Azole-based fungicides are among the market's most widely used and effective agents. However, their indiscriminate use can lead to reduced efficacy and increased pathogen resistance. This highlights the need for novel fungicides that offer improved efficiency and lower environmental impact for controlling phytopathogenic fungi. In this study, a series of 20 novel thymol derivatives, incorporating a 1,2,3-triazole moiety, were synthesized via a three-step process, with the key step being the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. The antifungal activity of these compounds was evaluated against Fusarium solani, the etiological agent of papaya fruit and stem rot. Additionally, molecular docking was performed to assess the binding energy and interaction modes of these derivatives with the F. solani lanosterol 14α-demethylase (FsCYP51) enzyme. Docking results demonstrated that all derivatives bound to the catalytic pocket of FsCYP51 with lower binding energy (<-10 kcal/mol) compared to the azole fungicide tebuconazole (-8.2 kcal/mol) and the substrate lanosterol (-9.0 kcal/mol). The observed fungicidal activity is likely due to the occupancy of the entrance tunnel and active site of the FsCYP51 by these derivatives, thereby blocking lanosterol and its conversion into ergosterol.

Aim: The design, synthesis, docking studies and evaluation of the in vitro antifungal and cytotoxic properties of eugenol (EUG) containing 1,2,3-triazole derivatives are reported. Most of the derivatives have not been reported. Materials & methods: The EUG derivatives were synthesized, molecular docked and tested for their antifungal activity. Results: The compounds showed potent antifungal activity against Trichophyton rubrum, associated with dermatophytosis. Compounds 2a and 2i exhibited promising results, with 2a being four-times more potent than EUG. The binding mode prediction was similar to itraconazole in the lanosterol-14-alpha-demethylase wild-type and G73E mutant binding sites. Additionally, the pharmacokinetic profile prediction suggests good gastrointestinal absorption and potential oral administration. Conclusion: Compound 2a is a promising antifungal agent against dermatophytosis caused by T. rubrum. [GRAPHICS]

A series of 19 novel eugenol derivatives containing a 1,2,3-triazole moiety was synthesized via a two-step process, with the key step being a copper(I)-catalyzed azide-alkyne cycloaddition reaction. The compounds were assessed for their antifungal activities against Colletotrichum gloeosporioides, the causative agent of papaya anthracnose. Triazoles 2k, 2m, 2l, and 2n, at 100 ppm, were the most effective, reducing mycelial growth by 88.3, 85.5, 82.4, and 81.4%, respectively. Molecular docking calculations allowed us to elucidate the binding mode of these derivatives in the catalytic pocket of C. gloeosporioides CYP51. The best-docked compounds bind closely to the heme cofactor and within the channel access of the lanosterol (LAN) substrate, with crucial interactions involving residues Tyr102, Ile355, Met485, and Phe486. From such studies, the antifungal activity is likely attributed to the prevention of substrate LAN entry by the 1,2,3-triazole derivatives. The triazoles derived from natural eugenol represent a novel lead in the search for environmentally safe agents for controlling C. gloeosporioides.

Aim: The assessment of the antileishmanial potential of 22 vanillin-containing 1,2,3-triazole derivatives against Leishmania braziliensis is reported. Materials & methods: Initial screening was performed against the parasite promastigote form. The most active compound, 4b, targeted parasites within amastigotes (IC50 = 4.2 +/- 1.0 mu mol l(-1)), presenting low cytotoxicity and a selective index value of 39. 4D quantitative structure-activity relationship and molecular docking studies provided insights into structure-activity and biological effects. Conclusion: A vanillin derivative with significant antileishmanial activity was identified. Enhanced activity was linked to increased electrostatic and Van der Waals interactions near the benzyl ring of the derivatives. Molecular docking indicated the inhibition of the Leishmania amazonensis sterol 14 alpha-demethylase, using Leishmania infantum sterol 14 alpha-demethylase as a model, without affecting the human isoform. Inhibition was active site competition with lanosterol.

