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Quantitative Structure Activity Relationship (QSAR) requires the use of chemical descriptors which are either empirical or non-empirical. Although the ease of computation of computationally derived parameters such as given by ChemDraw software like CAA, CMA, CSEV and Dragon parameters like Au, Nc, Vs, TIC3, ATS2p etc. are easier to be used in the QSAR studies, but they still lack the biological interpretation as no prior knowledge of their physicochemical significance and their interrelationship is available. Therefore, the QSAR models developed using such parameters may be useful only in prediction of activity but are meaningless in terms of understanding the mode of action of the bioactive molecules. Thus, to fulfil this knowledge gap, and in continuation of our earlier work on physicochemical significance of topological parameters this study has been attempted to understand the empiricism of such computationally derived parameters in terms of their physicochemical significance. Here, we report that most of the ChemDraw and Dragon computed parameters are also best correlated with MR similar to topological parameters. [ABSTRACT FROM AUTHOR]

The aim of this study was to optimise ultrasound-assisted extraction (UAE) of the herb Sanguisorba officinalis L. in terms of the antioxidant activity (DPPH and FRAP method) and total polyphenol content (TPC). Optimisation was performed using the response surface methodology (RSM) with a third-degree (33) Central Composite Design (CCD) approach. The RSM was applied to obtain the optimal combination of (1) raw material content (2.25–7.5 g raw material/100 mL of solvent), (2) ethanol concentration (20–60% v/v), and (3) extraction time (1–15 min). The optimal conditions for the extraction of polyphenols and antioxidant potential were a raw material content of 7.5 g/100 mL of solvent (solid/solvent ratio 13.3 mL/g), an ethanol concentration of 47% v/v, and an extraction time of 10 min. At these optimal extraction parameters, the maximum extraction of polyphenols and antioxidant activity obtained experimentally was found to be very close to its predicted value and was 12.9 mmol Trolox/L (DPPH method), 19.4 mmol FeSO4/L (FRAP method), and 2.1 g GA/L (TPC). The mathematical model developed was found to fit with the experimental data on the antioxidant potential and polyphenol extraction. The n-octanol/water partition coefficient of the optimised extract was used to determine their lipophilicity. Our studies have shown that the optimised extract is highly hydrophilic (log P < 0). Optimal parameters can be used for the industrial extraction of the S. officinalis herb for the needs of, among others, the pharmaceutical or cosmetic industry. [ABSTRACT FROM AUTHOR]

Dithiocarbamate fungicides have been widely used in agricultural practices due to their effective control of fungal diseases, thereby contributing to global food security and agricultural productivity. In this study, the inhibitory potency of eight compounds on human and rat aromatase (CYP19A1) activity was evaluated. The results revealed that zineb exhibited the highest inhibitory potency on human CYP19A1 (IC50, 2.79 μM). Maneb (IC50, 3.09 μM), thiram (IC50, 4.76 μM), and ferbam (IC50, 6.04 μM) also demonstrated potent inhibition on human CYP19A1. For the rat CYP19A1, disulfiram (IC50, 1.90 μM) displayed the strongest inhibition followed by maneb (2.16 μM), zineb (2.54 μM), and thiram (6.99 μM). These dithiocarbamates acted as mixed/non-competitive inhibitors of human and rat CYP19A1. Dithiothreitol (DTT), a reducing agent, partially rescued thiram-mediated inhibition when incubated at the same. Moreover, positive correlations were observed between log P, topological polar surface area, molecular weight, and heavy atoms and IC50 values. 3D-QSAR analysis revealed the hydrogen bond acceptor and donor play critical roles in the binding of dithiocarbamates to human CYP19A1. In silico analysis showed that dithiocarbamates bind to the haem binding site, containing Cys437 residues. In conclusion, some dithiocarbamates potently inhibit human and rat CYP19A1 via interacting with haem-binding Cys437 residues. [ABSTRACT FROM AUTHOR]

