Unraveling the Potential of Vitamin B3-Derived Salts with a Salicylate Anion as Dermal Active Agents for Acne Treatment.

This study is focused on the utilization of naturally occurring salicylic acid and nicotinamide (vitamin B3) in the development of novel sustainable Active Pharmaceutical Ingredients (APIs) with significant potential for treating acne vulgaris. The study highlights how the chemical structure of the cation significantly influences surface activity, lipophilicity, and solubility in aqueous media. Furthermore, the new ionic forms of APIs, the synthesis of which was assessed with Green Chemistry metrics, exhibited very good antibacterial properties against common pathogens that contribute to the development of acne, resulting in remarkable enhancement of biological activity ranging from 200 to as much as 2000 times when compared to salicylic acid alone. The molecular docking studies also revealed the excellent anti-inflammatory activity of N-alkylnicotinamide salicylates comparable to commonly used drugs (indomethacin, ibuprofen, and acetylsalicylic acid) and were even characterized by better IC50 values than common anti-inflammatory drugs in some cases. The derivative, featuring a decyl substituent in the pyridinium ring of nicotinamide, exhibited efficacy against Cutibacterium acnes while displaying favorable water solubility and improved wettability on hydrophobic surfaces, marking it as particularly promising. To investigate the impact of the APIs on the biosphere, the EC50 parameter was determined against a model representative of crustaceans─Artemia franciscana. The majority of compounds (with the exception of the salt containing the dodecyl substituent) could be classified as "Relatively Harmless" or "Practically Nontoxic", indicating their potential low environmental impact, which is essential in the context of modern drug development.

Investigation of antitumor activity and albumin interaction of new sulfosalicylate-based complex by spectroscopic and computational approaches.

In the present study, the drug delivery by albumin protein and antiproliferetaive activity of new transition metal complex i.e., [Pd (phen)(SSA)] (where phen and SSA represent 1, 10 phenanthroline and sulfosalicylic acid, respectively) was investigated. DFT (density functional theory) calculations were conducted at B3LYP level with 6-311G(d,p)/aug-ccpVTZ-PP basis set for the purpose of geometry optimization, frontier molecular orbital (FMO) analysis, molecular electrostatic potential (MEP), and natural bond orbital (NBO) analysis. Experimental tests were conducted to preliminarily assess the lipophilicity and antitumor activity of the metal complex, resulting in promising findings. In-silico prediction was accomplished to assess its toxicity and bioavailability. To evaluate the binding of the newly formed complex with DNA (which results in halting the cell cycle) or serum albumin protein (drug transporter to the tissues), in-silico molecular modeling was employed. Experimental results (spectroscopic and non-spectroscopic) showed that the new compound interacts with each biomolecule via hydrogen bond and van der Waals interactions. Molecular docking demonstrated the binding of this complex to the DNA groove and site I of BSA occurs mainly through hydrogen bonds. Molecular dynamics simulation confirmed the interactions between [Pd (phen)(SSA)] with DNA or BSA through stable hydrogen bonds.

Food additive salicylates inhibit human and rat placental 3ß-hydroxysteroid dehydrogenase: 3D-QSAR and in silico analysis.

The use of salicylates as flavoring agents in food and beverages is common, but their potential to disrupt the endocrine system remains unclear. Human placental 3ß-hydroxysteroid dehydrogenase 1 (h3ß-HSD1) plays a role in progesterone synthesis and is the potential target. This study evaluated the inhibition of 13 salicylates on h3ß-HSD1, structure-activity relationship (SAR) and compared with rat placental homolog r3ß-HSD4. Salicylates inhibited h3ß-HSD1, depending on carbon chain number in the alcohol moiety and the IC50 values for hexyl, ethylhexyl, homomenthyl, and menthyl salicylates were 53.27, 15.78, 2.35, and 2.31 µM, as mixed inhibitors, respectively, while methyl to benzyl salicylates were ineffective at 100 µM. Interestingly, only hexyl salicylate inhibited r3ß-HSD4 with IC50 of 31.05 µM. Bivariate analysis revealed a negative correlation between IC50 and hydrophobicity (LogP), molecular weight, heavy atoms, and carbon number in the alcohol moiety against h3ß-HSD1. Docking analysis demonstrated that these salicylates bind to cofactor binding sites or between the steroid and cofactor binding sites. Additionally, 3D-QSAR showed distinct binding via hydrogen bond donors and hydrophobic regions. In conclusion, the inhibition of h3ß-HSD1 by salicylates appears to be dependent on factors such as LogP, molecular weight, heavy atoms, and carbon-chain length and there is species-dependent inhibition sensitivity.

