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A unique prenylated bicarbazole alkaloid, clausanisumine (1), and two biogenetically related known monomer carbazole alkaloids, mukonal (2) and 3-methylcarbazole (3), were isolated from the fruits of Clausena anisum-olens. Clausanisumine (1) was an uncommon prenylated bicarbazole alkaloid, possessing an unprecedented carbon skeleton, which was composed of a simple carbazole alkaloid and a prenylated carbazole alkaloid. The chemical structure of 1 was established by a combination of comprehensive spectral methods. A plausible biosynthetic pathway of 1 was also proposed. Additionally, the potential anti-HIV activities of all isolates 1-3in vitro were evaluated. Compound 1 exhibited remarkable anti-HIV-1 reverse transcriptase effects showing an EC50 value of 18.58 nM. The discovery of the prenylated bicarbazole alkaloid from C. anisum-olens with notable anti-HIV activity would be meaningful to discovering and developing new anti-HIV drugs.

A pair of new oxindole alkaloids, named macrophyllines C (1) and D (2), together with two known oxindole alkaloids isorhynchophylline (3) and corynoxine (4) were isolated from Uncaria macrophylla. Their structures were elucidated based on detailed spectroscopic analysis and by comparison with literature data. In addition, all the isolates were tested for their anti-HIV activities and cytotoxicities in C8166 cells and compounds 2-4 showed weak anti-HIV activities with EC50 values of 11.31 ± 3.29 μM, 18.77 ± 6.14 μM and 30.02 ± 3.73 μM, respectively.

A new icetexane diterpenoid, 11, 12, 20α-trihydroxyl-7β-methoxyicetexa-8, 11, 13-triene-19, 10-lactone [Phyllane A (1)], and a new abietane diterpenoid, 7β, 20-epoxy-3β, 17-acetoxy-abieta-8, 11, 13...

A new method for the synthesis of glycyrrhizic acid (GA) conjugates with S-benzyl-L-cysteine using 1-ethyl-3-(3-dimethylaminoproopyl)carbodiimide is proposed. It is established that 3-O-{2-O-[N-(β-D-glucopyranosyluronyl)-L-cysteine-S-benzyl]-N-(β-D-glucopyranosyluronyl)-L-cysteine-S-benzyl}-(3β,20β)-11-oxo-30-(N-carbonyl-L-cysteine-S-benzyl)-30-norolean-12-ene is superior to GA in inhibiting the accumulation of HIV-I virus-specific protein p24 (viral antigen) in MT-4 cell culture (IC50 3 μg/mL, SI 90) and is 50 - 55 times less toxic to cells than azidothymidine.

Предложен новый способ синтеза конъюгатов глицирризиновой кислоты (ГК) с S-бензил-L-цистеином с использованием 1-этил-3-(3-диметиламинопропил)карбодиимида. Установлено, что 3-О-{2-О-[N-(β-D-глюкопиранозилуроноил)-L-цистеин-S-бензил]-N-(β-D-глюкопиранозилуроноил)-L-цистеин-S-бензил}-(3β,20β)-11-оксо-30-(N-карбонил-L- цистеин-S-бензил)-30-норолеан-12-ен превосходит ГК по ингибированию накопления вирусоспецифического белка р24 (вирусного антигена) ВИЧ-1 в культуре клеток МТ-4 (IC50 3 мкг/мл, SI 90) и является в 50 – 55 раз менее токсичным веществом для клеток, чем азидотимидин.

In the last 2-3 decades, the broad research in the application of benzimidazole derivatives made it important for mankind. Many scientists have worked on benzimidazole derivatives and they found that this compound has a diverse role in the field of medicinal chemistry. Few benzimidazole derivatives are currently in the market as a drug candidate against various diseases. Moreover, the benzimidazole derivatives exhibit pharmacological activities such as anti-tuberculosis, anti-malarial, antihistamine, antimicrobial, antiviral, antidiabetic, anticancer, anti-fungal, anti-inflammatory, analgesic, anti-HIV, etc. In this review, we have summarized various derivatives of benzimidazole which have been prepared by many researchers to understand the chemistry as well as diverse pharmacological activities. These findings may lead the scientists who are working in the field of medicinal chemistry to the development of benzimidazole based drug candidates in the future.

