Helichrysum stoechas (L.) Moench reduces body weight gain and modulates mood disorders via inhibition of silent information regulator 1 (SIRT1) by arzanol.

The prevalence of obesity is steadily rising, making safe and more efficient anti-obesity treatments an urgent medical need. Growing evidence correlates obesity and comorbidities, including anxiety and depression, with the development of a low-grade inflammation in peripheral and central tissues. We hypothesized that attenuating neuroinflammation might reduce weight gain and improve mood. We investigated the efficacy of a methanolic extract from Helichrysum stoechas (L.) Moench (HSE), well-known for its anti-inflammatory properties, and its main constituent arzanol (AZL). HPLC-ESI-MS2 and HPLC-UV were used to characterize the extract. HSE effects on mood and feeding behavior was assessed in mice. The mechanism of action of HSE and AZL was investigated in hippocampus samples and SH-SY5Y cells by western blotting and immunofluorescence. Oral administration of HSE for 3 weeks limited weight gain with no significant decrease in food intake. HSE produced an anxiolytic-like and antidepressant-like phenotype comparable to diazepam and amitriptyline, respectively, in the absence of locomotor and cognitive impairments and induced neuroprotective effects in glutamate-exposed SH-SY5Y cells. A dose-dependent reduction of SIRT1 expression was detected in SH-SY5Y cells and in hippocampal samples from HSE-treated mice. The inhibition of the SIRT1-FoxO1 pathway was induced in the hypothalamus. Molecular docking studies proposed a mechanism of SIRT1 inhibition by AZL, confirmed by the evaluation of inhibitory effects on SIRT1 enzymatic activity. HSE limited weight gain and comorbidities through an AZL-mediated SIRT1 inhibition. These activities indicate HSE an innovative therapeutic perspective for obesity and associated mood disorders.

BS148 Reduces the Aggressiveness of Metastatic Melanoma via Sigma-2 Receptor Targeting.

The management of advanced-stage melanoma is clinically challenging, mainly because of its resistance to the currently available therapies. Therefore, it is important to develop alternative therapeutic strategies. The sigma-2 receptor (S2R) is overexpressed in proliferating tumor cells and represents a promising vulnerability to target. Indeed, we have recently identified a potent S2R modulator (BS148) that is effective in melanoma. To elucidate its mechanism of action, we designed and synthesized a BS148 fluorescent probe that enters SK-MEL-2 melanoma cells as assessed using confocal microscopy analysis. We show that S2R knockdown significantly reduces the anti-proliferative effect induced by BS148 administration, indicating the engagement of S2R in BS148-mediated cytotoxicity. Interestingly, BS148 treatment showed similar molecular effects to S2R RNA interference-mediated knockdown. We demonstrate that BS148 administration activates the endoplasmic reticulum stress response through the upregulation of protein kinase R-like ER kinase (PERK), activating transcription factor 4 (ATF4) genes, and C/EBP homologous protein (CHOP). Furthermore, we show that BS148 treatment downregulates genes related to the cholesterol pathway and activates the MAPK signaling pathway. Finally, we translate our results into patient-derived xenograft (PDX) cells, proving that BS148 treatment reduces melanoma cell viability and migration. These results demonstrate that BS148 is able to inhibit metastatic melanoma cell proliferation and migration through its interaction with the S2R and confirm its role as a promising target to treat cancer.

Insights into the Structural Conformations of the Tau Protein in Different Aggregation Status.

Tau is a protein characterized by large structural portions displaying extended conformational changes. Unfortunately, the accumulation of this protein into toxic aggregates in neuronal cells leads to a number of severe pathologies, collectively named tauopathies. In the last decade, significant research advancements were achieved, including a better understanding of Tau structures and their implication in different tauopathies. Interestingly, Tau is characterized by a high structural variability depending on the type of disease, the crystallization conditions, and the formation of pathologic aggregates obtained from in vitro versus ex vivo samples. In this review, we reported an up-to-date and comprehensive overview of Tau structures reported in the Protein Data Bank, with a special focus on discussing the connections between structural features, different tauopathies, different crystallization conditions, and the use of in vitro or ex vivo samples. The information reported in this article highlights very interesting links between all these aspects, which we believe may be of particular relevance for a more informed structure-based design of compounds able to modulate Tau aggregation.

Investigation of the effect of different linker chemotypes on the inhibition of histone deacetylases (HDACs).

