anti-HIV Activity Research Articles

Structure-Activity-Relationship and Mechanistic Insights for Anti-HIV Natural Products.

Acquired Immunodeficiency Syndrome (AIDS), which chiefly originatesfroma retrovirus named Human Immunodeficiency Virus (HIV), has impacted about 70 million people worldwide. Even though several advances have been made in the field of antiretroviral combination therapy, HIV is still responsible for a considerable number of deaths in Africa. The current antiretroviral therapies have achieved success in providing instant HIV suppression but with countless undesirable adverse effects. Presently, the biodiversity of the plant kingdom is being explored by several researchers for the discovery of potent anti-HIV drugs with different mechanisms of action. The primary challenge is to afford a treatment that is free from any sort of risk of drug resistance and serious side effects. Hence, there is a strong demand to evaluate drugs derived from plants as well as their derivatives. Several plants, such as Andrographis paniculata, Dioscorea bulbifera, Aegle marmelos, Wistaria floribunda, Lindera chunii, Xanthoceras sorbifolia and others have displayed significant anti-HIV activity. Here, weattempt to summarize the main results, which focus on the structures of most potent plant-based natural products having anti-HIV activity along with their mechanisms of action and IC50 values, structure-activity-relationships and important key findings.

N-p-Tosyl-L-phenylalanine chloromethyl ketone (TPCK) inhibits HIV-1 by suppressing the activity of viral protease

Human Immunodeficiency Virus (HIV), the etiological agent for Acquired Immunodeficiency Syndrome (AIDS), continues to kill humans despite stupendous advances in antiviral research. With the presently available combination antiretroviral therapeutic arsenal, AIDS is now a manageable disease but with no cure available till date. The development of novel antivirals consumes an extensive amount of time and resources. Hence, repurposing of the established gold standard molecules for their anti-HIV application is enormously advantageous. In this study, we report that N-p-Tosyl-L-phenylalanine chloromethyl ketone (TPCK) inhibits HIV-1 replication in a highly-conserved manner. Further, TPCK inhibits HIV-1 replication at the late stages of its life cycle by impeding viral protease (PR) enzyme activity. Additionally, our results demonstrate that the combination of TPCK with established HIV-1 PR inhibitors shows significant synergistic inhibitory potential, suggesting the potential use of TPCK in cART regimen. Collectively, we report the anti-HIV activity of TPCK, which should be further characterized for its translational applications.

Design, Synthesis and In Vitro Evaluation of 2-Oxo-N-substituted Phenyl- 2H-chromene-3-carboxamide Derivatives as HIV Integrase Strand Transfer Inhibitors

Background: A series of eighteen 2-Oxo-N-substituted phenyl- 2H-chromene-3- carboxamide analogues has been evaluated for HIV-1 integrase (IN) inhibition. Methods: The derivatives were synthesized via a two-step pathway commencing with 2- hydroxybenzaldehyde and diethyl malonate followed by hydrolysis of ester and coupling with various aromatic amines. The HIV-1 IN inhibitory potential of these compounds has been studied relative to dolutegravir, a known HIV-1 IN inhibitor using a standard available kit. Results: Six molecules (compounds 13h, 13i, 13l, 13p to 13r) showed significant inhibition of HIV- 1 integrase 3′-strand transfer with IC50 values less than 1.7 μM. The presence of chromene-3- carboxamide motif was shown to be crucial for the enzymatic activity. In addition, molecular modelling studies were also done to justify the IN inhibition and in vitro-in silico correlation was drawn. Conclusion: However, these compounds did not show HIV-1 and HIV-2 inhibition below their cytotoxic concentration indicating that these compounds cannot be taken further for anti-HIV activity as such and require structural modification.

Pesticides, cosmetics, drugs: identical and opposite influences of various molecular features as measures of endpoints similarity and dissimilarity.

The similarity is an important category in natural sciences. A measure of similarity for a group of various biochemical endpoints is suggested. The list of examined endpoints contains (1) toxicity of pesticides towards rainbow trout; (2) human skin sensitization; (3) mutagenicity; (4) toxicity of psychotropic drugs; and (5) anti HIV activity. Further applying and evolution of the suggested approach is discussed. In particular, the conception of the similarity (dissimilarity) of endpoints can play the role of a "useful bridge" between quantitative structure property/activity relationships (QSPRs/QSARs) and read-across technique.