An expansion of the structure-activity relationship study of CXCR4 antagonists led to the synthesis of a series of isoquinolines, bearing a tetrahydroquinoline or a 3-methylpyridinyl moiety as head group. All compounds were investigated for CXCR4 affinity and antagonism in competition binding and calcium mobilization assays, respectively. In addition, the anti-HIV activity of all analogues was determined. All compounds showed excellent activity, with compound 24c being the most promising one, since it displayed consistently low nanomolar activity in the various assays. ispartof: MOLECULES vol:26 issue:20 ispartof: location:Switzerland status: published

Six dibenzo-1,4-dioxane derivatives (1–6) were isolated from the roots of a Hypericaceous plant Hypericum ascyron. Spectroscopic analyses revealed 2 and 4–6 to be new compounds. The partial racemic natures of 1–3 were concluded by chiral HPLC analyses, while 5 was confirmed to be a racemate. The absolute configurations 1–4 were deduced on the basis of ECD calculations. Biological activity evaluation of the dibenzo-1,4-dioxane derivatives along with two related compounds: hyperdioxanes A (7) and B (8), previously isolated from the same plant material by our group demonstrated that 7 exhibit an anti-HIV activity (IC50 5.3 μM, TI 7.2) while 8 showed an inhibitory effect on IL-1β production (inhibition rate: 72.3% at 6.3 μM) from LPS-stimulated microglial cells.

[Image: see text] Novel betulinic/betulonic acid–nucleoside hybrids were synthesized as possible new anti-HIV agents. Among the synthesized hybrids, two compounds were highly effective against HIV. Compared with AZT and DSB, compounds 10a (IC(50) = 0.0078 μM, CC(50) = 9.6 μM) and 10b (IC(50) = 0.020 μM, CC(50) = 23.8 μM) showed more potent or equipotent, respectively, anti-HIV activity but displayed lower cytotoxicity.

Anti retroviral drugs for HIV has problems with uncomfortable side effects and that endanger the lives of HIV sufferers. Several herbs have been empirically proven to have an effect on HIV eradication through inhibition of reverse transcriptase. One of such antiviral herbs is Justicia gendarussa (J. gendarussa). The aim of research is to evaluate anti-HIV activity of 70% fractionated-ethanol extract (with releasing alkaloids) and 70% ethanol extract (without releasing alkaloids) of J. gendarussa leaves on in vitro HIV-infected of MOLT-4 cells. The effect of the extracts in inhibiting viral replication and fusion process on acute HIV infection was identi- fied through syncytia formation assay. Effect of the extracts on HIV p24 antigen was evaluated using HIV-1 p24 ELISA kit. It was found that 70% fractionated-ethanol extract and 70% ethanol extract of J. gendarussa leaves significantly inhibited of HIV replication by inhibition of syncytia formation, where the 50% effective concen- tration (EC50) values of the 70% fractionated-ethanol extract and 70% ethanol extract are 70.5 μg/mL and 228.7 μg/mL, respec- tively. Both of the extracts were also significantly inhibited HIV replication by decreasing HIV p24 antigen level where the EC 50 values of the 70% fractionated-ethanol extract and 70% ethanol extract are 88.8 μg/mL and 540.7 μg/mL, respectively. Moreover, it was found that 70% fractionated-ethanol extract of J. gendarussa leaves has anti-HIV activity since its EC50 values less than 100 μg/mL. It was concluded that J. gendarussa could be potentially developed into a phytopharmaceutical product due to its anti-HIV activity.

Background T-705 (Favipiravir) is a broad spectrum antiviral agent approved for stockpiling in Japan and currently in Phase 3 testing in the United States. Against influenza, it acts as a prodrug, converted intracellularly to selectively inhibit viral RNA-dependent RNA polymerase or similar enzymes. This is regarded as a novel antiviral mechanism of action, reducing crossresistance to other existing anti-influenza drugs. Objective To develop new analogs, a class of 1,3-oxathiolane nucleoside derivatives of T-705 was designed and synthesized in this work. Results Anti-influenza activity and Anti-HIV activity of these compounds were evaluated. Compound 1a displayed activity against A H1N1 with an IC50 of 40.4 µmol/L. Compound 1b showed weak activity against HIV with a viral suppression rate of 70-80% at 30 µmol/L. Conclusion A class of 1,3-oxathiolane nucleoside derivatives of T-705 was designed and synthesized, and one of them was identified as a novel scaffold against viral infection.

Firstly discovered in 1980s, human immunodeficiency virus (HIV) continues to affect more and more people. However, there is no effective drug available for the therapy of HIV infection. Betulinic acid existing in various medicinal herbs and fruits exhibits multiple biological effects, especially its outstanding anti-HIV activity, which has drawn the attentions of many pharmacists. Among the derivatives of betulinic acid, some compounds exhibited inhibitory activities at the nanomolar concentration, and have entered phase II clinical trials. This paper summarizes the current investigations on the anti-HIV activity of betulinic acid analogues, and provides valuable data for subsequent researches.