Histone Deacetylases (HDACs) are among the most attractive and interesting targets in anticancer drug discovery. The clinical relevance of HDAC inhibitors (HDACIs) is testified by four FDA-approved drugs for cancer treatment. However, one of the main drawbacks of these drugs resides in the lack of selectivity against the different HDAC isoforms, resulting in severe side effects. Thus, the identification of selective HDACIs represents an exciting challenge for medicinal chemists. HDACIs are composed of a cap group, a linker region, and a metal-binding group interacting with the catalytic zinc ion. While the cap group has been extensively investigated, less information is available about the effect of the linker on isoform selectivity. To this aim, in this work, we explored novel linker chemotypes to direct isoform selectivity. A small library of 25 hydroxamic acids with hitherto unexplored linker chemotypes was prepared. In vitro tests demonstrated that, depending on the linker type, some candidates selectively inhibit HDAC1 over HDAC6 isoform or vice versa. Docking calculations were performed to rationalize the effect of the novel linker chemotypes on biologic activity. Moreover, four compounds were able to increase the levels of acetylation of histone H3 or tubulin. These compounds were also assayed in breast cancer MCF7 cells to test their antiproliferative effect. Three compounds showed a significant reduction of cancer proliferation, representing valuable starting points for further optimization.

Inhibitors of histone deacetylase 6 based on a novel 3-hydroxy-isoxazole zinc binding group.

Histone deacetylase 6 (HDAC6) is an established drug target for cancer treatment. Inhibitors of HDAC6 based on a hydroxamic acid zinc binding group (ZBG) are often associated with undesirable side effects. Herein, we describe the identification of HDAC6 inhibitors based on a completely new 3-hydroxy-isoxazole ZBG. A series of derivatives decorated with different aromatic or heteroaromatic linkers, and various cap groups were synthesised and biologically tested. In vitro tests demonstrated that some compounds are able to inhibit HDAC6 with good potency, the best candidate reaching an IC50 of 700 nM. Such good potency obtained with a completely new ZBG make these compounds particularly attractive. The effect of the most active inhibitors on the acetylation levels of histone H3 and α- tubulin and their anti-proliferative activity of DU145 cells were also investigated. Docking studies were performed to evaluate the binding mode of these new derivatives and discuss structure-activity relationships.

[Reorganization and public health management by the Department of Prevention during the COVID-19 emergency. An experience of integration between prevention and primary care in the proactive management of possible cases]. / Riorganizzazione e management di sanità pubblica del dipartimento di prevenzione nell'emergenza COVID-19. Un'esperienza di integrazione tra prevenzione e cure primarie nella gestione proattiva dei casi possibili.

OBJECTIVES: to describe the organisation and the role of the Department of Prevention of the Local Health Unit (APSS) of Trento (Trentino-Alto Adige Region, Northern Italy) against the spread of COVID-19 in the population, in the management of possible cases (with only clinical criteria of influenza-like illness, ILI, without diagnostic swab) reported by General practitioners (GPs) and by Family paediatricians (FPs) during the initial phase of the pandemic COVID-19 in Trentino-Alto Adige Region. DESIGN: descriptive study. SETTING AND PARTICIPANTS: this study analysed the reports of patients with ILI sent to the Healthcare company from 17 March to 17 April 2020 by their GPs or FP and subsequently classified into: redundant reports (people already known to the healthcare company as confirmed or probable case COVID-19); reports inconsistent with ILI criteria (patients not known to APSS as probable/confirmed case; without ILI criteria); appropriate reports (patients not known to APSS as probable/confirmed case; with ILI criteria). MAIN OUTCOME MEASURES: proportion of GPs and FPs who participated to report system reporting at least one patient, out of the total number of GPs and FPs; frequency of patients reported as ILI; time (in days) to manage reported patients. The cumulative weekly rate of "non-redundant" (not already known to APSS as probable/confirmed case) reports per thousand inhabitants was also calculated. RESULTS: over 80% of GPs and FPs voluntary participated into the reporting system of patients with COVID-19 clinical criteria. Overall, 4,270 patients were reported; of these, 2,865 (67%) were not known to APSS as probable/confirmed case. Response time in days decrease progressively during the period of activity (from a mean of 6 days to 0.4 days during the 12th and 16th week of 2020, respectively). The cumulative weekly rate of client reports which were not already known as probable or confirmed cases (per 1,000 population) ranges from 3.54 to 6.84 cases in the 12th and 16th week, respectively. Among the 4,270 reports, 1,471 patients considered possible COVID-19 cases were identified due to the presence of ILI symptoms, even in the absence of a swab or a positive history for close contact with COVID-19 case. From the epidemiological investigation into the 1,471 possible cases, 2,514 close contacts were identified and quarantined at home. Of the 2,514 close contacts, 127 (5.05%) people developed symptoms during quarantine. CONCLUSIONS: the integration among primary care, GPs and FPS, and the Department of Prevention could be an element of success in the management of the COVID-19 emergency and in the return to a normal phase. However, further assessments are required on the effectiveness and impact of the adopted model, especially in relation to the exit from phase 1 and phase 2 of the pandemic emergency.