Pyromellitic dianhydride crosslinked soluble cyclodextrin polymers: Synthesis, lopinavir release from sub-micron sized particles and anti-HIV-1 activity.

We report the synthesis of water soluble cyclodextrin (CD) polymers prepared by crosslinking pyromellitic dianhydride (PMDA) with two CD derivatives (methyl-β-CD - MβCD and (2-hydroxy)propyl-β-CD - HPβCD) and their evaluation as functional sub-micron sized carriers in the development of antiretroviral drug delivery systems. Using the protease inhibitor lopinavir (LPV) as model drug, LPV loaded CD polymers (pHPβCD and pMβCD) were prepared and fully characterized. The physicochemical characterization and in vitro drug release confirmed the successful synthesis of pHPβCD and pMβCD, the formation of sub-micron sized particles and a 12-14 fold increase in LPV solubility. Cytotoxicity assays indicated that both pHPβCD and pMβCD were able to improve the safety profile of LPV while the viral infectivity assay revealed a concentration independent anti-HIV-1 effect for both pHPβCD and pMβCD with a maximum percentage inhibition (MPI) of 79 and 91% respectively. After LPV loading, the antiviral profile of pHPβCD was reversed to the sigmoidal dose-response profile of LPV, while pMβCD maintained its dose-independent profile followed by a LPV mediated increase in viral inhibition. Overall, both pHPβCD and pMβCD demonstrated anti-HIV-1 activity, while drug loaded pMβCD indicated its potential as functional sub-micron sized drug delivery polymers for achieving synergistic anti-HIV activity.

PSGL-1 restricts HIV-1 infectivity by blocking virus particle attachment to target cells

P-selectin glycoprotein ligand-1 (PSGL-1) is a dimeric, mucin-like, 120-kDa glycoprotein that binds to P-, E-, and L-selectins. PSGL-1 is expressed primarily on the surface of lymphoid and myeloid cells and is up-regulated during inflammation to mediate leukocyte tethering and rolling on the surface of endothelium for migration into inflamed tissues. Although it has been reported that PSGL-1 expression inhibits HIV-1 replication, the mechanism of PSGL-1-mediated anti-HIV activity remains to be elucidated. Here we report that PSGL-1 in virions blocks the infectivity of HIV-1 particles by preventing the binding of particles to target cells. This inhibitory activity is independent of the viral glycoprotein present on the virus particle; the binding of particles bearing the HIV-1 envelope glycoprotein or vesicular stomatitis virus G glycoprotein or even lacking a viral glycoprotein is impaired by PSGL-1. Mapping studies show that the extracellular N-terminal domain of PSGL-1 is necessary for its anti-HIV-1 activity, and that the PSGL-1 cytoplasmic tail contributes to inhibition. In addition, we demonstrate that the PSGL-1-related monomeric E-selectin-binding glycoprotein CD43 also effectively blocks HIV-1 infectivity. HIV-1 infection, or expression of either Vpu or Nef, down-regulates PSGL-1 from the cell surface; expression of Vpu appears to be primarily responsible for enabling the virus to partially escape PSGL-1-mediated restriction. Finally, we show that PSGL-1 inhibits the infectivity of other viruses, such as murine leukemia virus and influenza A virus. These findings demonstrate that PSGL-1 is a broad-spectrum antiviral host factor with a unique mechanism of action.

Exploratory studies on CA-15L, an anti-HIV active HIV-1 capsid fragment

Utilizing overlapping fragment peptide libraries covering the whole sequence of an HIV-1 capsid (CA) protein with the addition of an octa-arginyl moiety, we had previously found several peptides with anti-HIV-1 activity. Herein, among these potent CA fragment peptides, CA-15L was examined because this peptide sequence overlaps with Helix 7, a helix region of the CA protein, which may be important for oligomerization of the CA proteins. A CA-15L surrogate with hydrophilic residues, and its derivatives, in which amino acid sequences are shifted toward the C-terminus by one or more residues, were synthesized and their anti-HIV activity was evaluated. In addition, its derivatives with substitution for the Ser149 residue were synthesized and their anti-HIV activity was evaluated because Ser149 might be phosphorylated in the step of degradation of CA protein oligomers. Several active compounds were found and might become new anti-HIV agents and new tools for elucidation of CA functions.