Context: Extensive studies using a trial-and-error approach have been conducted on low-rank coal flotation collectors. However, screening efficient collectors remains a considerable challenge due to the lack of suitable screening principles. It has proven that polar compounds such as carboxylic acids and esters are effective collectors for low-rank coal flotation. In this work, the effects of carboxylic acid, alcohol, and methyl ester on the floatability of low-rank coal were compared, the flotation performance of the polar collector was evaluated with theoretical calculations, a suitable evaluation parameter was determined and a screening principle based on this parameter was determined. The results show that the enhancement effects of polar collectors on low-rank coal floatability follow the order of methyl decanoate > methyl laurate > methyl octanoate > sec-octanol > methyl oleate (or methyl oleate > sec-octanol) > n-octanoic acid. Compared with the molecular polarity index, the hydrophobicity indices log P and dipole moment cannot be used to accurately evaluate different types of collectors and the same type of collectors, respectively. At room temperature, liquid polar compounds with molecular polarity indices in the range of 6.0 ~ 8.0 kcal/mol effectively enhance the floatability of low-rank coal. The molecular polarity index of the collector is used for the first time to screen effective collectors of low-rank coal in this work. This parameter is anticipated to be highly important for the development and research of low-rank coal and other mineral collectors. Methods: To obtain reasonable and accurate molecular structure, geometry optimization and frequency calculations of the studied collectors were conducted via the Gaussian 09 software package based on density functional theory at the B3LYP/6–311 + G (d, p) level. The integral equation formalism for the polarizable continuum model (IEF-PCM) was utilized with water as the solvent (dielectric constant = 78.36, T = 298 K) for all the calculations. Then, the atomic charge distributions (MPA and NPA) and electrostatic potential maps, the dipole moment and molecular polarity index, and the log P and water solubilities of studied collectors were shown or calculated by Gauss View 5.0, Mutiwfn program and website (https://www.molsoft.com/mprop/mprop.cgi), respectively. [ABSTRACT FROM AUTHOR]

The 5-heterocyclic 2-(2,4-dihydroxyphenyl)-1,3,4-thiadiazoles were obtained as potential biologically active compounds. Lipophilicity is one of the most important physicochemical properties of compounds and was already taken into account during the drug candidates design and development. The lipophilicity of compounds was determined using the computational (log P) and chromatography (log kw, RMw) methods. The experimental ones included the reverse-phase column high performance liquid chromatography RP (HPLC) with C8, C18, phosphatidylcholine (IAM), and cholesterol stationary phases and the thin layer chromatography (RP-HPTLC) with C8 and C18 stationary phases and various organic modifiers under the isocratic conditions. Descriptive statistics, correlation, and PCA analyses were used to compare the obtained results. For lipophilicity estimation of the tested compounds by HPTLC, dioxane and MeOH seem to be particularly beneficial as organic modifiers. The chromatographic lipophilicity parameters log kw (RMw) were well correlated and highly redundant (85%) compared with those calculated. Most compounds possess lipophilicity parameters within the recommended range for drug candidates. [ABSTRACT FROM AUTHOR]

Inclusion complexes require higher concentration of Beta cyclodextrins (βCD) resulting in increased formulation bulk, toxicity, and production costs. This systematic review offers a comprehensive analysis using Quality by design (QbD) as a tool to predict potential applications of Polyvinylpyrrolidone (PVP) as a ternary substance to address issues of inclusion complexes. We reviewed 623 documents from 2013 to 2023 and Eighteen (18) research papers were selected for statistical and meta-analysis using the QbD concept to identify the most critical factors for selecting drugs and effect of PVP on inclusion complexes. The QbD analysis revealed that Molecular weight (MW), Partition coefficient (Log P), and the auxiliary substance ratio directly affected complexation efficiency (CE), thermodynamic stability in terms of Gibbs free energy (ΔG), and percent drug release. However, Stability constant (Ks) remained unaffected by any of these parameters. The results showed that low MW (250), median Log P (6), and a βCD: PVP ratio of 2:3 would result in higher CE, lower G, and improved drug release. PVP improves drug solubility, enhances delivery and therapeutic outcomes, and counteracts increased drug ionization due to decreased pH. In certain cases, its bulky nature and hydrogen bonding with CD molecules can form non-inclusion complexes. The findings of the study shows that there is potential molecular interaction between PVP and β-cyclodextrins, which possibly enhances the stability of inclusion complexes for drug with low MW and log P values less than 9. The systematic review shows a comprehensive methodology based on QbD offers a replicable template for future investigations into drug formulation research. [ABSTRACT FROM AUTHOR]