Exhaustive CoMFA and CoMSIA analyses around different chemical entities: a ligand-based study exploring the affinity and selectivity profiles of 5-HT1A ligands.

The 5-hydroxytryptamine (5-HT1A) receptors represent an attractive target in drug discovery. In particular, 5-HT1A agonists and partial agonists are deeply investigated for their potential role in the treatment of anxiety, depression, ischaemic brain disorder and more recently, of pain. On the other hand, 5-HT1A antagonists have been revealed promising compounds in cognition disorders and, lately, in cancer. Thus, the discovery of 5HT1A ligands is nowadays an appealing research activity in medicinal chemistry. In this work, Comparative Molecular Fields Analysis (CoMFA) and Comparative Molecular Similarity Index Analysis (CoMSIA) were applied on an in-house library of 5-HT1A ligands bearing different chemical scaffolds in order to elucidate their affinity and selectivity for the target. Following this procedure, a number of structural modifications have been drawn for the development of much more effective 5-HT1AR ligands. [Formula: see text].

Discovery of potent pyrrolo-pyrimidine and purine HDAC inhibitors for the treatment of advanced prostate cancer.

The development of drugs for the treatment of advanced prostate cancer (PCA) remains a challenging task. In this study we have designed, synthesized and tested twenty-nine novel HDAC inhibitors based on three different zinc binding groups (trifluoromethyloxadiazole, hydroxamic acid, and 2-mercaptoacetamide). These warheads were conveniently tethered to variously substituted phenyl linkers and decorated with differently substituted pyrrolo-pyrimidine and purine cap groups. Remarkably, most of the compounds showed nanomolar inhibitory activity against HDAC6. To provide structural insights into the Structure-Activity Relationships (SAR) of the investigated compounds, docking of representative inhibitors and molecular dynamics of HDAC6-inhibitor complexes were performed. Compounds of the trifluoromethyloxadiazole and hydroxamic acid series exhibited promising anti-proliferative activities, HDAC6 targeting in PCA cells, and in vitro tumor selectivity. Representative compounds of the two series were tested for solubility, cell permeability and metabolic stability, demonstrating favorable in vitro drug-like properties. The more interesting compounds were subjected to migration assays, which revealed that compound 13 and, to a lesser extent, compound 15 inhibited the invasive behaviour of androgen-sensitive and -insensitive advanced prostate cancer cells. Compound 13 was profiled against all HDACs and found to inhibit all members of class II HDACs (except for HDAC10) and to be selective with respect to class I and class IV HDACs. Overall, compound 13 combines potent inhibitory activity and class II selectivity with favorable drug-like properties, an excellent anti-proliferative activity and marked anti-migration properties on PCA cells, making it an excellent lead candidate for further optimization.

Novel S1R agonists counteracting NMDA excitotoxicity and oxidative stress: A step forward in the discovery of neuroprotective agents.