Glycyrrhetinic acid interaction with solvated and free electrons studied by the CIDNP and dissociative electron attachment techniques.

Electron transfer plays a crucial role in living systems, including the generation of reactive oxygen species (ROS). Oxygen acts as the terminal electron acceptor in the respiratory chains of aerobic organisms as well as in some photoinduced processes followed by the formation of ROS. This is why the participation of exogenous antioxidants in electron transfer processes in living systems is of particular interest. In the present study, using chemically induced dynamic nuclear polarization (CIDNP) and dissociative electron attachment (DEA) techniques, we have elucidated the affinity of solvated and free electrons to glycyrrhetinic acid (GA)-the aglicon of glycyrrhizin (the main active component of Licorice root). CIDNP is a powerful instrument to study the mechanisms of electron transfer reactions in solution, but the DEA technique shows its effectiveness in gas phase processes. For CIDNP experiments, the photoionization of the dianion of 5-sulfosalicylic acid (HSSA2-) was used as a model reaction of solvated electron generation. DEA experiments testify that GA molecules are even better electron acceptors than molecular oxygen, at least under gas-phase conditions. In addition, the effect of the solvent on the energetics of the reactants is discussed.

Reduced estrogenic risks of a sunscreen additive: Theoretical design and evaluation of functionally improved salicylates.

Salicylic esters (SEs), the widely used ultraviolet (UV) absorbers in sunscreen products, have been found to have health risks such as skin sensitization and estrogenic effects. This study aims to design SE substitutes that maintain high UV absorbance while reducing estrogenicity. Using molecular docking and Gaussian09 software for initial assessments and further application of a combination of two-dimensional and three-dimensional quantitative structure-activity relationships (2D-QSAR and 3D-QSAR, respectively) models, we designed 73 substitutes. The best-performing molecules, ethylhexyl salicylate (EHS)-5 and EHS-15, significantly reduced estrogenicity (44.54 % and 17.60 %, respectively) and enhanced UV absorbance (249.56 % and 46.94 %, respectively). Through screening for human health risks, we found that EHS-5 and EHS-15 were free from skin sensitivity and eye irritation and exhibited reduced skin permeability compared with EHS. Furthermore, the photolysis and synthetic pathways of EHS-5 and EHS-15 were deduced, demonstrating their good photodegradability and potential synthesizability. In addition, we analyzed the mechanisms underlying the changes in estrogenic effects and UV absorption properties. We identified covalent hydrogen bond basicity and acidity Propgen value for atomic molecular properties and the highest occupied molecular orbital eigenvalue as the main factors affecting the estrogenic effect and UV absorbance of SEs, respectively. This study focuses on the design and screening of SEs, exhibiting enhanced functionality, reduced health risks, and synthetic feasibility.

Study of the preparation, characterization, and solubility of lidocaine complexed with 5-sulfosalicylic acid dihydrate.

OBJECTIVE: This study was to prepare solid dispersions of lidocaine (Lid) with 5-sulfosalicylic acid dihydrate (SSA) by freeze-drying (freeze-dried [FD] Lid/SSA = 1/1) and to evaluate their physical properties. METHODS: Here, we evaluated the physicochemical properties and solubility of solid dispersions of Lid and SSA prepared by freeze-drying (freeze-dried [FD] Lid/SSA = 1/1). RESULTS: Differential scanning calorimetry measurements showed that after freeze-drying, the endothermic peak due to Lid melting, the dehydration peak, and the endothermic peak due to SSA melting disappeared. Powder X-ray diffraction results showed that the characteristic Lid and SSA peaks disappeared after freeze-drying, indicating a halo pattern. The near-infrared spectroscopy results suggested that Lid-derived -NH and -CH groups and the Lid-derived -OH and -CH groups from the SSA peak shifted and broadened after freeze-drying, suggesting their involvement in complex formation through Lid/SSA intermolecular interactions. Nuclear Overhauser effect spectroscopy-nuclear magnetic resonance (NMR) measurements showed a cross-peak due to the interaction between the Lid-derived -CH group and the SSA-derived -OH group, suggesting hydrogen bonding. Diffusion-ordered spectroscopy NMR measurements showed that the diffusion coefficients of Lid and SSA aggregated in FD Lid/SSA, suggesting a change in Lid dispersibility in the solvent owing to the formation of a complex with SSA. The solubility of FD Lid/SSA was approximately 88 mg/mL (∼20-fold higher than that of Lid). CONCLUSIONS: These findings suggest that complex formation occurred in FD Lid/SSA; this enhanced the solubility of this dispersion.