This study was investigated the effect of adding fat to pork sausage on taste and aroma persistence. Sensory evaluation indicated that increasing fat content intensified umami and saltiness perception, enhancing the mouthfulness and flavor persistence, leading to Koku enhancing effect. Gas chromatography/mass spectrometry (GC/MS) analysis identified aroma compounds such as β-pinene, 3-carene, D-limonene, octanal, nonanal, caryophyllene, and methyl eugenol, which were consistently present regardless of fat content. These aroma compounds were less likely to be released as the fat content increased. Furthermore, the release of these aroma compounds from the sausage with addition of fat was larger than that without addition of fat in the presence of saline, indicating that the added fat retained these aroma compounds and released them in the presence of saline. This suggests that sausages with added fat release more aroma compounds during consumption, resulting in a more intense flavor and flavor persistence of Koku perception. These seven compounds detected in pork sausage were found to be easily retained by cholesterol and lecithin, likely due to differences in their log P values (octanol/water partition coefficients), which were greater than 3. [ABSTRACT FROM AUTHOR]

The aim of this study was to optimise ultrasound-assisted extraction (UAE) of the herb Sanguisorba officinalis L. in terms of the antioxidant activity (DPPH and FRAP method) and total polyphenol content (TPC). Optimisation was performed using the response surface methodology (RSM) with a third-degree (33) Central Composite Design (CCD) approach. The RSM was applied to obtain the optimal combination of (1) raw material content (2.25–7.5 g raw material/100 mL of solvent), (2) ethanol concentration (20–60% v/v), and (3) extraction time (1–15 min). The optimal conditions for the extraction of polyphenols and antioxidant potential were a raw material content of 7.5 g/100 mL of solvent (solid/solvent ratio 13.3 mL/g), an ethanol concentration of 47% v/v, and an extraction time of 10 min. At these optimal extraction parameters, the maximum extraction of polyphenols and antioxidant activity obtained experimentally was found to be very close to its predicted value and was 12.9 mmol Trolox/L (DPPH method), 19.4 mmol FeSO4/L (FRAP method), and 2.1 g GA/L (TPC). The mathematical model developed was found to fit with the experimental data on the antioxidant potential and polyphenol extraction. The n-octanol/water partition coefficient of the optimised extract was used to determine their lipophilicity. Our studies have shown that the optimised extract is highly hydrophilic (log P < 0). Optimal parameters can be used for the industrial extraction of the S. officinalis herb for the needs of, among others, the pharmaceutical or cosmetic industry.

The retention behavior of 10 previously synthesized α,β-unsaturated acids that exhibited antimicrobial activity was studied using 12 reversed-phase thin-layer chromatography (RP-TLC) systems. The mobile phases consisted of three solvent combinations (methanol‒water, acetonitrile‒water, and acetone‒water) in four different ratios (50:50, 60:40, 70:30, and 80:20, V/V). The chromatographic parameters R M 0 , a, and C0 were calculated for each system. The lipophilicity parameters of the tested compounds were predicted using various computational methods. The acetone‒water system demonstrated the highest correlation coefficients between the chromatographic and calculated lipophilicity parameters, which makes it the most suitable for evaluating the lipophilicity of the tested compounds. This system successfully reflected the effect of the lipophilic properties of the compounds on their retention behavior. To elucidate the retention mechanisms, the molecular properties of the tested compounds were calculated and a genetic algorithm was used to identify the properties with the greatest influence on the retention behavior. The interpretation of these descriptors revealed structural and physicochemical properties crucial for the behavior of the tested compounds. In addition, the pharmacokinetic properties of the compounds were estimated using in silico methods. The observed correlation between the retention mechanism and physicochemical properties affecting membrane transport and physiological binding ability highlights the applicability of RP-TLC conditions for rapid profiling of newly synthesized α,β-unsaturated acids. [ABSTRACT FROM AUTHOR]

The new Phenytoin derivatives have been synthesized, characterized, and compared for CNS activity. The synthesis was carried out in three steps. Firstly, the chloroacetylation of the 5,5-diphenyl hydantoin is carried out and then various substituted phenols are added into it and have been evaluated for anti-anxiety activity, muscle relaxant activity and anticonvulsant activity by using different models. The number of parameters have been optimized which reveal that the compound containing chloro group such as C3 and C6 show imperative potential when compared with the standard drug Diazepam. The newly synthesised compounds have the probability to be optimized further to engender new scaffolds to treat various CNS disorders. [ABSTRACT FROM AUTHOR]