Sigma-1 receptor (S1R) has been considered a promising therapeutic target for several neurodegenerative diseases and S1R agonists have shown neuroprotective activity against glutamate excitotoxicity and oxidative stress. Starting from a previously identified low nanomolar S1R agonist, in this work we prepared and tested novel benzylpiperidine/benzylpiperazine-based compounds designed by applying a ring opening strategy. Among them, 4-benzyl-1-(2-phenoxyethyl)piperidine 6b (S1R Ki = 0.93 nM) and 4-benzyl-1-(3-phenoxypropyl)piperidine 8b (S1R Ki = 1.1 nM) emerged as high affinity S1R ligands and showed selectivity over S2R and N-methyl-d-aspartate receptor (NMDAR). Candidate compounds behaved as potent S1R agonists being able to enhance the neurite outgrowth induced by nerve growth factor (NGF) in PC12 cell lines. In SH-SY5Y neuroblastoma cell lines they exhibited a neuroprotective effect against rotenone- and NMDA-mediated toxic insults. The neuroprotective activity of 6b and 8b was reverted by co-treatment with an S1R antagonist, PB212. Compounds 6b and 8b were tested for cytotoxicity in-vitro against three human cancer cell lines (A549, LoVo and Panc-1) and in-vivo zebrafish model, resulting in a good efficacy/safety profile, comparable or superior to the reference drug memantine. Overall, these results encourage further preclinical investigations of 6b and 8b on in-vivo models of neurodegenerative diseases.

Destabilizers of the thymidylate synthase homodimer accelerate its proteasomal degradation and inhibit cancer growth.

Drugs that target human thymidylate synthase (hTS), a dimeric enzyme, are widely used in anticancer therapy. However, treatment with classical substrate-site-directed TS inhibitors induces over-expression of this protein and development of drug resistance. We thus pursued an alternative strategy that led us to the discovery of TS-dimer destabilizers. These compounds bind at the monomer-monomer interface and shift the dimerization equilibrium of both the recombinant and the intracellular protein toward the inactive monomers. A structural, spectroscopic, and kinetic investigation has provided evidence and quantitative information on the effects of the interaction of these small molecules with hTS. Focusing on the best among them, E7, we have shown that it inhibits hTS in cancer cells and accelerates its proteasomal degradation, thus causing a decrease in the enzyme intracellular level. E7 also showed a superior anticancer profile to fluorouracil in a mouse model of human pancreatic and ovarian cancer. Thus, over sixty years after the discovery of the first TS prodrug inhibitor, fluorouracil, E7 breaks the link between TS inhibition and enhanced expression in response, providing a strategy to fight drug-resistant cancers.

Discovery of a new series of 5-HT1A receptor agonists.

Starting from compounds previously identified as alpha(1)-adrenoceptor antagonists that were also found to bind to the 5-HT(1A) receptor, in an attempt to separate the two activities, a new series of 5-HT(1A) receptor agonists was identified and shown to have high potency and/or high selectivity. Of these, compound 13, which combines high selectivity (5-HT(1A)/alpha(1)=151) and good agonist potency (pD(2)=7.82; E(max)=76), was found to be the most interesting.

Pharmacological properties and biochemical mechanisms of µ-opioid receptor ligands might be due to different binding poses: MD studies.

Background: Central and peripheral analgesia without adverse effects relies on the identification of µ-opioid agonists that are able to activate 'basal' antinociceptive pathways. Recently developed µ-selective benzomorphan agonists that are not antagonized by naloxone do not activate G-proteins and ß-arrestins. Which pathways do µ receptors activate? How can each of them be selectively activated? What role is played by allosteric binding sites? Methodology & results: Molecular modeling studies characterize the amino acid residues involved in the interaction with various classes of endogenous and exogenous ligands and with agonists and antagonists. Conclusions: Critical binding differences between various classes of agonists with different pharmacological profiles have been identified. MML series binding poses may be relevant in the search for an antinociception agent without side effects.

Novel Dithiolane-Based Ligands Combining Sigma and NMDA Receptor Interactions as Potential Neuroprotective Agents.

Sigma receptors (SRs) are recognized as valuable targets for the treatment of neurodegenerative disorders. A series of novel SRs ligands were designed by combining key pharmacophoric amines (i.e., benzylpiperidine or benzylpiperazine) with new 1,3-dithiolane-based heterocycles and their bioisosters. The new compounds exhibited a low nanomolar affinity for sigma-1 and sigma-2 receptors. Five selected compounds were evaluated for their neuroprotective capacity on SH-SY5Y neuroblastoma cell line. They were able to counteract the neurotoxicity induced by rotenone, oligomycin and NMDA. Competition studies with PB212, a S1R antagonist, confirmed the involvement of S1R in neuroprotection from the oxidative stress induced by rotenone. Electrophysiological experiments performed on cortical neurons in culture highlighted the compounds ability to reduce NMDA-evoked currents, suggesting a negative allosteric modulator activity toward the NMDA receptor. Altogether these results qualify our novel dithiolane derivatives as potential agents for fighting neurodegeneration.