Vanillin is the main component of natural vanilla extract and is responsible for its flavoring properties. Besides its well-known applications as an additive in food and cosmetics, it has also been reported that vanillin can inhibit fungi of clinical interest, such as Candida spp., Cryptococcus spp., Aspergillus spp., as well as dermatophytes. Thus, the present work approaches the synthesis of a series of vanillin derivatives with 1,2,3-triazole fragments and the evaluation of their antifungal activities against Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis, Cryptococcus neoformans, Cryptococcus gattii, Trichophyton rubrum, and Trichophyton interdigitale strains. Twenty-two vanillin derivatives were obtained, with yields in the range of 60%-91%, from copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) click reaction between two terminal alkynes prepared from vanillin and different benzyl azides. In general, the evaluated compounds showed moderate activity against the microorganisms tested, with minimum inhibitory concentration (MIC) values ranging from 32 to >512 µg mL-1 . Except for compound 3b against the C. gattii R265 strain, all vanillin derivatives showed fungicidal activity for the yeasts tested. The predicted physicochemical and ADMET (absorption, distribution, metabolism, excretion, and toxicity) properties for the compounds indicated favorable profiles for drug development. In addition, a four-dimensional structure-activity relationship (4D-SAR) analysis was carried out and provided useful insights concerning the structures of the compounds and their biological profile. Finally, molecular docking calculations showed that all compounds bind favorably at the lanosterol 14α-demethylase enzyme active site with binding energies ranging from -9.1 to -12.2 kcal/mol.

Vanillin (C8H8O3, 4-hydroxy-3-methoxy benzaldehyde) is a flavoring compound broadly used worldwide in the food, nutraceutical, beverage, and pharmaceutical industries, presenting a general biosafety. This phenolic natural product presents several biological activities, including leishmanicidal. It is described in the present investigation the synthesis and leishmanicidal activity evaluation of vanillin derivatives possessing 1,2,3-triazole fragments. The 1,2,3-triazole are versatile heterocyclic with several medicinal attributes, including antileishmanial effects. A series of twenty-two vanillin triazole derivatives were prepared, having the CuAAC reaction as the key step. The evaluation of the derivatives on promastigotes of Leishmania amazonensis revealed that they are more active than vanillin and inhibited the growth of the parasite with different degrees of efficacy (IC50 ranging from 303.5 ± 05 to 1.1 ± 0.2 µmol L-1). The most effective derivative 3-methoxy-4-(3-(1-(4-nitrobenzyl)-1H-1,2,3-triazol-4-yl)propoxy)benzaldehyde (4b) targeted leishmania inside macrophages (IC50 = 4.2 ± 1.0 µmol L-1), presented low cytotoxicity (IC50 = 163.8 ± 2.2 µmol L-1), and selective index of 39, being more effective than Glucantime. With the aim to investigate the modifications in the structure that could lead to an increase in the biological activity, a four-dimensional quantitative structure-activity analysis (4D-QSAR) was applied to this set of vanillin derivatives, through partial least square regression (PLS). The selected field descriptors, of Coulomb (C) and Lennard-Jones (L) nature, indicated that the leishamanicidal activity is favored by polar groups close to the vanillin moiety and both, polar and bulky nonpolar groups in the proximities of the benzyl ring. The statistics presented by the regression model were R2=0.79, SEC=0.23, Q2=0.73 and SEV=0.24.

As has been documented numerous times over the years, nuclear magnetic resonance (NMR) experiments are intrinsically quantitative. Still, quantitative NMR methods have not been widely adopted or largely introduced into pharmacopoeias. Here, we describe the quantitative interpretation of the 1D proton NMR experiment using only absolute signal intensities with the variation of common experimental parameters and their application.

The nuclear magnetic resonance extracted data (NMReDATA) format has been proposed as a way to store, exchange, and disseminate nuclear magnetic resonance (NMR) data and physical and chemical metadata of chemical compounds. In this paper, we report on analytical workflows that take advantage of the uniform and standardized NMReDATA format. We also give access to a repository of sample data, which can serve for validating software packages that encode or decode files in NMReDATA format.

It is herein described the synthesis of a series of thirty novel 1,2,3-triazole-1,4-disubstituted compounds inspired on the known SRPKs inhibitor N-(2-(piperidin-1-yl)-5 (trifluoromethyl)phenyHisonicotinamide (SRPIN340) and biological evaluation of them against human glioblastoma multiforme cell line U87MG. Starting with 1-fluoro-2-nitro-4-(trifluoromethyl)benzene (1), the substances were prepared via a five-step synthetic route. The crucial step corresponded to the copper-catalyzed cycloaddition reaction between trifluoromethyl phenyl azides and different alkynes. In general, the compounds were obtained with good yields and they were characterized utilizing spectroscopic (IR and NMR) and spectrometric (HRMS) techniques. The evaluation of the synthesized compounds at three different treatment time (24 h, 48 h, and 72 h) and concentrations (50, 100, and 150 mu mol L-1) revealed that five derivatives were capable of reducing cell viability by 50% after 72 h of treatment at the highest concentration. On the contrary, three derivatives significantly increased cell viability being this effect more pronounced after 48 h of treatment. In this regard, it stands out the compound 2((1-(2-morpholino-5-(trifluoromethyl)phenyl)-1H-1,2,3-triazol-4-yemethyl)isoindoline-1,3-dione (7) which increased cell viability in approximately 300% after 48 h of treatment at 100 mu mol L-1. The substances that increased cell viaiblity present as common structural features the presence of a saturated nitrogen-containing six-membered ring and carbonylated fragments.