Formulation study of PLGA in situ films for topical delivery of salicylates.

A film-forming system (FFS) represents a convenient topical dosage form for drug delivery. In this study, a non-commercial poly(lactic-co-glycolic acid) (PLGA) was chosen to formulate an FFS containing salicylic acid (SA) and methyl salicylate (MS). This unique combination is advantageous from a therapeutic point of view, as it enabled modified salicylate release. It is beneficial from a technological perspective too, because it improved thermal, rheological, and adhesive properties of the in situ film. DSC revealed complete dissolution of SA and good miscibility of MS with the polymer. MS also ensures optimal viscoelastic and adhesive properties of the film, leading to prolonged and sustained drug release. The hydrolysis of MS to active SA was very slow at skin pH 5.5, but it apparently occurred at physiological pH 7.4. The film structure is homogeneous without cracks, unlike some commercial preparations. The dissolution study of salicylates revealed different courses in their release and the influence of MS concentration in the film. The formulated PLGA-based FFS containing 5 % SA and 10 % MS is promising for sustained and prolonged local delivery of salicylates, used mainly for keratolytic and anti-inflammatory actions and pain relief.

Use of in vitro ADME methods to identify suitable analogs of homosalate and octisalate for use in a read-across safety assessment.

Case studies are needed to demonstrate the use of human-relevant New Approach Methodologies in cosmetics ingredient safety assessments. For read-across assessments, it is crucial to compare the target chemical with the most appropriate analog; therefore, reliable analog selection should consider physicochemical properties, bioavailability, metabolism, as well as the bioactivity of potential analogs. To complement in vitro bioactivity assays, we evaluated the suitability of three potential analogs for the UV filters, homosalate and octisalate, according to their in vitro ADME properties. We describe how technical aspects of conducting assays for these highly lipophilic chemicals were addressed and interpreted. There were several properties that were common to all five chemicals: they all had similar stability in gastrointestinal fluids (in which no hydrolysis to salicylic occurred); were not substrates of the P-glycoprotein efflux transporter; were highly protein bound; and were hydrolyzed to salicylic acid (which was also a major metabolite). The main properties differentiating the chemicals were their permeability in Caco-2 cells, plasma stability, clearance in hepatic models, and the extent of hydrolysis to salicylic acid. Cyclohexyl salicylate, octisalate, and homosalate were identified suitable analogs for each other, whereas butyloctyl salicylate exhibited ADME properties that were markedly different, indicating it is unsuitable. Isoamyl salicylate can be a suitable analog with interpretation for octisalate. In conclusion, in vitro ADME properties of five chemicals were measured and used to pair target and potential analogs. This study demonstrates the importance of robust ADME data for the selection of analogs in a read-across safety assessment.

Self-assembly of CuAuTA nanozymes for intelligent detection of ginkgolic acids.

Toxic ginkgolic acids (GAs) are a challenge for Ginkgo biloba-related food. Although a detection method for GAs is available, bulky instruments limit the field testing of GAs. Herein, by assembling gold nanoclusters with copper tannic acid (CuTA), CuAuTA nanocomposites were designed as peroxidase mimics for the colorimetric determination of GAs. Compared with single CuTA, the obtained CuAuTA nanocomposites possessed enhanced peroxidase-like properties. Based on the inhibitory effect of GAs for the catalytic activity of CuAuTA nanozymes, CuAuTA could be utilized for the colorimetric sensing of GAs with a low limit of quantitation of 0.17 µg mL-1. Using a smartphone and the ImageJ software in conjunction, a nanozyme-based intelligent detection platform was developed with a detection limit of 0.86 µg mL-1. This sensing system exhibited good selectivity against other potential interferents. Experimental data demonstrated that GAs might bind to the surface of CuAuTA, blocking the catalytically active sites and resulting in decreased catalytic activity. Our CuAuTA nanozyme-based system could also be applied to detect real ginkgo nut and ginkgo powder samples with recoveries of 93.12-111.6% and relative standard deviations less than 0.3%. Our work may offer a feasible strategy for the determination of GAs and expand the application of nanozymes in food safety detection.