Identification of a Potent and Selective 5-HT1A Receptor Agonist with In Vitro and In Vivo Antinociceptive Activity.

Opioids are the gold standard drugs for the treatment of acute and chronic severe pain, although their serious side effects constitute a big limitation. In the search for new and safer drugs, 5-HT1AR agonists are emerging as potential candidates in pain relief therapy. In this work, we evaluated the affinity and activity of enantiomers of the two newly synthesized, potent 5-HT1AR agonists N-[(2,2-diphenyl-1,3-dioxolan-4-yl)methyl]-2-[2-(pyridin-4-yl)phenoxy]ethan-1-ammonium hydrogenoxalate (rac-1) and N-((2,2-diphenyl-1,3-dioxolan-4-yl)methyl)-2-(2-(1-methyl-1H-imidazol-5-yl)phenoxy)ethan-1-ammonium hydrogenoxalate (rac-2) in vitro and in vivo. The role of chirality in the interaction with 5-HT1AR was evaluated by molecular docking. The activity of the rac-1 was tested in mouse models of acute pain (hot plate) and severe tonic nociceptive stimulation (intraplantar formalin test). Rac-1 was active in the formalin test with a reduction in paw licking in both phases at 10 mg/kg, and its effect was abolished by the selective 5-HT1AR antagonist, WAY-100635. The eutomer (S)-1, but not the racemate, was active during the hot plate test at 10 and 20 mg/kg, and this effect was abolished by 30 min treatment with WAY-100635 at 30 min. Similarly to 8-OH-DPAT, (S)-1 evoked a slow outward current and depressed spontaneous glutamatergic transmission in superficial dorsal horn neurons, more effectively than rac-1. The eutomer (S)-1 showed promising developability properties, such as high selectivity over 5-HT subtypes, no interaction with the µ receptors, and low hepato- and cardiotoxicity. Therefore, (S)-1 may represent a potential candidate for the treatment of acute and chronic pain without having the adverse effects that are commonly associated with the classic opioid drugs.

Multitarget 1,4-Dioxane Compounds Combining Favorable D2-like and 5-HT1A Receptor Interactions with Potential for the Treatment of Parkinson's Disease or Schizophrenia.

The effect of methoxy and hydroxy substitutions in different positions of the phenoxy moiety of the N-((6,6-diphenyl-1,4-dioxan-2-yl)methyl)-2-phenoxyethan-1-amine scaffold on the affinity/activity for D2-like, 5-HT1A, and α1-adrenoceptor subtypes was evaluated. Multitarget compounds with suitable combinations of dopaminergic and serotoninergic profiles were discovered. In particular, the 2-methoxy derivative 3 showed a multitarget combination of 5-HT1A/D4 agonism and D2/D3/5-HT2A antagonism, which may be a favorable profile for the treatment of schizophrenia. Interestingly, the 3-hydroxy derivative 8 behaved as a partial agonist at D2 and as a potent full agonist at D3 and D4 subtypes. In addition to its potent 5-HT1A receptor agonism, such a dopaminergic profile makes 8 a potential multitarget compound for the treatment of Parkinson's disease (PD). Indeed, the activation of 5-HT1A receptors might be helpful in reducing dyskinetic side effects associated with dopaminergic stimulation.

1,3-Dioxane as a scaffold for potent and selective 5-HT1AR agonist with in-vivo anxiolytic, anti-depressant and anti-nociceptive activity.

A series of compounds generated by ring expansion/opening and molecular elongation/simplification of the 1,3-dioxolane scaffold were prepared and tested for binding affinity at 5-HT1AR and α1 adrenoceptors. The compounds with greater affinity were selected for further functional studies. N-((2,2-diphenyl-1,3-dioxan-5-yl)methyl)-2-(2-methoxyphenoxy)ethan-1-ammonium hydrogen oxalate (12) emerged as highly potent full agonist at the 5-HT1AR (pKi 5-HT1A = 8.8; pD2 = 9.22, %Emax = 92). The pharmacokinetic data in rats showed that the orally administered 12 has a high biodistribution in the brain compartment. Thus, 12 was further investigated in-vivo, showing an anxiolytic and antidepressant effect. Moreover, in the formalin test, 12 was able to decrease the late response to the noxious stimulus, indicating a potential use in the treatment of chronic pain.