Flavonoids are hydroxylated polyphenols that are widely distributed in plants with diverse health benefits. Despite their popularity, the bioavailability of flavonoids is often overlooked, impacting their efficacy and the comparison of products. The study discusses the bioavailability-related physicochemical properties of flavonoids, with a focus on the poorly soluble compounds commonly found in dietary supplements and herbal products. This review sums up the values of pKa, log P, solubility, permeability, and melting temperature of flavonoids. Experimental and calculated data were compiled for various flavonoid subclasses, revealing variations in their physicochemical properties. The investigation highlights the challenges posed by poorly soluble flavonoids and underscores the need for enabling formulation approaches to enhance their bioavailability and therapeutic potential. Compared to aglycones, flavonoid glycosides (with sugar moieties) tend to be more hydrophilic. Most of the reviewed aglycones and glycosides exhibit relatively low log P and high melting points, making them "brick dust" candidates. To improve solubility and absorption, strategies like size reduction, the potential use of solid dispersions and carriers, as well as lipid-based formulations have been discussed. [ABSTRACT FROM AUTHOR]

The 5-heterocyclic 2-(2,4-dihydroxyphenyl)-1,3,4-thiadiazoles were obtained as potential biologically active compounds. Lipophilicity is one of the most important physicochemical properties of compounds and was already taken into account during the drug candidates design and development. The lipophilicity of compounds was determined using the computational (log P) and chromatography (log kw, RMw) methods. The experimental ones included the reverse-phase column high performance liquid chromatography RP (HPLC) with C8, C18, phosphatidylcholine (IAM), and cholesterol stationary phases and the thin layer chromatography (RP-HPTLC) with C8 and C18 stationary phases and various organic modifiers under the isocratic conditions. Descriptive statistics, correlation, and PCA analyses were used to compare the obtained results. For lipophilicity estimation of the tested compounds by HPTLC, dioxane and MeOH seem to be particularly beneficial as organic modifiers. The chromatographic lipophilicity parameters log kw (RMw) were well correlated and highly redundant (85%) compared with those calculated. Most compounds possess lipophilicity parameters within the recommended range for drug candidates.

Although fentanyl and a small number of derivatives used for medical or veterinary procedures are well characterized, physiochemical properties have not been determined for many of the newer fentanyl analogs. Partition coefficients (Log P) were determined for 19 fentalogs using the shake‐flask method and liquid chromatography–tandem mass spectrometry (LC–MS/MS). Experimentally determined partition coefficients were compared with computationally derived data using six independent software sources (ACD/LogP, LogKOWWIN v 1.69, miLogP 2.2, OsirisP, XLOGP 3.0, ALogPS 2.1). Fentalogs with a wide variety of structural modifications were intentionally selected, yielding Log P values ranging from 1.21 to 4.90. Comparison of experimental and computationally derived Log P values were highly correlated (R2 0.854–0.967). Overall, substructure‐based modeling using fragmental methods or property‐based topological approaches aligned more closely with experimentally determined Log P values. LC–MS/MS was also used to estimate pKa values for fentalogs with no previously reported data. Lipophilicity and pKa are important considerations for analytical detection and toxicological interpretation. In silico methods allow the determination of physicochemical information prior to certified reference materials being readily available for in vitro or in vivo studies. Computationally derived data can provide insight regarding physiochemical characteristics of future fentalogs and other classes of synthetic analogs that have yet to emerge. [ABSTRACT FROM AUTHOR]

The sorption of flavour compounds by PET and 15 copolyesters (PET copolymerized with isophthalic acid, adipic acid, sebacic acid, tetramethylene glycol, diethylene glycol, triethylene glycol and neopentyl glycol in the range of 5 to 18 mol%) was studied. Biaxially oriented films of each resin were immersed in aqueous solutions containing 37 types of flavour compounds for 4 weeks at 37°C. The amount of flavour compounds sorbed by the films was highly dependent on the copolymer composition. Among the tested films, the copolyester film containing 11 mol% sebacic acid exhibited the highest sorption of the 37 compounds, which was approximately 40 times that of PET. The copolyester film containing 11 mol% isophthalic acid exhibited the lowest sorption, approximately half that of PET. The relationship between sorption and the characteristic values of the polyester films was studied. Sorption was negatively correlated with the solubility parameter and density of the amorphous area and strongly negatively correlated with the glass transition temperature. It was concluded that the dynamic free volume involved in diffusion dominates the sorption of flavour compounds by copolyesters. The log P value and molecular size of the compounds had a strong effect on the sorption of individual flavour compounds by the films in aqueous solutions. [ABSTRACT FROM AUTHOR]