The index of ideality of correlation and the variety of molecular rings as a base to improve model of HIV-1 protease inhibitors activity

Computational prediction of HIV-1 protease inhibitor via quantitative structure–activity relationships (QSARs) is a popular study in the field of computational chemistry. The aim of the present study was building up of QSAR models for anti-HIV activity by means of the CORAL software ( http://www.insilico.eu/coral ). Applying of correlation weights for five and six-member molecular rings as components of the target function in the Monte Carlo optimization that is aimed to build up correlation between activity of HIV-1 protease inhibitors expressed as pIC50 = lg[1/(IC50 × 109)] and optimal descriptor improves the predictive potential. Simplified molecular input-line entry system (SMILES) is used as the representation of the molecular structure of HIV-1 protease inhibitors for the QSAR analysis. New criterion of predictive potential so-called index of ideality of correlation (IIC) has been appllied to improve the model for HIV-1 protease inhibitors activity. High correlation coefficients were observed between the experimental and predicted anti-HIV activity. Applying of special ring code as component of the Monte Carlo calculation significantly improves the statistical quality of the model. Furthermore, applying of the IIC as component of the Monte Carlo optimization improves the predictive potential of the CORAL models. The presence of the rings and the quality of these are very important molecular features which are able to improve statistical quality of model for anti-HIV activity. In addition, the ability of IIC to improve predictive potential of a model has been confirmed.

Jatrophane and rearranged jatrophane-type diterpenes: biogenesis, structure, isolation, biological activity and SARs (1984-2019).

Diterpene compounds specially macrocyclic ones comprising jatrophane, lathyrane, terracinolide, ingenane, pepluane, paraliane, and segetane skeletons occurring in plants of the Euphorbiaceae family are of considerable interest in the context of natural product drug discovery programs. They possess diverse complex skeletons and a broad spectrum of therapeutically relevant biological activities including anti-inflammatory, anti-chikungunya virus, anti-HIV, cytotoxic, and multidrug resistance-reversing activities as well as curative effects on thrombotic diseases. Among macrocyclic diterpenes of Euphorbia, the discovery of jatrophane and modified jatrophane diterpenes with a wide range of structurally unique polyoxygenated polycyclic derivatives and as a new class of powerful inhibitors of P-glycoprotein has opened new frontiers for research studies on this genus. In this review, an attempt has been made to give in-depth coverage of the articles on the naturally occurring jatrophanes and rearranged jatrophane-type diterpenes isolated from species belonging to the Euphorbiaceae family published from 1984 to March 2019, with emphasis on the biogenesis, isolation methods, structure, biological activity, and structure–activity relationship. Electronic supplementary materialThe online version of this article (10.1007/s11101-020-09667-8) contains supplementary material, which is available to authorized users.

Electronic Structure and Molecular Docking Studies of an anti-HIV Drug: Stavudine

For anti HIV activity, Stavudine (or D4T or Zerit) is an important nucleoside reverse transcriptase inhibitor (NRTI). Molecular geometry of this compound has been optimized by DFT B3LYP/6–31G (d,p) method using Gaussian 03 software package. In order to examine global reactivity descriptors of the drug molecule, Frontier orbital analysis has been carried out. Using molecular docking inhibition activity of the drug against HIV-1 reverse transcriptase (6AN2) has been investigated. Attempts have been made to elucidate the chemical and biological properties of the drug.

Scaffold Hopping in Discovery of HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitors: From CH(CN)-DABOs to CH(CN)-DAPYs.

Scaffold hopping is a frequently-used strategy in the development of non-nucleoside reverse transcriptase inhibitors. Herein, CH(CN)-DAPYs were designed by hopping the cyano-methylene linker of our previous published CH(CN)-DABOs onto the etravirine (ETR). Eighteen CH(CN)-DAPYs were synthesized and evaluated for their anti-HIV activity. Most compounds exhibited promising activity against wild-type (WT) HIV-1. Compounds B4 (EC50 = 6 nM) and B6 (EC50 = 8 nM) showed single-digit nanomolar potency against WT HIV-1. Moreover, these two compounds had EC50 values of 0.06 and 0.08 μM toward the K103N mutant, respectively, which were comparable to the reference efavirenz (EFV) (EC50 = 0.08 μM). The preliminary structure–activity relationship (SAR) indicated that introducing substitutions on C2 of the 4-cyanophenyl group could improve antiviral activity. Molecular docking predicted that the cyano-methylene linker was positioned into the hydrophobic cavity formed by Y181/Y188 and V179 residues.

