) on hu- man immunodeficiency vires type 1 (HIV-1 ), CD4^ + cells were used as the target cells for acute infection with HIV-1, and experiments were peffomed separately with the interaction of different concentrations of HNP-1 with free vires particles, un-infected and infected CD4^+ cells. The activity of reverse transcriptase (RT) in the supematant of cell cultures of different lots of experiments were then assayed accordingly, and the toxicity effect on human lymphocytic cells MT4 was measured by MTT assay. The experimental results showed that pre-incubation of HNP-1 with the concentrated stock of vires could block the binding of vires to target cells with EC50 of 2.49 μg/ml, while pre-treatment of CD4^+ cells with HNP- 1 prior to inoculation could reduce the ability of cells to bind vires with EC50 of 20.7 μg/ml. In addition, When culturing the infected CD4^+ cells in the continuous presence of various concentrations of HNP-1 added immediately after infection, HNP-1 exhibited modest inhibitory effect on viral replication with reduced RT activities in comparison with those of the control group ( P 〈 0.05 at 100 μg/ml of the highest concentration) . No cytotoxieity effect of HNP-1 was observed as demonstrated by MTT assay. These results indicate that HNP-1 exerts anti-HIV activity by at least two levels: direct inactivation of vires particles and effect on the ability of target cells to bind with viruses. The evaluation of two parameters, inhibitoty effect and the cytotoxicity renders HNP-1 an available candidate for anti-HIV therapeutic agent.