IntroductionThe aim of this retrospective study was to analyze the effect and potential adverse effects of intravenous lipid emulsion (ILE) in poisoned dogs and cats over a 5 years period.MethodsMedical records of 313 dogs and 100 cats receiving ILE between 2016–2020 were analyzed for suspected toxicant, clinical signs, ILE dosages and frequency, the effect and adverse effects of ILE, and patient outcome.ResultsDogs and cats were poisoned with mostly unidentified toxicants (48%), rodenticides (8%), recreational drugs and nuts (7% each) and other toxicants. Clinical signs included neurologic deficits (63%), cardiovascular signs (29%), thermoregulation (21%) or gastrointestinal abnormalities (17%). Treatment with ILE was initiated within a median of 6.0 h (1.0–91.0 h) after poisoning. Dogs and cats received a total amount of median 8.0 mL/kg (1.5–66.6 mL/kg) and 15.8 mL/kg (1.8–69.4 mL/kg) ILE, respectively. A positive effect was observed in 74% of the patients, whereas clinical signs worsened in 4% of the patients after ILE administration. No subjective effect was detected in 22% of the patients. Suspected or possible adverse effects of ILE occurred in 6% of the patients, including neurological signs (temporarily reduced consciousness and ataxia), bradycardia, hyperthermia, vomiting, diarrhea, respiratory distress, worsening of the general behavior, facial swelling, and thrombophlebitis. The overall survival rate was 96%. One dog who potentially experienced adverse events was euthanized.ConclusionILE treatment was successful in most patients but can be associated with adverse effects. Administration of ILE should be carefully selected on an individual basis after weighing the possible benefits against potential adverse effects.

Flavonoids are hydroxylated polyphenols that are widely distributed in plants with diverse health benefits. Despite their popularity, the bioavailability of flavonoids is often overlooked, impacting their efficacy and the comparison of products. The study discusses the bioavailability-related physicochemical properties of flavonoids, with a focus on the poorly soluble compounds commonly found in dietary supplements and herbal products. This review sums up the values of pKa, log P, solubility, permeability, and melting temperature of flavonoids. Experimental and calculated data were compiled for various flavonoid subclasses, revealing variations in their physicochemical properties. The investigation highlights the challenges posed by poorly soluble flavonoids and underscores the need for enabling formulation approaches to enhance their bioavailability and therapeutic potential. Compared to aglycones, flavonoid glycosides (with sugar moieties) tend to be more hydrophilic. Most of the reviewed aglycones and glycosides exhibit relatively low log P and high melting points, making them “brick dust” candidates. To improve solubility and absorption, strategies like size reduction, the potential use of solid dispersions and carriers, as well as lipid-based formulations have been discussed.

Food-derived electrophilic compounds (FECs) are small molecules with electrophilic groups with potential cytoprotective effects. This study investigated the differential effects of six prevalent FECs on colitis in dextran sodium sulfate (DSS)-induced mice and the underlying relationship with molecular characteristics. Fumaric acid (FMA), isoliquiritigenin (ISO), cinnamaldehyde (CA), ferulic acid (FA), sulforaphane (SFN), and chlorogenic acid (CGA) exhibited varying improvements in colitis on clinical signs, colonic histopathology, inflammatory and oxidative indicators, and Nrf2 pathway in a sequence of SFN, ISO > FA, CA > FMA, CGA. Representative molecular characteristics of the "penetration-affinity–covalent binding" procedure, logP value, Keap1 affinity energy, and electrophilic index of FECs were theoretically calculated, among which logP value revealed a strong correlation with colitis improvements, which was related to the expression of Nrf2 and its downstream proteins. Above all, SFN and ISO possessed high logP values and effectively improving DSS-induced colitis by activating the Keap1–Nrf2 pathway to alleviate oxidative stress and inflammatory responses. [ABSTRACT FROM AUTHOR]

Molecular docking of 24 N-substituted 3,5-dibromo(H)anthranilic acid amides and hydrazides (I-XXIV) with the enzymes cyclooxygenase 1 (COX-1) and 2 (COX-2) is described. The dependences of experimental analgesic activities (AAexp) on scoring functions (BeCOX1, ImeCOX1, KiCOX1, BeCOX2, ImeCOX2, KiCOX2) and lipophilicity (log Pcalc) and ionization constants (pKacalc, pKbcalc) are studied. The optimum regression equation [Eq. (2)] chosen for the search for biologically active compounds with AA is AAcalc = –9.058 + 5.315·pKacalc + 7.157·ImeCOX1 – 7.382·BeCOX1 – 0.003·KiCOX1 – 0.86·BeCOX2 (R = 0.80; F = 6.49; S = 4.91; Q2LOO = 0.65). The regression equation [Eq. (2)] is verified by predicting the AA (AAcalc) as compared to experimental data (AAexp) obtained by the hot-plate method with mice for an independent set of six compounds (XXV-XXX), which showed a high correlation coefficient (R = 0.713) between AAcalc and AAexp. [ABSTRACT FROM AUTHOR]

