Effects of geographical origin and post-harvesting processing on the bioactive compounds and sensory quality of Brazilian specialty coffee beans.

Specialty coffee beans are those produced, processed, and characterized following the highest quality standards, toward delivering a superior final product. Environmental, climatic, genetic, and processing factors greatly influence the green beans' chemical profile, which reflects on the quality and pricing. The present study focuses on the assessment of eight major health-beneficial bioactive compounds in green coffee beans aiming to underscore the influence of the geographical origin and post-harvesting processing on the quality of the final beverage. For that, we examined the non-volatile chemical profile of specialty Coffea arabica beans from Minas Gerais state, Brazil. It included samples from Cerrado (Savannah), and Matas de Minas and Sul de Minas (Atlantic Forest) regions, produced by two post-harvesting processing practices. Trigonelline, theobromine, theophylline, chlorogenic acid derivatives, caffeine, caffeic acid, ferulic acid, and p-coumaric acid were quantified in the green beans by high-performance liquid chromatography with diode array detection. Additionally, all samples were roasted and subjected to sensory analysis for coffee grading. Principal component analysis suggested that Cerrado samples tended to set apart from the other geographical locations. Those samples also exhibited higher levels of trigonelline as confirmed by two-way ANOVA analysis. Samples subjected to de-pulping processing showed improved chemical composition and sensory score. Those pulped coffees displayed 5.8% more chlorogenic acid derivatives, with an enhancement of 1.5% in the sensory score compared to unprocessed counterparts. Multivariate logistic regression analysis pointed out altitude, ferulic acid, p-coumaric acid, sweetness, and acidity as predictors distinguishing specialty coffee beans obtained by the two post-harvest processing. These findings demonstrate the influence of regional growth conditions and post-harvest treatments on the chemical and sensory quality of coffee. In summary, the present study underscores the value of integrating target metabolite analysis with statistical tools to augment the characterization of specialty coffee beans, offering novel insights for quality assessment with a focus on their bioactive compounds.

LC-MS/DIA-based strategy for comprehensive flavonoid profiling: an Ocotea spp. applicability case.

We introduce a liquid chromatography - mass spectrometry with data-independent acquisition (LC-MS/DIA)-based strategy, specifically tailored to achieve comprehensive and reliable glycosylated flavonoid profiling. This approach facilitates in-depth and simultaneous exploration of all detected precursors and fragments during data processing, employing the widely-used open-source MZmine 3 software. It was applied to a dataset of six Ocotea plant species. This framework suggested 49 flavonoids potentially newly described for these plant species, alongside 45 known features within the genus. Flavonols kaempferol and quercetin, both exhibiting O-glycosylation patterns, were particularly prevalent. Gas-phase fragmentation reactions further supported these findings. For the first time, the apigenin flavone backbone was also annotated in most of the examined Ocotea species. Apigenin derivatives were found mainly in the C-glycoside form, with O. porosa displaying the highest flavone : flavonol ratio. The approach also allowed an unprecedented detection of kaempferol and quercetin in O. porosa species, and it has underscored the untapped potential of LC-MS/DIA data for broad and reliable flavonoid profiling. Our study annotated more than 50 flavonoid backbones in each species, surpassing the current literature.

Chemical annotation of the infusion of Jungia floribunda Less and its inhibitory potential on the elastase enzyme.

Jungia floribunda Less. is a shrub belonging to the Asteraceae. The infusion of its leaves has been used, in folk medicine of several South American countries, as anti-inflammatory and hypoglycaemic agent. In the present study, the infusion of leaves from J. floribunda was obtained and its chemical composition was determined by UHPLC-MS associated with molecular network allowing the annotation of flavonoids, sesquiterpene lactones, coumarins, and chlorogenic acid derivatives. Besides, in vitro elastase activity assay was carried out with the infusion. As observed, elastase was inhibited at concentrations ranging from 15 to 240 µg/mL, reaching to 71% of inhibition at the maximum of evaluated concentration. Given that species of plants are promising sources for the discovery of new drugs, these results corroborate the infusion of J. floribunda as a potential source of bioactive compounds for the discovery of new inhibitors for elastase, besides its ethnopharmacological aspects.