Methyl-salicylate (MeSA)-mediated airborne defence.

Stressed plants emit a variety of chemicals into the environment, leading to increased pest resistance in neighbouring plants but the genetic and molecular mechanisms of the emissions remain obscure. Recently, Gong et al. identified novel methyl salicylate (MeSA)-mediated airborne defence that confers resistance to neighbouring plants against aphids and viruses.

Structural variation underlies functional diversity at methyl salicylate loci in tomato.

Methyl salicylate is an important inter- and intra-plant signaling molecule, but is deemed undesirable by humans when it accumulates to high levels in ripe fruits. Balancing the tradeoff between consumer satisfaction and overall plant health is challenging as the mechanisms regulating volatile levels have not yet been fully elucidated. In this study, we investigated the accumulation of methyl salicylate in ripe fruits of tomatoes that belong to the red-fruited clade. We determine the genetic diversity and the interaction of four known loci controlling methyl salicylate levels in ripe fruits. In addition to Non-Smoky Glucosyl Transferase 1 (NSGT1), we uncovered extensive genome structural variation (SV) at the Methylesterase (MES) locus. This locus contains four tandemly duplicated Methylesterase genes and genome sequence investigations at the locus identified nine distinct haplotypes. Based on gene expression and results from biparental crosses, functional and non-functional haplotypes for MES were identified. The combination of the non-functional MES haplotype 2 and the non-functional NSGT1 haplotype IV or V in a GWAS panel showed high methyl salicylate levels in ripe fruits, particularly in accessions from Ecuador, demonstrating a strong interaction between these two loci and suggesting an ecological advantage. The genetic variation at the other two known loci, Salicylic Acid Methyl Transferase 1 (SAMT1) and tomato UDP Glycosyl Transferase 5 (SlUGT5), did not explain volatile variation in the red-fruited tomato germplasm, suggesting a minor role in methyl salicylate production in red-fruited tomato. Lastly, we found that most heirloom and modern tomato accessions carried a functional MES and a non-functional NSGT1 haplotype, ensuring acceptable levels of methyl salicylate in fruits. Yet, future selection of the functional NSGT1 allele could potentially improve flavor in the modern germplasm.

Measuring Enzyme Kinetics of Glycoside Hydrolases Using the 3,5-Dinitrosalicylic Acid Assay.

Use of the 3,5-dinitrosalicylic acid reagent allows the simple, rapid quantification of reducing sugars. The method can be used for analysis of biological samples or in characterization of enzyme reactions, as new reducing ends are generated when a polysaccharide substrate undergoes hydrolytic cleavage. Presented here is an application of the method in measuring the kinetics of a glycoside hydrolase reaction, including the optimization of the DNSA reagent, and the production of a standard curve of absorbance versus sugar concentration.

The salicylate 1,2-dioxygenase from Pseudaminobacter salicylatoxidans DSM 6986T is a bifunctional enzyme that inactivates the mycotoxin ochratoxin A by a novel amidohydrolase activity.