Naphthenic Acids (NA) are important oil extraction subproducts. These chemical species are one of the leading causes of marine pollution and duct corrosion. For this reason, understanding the behavior of NAs in different saline conditions is one of the challenges in the oil industry. In this work, we simulated several naphthenic acid species and their mixtures, employing density functional theory calculations with the MST-IEFPCM continuum solvation model, to obtain the octanol–water partition coefficients, together with microsecond classical molecular dynamics. The latter consisted of pure water, low-salinity, and high-salinity environment simulations, to assess the stability of NAs aggregates and their sizes. The quantum calculations have shown that the longer chain acids are more hydrophobic, and the classical simulations corroborated: that the longer the chain, the higher the order of the aggregate. In addition, we observed that larger aggregates are stable at higher salinities for all the studied NAs. This can be one factor in the observed low-salinity-enhanced oil recovery, which is a complex phenomenon. The simulations also show that stabilizing the aggregates induced by the salinity involves a direct interplay of Na+ cations with the carboxylic groups of the NAs inside the aggregates. In some cases, the ion/NA organization forms a membrane-like circular structural arrangement, especially for longer chain NAs. [ABSTRACT FROM AUTHOR]

Lipophilicity is one of many parameters involved in the biological activity of drugs, as it affects their pharmacokinetic and pharmacodynamic behavior. Generally, lipophilicity is assessed by the partition coefficient of a compound between a nonpolar phase (n-octanol) and an aqueous phase (water), expressed as P (partition coefficient) or as its decimal logarithm (Log P). The gold standard method for the experimental determination of Log P is the shake-flask method. In this context, chromatographic methods enable the direct and simple quantification of the partitioned compound between the two phases. This review discusses the use of liquid chromatography (LC) for direct and indirect determination of lipophilicity. Beyond the classical isotropic log P determination, methods for assessing anisotropic lipophilicity are also reviewed. Several examples are discussed that highlight the versatility of LC technique and current trends. The last section of this review focuses on a case study describing an experience of our group and emphasizing the dual role of LC in determining Log P. [ABSTRACT FROM AUTHOR]

The dynamic drug release mechanisms from Carbomer 940 (CP) hydrogels have not been systematically explored elsewhere. This study aimed to investigate the quantitative structure−activity relationship of licorice flavonoids (LFs) compounds on their drug release from CP hydrogels based on LFs-CP interactions and drug solubility in the release medium. Ten LFs-CP hydrogels were formulated, and their in vitro release study was conducted. The intermolecular forces of LFs-CP systems were characterized by FTIR, molecular docking and molecular dynamic simulation. Ten LFs compounds were classified into I (high-release capability) LFs and II (low-release capability) LFs according to the different negative correlations between drug release percent at 48 h and intermolecular forces of drugs-CP, respectively. Moreover, high-release LFs possessed significantly lower log P and higher drug solubility in the release medium than low-release LFs. All I LFs release behaviors best followed the first-order equation, while II LFs release characteristics best fitted the zero-order equation except for isoliquiritigenin. Log P mainly affect the hydrogel relaxation process for I drugs release and the drug diffusion process for II drugs release. Higher log P values for LFs resulted in higher intermolecular strength for I drugs-CP systems and lower drug solubility in the release medium for II drugs, which hindered drug release. Hydrophobic association forces in drug-CP hydrogel played a more and more dominant role in hindering I LFs release with increasing release time. On the other hand, lower drug solubility in the release medium restricted II LFs release, and the dominant role of drug solubility in the release medium increased in 24 h followed by a significant decline after 36 h. Collectively, log P of LFs served as a bridge to determine LFs compound release behaviors and classification from CP hydrogels, which provided guidelines for reasonable design of LFs hydrogels in pharmaceutical topical formulations. [ABSTRACT FROM AUTHOR]

Marvin Sketch is the fast and accurate software used for drawing of chemical compounds and reactions. This software also provide guidance and is integrated with calculators for obtaining the suitable results of properties. Marvin sketch 20.8 software is well equipped with advanced chemical viewer for studying the chemical structures both single and multiple 2D/3D, as well as chemical reactions and its related data. It can display all the details, like molecule name, generated IUPAC name and SMILES strings of molecules. With the help of Marvin Sketch 20.8 software the compound N'-[(1E)-1-phenylethylidene]-1,3-benzothiazole-2-carbohydrazide(PEBTH) is characterized and all its properties were determined. [ABSTRACT FROM AUTHOR]