Anti-HIV tigliane diterpenoids from Reutealis trisperma

Bioassay-guided fractionation of the n-butanol extract from the branches and leaves of Reutealis trisperma resulted in the isolation of six undescribed (crotignoids L ~ Q) together with two known (12-deoxyphorbol-13-hexadecanoate and 12-deoxyphorbol-13-myristate) tigliane diterpenoids. Their structures, especially the absolute configurations, were determined from extensive spectroscopic studies, including 2D NMR spectra, CD data analysis and electronic circular dichroism (ECD) calculations. All isolates were tested for anti-HIV activity against HL4-3 virus in MT4 cells. Except for crotignoid Q, the remaining seven tigliane diterpenoids exhibited potent anti-HIV activity with IC50 values ranging from 0.0023 to 4.03 μM.

Design, synthesis and biological evaluation of novel 5-((substituted quinolin-3-yl/1-naphthyl) methylene)-3-substituted imidazolidin-2,4-dione as HIV-1 fusion inhibitors.

A series of novel 5-(substituted quinolin-3-yl or 1-naphthyl)methylene)-3-substituted imidazolidin-2,4-dione 9-26 was designed and synthesized. The prepared compounds were identified using 1H NMR, 13C NMR as well as elemental analyses. The inhibitory activity of 9-26 on HIV-1IIIB replication in MT-2 cells was evaluated. Some derivatives showed good to excellent anti-HIV activities as compounds 13, 18, 19, 20, 22 and 23. They showed EC50 of 0.148, 0.460, 0.332, 0.50, 0.271 and 0.420μM respectively being more potent than compound I (EC50=0.70μM) and II ( EC50=2.40μM) as standards. The inhibitory activity of 9-26 on infected primary HIV-1 domain, 92US657 (clade B, R5) was investigated. All the tested compounds consistently inhibited infection of this virus with EC50 from 0.520 to 11.857μM. Results from SAR studies showed that substitution on ring A with 6/7/8-methyl group resulted in significant increase in the inhibitory activity against HIV-1IIIB infection (5- >300 times) compared to the unsubstituted analog 9. The cytotoxicity of these compounds on MT-2 cells was tested and their CC50 values ranged from 11 to 85μM with selectivity indexes ranged from 0.53 to 166. The docking study revealed nice fitting of the new compounds into the hydrophobic pocket of HIV-1 gp41 and higher affinity than NB-64. Compound 13, the most active in preventing HIV-1IIIB infection, adopted a similar orientation to compound IV. Molecular docking analysis of the new compounds revealed hydrogen bonding interactions between the imidazolidine-2,4-dione ring and LYS574 which were missed in the weakly active derivatives.

Interaction between sulfated 3-O-octadecyl-α-(1→6)-d-glucan and liposomes analyzed by surface plasmon resonance

To elucidate the role of long alkyl group in sulfated poly- and oligosaccharides on anti-HIV activity, the interaction between sulfated 3-O-octadecyl-(1→6)-α-d-glucopyranan with potent anti-HIV activity and liposomes with diameters of 58 ± 20 nm and 107 ± 28 nm as models of HIV were investigated. SPR measurements of sulfated 3-O-octadecyl-(1→6)-α-d-glucopyranans bearing 2.8 mol% of the octadecyl group and the liposome (diameter = 58 ± 20.0 nm and ζ=0 mV) resulted in an apparent association- ka = 6 × 105 1/M, a dissociation-rate kd = 4 × 10−4 1/s, and a dissociation constants KD = 8 × 10-10 M. The particle size of the sulfated 3-O-octadecyl-(1→6)-α-d-glucopyranan (67 ± 14 nm) measured by DLS increased to 104 ± 25 nm, whereas the ζ potential (−29 mV) was unchanged (−33 mV). For dextran sulfate without an alkyl group, no interaction was observed. These results suggest that the long octadecyl group penetrated into the liposome and sulfated glucopyranan was covered on the liposome to increase the anti-HIV activity. The 107 nm liposome exhibited similar results.