Novel 4′-C-ethynyl isomeric dioxolane nucleoside analogues (β- d , α- d , β- l , and α- l , respectively) are successfully synthesized via a divergent strategy from the common starting material, (Z)-but-2-ene-1,4-diol, and are characterized and evaluated for their anti-HIV-1 and anti-HIV-2 activities. The β- d and β- l products display potent in vitro activities against HIV-1 (IIIB) with EC50 values of 0.75 and 0.87 μM, respectively, and against HIV-2 (ROD) with EC50 values of 0.75 and 0.35 μM, respectively, being better in comparison with 3TC [EC50, 5.27 μM (HIV-1) and 1.30 μM (HIV-2)]. The β- d and β- l nucleosides also potently inhibit different drug-resistant strains of the HIV-1 virus (L100I, K103N, Y181C, and V106A). The selectivity indices and cytotoxic profiles of the β- d and β- l nucleosides are much better than those of the standard drugs AZT and d4T.

A new series of mononuclear ruthenium(II) complexes of the type [Ru(PPh3)2(N,S-L1–3)2] 2H3O+.(Cl−)2.XH2O, [RuCl(dmso)3(N,S-L1–3)], and [Ru2(Cl−)2(N,S-L1–3)2].XH2O, where L1 is ethyl 4-(3-hydroxyphenyl)-6-methyl-2-thioxo-pyrimidine-5-carboxylate (monastrol), and L2 and L3 are the 4-hydroxyphenyl and 4-bromophenyl analogs of monastrol have been prepared and characterized by elemental analysis, 1H, and 13C NMR spectroscopy. All the complexes were assayed for their anti-HIV-1 and HIV-2 activity in MT-4 cells, and cytotoxicity was also investigated in mock-infected in MT-4 cells by using MTT assay. All the complexes exhibited no anti-HIV activity, however complexes [RuCl(dmso)3(N,S-L1)] (7) and [RuCl(dmso)3(N,S-L2)] (8) showed cytotoxicity values of > 0.21 and > 2.14 µM, respectively against mock-infected MT-4 cells. In addition, complexes [Ru(PPh3)2(N,S-L3)2].2H3O+.2Cl−.H2O (4), 7, and [RuCl2(N,S-L1)] (10) have been selected for evaluation of their dual inhibition activity against dual-specificity tyrosine phosphorylation-regulated kinase (Dyrk1A).

We report the preparation and characterization of five new [60]fullerene derivatives formed in the novel reaction of C60Cl6 with dimethyl 2,2′-(1,4-phenylenebis-(oxy))diacetate, which were isolated by preparative HPLC and characterized by APCI-MS, 1H, 13C, and 2D NMR spectroscopy. Acidic hydrolysis of the ester groups in the synthesized compounds produced a series of water-soluble fullerene derivatives, which demonstrated pronounced activities against Human Immunodeficiency Virus (HIV) replication. Correlations between the structures of the fullerene derivatives and their antiviral activity were established.

A series of novel 3-aryl-6-adamantylmethyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles 6a–l were synthesized by a simple method with the aim of developing novel HIV non-nucleoside reverse transcriptase inhibitors. All the synthesized compounds were structurally confirmed by spectral analyses. The structure of 6a was unambiguously verified by X-ray structure determination. The synthesized compounds were evaluated for their anti-HIV activity and four analogs displayed moderate inhibitory activity with EC50 values ranging from 10.10 to 12.40 μg mL–1. Molecular docking of 6g with HIV-1 reverse transcriptase was studied to rationalize some structure-activity relationships (SARs).

Searching for more safe and effective agents for HIV treatments is still an urgent topic worldwide. Based on our continuous modifications on the benzophenone derivatives as HIV-1 reverse transcriptase (RT) inhibitors, a new template bearing N-phenylbenzenesulfonamide (PBSA) structure was designed to enhance the interactions with HIV-1 RT. In this manuscript, a series of PBSA derivatives were synthesized and evaluated for their anti-HIV-1 activity. The preliminary test showed that these compounds were potent to inhibit wild-type HIV-1 with EC50 values ranging of 0.105–14.531 μmol/L. In particular, compound 13f not only has high anti-HIV-1 activity (0.108 μmol/L), but also possesses low toxicity with a TI value of 1816.6. Furthermore, the major interactions of the inhibitor 13f with HIV-1 RT were also investigated using the molecular modelling. Our discovered structure-activity relationships (SARs) of these analogues may serve as an important clue for further optimizations.

Three new compounds (1 - 3), including two euphane type triterpenes, 24,24-dimethoxy-25,26,27-trinoreuphan-3β-ol (1) and (24S)-24-hydroperoxyeupha-8,25-dien-3β-ol (2), and an ent-atisine diterpene, ent-atisane-3α,16α,17-triol (3), were isolated from an acetone extract of the stems of Euphorbia antiquorum, together with eight known diterpenes (4 - 11). The structures of compounds (1 - 11) were elucidated using NMR and MS spectroscopic methods. Compound 7 showed moderate activity against HIV-1 replication in vitro (EC50 = 1.38 μm).