Molecular polarity governs lipophilicity, which in turn determines important agrochemical and environmental properties, such as soil sorption and bioconcentration of organic compounds. Since the C–F bond is the most polar in organic chemistry, the orientation of fluorine substituents originating from the rotation around C–C(F) bonds should affect the polarity and, consequently, the physicochemical and biological properties of fluorine-containing agrochemicals. Accordingly, this study aims to determine the most likely conformers of some fluorine-containing agrochemicals and to correlate their molecular dipole moments with the respective n-octanol/water partition coefficients (log P), in order to investigate the dependence of the lipophilicity with the molecular conformation.

Abstract The aim of the study was to determine the antioxidant activity and assess the lipophilicity and skin penetration of eugenyl chloroacetate (EChA), eugenyl dichloroacetate (EDChA), and eugenyl trichloroacetate (ETChA). Identification of the obtained products was based on gas chromatography (GC), infrared spectroscopy (FTIR/ATR), gas chromatography coupled with mass spectrometry (GC-MS), and the analysis of 13C-NMR and 1H-NMR spectra. The antioxidative capacity of the derivatives obtained was determined by the DPPH free radical reduction method, while the octanol/water partition coefficient (shake-flask method) was tested to determine the lipophilicity of these compounds. In the next stage of testing EDChA and ETChA–(compounds characterized by the highest degree of free radical scavenging), the penetration of DPPH through pig skin and its accumulation in the skin were evaluated. For comparison, penetration studies of eugenol alone as well as dichloroacetic acid (DChAA) and trichloroacetic acid (TChAA) were also carried out. The antioxidant activity (DPPH, ABTS, and Folin–Ciocalteu methods) of the fluid that penetrated through pig skin was also evaluated. The in vitro pig skin penetration study showed that eugenol derivatives are particularly relevant for topical application. The obtained derivatives were characterized by a high level of antioxidant activity estimated after 24 h of conducting the experiment, which indicates long-term protection against reactive oxygen species (ROS) in the deeper layers of the skin.

1,4-disubstituted 1H-1,2,3-triazole with a hydrophobic and hydrophilic moiety were synthesized by using Cu(I) catalyzed alkyne-azide 1,3-dipolar cycloaddition reaction. The hydrophilic moiety was d-galactopiranosyl or l-galactitoyl while an alkyl chain of eight to sixteen carbons corresponds to the hydrophobic portion. All compounds were characterized by NMR and mass spectrometry. Partition coefficient was experimentally determinate by HPLC ranging from 0.7 to 4.5. Compounds with the lowest partition coefficient showed self-aggregation in water leading to supramolecular structure, with size ranging from 108 to 588 nm.

Blind predictions of octanol/water partition coefficients at 298.15 K for 22 drug-like compounds were made for the SAMPL7 challenge. The octanol/water partition coefficients were predicted using solvation free energies computed using molecular dynamics simulations, wherein we considered the use of both pure and water-saturated 1-octanol to model the octanol-rich phase. Water and 1-octanol were modeled using TIP4P and TrAPPE-UA, respectively, which have been shown to well reproduce the experimental mutual solubility, and the solutes were modeled using GAFF. After the close of the SAMPL7 challenge, we additionally made predictions using TIP4P/2005 water. We found that the predictions were sensitive to the choice of water force field. However, the effect of water in the octanol-rich phase was found to be even more significant and non-negligible. The effect of inclusion of water was additionally sensitive to the chemical structure of the solute. [ABSTRACT FROM AUTHOR]

The lipophilicity of a drug is an important parameter for its eventual development by the pharmaceutical industry. It is usually measured by HPLC following partition of the compound between water and 1-octanol. We present here an alternative, simple, sensitive and quantitative ¹H nuclear magnetic resonance (NMR) method for the experimental measurement of partition coefficients of natural compounds and pharmaceutical drugs. It is based on measuring concentrations in the water phase, before and after partitioning and equilibration between water and octanol, using the ERETIC (Electronic Reference To Access In Vivo Concentration) technique. The signal to noise ratio is improved by a Water Suppression by Excitation Sculpting sequence. Quantification is based on an electronic reference signal and does not need addition of a reference compound. The log P values of 22 natural metabolites and four pharmaceutical drugs were determined and the experimental results are in excellent agreement with literature data. The experiments were run on -2 mg material. This technique proved to be robust, reproducible and suitable for log P values between -2 and +2. [ABSTRACT FROM AUTHOR]