Discovery of a new dihydroeugenol-chalcone hybrid with cytotoxic and anti-migratory potential: A dual-action hit for cancer therapeutics.

Cancer still represents a serious public health problem and one of the main problems related to the worsening of this disease is the ability of some tumors to develop metastasis. In this work, we synthesized a new series of chalcones and isoxazoles derived from eugenol and analogues as molecular hybrids and these compounds were evaluated against different tumor cell lines. This structural pattern was designed considering the cytotoxic potential already known for eugenol, chalcones and isoxazoles. Notably, chalcones 7, 9, 10, and 11 displayed significant activity (4.2-14.5 µM) against two cancer cell lines, surpassing the potency of the control drug doxorubicin. The reaction of chalcones with hydroxylamine hydrochloride provided the corresponding isoxazoles that were inactive against these cancer cells. The dihydroeugenol chalcone 7 showed the most promising results, demonstrating higher potency against HepG2 (CC50: 4.2 µM) and TOV-21G (CC50: 7.2 µM). Chalcone 7 was also three times less toxic than doxorubicin considering HepG2 cells, with a selectivity index greater than 11. Further investigations including clonogenic survival, cell cycle progression and cell migration assays confirmed the compelling antitumoral potential of chalcone 7, as it reduced long-term survival due to DNA fragmentation, inducing cell death and inhibiting HepG2 cells migration. Moreover, in silico studies involving docking and molecular dynamics revealed a consistent binding mode of chalcone 7 with metalloproteinases, particularly MMP-9, shedding light on its potential mechanism of action related to anti-migratory effects. These significant findings suggest the inclusion of compound 7 as a promising candidate for future studies in the field of cancer therapeutics.

Potential anti-inflammatory biomarkers from Myrtaceae essential oils revealed by untargeted metabolomics.

Many species from Myrtaceae have traditionally been used in traditional medicine as anti-inflammatory, antimicrobial, antidiarrheal, antioxidant and antirheumatic, besides in blood cholesterol reduction. In the present work, the anti-inflammatory activity of essential oils from eighteen Myrtaceae spp. were evaluated according to their ex-vivo anti-inflammatory activity in human blood, and the corresponding biomarkers were determined using untargeted metabolomics data and multivariate data analysis. From these studied species, six displayed anti-inflammatory activity with percentage rates of inhibition of PGE2 release above 70%. Caryophyllene oxide (1), humulene epoxide II (2), ß-selinene (3), α-amorphene (4), α-selinene (5), germacrene A (6), ß-bisabolene (7), α-muurolene (8), α-humulene (9), ß-gurjunene (10), myrcene (11), ß-elemene (12), α-cadinol (13), α-copaene (14), E-nerolidol (15) and ledol (16) were annotated as potential anti-inflammatory biomarkers. The results obtained in this study point to essential oils from species of the Myrtaceae family as a rich source of anti-inflammatory agents.

Ex vivo inhibition of PGE2 formation in human blood by four bicyclico [3.2.1] octane neolignans isolated from Aniba firmula bark, two with unusual structural pattern.

The phytochemical investigation of the stem bark crude extract of Aniba firmula (Lauraceae) led to the isolation of undescribed bicyclic [3.2.1] octane neolignans, 1 and 2, characterized by unusual bicyclic patterns and two other known bicyclic neolignans 3 and 4. Anti-inflammatory bicyclic [3.2.1] octane neolignans metabolites were previously reported in the literature, and the A. firmula stands out in the Lauraceae family as a source of potentially bioactive compounds. Thus, herein the anti-inflammatory potential of four isolated compounds from A. firmula was accessed via an ex vivo anti-inflammatory model that included plasmatic quantification of the prostaglandin E2 (PGE2) inflammatory mediator. Compounds 2 and 3 exhibited significant anti-inflammatory activity by inhibiting the production of PGE2 in plasma samples, thus by interference with the cyclooxygenase (COX) inflammatory pathway. Therefore, these findings demonstrate that the bicyclic octane neolignan classes [3.2.1] can present anti-inflammatory potential.