The salicylate 1,2-dioxygenase from the bacterium Pseudaminobacter salicylatoxidans DSM 6986T (PsSDO) is a versatile metalloenzyme that participates in the aerobic biodegradation of aromatic compounds, such as gentisates and salicylates. Surprisingly, and unrelated to this metabolic role, it has been reported that PsSDO may transform the mycotoxin ochratoxin A (OTA), a molecule that appears in numerous food products that results in serious biotechnological concern. In this work, we show that PsSDO, together with its dioxygenase activity, behaves as an amidohydrolase with a marked specificity for substrates containing a C-terminal phenylalanine residue, similar to OTA, although its presence is not an absolute requirement. This side chain would establish aromatic stacking interactions with the indole ring of Trp104. PsSDO hydrolysed the amide bond of OTA rendering the much less toxic ochratoxin α and L-ß-phenylalanine. The binding mode of OTA and of a diverse set of synthetic carboxypeptidase substrates these substrates have been characterized by molecular docking simulations, which has permitted us to propose a catalytic mechanism of hydrolysis by PsSDO that, similarly to metallocarboxypeptidases, assumes a water-induced pathway following a general acid/base mechanism in which the side chain of Glu82 would provide the solvent nucleophilicity required for the enzymatic reaction. Since the PsSDO chromosomal region, absent in other Pseudaminobacter strains, contained a set of genes present in conjugative plasmids, it could have been acquired by horizontal gene transfer, probably from a Celeribacter strain.

The copper (II) complex of salicylate phenanthroline inhibits proliferation and induces apoptosis of hepatocellular carcinoma cells.

In the present study, we investigated the antitumor effect and associated molecular mechanisms of the copper (II) complex of salicylate phenanthroline [Cu(sal)(phen)] against hepatocellular carcinoma (HCC). Cu(sal)(phen) inhibited the proliferation of HCC cells (HepG2 and HCC-LM9) and induced apoptosis of HCC cells in a dose-dependent manner by upregulating mitochondrial reactive oxygen species (ROS) production. The expression of the antiapoptotic proteins survivin and Bcl-2 was decreased, while the expression of the DNA damage marker γ-H2 AX and the apoptotic marker cleaved PARP was upregulated with Cu(sal)(phen) treatment. In vivo, the growth of HepG2 subcutaneous xenograft tumors was greatly attenuated by Cu(sal)(phen) treatment. Immunohistochemistry staining showed that the expression of survivin, Bcl-2, and Ki67 in the tumor was downregulated by Cu(sal)(phen). Toxicity experiments with BALB/c mice revealed that Cu(sal)(phen) is a relatively safe drug. Our results indicate that Cu(sal)(phen) possesses great potential as a therapeutic drug for HCC.

In vitro, in vivo and in silico evaluation of analgesic, anti-inflammatory, and anti-pyretic activity of salicylate rich fraction from Gaultheria trichophylla Royle (Ericaceae).

ETHNOPHARMACOLOGICAL RELEVANCE: Medicinal properties of Gaultheria have been used in traditional medicine to treat pain and inflammation. AIM OF THE STUDY: Hence, the purpose of this study was to evaluate the analgesic, antipyretic, and anti-inflammatory properties of Gaultheria trichophylla Royle extract and salicylate-rich fraction in vivo, in vitro, and in silico. MATERIALS AND METHODS: In vivo analgesic, antipyretic, and anti-inflammatory of extract and a salicylate-rich fraction (at doses of 100, 200, 300, and 150 mg/kg) were assessed using healthy albino mice employing acetic acid-induced writhing, tail immersion test, carrageenan-induced inflammation, and croton oil-induced edema. For in vitro testing of extracts COX and LOX enzyme inhibition assays were used. Molecular docking studies were conducted for in silico testing of the inhibitory activity of the dominant compound Gaultherin against COX and LOX. RESULTS: G-EXT 200 and 300 and G-SAL 150 mg/kg reduced pyrexia significantly (P < 0.05 and P < 0.01). G-EXT-200, 300, and G-SAL 150 reduce the writing to a significant level (p > 0.05, p < 0.01). G-EXT 200 and 300 and G-SAL 150 mg/kg doses the analgesic effect was significant (p > 0.05, p > 0.01) and was comparable to tramadol. G-EXT 100 200, 300 mg/kg showed 43.8%, 47.94% and 56% respectively. G-SAL 150 mg, rich in salicylates, showed maximum inhibition of 65.75% next to standard drug diclofenac with 76.7% inhibition. G-EXT 100 and 200 mg/kg dose showed significant (p < 0.05) reduction in ear edema. With 300 mg/kg dose the effect was more (61.89%, p < 0.01). The salicylate-rich fraction G-SAL and Celecoxib showed an almost similar effect (p < 0.01). Significance inhibition was shown in the COX-2 test (G-EXT 39.70 and G-SAL 77.20 IC50 µg/ml) and in the 5-LOX test (G-EXT 28.3 and G-SAL 39.70 IC50 µg/ml). The preliminary in silico results suggest that the investigated compound showed excellent inhibitory activity against COX and LOX enzymes as evident from the free binding energy. Molecular docking revealed that Gaultherin binds well in the COX and LOX enzyme catalytic region. CONCLUSION: The extract and salicylate-rich fraction obtained from G. trichophylla showed significant analgesic, anti-inflammatory, and antipyretic effects in vivo, in vitro, and in silico assays that support its use in traditional medicine.