SYNTHESIS OF NOVEL 1,2,3-TRIAZOLES INSPIRED ON THE SRPIN340 AND EVALUATION OF THEIR EFFECTS ON HUMAN GLIOBLASTOMA CELL LINE. It is herein described the synthesis of a series of thirty novel 1,2,3-triazole1,4-disubstituted compounds inspired on the known SRPKs inhibitor N-(2-(piperidin-1-yl)-5-(trifluoromethyl)phenyl)isonicotinamide (SRPIN340) and biological evaluation of them against human glioblastoma multiforme cell line U87MG. Starting with 1-fluoro2-nitro-4- (trifluoromethyl)benzene (1), the substances were prepared via a five-step synthetic route. The crucial step corresponded to the copper-catalyzed cycloaddition reaction between trifluoromethyl phenyl azides and different alkynes. In general, the compounds were obtained with good yields and they were characterized utilizing spectroscopic (IR and NMR) and spectrometric (HRMS) techniques. The evaluation of the synthesized compounds at three different treatment time (24 h, 48 h, and 72 h) and concentrations (50, 100, and 150 µmol L-1) revealed that five derivatives were capable of reducing cell viability by 50% after 72 h of treatment at the highest concentration. On the contrary, three derivatives significantly increased cell viability being this effect more pronounced after 48 h of treatment. In this regard, it stands out the compound 2-((1-(2-morpholino-5-(trifluoromethyl)phenyl)-1H-1,2,3-triazol4-yl)methyl)isoindoline-1,3-dione (7) which increased cell viability in approximately 300% after 48 h of treatment at 100 µmol L-1. The substances that increased cell viaiblity present as common structural features the presence of a saturated nitrogen-containing six-membered ring and carbonylated fragments.

Over the past decades, different software programs have been developed for the Computer-Assisted Structure Elucidation (CASE) with NMR data using with various approaches. WebCocon is one of them that has been continuously improved over the past 20 years. Here, we present the inclusion of (4)J(CH) correlations ((4)J-HMBC) in the HMBC interpretation of Cocon and NOE data in WebCocon. The (4)J-HMBC data is used during the structure generation process, while the NOE data is used in post-processing of the results. The marine natural product oxocyclostylidol was selected to demonstrate WebCocon's enhanced HMBC data processing capabilities. A systematic study of the (4)J(CH) correlations of oxocyclostylidol was performed. The application of NOEs in CASE is demonstrated using the NOE correlations of the diterpene pyrone asperginol A known from the literature. As a result, we obtained a conformation that corresponds very well to the existing X-ray structure.

Structure elucidation with NMR correlation data is dicey, as there is no way to tell how ambiguous the data set is and how reliably it will define a constitution. Many different software tools for computer assisted structure elucidation (CASE) have become available over the past decades, all of which could ensure a better quality of the elucidation process, but their use is still not common. Since 2011, WebCocon has integrated the possibility to generate theoretical NMR correlation data, starting from an existing structural proposal, allowing this theoretical data then to be used for CASE. Now, WebCocon can also read the recently presented NMReDATA format, allowing for uncomplicated access to CASE with experimental data. With these capabilities, WebCocon presents itself as an easily accessible Web-Tool for the quality control of proposed new natural products. Results of this application to several molecules from literature are shown and demonstrate how CASE can contribute to improve the reliability of Structure elucidation with NMR correlation data.

The endophytic fungus Mycosphaerella sp. (UFMGCB2032) was isolated from the healthy leaves of Eugenia bimarginata, a plant from the Brazilian savanna. Two novel usnic acid derivatives, mycousfuranine (1) and mycousnicdiol (2), were isolated from the ethyl acetate extract, and their structure was elucidated by NMR and MS analyses. Compounds 1 and 2 exhibited moderate antifungal activities against Cryptococcus neoformans and Cryptococcus gattii, each with minimum inhibitory concentration values of 50.0 μg/mL and 250.0 μg/mL, respectively.