Chemical fractionation of the ethanolic extract of Flueggea virosa yielded a group of Securinega alkaloids including flueggenines E (1) and F (2) as novel hybrid structures, flueggenines G–I (3–5) as new dimers and fluevirosines E–H (6–9) as new trimers, along with six known biosynthetically related compounds. The diverse structures of these isolates were characterized via comprehensive spectroscopic analyses and comparison with literature data. Compounds 1 and 2 are rare Securinega alkaloid hybrids incorporating tryptamine and piperidine residues, respectively, while 3 represents the first example bearing a securinine-type monomeric unit among Securinega alkaloid dimers. An in vitro anti-HIV screening of all available alkaloids revealed weak to moderate activities for over half of these isolates with EC50 values ranging from 7.8 to 122 μM. Among the tested compounds, the known dimer flueggenine D exhibited the best activity with an EC50 of 7.8 ± 0.8 μM.

A new steroid glucoside (1), along with nine known steroids (2-10) and four known sorbicillinoids (11-14), were isolated from the endophytic fungus Trichoderma sp. Xy24. Their structures were elucidated on the basis of spectroscopic data analyses and by comparison with reported data. Compounds 3, 5-7, 9, 10, and 13 exhibited significant inhibitory effects on HIV-1 virus with IC

A new series of 2-amino-6-((4-aryldiazenyl)benzyloxy)-4-chloropyrimidine derivatives 4 - 13 and 2,6-diamino-5-arylazo-4-chloro-pyrimidine analogs 15 - 20 were synthesized from the pyrimidine scaffolds 3 and 14, respectively, via diazotization with various amines. Nucleophilic displacement at the 2,4-diamino-5-arylazo-6-chloro-pyrimidine 16 by different amines afforded the 4-alkylamino analogs 21 - 27. All new compounds were evaluated for their in vitro anti-HIV activity in MT-4 cells as non-nucleoside reverse transcriptase inhibitors on the basis of our previous work. Screening results indicated that 10 and 11 were found to be the only compounds in the series inhibiting HIV-1 replication in cell cultures with EC50 of >1:23 and >2:92 μg mL-1 of a CC50 of 12.30 and 17.52 μg mL-1, resulting in a selectivity index of 10 and 6, respectively. In addition, preliminary structure-activity relationships and molecular modeling of these new analogs are detailed in this manuscript.

In search of potential 2′,3′-dideoxyguanosine (ddG) and 2′,3′-didehydro-2′,3′-dideoxyguanosine (D4G) prodrugs, a series of 6-modified ddG, D4G analogs were synthesized and evaluated for their anti-HIV activities and cytotoxities in cell-based assays. All analogs showed low cytotoxicities and some of them displayed benign anti-HIV activities. The active triphosphate forms in vivo, ddGTP and D4TTP, were also synthesized by a novel and facile "one-pot" method. The recognition of ddGTP and D4TTP by Taq, Therminater DNA polymerase and HIV reverse transcriptase (RT) incorporated in DNA/RNA strands were investigated by a non-radioactivity method and Km were determined.

Triazolo-fused 3′,4′-cyclic nucleoside 4′-spiro nucleoside analogues were synthesized by an intramolecular 1,3-dipolar cycloaddition of 4′-azido nucleoside derived azido-alkynes in a regio- and stereo-specific manner. The thymine nucleoside base in these target compounds was transformed into the corresponding 5-methyl cytosine component. The synthesized compounds were examined in an MAGI(multinuclear-activation galactosidase indicator) assay for exploring the anti-HIV activity and in a H9 T(human T lymphocytes H9) assay for measuring the cell toxicity.

Artemisinin and synthetic derivatives of dihydroartemisinin are known to possess various biological activities. Post-functionalization of dihydroartemisinin with triazole heterocycles has been proven to lead to enhanced therapeutic potential. By using our newly developed triazolization strategy, a library of unexplored fused and 1,5-disubstituted 1,2,3-triazole derivatives of dihydroartemisinin were synthesized in a single step. All these newly synthesized compounds were characterized and evaluated for their anti-HIV (Human Immunodeficiency Virus) potential in MT-4 cells. Interestingly; three of the synthesized triazole derivatives of dihydroartemisinin showed activities with half maximal inhibitory concentration (IC50) values ranging from 1.34 to 2.65 µM. ispartof: Molecules vol:22 issue:2 pages:303- ispartof: location:Switzerland status: published

Flueggether A (I), the first example of Securinega alkaloid oligomers with an ether bridge, and virosinine A (II), possessing a novel heterocyclic backbone, exhibit weak in vitro anti-HIV activity.