High yield production of recombinant cyanovirin-N (antiviral lectin) exhibiting significant anti-HIV activity, from a rationally selected Escherichia coli strain

Cyanovirin-N (CV-N), a lectin of cyanobacterial origin, has important medical implications due to its highly effective virucidal activity. However, its low production yield has limited its application till date. In this study, we demonstrate for the first time, a simple process for a break-through production of soluble and bioactive recombinant CV-N (rCV-N) in a newer strain called Escherichia coli SHuffle® T7 Express lysY that is engineered for enhanced production of correctly disulphide bonded proteins. As rCV-N contains two critical disulphide bonds required for its anti-HIV activity, rational choice of this expression host could produce high yield of soluble rCV-N (∼24 mg/ 100 ml) in simple Erlenmeyer flask at 20 °C. The protein could be obtained to near purity in single-step affinity purification (mixture of monomer, dimer and higher order oligomers together referred to as mixed form) which was further resolved into monomer and dimer by size exclusion chromatography. The purified rCV-N had a monomeric mass of 11.962 kDa and a prominent β-sheet secondary structure. The three forms of rCV-N i.e. mixed, monomer and dimer exhibited significant anti-HIV activity (IC50 0.5−5 nM) and a therapeutic index of ∼1,000–10,000 in vitro (negligible cytotoxicity up to 5 μM). All rCV-N forms had low endotoxins.

In vitro anti-HIV activity of some Indian medicinal plant extracts

BackgroundHuman Immunodeficiency Virus (HIV) persists to be a significant public health issue worldwide. The current strategy for the treatment of HIV infection, Highly Active Antiretroviral Therapy (HAART), has reduced deaths from AIDS related disease, but it can be an expensive regime for the underdeveloped and developing countries where the supply of drugs is scarce and often not well tolerated, especially in persons undergoing long term treatment. The present therapy also has limitations of development of multidrug resistance, thus there is a need for the discovery of novel anti-HIV compounds from plants as a potential alternative in combating HIV disease.MethodsTen Indian medicinal plants were tested for entry and replication inhibition against laboratory adapted strains HIV-1IIIB, HIV-1Ada5 and primary isolates HIV-1UG070, HIV-1VB59 in TZM-bl cell lines and primary isolates HIV-1UG070, HIV-1VB59 in PM1 cell lines. The plant extracts were further evaluated for toxicity in HEC-1A epithelial cell lines by transwell epithelial model.ResultsThe methanolic extracts of Achyranthes aspera, Rosa centifolia and aqueous extract of Ficus benghalensis inhibited laboratory adapted HIV-1 strains (IC80 3.6–118 μg/ml) and primary isolates (IC80 4.8–156 μg/ml) in TZM-bl cells. Methanolic extract of Strychnos potatorum, aqueous extract of Ficus infectoria and hydroalcoholic extract of Annona squamosa inhibited laboratory adapted HIV-1 strains (IC80 4.24–125 μg/ml) and primary isolates (IC80 18–156 μg/ml) in TZM-bl cells. Methanolic extracts of Achyranthes aspera and Rosa centifolia, (IC801-9 μg/ml) further significantly inhibited HIV-1 primary isolates in PM1cells. Methanolic extracts of Tridax procumbens, Mallotus philippinensis, Annona reticulate, aqueous extract of Ficus benghalensis and hydroalcoholic extract of Albizzia lebbeck did not exhibit anti-HIV activity in all the tested strains. Methanolic extract of Rosa centifolia also demonstrated to be non-toxic to HEC-1A epithelial cells and maintained epithelial integrity (at 500 μg/ml) when tested in transwell dual-chamber.ConclusionThese active methanolic extracts of Achyranthes aspera and Rosa centifolia, could be further subjected to chemical analysis to investigate the active moiety responsible for the anti-HIV activity. Methanolic extract of Rosa centifolia was found to be well tolerated maintaining the epithelial integrity of HEC-1A cells in vitro and thus has potential for investigating it further as candidate microbicide.

Bioactive prenylated coumarins as potential anti-inflammatory and anti-HIV agents from Clausena lenis.