Immunological Modulation and Control of Parasitaemia by Ayahuasca Compounds: Therapeutic Potential for Chagas's Disease.

Ayahuasca is a psychoactive and psychedelic decoct composed mainly of Banisteriopsis caapi and Psychotria viridis plant species. The beverage is rich in alkaloids and it is ritualistically used by several indigenous communities of South America as a natural medicine. There are also reports in the literature indicating the prophylaxis potential of Ayahuasca alkaloids against internal parasites. In the present study, Ayahuasca exhibited moderate in vitro activity against Trypanosoma cruzi trypomastigotes (IC50 95.78 µg/mL) compared to the reference drug benznidazole (IC50 2.03 µg/mL). The ß-carboline alkaloid harmine (HRE), isolated from B. caapi, was considered active against the trypomastigotes forms (IC50 6.37), and the tryptamine N, N-dimethyltryptamine (DMT), isolated from P. viridis was also moderately active with IC50 of 21.02 µg/mL. Regarding the in vivo evaluations, no collateral effects were observed. The HRE alone demonstrated the highest trypanocidal activity in a dose-responsive manner (10 and 100 mg/kg). The Ayahuasca and the association between HRE and DMT worsened the parasitaemia, suggesting a modulation of the immunological response during the T. cruzi infection, especially by increasing total Immunoglobulin (IgG) and IgG1 antibody levels. The in silico molecular docking revealed HRE binding with low energy at two sites of the Trypanothione reductase enzyme (TR), which are absent in humans, and thus considered a promissory target for drug discovery. In conclusion, Ayahuasca compounds seem to not be toxic at the concentrations of the in vivo evaluations and can promote trypanocidal effect in multi targets, including control of parasitaemia, immunological modulation and TR enzymatic inhibition, which might benefit the treatments of patients with Chagas' disease. Moreover, the present study also provides scientific information to support the prophylactic potential of Ayahuasca against internal parasites.

In vitro and in silico evaluation of the schistosomicidal activity of eugenol derivatives using biochemical, molecular, and morphological tools.

Background: Eugenol shows both antibacterial and antiparasitic activities, suggesting that it might be evaluated as an option for the treatment of praziquantel-resistant schistosome. Methods: The in vitro activities of three eugenol derivatives (FB1, FB4 and FB9) on adult worms from Schistosoma mansoni were examined by fluorescence and scanning electron microscopy to analyze effects on the excretory system and integument damage, respectively. Biochemical tests with verapamil (a calcium channel antagonist) and ouabain (a Na+/K+-ATPase pump inhibitor) were used to characterize eugenol derivative interactions with calcium channels and the Na+/K+-ATPase, while in silico analysis identified potential Na+/K+-ATPase binding sites. Results: The compounds showed effective doses (ED50) of 0.324 mM (FB1), 0.167 mM (FB4), and 0.340 mM (FB9). In addition, FB4 (0.322 mM), which showed the lowest ED50, ED90 and ED100 (p < 0.05), caused the most damage to the excretory system and integument, according to both fluorescence and scanning electron microscopy analysis. The death of adult worms was delayed by ouabain treatment plus FB1 (192 versus 72 hours) and FB9 (192 versus 168 hours), but the response to FB4 was the same in the presence or absence of ouabain. Besides, no changes were noted when all of the eugenol derivatives were combined with verapamil. Moreover, FB1 and FB9 inhibited Na+/K+-ATPase activity according to in silico analysis but FB4 did not show a time-dependent relationship and may act on targets other than the parasite Na+/K+-ATPase. Conclusion: Eugenol derivatives, mainly FB4 when compared to FB1 and FB9, seem to act more effectively on the integument of adult S. mansoni worms.