Chemical fractionation of the ethanolic extract of Flueggea virosa yielded a group of Securinega alkaloids including flueggenines E (1) and F (2) as novel hybrid structures, flueggenines G–I (3–5) as new dimers and fluevirosines E–H (6–9) as new trimers, along with six known biosynthetically related compounds. The diverse structures of these isolates were characterized via comprehensive spectroscopic analyses and comparison with literature data. Compounds 1 and 2 are rare Securinega alkaloid hybrids incorporating tryptamine and piperidine residues, respectively, while 3 represents the first example bearing a securinine-type monomeric unit among Securinega alkaloid dimers. An in vitro anti-HIV screening of all available alkaloids revealed weak to moderate activities for over half of these isolates with EC50 values ranging from 7.8 to 122 μM. Among the tested compounds, the known dimer flueggenine D exhibited the best activity with an EC50 of 7.8 ± 0.8 μM.

The development of new HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs) offers the possibility of generating structures of increased potency. To this end, a series of 1-(1-benzyl-2-ethyl- 4-nitro-1H-imidazol-5-yl)-4-(1,1'-biaryl)-4-yl-piperazine derivatives (6a-l) was synthesized via the Suzuki coupling reaction. Analogously, coupling of the acid derivative 5, prepared from 4, with various amino acid methyl esters in the presence of HOBt/DCC reagents afforded the benzamide derivatives 8-11. The newly synthesized compounds were assayed against HIV-1 and HIV-2 in MT- 4 cells. All compounds are inactive, except compound 6f which showed inhibition of HIV-1 with EC50 = 2:60μgmL-1 with a selectivity index (SI) of 9

The first total syntheses of oresbiusin A in the (+)-, (–)-, and (±)-forms were accomplished in five steps with overall yields of ca. 70 %. The key intermediates with optical activity were generated through a Sharpless asymmetric dihydroxylation reaction. These efforts allowed us to establish the absolute configuration of this natural product with dextrorotary and a 2S configuration. In addition, the total syntheses of both enantiomers of oresbiusin B along with its racemate were accomplished in six steps with overall yields of 58 %. Among these compounds, the unnatural oresbiusin A with a levorotary rotation was found to possess dose dependent anti-HIV-1 activity in H9 cells, whereas the other compounds were inactive.

New synthetic protocol for the preparation of nucleoside 5'-(N-aryl)phosphoramidate monoesters 4 was developed. It consisted of a condensation of the corresponding nucleoside 5'-H-phosphonates with aromatic- or heteroaromatic amines promoted by diphenyl phosphorochloridate, followed by oxidation of the produced H-phosphonamidates with iodine/water. 5'-(N-Aryl)phosphoramidate monoesters derived from 3'-azido-3'-deoxythymidine (AZT) or 2',3'-dideoxyuridine (ddU) nucleosides and various aromatic and heteroaromatic amines were evaluated as potential anti-HIV drugs. It was found that these compounds act most likely as pronucleotides and that some of them have therapeutic indices superior to those of the reference AZT.

There is an urgent need for the design and development of new and safer drugs for the treatment of HIV infection, active against the currently resistant viral strains. New derivatives of the non-steroidal anti-inflammatory drug indomethacin bearing benzimidazoles, benzothiazole, purine and pyridine residues 8 - 13 were synthesized with the aim of developing new non-nucleoside reverse transcriptase inhibitors (NNRTIs).Alternatively, new imine analogs 16 - 20 were synthesized from condensation of indomethacinyl hydrazide 15, prepared from the ester 14, with various ketone precursors. Treatment of 15 with phenyl isothiocyanate or triethyl orthoformate afforded the phenylcarbonothioyl and the oxadiazole derivatives 21 and 22, respectively. The new compounds were assayed against HIV-1 and HIV-2 in MT-4 cells. Compounds 9 and 10 were the most active in inhibiting HIV-2 and HIV-1, respectively, with EC50 ≥ 17.60 μgmL−1 and > 1.15 μgmL−1 (therapeutic indexes (SI) of ≥ 3 and < 1, respectively), and are leading candidates for further development.

A series of N-(3-(substituted-alkyl- or halophenyl)-4-methylthiazol-2(3H)-ylidene)-substituted alkyl- or halo-benzamides 21 - 40 were prepared by base-catalyzed cyclization of the corresponding 1-(substituted-alkyl- or halo-benzoyl)-3-(substituted-halophenyl)thioureas 1 - 20. Substituted pyrazolo[ 4,3-d]thiazol-5(6aH)-ylidene)benzamides 45a - d were synthesized by cycloaddition of compound 45 with the reactive cumulene intermediates 42a - d. All compounds were evaluated for their antiviral activity against the replication of HIV-1 and HIV-2 in MT-4. Compounds 35 and 39 showed an IC50 of 2.02 μgmL−1 and 0.40 μgmL−1 against the HIV-2 strain ROD with CC50 of ≥ 104.00 μgmL−1 and > 125.00 μgmL−1, respectively, resulting in a selectivity index of ≥ 52 and > 313. Based on the chemical structure of compounds 35 and 39, these molecules can be proposed to act as NNRTIs. However, it is exceptional to observe an antiretroviral activity that is limited to HIV-2