Molecular modeling and biological studies show that some µ-opioid receptor agonists might elicit analgesia acting as MMP-9 inhibitors.

Aim: Despite the serious side effects, analgesics acting on opioid receptors are still considered the best way to get antinociception. Matrix metalloproteinases, a large family of zinc-dependent proteases implicated in many pathological conditions, such as diabetes and osteoarthritis, are also involved in inflammation and pain. Methodology & results: Looking for evidence of possible interactions of opioid pathways and inflammation mediators, molecular modeling studies of a series of recently developed µ-opioid receptor benzomorphanic agonists together with biological data on pain and inflammation molecular targets, allowed us to hypothesize a possible correlation between µ-opioid receptor system and MMP-9. Conclusion: A new compound, (-)-MML1017, emerged as a possible dual-acting agent able to interact selectively and potently with the two molecular targets.

Fluorometric detection of protein-ligand engagement: The case of phosphodiesterase5.

Phosphodiesterases (PDEs) regulate the intracellular levels of cAMP and cGMP. The great clinical success of the PDE5 inhibitors, Sildenafil (Viagra), Vardenafil (Levitra) and Tadalafil (Cialis) has led to an increasing interest for this class of enzymes. Recent studies have shown a correlation between tumor growth and PDE5 overexpression, making PDE5-selective inhibitors promising candidates for cancer treatment. The search for such inhibitors rests today on radioactive assays. In this work, we exploit the conserved catalytic domain of the enzyme and propose a faster and safer method for detecting the binding of ligands and evaluate their affinities. The new approach takes advantage of Förster Resonance Energy Transfer (FRET) between, as the donor, a fluorescein-like diarsenical probe able to covalently bind a tetracysteine motif fused to the recombinant PDE5 catalytic domain and, as the acceptor, a rhodamine probe covalently bound to the pseudosubstrate cGMPS. The FRET efficiency decreases when a competitive ligand binds the PDE5 catalytic site and displaces the cGMPS-rhodamine conjugate. We have structurally investigated the PDE5/cGMPS-rhodamine complex by molecular modelling and have used the FRET signal to quantitatively characterize its binding equilibrium. Competitive displacement experiments were carried out with tadalafil and cGMPS. An adaptation of the competitive-displacement equilibrium model yielded the affinities for PDE5 of the incoming ligands, nano- and micromolar, respectively.

Synthesis and biological evaluation of 1,3-dioxolane-based 5-HT1A receptor agonists for CNS disorders and neuropathic pain.

AIM: Targeting 5-HT1A receptor (5-HT1AR) as a strategy for CNS disorders and pain control. METHODOLOGY: A series of 1,3-dioxolane-based 2-heteroaryl-phenoxyethylamines was synthesized by a convergent approach and evaluated at α1-adrenoceptors and 5-HT1AR by binding and functional experiments. Absorption, distribution, metabolism, excretion and toxicity prediction studies were performed to explore the drug-likeness of the compounds. RESULTS & CONCLUSION: The most promising compound, the pyridin-4-yl derivative, emerged as a potent and selective 5-HT1AR agonist (pKi = 9.2; pD2 = 8.83; 5-HT1A/α1 = 135). In vitro it was able to permeate by passive diffusion MDCKII-MDR1 monolayer mimicking the blood-brain barrier and showed promising neuroprotective activity.

Synthesis, structural characterization and biological evaluation of 4'-C-methyl- and phenyl-dioxolane pyrimidine and purine nucleosides.

Nucleoside analogues play an important role in antiviral, antibacterial and antineoplastic chemotherapy. Herein we report the synthesis, structural characterization and biological activity of some 4'-C -methyl- and -phenyl dioxolane-based nucleosides. In particular, α and ß anomers of all natural nucleosides were obtained and characterized by NMR, HR-MS and X-ray crystallography. The compounds were tested for antimicrobial activity against some representative human pathogenic fungi, bacteria and viruses. Antitumor activity was evaluated in a large variety of human cancer cell-lines. Although most of the compounds showed non-significant activity, 23α weakly inhibited HIV-1 multiplication. Moreover, 22α and 32α demonstrated a residual antineoplastic activity, interestingly linked to the unnatural α configuration. These results may provide structural insights for the design of active antiviral and antitumor agents.