Anti-Inflammatory Markers of Hops Cultivars (Humulus lupulus L.) Evaluated by Untargeted Metabolomics Strategy.

Hops (Humulus lupulus L.) are edible flowers commonly used to add flavour and aroma to beer, besides they have rich chemical diversity and medicinal potential. In this work, an ex vivo anti-inflammatory assay via the LPS-induced signalling pathway and metabolomics approaches were performed to evaluate the ability of hops to inhibit the production of prostaglandin E2 (PGE2) inflammatory mediator and analyze which metabolites produced by the nine different hop cultivars are potential anti-inflammatory markers. Columbus, Chinook and Hallertau Mittelfrüh hop cultivars yielded extracts with PGE2 release inhibition rates of 86.7, 92.5 and 73.5 %, respectively. According to the multivariate statistical analysis, the majority of the metabolites correlated with the activity were prenylated phloroglucinol and phenolic homologs. These results suggest promissory anti-inflammatory hop metabolites.

Synthesis of eugenol-derived glucosides and evaluation of their ability in inhibiting the angiotensin converting enzyme.

We report here a series of glucosides which are active as inhibitors of the angiotensin converting enzyme (ACE). They are structurally related to the natural compound eugenol and exhibited significant inhibition values. Their syntheses were expeditious and we could obtain informative docking plots of them complexed to this enzyme. A glucoside derived from eugenol, carrying a carboxylic group in the aglycone, was the most active of them (with an IC50 of 0.4 mM) and showed good binding energies in docking studies with ACE. Moreover, computational prediction of toxicity risks, physicochemical properties and drug score show that the glucoside derivative of eugenol is a suitable compound for optimisation studies aimed at finding new drug candidates.

In vitro and in silico evaluation of the schistosomicidal activity of eugenol derivatives using biochemical, molecular, and morphological tools

Background Eugenol shows both antibacterial and antiparasitic activities, suggesting that it might be evaluated as an option for the treatment of praziquantel-resistant schistosome. Methods The in vitro activities of three eugenol derivatives (FB1, FB4 and FB9) on adult worms from Schistosoma mansoni were examined by fluorescence and scanning electron microscopy to analyze effects on the excretory system and integument damage, respectively. Biochemical tests with verapamil (a calcium channel antagonist) and ouabain (a Na+/K+-ATPase pump inhibitor) were used to characterize eugenol derivative interactions with calcium channels and the Na+/K+-ATPase, while in silico analysis identified potential Na+/K+-ATPase binding sites. Results The compounds showed effective doses (ED50) of 0.324 mM (FB1), 0.167 mM (FB4), and 0.340 mM (FB9). In addition, FB4 (0.322 mM), which showed the lowest ED50, ED90 and ED100 (p < 0.05), caused the most damage to the excretory system and integument, according to both fluorescence and scanning electron microscopy analysis. The death of adult worms was delayed by ouabain treatment plus FB1 (192 versus 72 hours) and FB9 (192 versus 168 hours), but the response to FB4 was the same in the presence or absence of ouabain. Besides, no changes were noted when all of the eugenol derivatives were combined with verapamil. Moreover, FB1 and FB9 inhibited Na+/K+-ATPase activity according to in silico analysis but FB4 did not show a time-dependent relationship and may act on targets other than the parasite Na+/K+-ATPase. Conclusion Eugenol derivatives, mainly FB4 when compared to FB1 and FB9, seem to act more effectively on the integument of adult S. mansoni worms.(AU)

Glucosyl-1,2,3-triazoles derived from eugenol and analogues: Synthesis, anti-Candida activity, and molecular modeling studies in CYP-51.