Defensins are highly abundant antimicrobial peptides in the female genital mucosa. We have previously shown that human defensins 5 and 6 (HD5 and HD6), produced by cervicovaginal epithelial cells, significantly enhance HIV infectivity in vitro. Candidate polyanion microbicides, including PRO 2000, cellulose sulfate and carrageenan, failed to protect women against HIV infection in large-scale clinical trials, but the molecular basis of ineffectiveness was not clear. We hypothesized that mucosal host factors such as HD5 an HD6 may alter the activity of polyanion microbicides against HIV. Our results demonstrated that HD5 and HD6 but not their linear analogs antagonized the anti-HIV activity of PRO 2000, cellulose sulfate and carrageenan in vitro. Polyanion microbicides also reduced the HIV-enhancing effect of these defensins. We conclude that mucosal host factors could negatively impact the efficacy of topical microbicides against HIV, and their impact on the activity of candidate microbicides needs to be considered during the preclinical evaluation.

Novel 4'-ethyl-5'-norcarbocyclic adenosine phosphonic acid analogues were synthesized from propionaldehyde 5 through a de novo acyclic synthetic route using reiterative Grignard additions and ring-closing metathesis (RCM) as key reactions. The synthesized nucleoside phosphonic acids analogues 17, 18, 19, and 21 were subjected to antiviral screening against human immunodeficiency virus.

A series of new Cu(II), Pt(II), VO(II), Fe(II), and Co(II) complexes (1--5) with 3-methyl-6,7-diphenyllumazine are described. Similarly, complexes from 2-thiouracil with Cu(II) (6,7) and Pt(II) (8) have been prepared and characterized by spectroscopic methods. All the complexes were assayed for their anti-HIV-1 and HIV-2 activity by examination of their inhibition of HIV-induced cytopathogenicity in MT-4 cells. Compound 3 was found to be the most active inhibitor against HIV-2 in cell culture (EC50 = >18.9 μ g/mL, selectivity index (SI) = 3), which provided a good lead for further optimization. Compounds 6 and 7 exhibited some activity (EC50 = >7.12 μ g/mL and >2.23 μ g/mL) against HIV-1 and HIV-2, but no selectivity was observed (SI

A series of N-{2-oxo-2-[4-(1,3-benzothiazol-2-yl)piperazin-1-yl]}-(het)arenecarboxamides 4a - l, sulfonamide derivatives 8a - i as well as benzothiazole-containing N1-(2-oxoethyl)-N1-arylthioureas 9a - c have been synthesized. Compounds 4a - l and 9a were evaluated, in vitro, for their antiproliferative activity against a large panel of human tumor-derived cell lines. Compounds 4l and 9a were the most potent analogs in this series, showing remarkable effects on human splenic B-lymphoblastoid cells (WIL-2NS) and human acute B-lymphoblastic leukemia (CCRF-SB) cell lines (4l: CC50 = 5.1 and 7.3 μM, respectively), and compound 5 against CCRF-SB cell lines with CC50 = 2.3 μM. These compounds are leading candidates for further development. Compounds 6 - 7a - i were screened as inhibitors against HIV-1 and HIV-2, and no activity has been witnessed.

This study evaluated the variability in the production of an HIV-1 antiviral diterpene in individuals of Dictyota menstrualis throughout reproductive stages. The brown alga Dictyota has an isomorphic biphasic life cycle. The quantification of the active principle by GC–FID indicated a greater production of the diterpene in the female gametophytic phase (42.11 ppm). However, these individuals had the highest variation between individuals (standard deviation of 68.20 ppm in the range from 0.39 to 227 ppm). Sporophytic individuals showed less variability. This variability in the production of the antiviral diterpene is important to the development of future antiviral drugs.

New esters (sulfate, nicotinates, and 4-methoxycinnamate) of 18α-glycyrrhizic acid (18α-GA) were synthesized; these were D/E-trans-isomers of natural 18β-GA (GA), which is the major triterpene glycoside in the roots of Spanish licorice and Urals licorice (Glycyrrhiza glabra L. and Gl. uralensis Fisher). Changes in the stereochemistry of the GA aglycone led to significant decreases in its anti-HIV-1 activity.

A new method for synthesizing triterpene 3-O-galactosides, analogs of glycyrrhizic acid (GA) based on 18βglycyrrhetic acid (GLA) methyl esters and 18,19-dehydro-GLA, using 2,3,4,6-tetra-O-acetyl-a-Dgalactopyranosyl bromide as the glycosyl donor, I–Br promoter, and 4-A molecular sieves was developed. The method could produce primarily 3-O-α-D- or β-D-galactopyranosides depending on the reaction conditions. The 3-O-α-D-galactopyranoside of GLA exhibited an index of selectivity (IS) 2.9 times greater than that of GA for inhibition of accumulation of virus-specific protein p24 of HIV-1. β-D-Galactopyranoside of GLA was more cytotoxic for MT-4 cells and exhibited weak anti-HIV-1 activity.