Extraction, Purification, and Elucidation of Six Ginkgol Homologs from Ginkgo biloba Sarcotesta and Evaluation of Their Anticancer Activities.

Ginkgols are active constituents from Ginkgo biloba L. (GB) and have pharmacological activities, such as antibacterial and antioxidant activities. In our previous report, only five ginkgols were separated. However, ginkgol C17:1 had two isomers, for which their separation, identification, and bioactivities have not yet been investigated. Hence, this research reports the successful isolation of six ginkgol homologs with alkyl substituents-C17:1-Δ12, C15:1-Δ8, C13:0, C17:2, C17:1-Δ10, and C15:0-for the first time using HPLC. This was followed by the identification of their chemical structures using Fourier transform infrared (FTIR), ultraviolet (UV), gas chromatography and mass spectrometry (GC-MS), carbon-13 nuclear magnetic resonance (13C-NMR), and proton nuclear magnetic resonance (1H-NMR) analysis. The results showed that two ginkgol isomers, C17:1-Δ12 and C17:1-Δ10, were obtained simultaneously from the ginkgol C17:1 mixture and identified entirely for the first time. That aside, the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay showed that the six ginkgol homologs possessed significant antiproliferation effects against HGC and HepG2 cells. Furthermore, the ginkgols with unsaturated side chains (C17:2, C15:1-Δ8, C17:1-Δ12, and C17:1-Δ10) exhibited more potent inhibitory effects than ginkgols with saturated side chains (C13:0, C15:0). In addition, unsaturated ginkgol C15:1-Δ8 showed the most potent cytotoxicity on HepG2 and HGC cells, of which the half-maximal inhibition concentrations (IC50) were 18.84 ± 2.58 and 13.15 ± 2.91 µM, respectively. The IC50 for HepG2 and HGC cells for the three unsaturated ginkgols (C17:1-Δ10, C17:2 and C17:1-Δ12) were ~59.97, ~60.82, and ~68.97 µM for HepG2 and ~30.97, ~33.81, and ~34.55 µM for HGC cells, respectively. Comparing the ginkgols' structure-activity relations, the findings revealed that the position and number of the double bonds of the ginkgols with 17 side chain carbons in length had no significant difference in anticancer activity.

Kinome-Wide Profiling Identifies Human WNK3 as a Target of Cajanin Stilbene Acid from Cajanus cajan (L.) Millsp.

Pigeon Pea (Cajanus cajan (L.) Millsp.) is a common food crop used in many parts of the world for nutritional purposes. One of its chemical constituents is cajanin stilbene acid (CSA), which exerts anticancer activity in vitro and in vivo. In an effort to identify molecular targets of CSA, we performed a kinome-wide approach based on the measurement of the enzymatic activities of 252 human kinases. The serine-threonine kinase WNK3 (also known as protein kinase lysine-deficient 3) was identified as the most promising target of CSA with the strongest enzymatic activity inhibition in vitro and the highest binding affinity in molecular docking in silico. The lowest binding affinity and the predicted binding constant pKi of CSA (-9.65 kcal/mol and 0.084 µM) were comparable or even better than those of the known WNK3 inhibitor PP-121 (-9.42 kcal/mol and 0.123 µM). The statistically significant association between WNK3 mRNA expression and cellular responsiveness to several clinically established anticancer drugs in a panel of 60 tumor cell lines and the prognostic value of WNK3 mRNA expression in sarcoma biopsies for the survival time of 230 patients can be taken as clues that CSA-based inhibition of WNK3 may improve treatment outcomes of cancer patients and that CSA may serve as a valuable supplement to the currently used combination therapy protocols in oncology.