This work describes the synthesis, anti-Candida, and molecular modeling studies of eighteen new glucosyl-1,2,3-triazoles derived from eugenol and correlated phenols. The new compounds were characterized by combined Fourier Transform Infrared, 1 H and 13 C nuclear magnetic resonance and spectroscopy of high-resolution mass spectrometry. The synthesized compounds did not show significant cytotoxicity against healthy fibroblast human cells (MCR-5) providing interesting selectivity indexes (SI) to active compounds. Considering the antifungal activity, nine compounds showed anti-Candida potential and the peracetylated triazoles 17 and 18 were the most promising ones. Eugenol derivative 17 was active against three species of Candida at 26.1-52.1 µM. This compound was four times more potent than fluconazole against Candida krusei and less toxic (SI > 6.6) against the MCR-5 cells than fluconazole (SI > 3.3) considering this strain. Dihydroeugenol derivative 18 showed similar activity to 17 and was four times more potent and less toxic than fluconazole against C. krusei. The deacetylated glucosides and non-glucosylated corresponding derivatives did not show considerable antifungal action, suggesting that the acetyl groups are essential for their anti-Candida activity. Molecular docking coupled with molecular dynamics showed that 14α-lanosterol demethylase is a feasible molecular target, since 17 and 18 could bind to this enzyme once deacetylated in vivo, thereby acting as prodrugs. Also, these studies demonstrated the importance of hydrophobic substituents at the phenyl ring.

In vivo anti-inflammatory activity of Fabaceae species extracts screened by a new ex vivo assay using human whole blood.

INTRODUCTION: Plants have been considered a promising source for discovering new compounds with pharmacological activities. The Fabaceae family comprises a large variety of species that produce substances with diverse therapeutic potential, including anti-inflammatory activity. The limitations of current anti-inflammatories generate the need to research new anti-inflammatory structures with higher efficacy as well as develop methods for screening multiple samples, reliably and ethically, to assess such therapeutic properties. OBJECTIVE: Validate and apply a quantification method for prostaglandin E2 (PGE2 ) production from an ex vivo assay in human blood in order to screen anti-inflammatory activity present in many Fabaceae species extracts. METHODS: Human blood was incubated with extracts from 47 Fabaceae species. After lipopolysaccharide (LPS)-induced inflammation, PGE2 was quantified in the plasma by liquid chromatography with tandem mass spectrometry (LC-MS/MS). The extracts that presented PGE2 production inhibition were further assessed through in vivo assay and then chemically characterised through an analysis of ultra-performance liquid chromatography electrospray ionisation quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-QTOF-MS2 ) data. RESULTS: The new ex vivo anti-inflammatory assay showed that five out of the 47 Fabaceae species inhibited PGE2 production. Results from an in vivo assay and the metabolic profile of the active extracts supported the anti-inflammatory potential of four species. CONCLUSION: The quantification method for PGE2 demonstrated fast, sensitive, precise, and accurate results. The new ex vivo anti-inflammatory assay comprised a great, reliable, and ethical approach for the screening of a large number of samples before an in vivo bioassay. Additionally, the four active extracts in both ex vivo and in vivo assays may be useful for the development of more efficient anti-inflammatory drugs.

Confirmation of ethnopharmacological anti-inflammatory properties of Ocotea odorifera and determination of its main active compounds.