As part of our studies to discover new HIV-1 reverse transcriptase inhibitors, a series of 3,4-dichlorophenyl substituted 1,2,3-thiadiazole thioacetanilide (TTA=[(1,2,3-thiadiazole-5-yl)sulfanyl]acetanilide) derivatives were synthesized, and in vitro anti-HIV activity was evaluated. The results revealed that nearly half of the compounds show moderate-to-good inhibitory potency against HIV-1. In particular, compound 7f is highly potent, with an EC(50) value of 0.95+/-0.33 microM. The preliminary structure-activity relationship among the newly synthesized congeners is discussed.

Density functional theory (DFT; B3LYP) and Hartree–Fock (HF; 3-21G, 6-31G(d) and 6-311G(d,p)) calculations with complete geometry optimisations are carried out in the ground state on five 6-aminoquinolone derivatives, which have been proved to be highly effective in inhibiting HIV replication, to study their structures, energetics and HOMO–LUMO correlation with physiological action. The gas-phase calculations and single-point polarisable continuum model water-phase calculations show that the molecules are highly effective in inhibiting HIV replication, which is in excellent agreement with the experiment. Structural features, energies, charge densities and HOMO–LUMO correlation have been found to substantiate the experimental findings. Compound 4 (pyrazine) shows some special features in DFT calculations which are not found in HF calculations. In the present series, HF results are more reliable as expected.

Plants are an important source of a variety of bioactive compounds with different modes of action. Anti-HIV agents from plant sources can be useful in developing novel therapies for inhibiting HIV infection. Based on the reported anti-HIV activity of plant derived phloroglucinols, several new dimeric phloroglucinols were synthesized in the present study by varying substitution on aromatic ring and at methylene bridge. Some of the synthesized compounds have shown good HIV inhibitory activity in a human CD4+ T cell line (CEM-GFP) infected with HIV-1 NL 4.3 virus isolate. Structure–activity studies indicate that phenyl, 4-benzyloxy-1-phenyl and cyclohexyl substitution at methylene bridge gave compounds with better anti-HIV activity. Compounds 22 and 24 showed highest anti-HIV activity with an IC 50 of 0.28 μM and 2.71 μM, respectively, former was more active than the positive standard AZT in cell based assay.

A number of new 5-[(naphthalen-5-yloxy)methyl]-1,3,4-oxadiazole derivatives, 2 - 5 and 8 - 11, were synthesized. The 2-{5-[(naphthalen-5-yloxy)methyl]-1,3,4-oxadiazol-2-ylthio}acetohydrazones 6a and 6b were synthesized by the reaction of the hydrazide 4 with the corresponding monosaccharides. Cyclization of the sugar hydrazones 6a and 6b with acetic anhydride afforded the substituted oxadiazoline derivatives 7a and 7b. The synthesized compounds were evaluated for their antiviral activity against, the human immunodefi ciency virus (HIV-1) and some of these compounds showed moderate to high antiviral activity.

New Schiff base ligands (6–9) derived from 5-amino-4-phenyl-4H-1,2,4-triazole-3-thiol 1 and substituted benzaldehydes (2–5) as well as their metal complexes with Cu(II), Fe(II), Au(III), and Mn(II) (12–17) have been synthesized. A new benzothiazole derivative (11) was prepared from coupling of 7 with N-(benzothiazol-2-yl)-2-chloroacetamide 10. Their spectral properties were investigated. The newly designed and synthesized Schiff base ligands and the metal complexes were assayed for anti-HIV-1 and HIV-2 activity by examination of their inhibition of HIV-induced cytopathogenicity in MT-4 cells. Compounds 11 and 16 were found to be the most active inhibitors in cell culture (EC50 = 12.2 μg/mL (SI = 4) and > 2.11 μg/mL (SI = > 1), respectively) against HIV-1, whereas 11 showed inhibition against HIV-2 of EC50 > 10.2 μg/mL with SI = 9, which provided a good lead for further optimization.

A series of novel 6-sulfamoyl-4-oxoquinoline-3-carboxylic acids derivatives have been synthesized and screened for HIV integrase inhibition activity. Their structures were confirmed by ESI-MS, 1H NMR and 13C NMR.