The phytochemical study on the stems of Clausena lenis resulted in the isolation of three new prenylated coumarins, clauselenins A-C (1-3), together with nine known prenylated coumarins (4-12). The chemical structures of new prenylated coumarins (1-3) were elucidated by means of comprehensive spectral analyses and the known compounds (4-12) were determined by means of comparing their experimental spectral data with those described data in the literatures. All isolated prenylated coumarins were assessed for their anti-inflammatory effects together with anti-HIV activities in vitro. Prenylated coumarins 1-12 displayed remarkable inhibitory effects against nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro with the IC50 values which are comparable to hydrocortisone. Meanwhile, prenylated coumarins 1-12 exhibited considerable anti-HIV-1 reverse transcriptase (RT) activities possessing EC50 values in the range of 0.17-9.08µM. These findings indicate that the isolation and identification of these prenylated coumarins with pronounced anti-inflammatory effects as well as anti-HIV activities separated from the stems of C. lenis could be of great significance to the development of new anti-inflammatory and anti-HIV agents and their potential applications in the pharmaceutical industry.

SYNTHESIS AND ANTI-HIV EVALUATION OF SUBSTITUTED INDOLE-3-CARBALDEHYDE DERIVATIVES

In the present study, a series of indole-3-carbaldehydes having substituted N-sulfonyl phenyl or Nphenacyl group was synthesized and evaluated for anti-HIV activity, in particular, in vitro and in silico HIV-1 integrase inhibition. Three compounds (8b, 8c and 8g) exhibited significant inhibition of HIV-1 IN (IC50 ≤5.32 μM). Molecular docking studies were also performed to justify the IN inhibition and in vitro in silico correlation was drawn. Compound 8b exhibited significant anti-HIV activity against HIV-1 strain IIIB (IC50 3.16 μM). HIV integrase inhibitors are also reported to inhibit reverse transcriptase. When 8b was further examined against various single and double mutant reverse transcriptase (RT) strains, it showed promising activity against E138K with IC50 value of 2.43 μM with safety index of 3. Therefore, compound 8b can be a starting point for the development of dual inhibitors of HIV integrase as well as reverse transcriptase.

Biotechnological production of betulinic acid and derivatives and their applications.

Betulinic acid (BA), a lupane-type triterpenoid, mainly distributes in birch plants. It has been reported that BA and its derivatives possess potent anticancer and anti-HIV activities. Commercial production of BA to date depends on phytochemical extraction and semi-synthesis from betulin (a biosynthetic precursor of BA). The biosynthetic pathway of BA has been completely revealed so far. The relevant enzymes involved in BA biosynthesis are summarized in this review. The studies on construction of biotechnological platforms for production of BA and other related triterpenoids are subsequently reviewed. The engineering strategies include overexpression of rate-limiting enzymes of triterpenoid biosynthesis, balancing flux between triterpenoid biosynthetic pathway and others, engineering endoplasmic reticulum, and improving cofactor availability. At the end, this review also attempted to provide future perspectives on potential strategies for further optimizing biosynthesis of BA and other triterpenoids in microbial hosts. KEY POINTS: • Summarizes the relevant enzymes involved in betulinic acid (BA) biosynthesis. • Highlights recent advances in biotechnological production of BA-related compounds. • Provides future perspectives on strategies for optimizing triterpenoid biosynthesis.

Spiro-Lactams as Novel Antimicrobial Agents.

Structural modulation of previously identified lead spiro-β-lactams with antimicrobial activity was carried out. The main objective of this work was to synthesize and evaluate the biological activity of novel spiro-lactams based on previously identified lead compounds with antimicrobial activity. The target chiral spiro-γ-lactams were synthesized through 1,3-dipolar cycloaddition reaction of a diazo-γ-lactam with electron-deficient dipolarophiles. In vitro activity against HIV and Plasmodium of a wide range of spiro-β-lactams and spiro-γ-lactams was evaluated. Among these compounds, one derivative with good anti-HIV activity and two with promising antiplasmodial activity (IC50 < 3.5 µM) were identified. A novel synthetic route to chiral spiro-γ-lactams has been established. The studied β- and γ- lactams were not cytotoxic, and three compounds with promising antimicrobial activity were identified, whose structural modulation may lead to new and more potent drugs. The designed structural modulation of biologically active spiro-β-lactams involved the replacement of the four-membered β-lactam ring by a five-membered γ-lactam ring. Although conformational and superimposition computational studies revealed no significant differences between β- and γ- lactam pharmacophoric features, the studied structural modulation did not lead to compounds with a similar biological profile. The observed results suggest that the β-lactamic core is a requirement for the activity against both HIV and Plasmodium.