ETHNOPHARMACOLOGICAL RELEVANCE: Ocotea odorifera (Vell.) Rohwer has been used in traditional medicine in the south of Brazil for the treatment of inflammatory-related conditions, such as rheumatism. However, there is not any scientific evidence for popular use. AIMS OF THE STUDY: To investigate the O. odorifera anti-inflammatory potential and identification of the main active compounds through metabolomic approaches. MATERIALS AND METHODS: In order to in vivo evaluate the inhibition of the main inflammatory pathways, the leaf decoction, leaf extract, its fractions and the essential oils from leaves and branches were submitted to the ear oedema and the neutrophils recruitment assays. The samples were chemically investigated by UHPLC-HRMS or GC-MS. The multivariate statistical analysis (PLS-DA) was used to determine the substances correlated with the anti-inflammatory properties. RESULTS: The in vivo studies indicated a promissory anti-inflammatory effect on both oedema and neutrophil recruitment for some samples including the decoction; hydroethanolic, ethyl acetate, and chloroform fractions; and the essential oils. According to the PLS-DA, the S-(+)-reticuline was evidenced as one of the three compounds of the plant most correlated with both anti-inflammatory mechanisms. Thus, S-(+)-reticuline was isolated and the anti-inflammatory activity was confirmed. Moreover, for the first time, the dual inhibition of oedema and neutrophil recruitment was uncovered and reported. Another compound positively correlated with the anti-inflammatory activity is likely to be a new compound since zero hit on the comprehensive mass database were encountered. The compounds found in the essential oils also showed significant anti-inflammatory activity, and thus indeed the plant has different classes of active substances. CONCLUSIONS: The decoction of O. odorifera and different fractions from its ethanolic extract demonstrated anti-inflammatory activity through dual inhibition of oedema and neutrophil recruitment. Thus, corroborating the popular medicinal use of the decoction of leaves from O. odorifera as an anti-inflammatory medicine. Besides, reticuline, one of the main active compounds, was isolated and proved to display the dual mechanism of action, indicating the O. odorifera as a promising source of active compounds for the treatment of inflammatory conditions.

From Antibacterial to Antitumour Agents: A Brief Review on The Chemical and Medicinal Aspects of Sulfonamides.

Sulfonamides have been in clinical use for many years, and the development of bioactive substances containing the sulfonamide subunit has grown steadily in view of their important biological properties such as antibacterial, antifungal, antiparasitic, antioxidant, and antitumour properties. This review addresses the medicinal chemistry aspects of sulfonamides; covering their discovery, the structure- activity relationship and the mechanism of action of the antibacterial sulfonamide class, as well as the physico-chemical and pharmacological properties associated with this class. It also provides an overview of the various biological activities inherent to sulfonamides, reporting research that emphasises the importance of this group in the planning and development of bioactive substances, with a special focus on potential antitumour properties. The synthesis of sulfonamides is considered to be simple and provides a diversity of derivatives from a wide variety of amines and sulfonyl chlorides. The sulfonamide group is a non-classical bioisostere of carboxyl groups, phenolic hydroxyl groups and amide groups. This review highlights that most of the bioactive substances have the sulfonamide group, or a related group such as sulfonylurea, in an orientation towards other functional groups. This structural characteristic was observed in molecules with distinct antibacterial activities, demonstrating a clear structure-activity relationship of sulfonamides. This short review sought to contextualise the discovery of classic antibacterial sulfonamides and their physico-chemical and pharmacological properties. The importance of the sulfonamide subunit in Medicinal Chemistry has been highlighted and emphasised, in order to promote its inclusion in the planning and synthesis of future drugs.

Synthesis, activity, and molecular modeling studies of 1,2,3-triazole derivatives from natural phenylpropanoids as new trypanocidal agents.

The search for compounds with new structural scaffolds is an important tool to the discovery of new drugs against Chagas disease. We report herein the synthesis of 1,2,3-triazoles obtained from eugenol and di-hydroeugenol and their in vitro and in vivo trypanocidal activity. These derivatives were obtained by a three-step objective route and were suitably characterized by 1 H and 13 C nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. Two compounds (9 and 10) showed activity against epimastigote forms of Trypanosoma cruzi (Y strain) in the range 42.8-88.4 µM and were weakly toxic to cardiomyoblast cells (H9c2 cells). The triazole 10 was the most active derivative and could reduce more than 50% of parasitemia after a 100-mg/kg oral treatment of mice infected with T. cruzi. Molecular docking studies suggested this compound could act as a trypanocidal agent by inhibiting cruzain, an essential enzyme for T. cruzi metabolism, usually inhibited by triazole compounds.

Fast and Efficient Method to Obtain Tagitinin F by Photocyclization of Tagitinin C.