Cyanovirin-N (CV-N) is a cyanobacterial lectin that binds to specific oligomannoses on the surface of gp120, resulting in nanomolar antiviral activity against HIV. In its monomeric form, CV-N contains two functional carbohydrate-binding domains, A and B. When refolded at high concentration, the protein can form a domain-swapped dimer. To clarify the role of multiple-binding sites in CV-N, we previously designed a monomeric mutant, P51G-m4-CVN, in which the binding site on domain A was rendered ineffective by four mutations (m4); in addition, a hinge region mutation (P51G) hinders the formation of a domain swapped dimer. The protein bound gp120 with diminished affinity and was completely inactive against HIV. Here, we present two mutants, ΔQ50-m4-CVN and S52P-m4-CVN, which fold exclusively as domain-swapped dimers while containing the four mutations that abolish domain A. The dimers contain two intact B domains, thus restoring multivalency. ΔQ50-m4-CVN and S52P-m4-CVN bind gp120 at low-nanomolar concentrations and recover in part the antiviral activity of wt CV-N. These results indicate that the number of carbohydrate binding domains, rather than their identity, is crucial to CV-N functionality. © 2009 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 92: 194–200, 2009. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com

α,α′-Dichloroazo compounds 6 react with Lewis acid to furnish 1-(chloroalkyl)-1-aza-2-azoniaallene salts 4. The cations 4 react with acetylenes, isothiocyanates, isocyanates, and carbodiimides under [3+2]-cycloaddition. The cycloadducts undergo consecutive reactions, e.g., [1,2]-shifts of alkyl groups. The newly synthesized products were evaluated for their anti-HIV-1 and anti-HIV-2 activity in MT-4 cells.

Human immunodeficiency virus type-1 (HIV-1) is a pathogenic retrovirus and the causative agent of acquired immunodeficiency syndrome (AIDS). HIV-1 RT is one of the key enzymes in the duplication of HIV-1. Inhibitors of HIV-1 RT are classified as nonnucleoside reverse transcriptase inhibitors (NNRTIs) and NRTIs. NNRTIs bind in a region not associated with the active site of the enzyme. Within the NNRTIs category, there is a set of inhibitors commonly referred to as phenyl or pyridyl ethyl thiourea (PET) derivatives. The present three-dimensional (3D) quantitative structure–activity relationship (QSAR) study attempts to explore the structural requirements of (phenyl ethyl thiourea) PET derivatives for anti-HIV activity. Based on the structures and biodata of previous PET analogs, comparative molecular similarity indices analysis (CoMSIA) is performed to explain the structural requirements for the anti-HIV activity of PET derivatives. The CoMSIA studies resulted in reliable computational models. The obtained CoMSIA model has high predictive ability, q 2 = 0.584, r 2 = 0.882 and standard error of estimation (SEE) = 0.352, explaining the majority of the variance in the data with four partial least square (PLS) components. The predictive ability of the developed models (3D QSAR) was also confirmed by using a test (external validation) set comprised of 11 molecules with a predicted r 2 value of 0.871. It is shown that the steric, electrostatic, hydrophobic, and hydrogen-bond acceptor and donor properties predicted by CoMSIA contours can be related to anti-HIV activity. This model is a significant guide to trace the features that really matter especially with respect to the design of novel compounds. Comparative molecular similarity indices analysis for predicting anti-HIV activity of phenyl ethyl thiourea (PET) derivatives The parameters indicated in the substitution position of compound are responsible for anti-HIV activity.

A series of acyclonucleosides substituted 1-(4,5-dihydroxypentyl) (13-8) and 2-(4,5-dihydroxypentyloxy)quinoxalines (19-24) were synthesized by the sharpless asymmetric dihydroxylation of the derivatives 1-6 and 7-12, respectively. Treatment of the quinoxaline base 26 with (R)-2,2-dimethyl-1,3-dioxolan-4-ylmethyl-p-toluenesulfonate (27) in the presence of NaH/DMF furnished 28. Acid hydrolysis of 28 gave 1-(2,3-dihydroxypropyl)-6,7-dimethyl-quinoxaline-2-one (29). Alternatively, 29 was prepared by sharpless dihydroxylation of 30. All the compounds were evaluated for their in vitro anti-HIV-1 and HIV-2 in MT-4 cell and found inactive, except 29, which showed inhibition of HIV-1 with EC50 value of 0.15 +/- 0.1 microg/ml and a therapeutic index (SI) of 73.

A new series of coumarin and benzofuran derivatives were synthesized as potential non-nucleoside reverse transcriptase inhibitors (NNRTIs) by reacting, separately, 4-bromomethylcoumarins, their sulphonyl chlorides, and ethyl 3-(bromomethyl)-6-methoxy-1-benzofuran-2-carboxylate with different imidazoles and their benzo analogs. The antiviral (HIV-1, HIV-2) properties of the newly synthesized compounds were investigated in vitro and all compounds were found to be inactive, except 10 which showed inhibition of HIV-2 with EC50 > 0.51 μgmL−1. The in vitro cytotoxicity of 17 and 19 was assayed against a panel of tumor cell lines consisting of CD4 human T-cells.