161 research outputs found
Synthesis and biological evaluation of anti-Toxoplasma gondii activity of a novel scaffold of thiazolidinone derivatives
We designed and synthesised novel N-substituted 1,3-thiazolidin-4-one derivatives for the evaluation of their anti-Toxoplasma gondii efficacy. This scaffold was functionalised both at the N1-hydrazine portion with three structurally different moieties and at the lactam nitrogen with substituted benzyl groups selected on the basis of our previous structure-activity relationships studies. Using three different assay methods, the compounds were assessed in vitro to determine both the levels of efficacy against the tachyzoites of T. gondii (IC50 = 5-148 μM), as well as any evidence of cytotoxicity towards human host cells (TD50 = 68 to ≥320 μM). Results revealed that ferrocene-based thiazolidinones can possess potent anti-tachyzoite activity (TI =2-64)
Novel 1,3-thiazolidin-4-one derivatives as promising anti-Candida agents endowed with anti-oxidant and chelating properties
Pursuing our recent outcomes regarding the antifungal activity of N-substituted 1,3-thiazolidin-4-ones, we synthesized thirty-six new derivatives introducing aliphatic, cycloaliphatic and heteroaromatic moieties at N1-hydrazine connected with C2 position of the thiazolidinone nucleus and functionalizing the lactam nitrogen with differently substituted (NO2, NH2, Cl and F) benzyl groups. These compounds were tested to evaluate their minimum inhibitory concentration (MIC) against several clinical Candida spp. with respect to topical and systemic reference drugs (clotrimazole, fluconazole, ketoconazole, mi- conazole, tioconazole, amphotericin B). Moreover, anti-oxidant properties were also evaluated by using different protocols including free radical scavenging (DPPH and ABTS), reducing power (CUPRAC and FRAP), metal chelating and phosphomolybdenum assays. Moreover, for the most active derivatives we assessed the toxicity (CC50) against Hep2 human cells in order to characterize them as multi-target agents for fungal infections
Design, synthesis, docking studies and monoamine oxidase inhibition of a small library of 1-acetyl- and 1-thiocarbamoyl-3,5-diphenyl-4,5-dihydro-(1h)-pyrazoles
New N-acetyl/N-thiocarbamoylpyrazoline derivatives were designed and synthesized in high yields to assess their inhibitory activity and selectivity against human monoamine oxidase A and B. The most important chiral compounds were separated into their single enantiomers and tested. The impact of the substituents at N1, C3 and C5 positions as well the influence of the configuration of the C5 on the biological activity were analyzed. Bulky aromatic groups at C5 were not tolerated. p-Prenyloxyaryl moiety at C3 oriented the selectivity toward the B isoform. The results were also corroborated by molecular modelling studies providing new suggestions for the synthesis of privileged structures to serve as lead compounds for the treatment of mood disorders and neurodegenerative diseases
3-(Phenyl-4-oxy)-5-phenyl-4,5-dihydro-(1H)-pyrazole: a fascinating molecular framework to study the enantioseparation ability of the amylose (3,5-dimethylphenylcarbamate) chiral stationary phase. Part I. Structure-enantioselectivity relationships
Chiral stationary phases (CSPs) based on amylose (3,5-dimethylphenylcarbamate) (ADMPC) exhibit awide-range of enantioselectivity in high-performance liquid chromatography (HPLC) and supercriticalfluid chromatography (SFC). Although this class of CSPs has been extensively used, chiral discriminationsat receptorial level, which are useful to develop predictive molecular models, have been rarely reportedin the literature.Herein, we describe the results obtained in the enantioselective HPLC of a set of six C5-chiral 4,5-dihydro-(1H)-pyrazole derivatives on the ADMPC-based Chiralpak AD-3 CSP (CSP) under normal-phaseand polar organic conditions. Using pure methanol as a mobile phase the exceptional enantioseparationfactor value of 50 at 25â—¦C was found for one of the investigated analytes. To the best of our knowledge, theenantiomeric bias represents the most outstanding enantioseparation ever recorded on ADMPC-basedCSPs.Systematic variations in chemical groups in specific positions of the 3-(phenyl-4-oxy)-5-phenyl-4,5-dihydro-(1H)-pyrazole molecular framework resulted in peculiar changes in retention andenantioselectivity. A careful analysis of the chromatographic data permitted to advance some hypothesesconcerning the role played by the individual chemical groups in determining the exceptional enantiosep-aration.In particular, under methanol-rich mode, the prenyl moiety of the second eluted enantiomer of thebetter resolved analyte was recognized as a critical structural element to establish direct and favorablesolvophobic interactions with apolar portions of selector
Identification of new anti-Candida compounds by ligand-based pharmacophore virtual screening
Candida albicans represents the most prevalent microbial population in mucosal and systemic infections, usually confined to severely immunocompromised people. Considering the increase
of resistant strains and the demand for new antifungal drugs endowed with innovative mechanism of action, we performed a ligand-based virtual screening in order to identify new
anti-Candida compounds. Starting from a large library of natural/semisynthetic products and several published synthesized compounds, three coumarin derivatives were discovered in silico
as new hit compounds and submitted to the in vitro assay in order to confirm their predicted biological activity
4-(3-Nitrophenyl)thiazol-2-ylhydrazone derivatives as antioxidants and selective hMAO-B inhibitors: synthesis, biological activity and computational analysis
A new series of 4-(3-nitrophenyl)thiazol-2-ylhydrazone derivatives were designed, synthesised, and evaluated to assess their inhibitory effect on the human monoamine oxidase (hMAO) A and B isoforms. Different (un)substituted (hetero)aromatic substituents were linked to N1 of the hydrazone in order to establish robust structure–activity relationships. The results of the biological testing demonstrated that the presence of the hydrazothiazole nucleus bearing at C4 a phenyl ring functionalised at the meta position with a nitro group represents an important pharmacophoric feature to obtain selective and reversible human MAO-B inhibition for the treatment of neurodegenerative disorders. In addition, the most potent and selective MAO-B inhibitors were evaluated in silico as potential cholinesterase (AChE/BuChE) inhibitors and in vitro for antioxidant activities. The results obtained from molecular modelling studies provided insight into the multiple interactions and structural requirements for the reported MAO inhibitory properties
Neem oil nanoemulsions: characterisation and antioxidant activity
The aim of the present work is to develop nanoemulsions (NEs), nanosized emulsions, manufactured for
improving the delivery of active pharmaceutical ingredients. In particular, nanoemulsions composed of
Neem seed oil, contain rich bioactive components, and Tween 20 as nonionic surfactant were prepared.