The constitutional assignment of natural products by NMR spectroscopy is usually based on 2D NMR experiments like COSY, HSQC, and HMBC. The actual difficulty of the structure elucidation problem depends more on the type of the investigated molecule than on its size. The moment HMBC data is involved in the process or a large number of heteroatoms is present, a possibility of multiple solutions fitting the same data set exists. A structure elucidation software can be used to find such alternative constitutional assignments and help in the discussion in order to find the correct solution. But this is rarely done. This article describes the use of theoretical NMR correlation data in the structure elucidation process with WEBCOCON, not for the initial constitutional assignments, but to define how well a suggested molecule could have been described by NMR correlation data. The results of this analysis can be used to decide on further steps needed to assure the correctness of the structural assignment. As first step the analysis of the deviation of carbon chemical shifts is performed, comparing chemical shifts predicted for each possible solution with the experimental data. The application of this technique to three well known compounds is shown. Using NMR correlation data alone for the description of the constitutions is not always enough, even when including 13C chemical shift prediction.

The constitutional assignment of natural products by NMR spectroscopy is usually based on 2D NMR experiments like COSY, HSQC, and HMBC. The difficulty of a structure elucidation problem depends more on the type of the investigated molecule than on its size. Saturated compounds can usually be assigned unambiguously by hand using only COSY and 13C-HMBC data, whereas condensed heterocycles are problematic due to their lack of protons that could show interatomic connectivities. Different computer programs were developed to aid in the structural assignment process, one of them COCON. In the case of unsaturated and substituted molecules structure generators frequently will generate a very large number of possible solutions. This article presents a "statistical filter" for the reduction of the number of results. The filter works by generating 3D conformations using smi23d, a simple MD approach. All molecules for which the generation of constitutional restraints failed were eliminated from the result set. Some structural elements removed by the statistical filter were analyzed and checked against Beilstein. The automatic removal of molecules for which no MD parameter set could be created was included into WEBCOCON. The effect of this filter varies in dependence of the NMR data set used, but in no case the correct constitution was removed from the resulting set.

A new method based on NMR spectroscopy is introduced to determine the absolute configuration of natural compounds and has been successfully applied to sucro-neolambertellin. The method relies on the measurement of residual dipolar couplings (RDCs), which allow the absolute configuration of unknown stereocenters to be related with known stereocenters (see picture). The approach is used to determine the configuration of the D-threo-2,5-hexodiulofuranose moiety by relating it to α-D-glucose.

Max-Planck Institute for Biophysical Chemistry: NMR-based Structural Biology and Theoretical Structural Biology, Am Fassberg 11, 37077 Göttingen, Germany; Department of Chemistry and Biochemistry/SSPPS, 6100A/B Pacific Hall, MC 0358, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 920930358, USA; Faculty of Agriculture and Lifescience, Hirosaki University, 3-Bunkyo-Cho, Hirosaki, 036-8561, Japan; University of Reims, 51687 REIMS Cédex 2, France, 6 Department of Chemical and Analytical Sciences/Structural Biology, Sanofi Aventis Deutschland GmbH, Industriepark Höchst, 65926 Frankfurt, Germany

Sagittamide A is a long-chain acyclic α,ω-dicarboxylic acid with eight stereocenters. The central hexahydroxyhexane moiety carries six of them. For this moiety, two different relative stereochemical assignments were published in 2006. In this communication, one relative configuration is clearly singled out based on NOEs, J- and residual dipolar couplings despite conformational averaging that is present in this moiety. The proposed NMR method relies on the measurement of dipolar couplings in recently introduced alignment media that are compatible with organic solvents, and cross validating the NMR determined ensemble of conformations against the residual dipolar couplings. The method is easily applicable to many other stereochemical problems.

The formation of the Tat-protein/TAR-RNA complex is a crucial step in the regulation of human immunodeficiency virus (HIV)-gene expression. To obtain full-length viral transcripts the Tat/TAR complex has to recruit the positive transcription elongation factor complex (P-EFTb), which interacts with TAR through its cyclin T1 (CycT1) component. Mutational studies identified the TAR hexanucleotide loop as a crucial region for contacting CycT1. Interfering with the interaction between the Tat/CycT1 complex and the TAR-RNA is an attractive strategy for the design of anti-HIV drugs. Positively charged molecules, like aminoglycosides or peptidomimetics, bind the TAR-RNA, disrupting the Tat/TAR complex. Here, we investigate the complex between the HIV-2 TAR-RNA and a neooligoaminodeoxysaccharide by NMR spectroscopy. In contrast to other aminoglycosides, this novel aminoglycoside analogue contacts simultaneously the bulge residues required for Tat binding and the A35 residue of the hexanucleotide loop. Upon complex formation, the loop region undergoes profound conformational changes. The novel binding mode, together with the easy accessibility of derivatives for the neooligoaminodeoxysaccharide, could open the way to the design of a new class of TAR-RNA binders, which simultaneously inhibit the formation of both the Tat/TAR binary complex and the Tat/TAR/CycT1 ternary complex by obstructing both the bulge and loop regions of the RNA.