There is some evidence in the literature of the photocyclization reaction of Tagitinin C (1) to Tagitinin F (2). Compound 2 has high pharmacological potential, but it is not easy to obtain, while compound 1 is easily obtained from a widespread plant, Tithonia diversifolia. Among different reaction conditions monitored, one was found that allowed the cyclization of 1 into 2 in <15 min in a photo-dependent reaction. Scaling-up the photocyclization of the pure compound 1 into 2 demonstrated 100% yield, and the isolation of 2 from a UV-irradiated extract was eight-fold higher than the quantity isolated from the non-UV-irradiated extract. We were also able to better understand the process of photoconversion and determine methods to isolate and quantify these compounds, which are known for their important antitumoral activities among other important pharmacological properties.

Phenylpropanoid-based sulfonamide promotes cyclin D1 and cyclin E down-regulation and induces cell cycle arrest at G1/S transition in estrogen positive MCF-7 cell line.

Cancer is one of the most critical problems of public health in the world and one of the main challenges for medicine. Different biological effects have been reported for sulfonamide-based compounds including antibacterial, antifungal, and antitumor activities. Herein, a series of phenylpropanoid-based sulfonamides (4a, 4a', 4b, 4b', 5a, 5a', 5b and 5b') were synthesized and their cytotoxic activity was evaluated against four cell lines derived from human tumours (A549 - lung, MCF-7 - breast, Hep G2 - hepatocellular carcinoma, and HT-144-melanoma). Cell viability was significantly reduced in the MCF-7 cell line when compounds 4b, 4b' and 5a were used; IC50 values were lower than those found for their precursors (eugenol and dihydroeugenol) and sulfanilamide. We observed that 4b induced cell cycle arrest at G1/S transition. This is probably due to its ability to reduce cyclin D1 and cyclin E expression. Moreover, 4b also induced apoptosis in MCF-7 cells as demonstrated by an increase in the cell population positive for annexin V in treated cultures in comparison to the control group. Taken together, the data showed that 4b is a promising antitumor agent and it should be considered for further in vivo studies.

Synthesis, activity, and docking studies of eugenol-based glucosides as new agents against Candida sp.

Seventeen new synthetic derivatives of eugenol (6, 8-15 and 8'-15') were planned following literature reports on antifungal activities of nitroeugenol and eugenol glucoside. The anti-Candida activity of these compounds was investigated by in vitro assay, and the cytotoxicity evaluation was performed with the most active compounds. The peracetylated glucosides presented better biological results than their hydroxylated analogues. The glucoside 11, a 4-nitrobenzamide, showed the best potency (MIC50 range 11.0-151.84 µm), the wider spectrum of action, and overall the best selectivity indexes, especially against C. tropicalis (~30) and C. krusei (~15). To investigate its possible mechanism of action, glucoside 11 was subjected to molecular docking studies with Candida sp. enzymes involved in ergosterol biosynthesis. Results have shown that the peracetyl glucosyl moiety and the 4-nitrobenzamide group in 11 are effectively involved in its high affinity with the active site of squalene epoxidase.

New Eugenol Glucoside-based Derivative Shows Fungistatic and Fungicidal Activity against Opportunistic Candida glabrata.

A new series of glucosides modified in their saccharide units were synthesized, evaluated against Candida sp., and compared to prototype 1, an eugenol tetracetyl glucoside previously synthesized and shown to be active against Candida glabrata. Among the new glucosides, benzyl derivative 5 was the most promising, showing fungistatic activity at IC50 18.1 µm against Candida glabrata (threefold higher than fluconazole) and fungicidal activity with a low IC90 value of 36.2 µm. Moreover, the cytotoxic activity of compound 5 (CC50 : 580.9 µm), tested in peripheral blood mononuclear cells, suggests its potential as an agent to treat Candida glabrata infections, with a selectivity index of 32. The new eugenol glucoside 5 may be considered as a novel structural pattern in the development of new anti-Candida drugs.