A mean droplet size ranging from 10 to 100nm was obtained by modulating the oil/surfactant ratio.
Physicochemical characterisation was carried out evaluating size, f-potential, microviscosity, polarity and
turbidity of the external shell and morphology, along with stability in simulated cerebrospinal fluid (CSF),
activity of Neem oil alone and in NEs, HEp-2 cell interaction and cytotoxicity studies. This study confirms
the formation of NEs by Tween 20 and Neem oil at different weight ratios with small and homogenous
dimensions. The antioxidant activity of Neem oil alone and in NEs was comparable, whereas its cytotoxicity
was strongly reduced when loaded in NEs after interaction with HEp-2 cells
Atriplex mollis desf. Aerial parts: extraction procedures, secondary metabolites and color analysis
A method using high-performance liquid chromatography coupled with a photodiode array detector was proposed for the rapid characterization of different phenolic constituents from the extracts of Atriplex mollis aerial parts. Atriplex species are known for their multiple biological activities, but no information is available in the literature about A. mollis. With the aim to firstly characterize the main secondary metabolites of this plant, so as to orient better the biological evaluation, we applied three different extraction procedures and compared the chromatographic results. Microwave-assisted extraction gave the best yield and recovery of important compounds such as gallic acid, catechin, chlorogenic acid, p-OH benzoic acid, rutin, sinapinic acid, t-ferulic acid, naringenin and benzoic acid. These constituents belong to three important chemical classes: phenolic acids, flavonoids and monoterpenes. Color evaluation and analysis of chlorophylls (a and b) and carotenoids complete the preliminary profile of this plant. From these analyses, Atriplex mollis is a source of bioactive compounds (especially rutin, t-ferulic acid and gallic acid) and could be recommended as a plant of phyto-pharmaceutical relevance, opening new perspectives on this salt-tolerant plant
Histone acetyltransferase inhibitor CPTH6 preferentially targets lung cancer stem-like cells
Cancer stem cells (CSCs) play an important role in tumor initiation, progression,
therapeutic failure and tumor relapse. In this study, we evaluated the efficacy of
the thiazole derivative 3-methylcyclopentylidene-[4-(4’-chlorophenyl)thiazol-2-yl]
hydrazone (CPTH6), a novel pCAF and Gcn5 histone acetyltransferase inhibitor, as a
small molecule that preferentially targets lung cancer stem-like cells (LCSCs) derived
from non-small cell lung cancer (NSCLC) patients. Notably, although CPTH6 inhibits
the growth of both LCSC and NSCLC cell lines, LCSCs exhibit greater growth inhibition
than established NSCLC cells. Growth inhibitory effect of CPTH6 in LCSC lines is
primarily due to apoptosis induction. Of note, differentiated progeny of LCSC lines
is more resistant to CPTH6 in terms of loss of cell viability and reduction of protein
acetylation, when compared to their undifferentiated counterparts. Interestingly, in
LCSC lines CPTH6 treatment is also associated with a reduction of stemness markers.
By using different HAT inhibitors we provide clear evidence that inhibition of HAT
confers a strong preferential inhibitory effect on cell viability of undifferentiated
LCSC lines when compared to their differentiated progeny. In vivo, CPTH6 is able to
inhibit the growth of LCSC-derived xenografts and to reduce cancer stem cell content
in treated tumors, as evidenced by marked reduction of tumor-initiating capacity in
limiting dilution assays. Strikingly, the ability of CPTH6 to inhibit tubulin acetylation
is also confirmed in vivo. Overall, our studies propose histone acetyltransferase
inhibition as an attractive target for cancer therapy of NSCLC
Benzo[b]tiophen-3-ol derivatives as effective inhibitors of human monoamine oxidase: design, synthesis, and biological activity
A series of benzo[b]thiophen-3-ols were synthesised and investigated as potential human monoamine oxidase (hMAO) inhibitors in vitro as well as ex vivo in rat cortex synaptosomes by means of evaluation of 3,4-dihydroxyphenylacetic acid/dopamine (DOPAC/DA) ratio and lactate dehydrogenase (LDH) activity. Most of these compounds possessed high selectivity for the MAO-B isoform and a discrete antioxidant and chelating potential. Molecular docking studies of all the compounds underscored potential binding site interactions suitable for MAO inhibition activity, and suggested structural requirements to further improve the activity of this scaffold by chemical modification of the aryl substituents. Starting from this heterocyclic nucleus, novel lead compounds for the treatment of neurodegenerative disease could be developed
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