The prediction of log P values is one part of the statistical assessment of the modeling of proteins and ligands (SAMPL) blind challenges. Here, we use a molecular graph representation method called Geometric Scattering for Graphs (GSG) to transform atomic attributes to molecular features. The atomic attributes used here are parameters from classical molecular force fields including partial charges and Lennard–Jones interaction parameters. The molecular features from GSG are used as inputs to neural networks that are trained using a "master" dataset comprised of over 41,000 unique log P values. The specific molecular targets in the SAMPL7 log P prediction challenge were unique in that they all contained a sulfonyl moeity. This motivated a set of ClassicalGSG submissions where predictors were trained on different subsets of the master dataset that are filtered according to chemical types and/or the presence of the sulfonyl moeity. We find that our ranked prediction obtained 5th place with an RMSE of 0.77 log P units and an MAE of 0.62, while one of our non-ranked predictions achieved first place among all submissions with an RMSE of 0.55 and an MAE of 0.44. After the conclusion of the challenge we also examined the performance of open-source force field parameters that allow for an end-to-end log P predictor model: General AMBER Force Field (GAFF), Universal Force Field (UFF), Merck Molecular Force Field 94 (MMFF94) and Ghemical. We find that ClassicalGSG models trained with atomic attributes from MMFF94 can yield more accurate predictions compared to those trained with CGenFF atomic attributes. [ABSTRACT FROM AUTHOR]

The Statistical Assessment of Modeling of Proteins and Ligands (SAMPL) challenges focuses the computational modeling community on areas in need of improvement for rational drug design. The SAMPL7 physical property challenge dealt with prediction of octanol-water partition coefficients and pKa for 22 compounds. The dataset was composed of a series of N-acylsulfonamides and related bioisosteres. 17 research groups participated in the log P challenge, submitting 33 blind submissions total. For the pKa challenge, 7 different groups participated, submitting 9 blind submissions in total. Overall, the accuracy of octanol-water log P predictions in the SAMPL7 challenge was lower than octanol-water log P predictions in SAMPL6, likely due to a more diverse dataset. Compared to the SAMPL6 pKa challenge, accuracy remains unchanged in SAMPL7. Interestingly, here, though macroscopic pKa values were often predicted with reasonable accuracy, there was dramatically more disagreement among participants as to which microscopic transitions produced these values (with methods often disagreeing even as to the sign of the free energy change associated with certain transitions), indicating far more work needs to be done on pKa prediction methods. [ABSTRACT FROM AUTHOR]

Naphthenic Acids (NA) are important oil extraction subproducts. These chemical species are one of the leading causes of marine pollution and duct corrosion. For this reason, understanding the behavior of NAs in different saline conditions is one of the challenges in the oil industry. In this work, we simulated several naphthenic acid species and their mixtures, employing density functional theory calculations with the MST-IEFPCM continuum solvation model, to obtain the octanol–water partition coefficients, together with microsecond classical molecular dynamics. The latter consisted of pure water, low-salinity, and high-salinity environment simulations, to assess the stability of NAs aggregates and their sizes. The quantum calculations have shown that the longer chain acids are more hydrophobic, and the classical simulations corroborated: that the longer the chain, the higher the order of the aggregate. In addition, we observed that larger aggregates are stable at higher salinities for all the studied NAs. This can be one factor in the observed low-salinity-enhanced oil recovery, which is a complex phenomenon. The simulations also show that stabilizing the aggregates induced by the salinity involves a direct interplay of Na+ cations with the carboxylic groups of the NAs inside the aggregates. In some cases, the ion/NA organization forms a membrane-like circular structural arrangement, especially for longer chain NAs.

Lipophilicity is one of many parameters involved in the biological activity of drugs, as it affects their pharmacokinetic and pharmacodynamic behavior. Generally, lipophilicity is assessed by the partition coefficient of a compound between a nonpolar phase (n-octanol) and an aqueous phase (water), expressed as P (partition coefficient) or as its decimal logarithm (Log P). The gold standard method for the experimental determination of Log P is the shake-flask method. In this context, chromatographic methods enable the direct and simple quantification of the partitioned compound between the two phases. This review discusses the use of liquid chromatography (LC) for direct and indirect determination of lipophilicity. Beyond the classical isotropic log P determination, methods for assessing anisotropic lipophilicity are also reviewed. Several examples are discussed that highlight the versatility of LC technique and current trends. The last section of this review focuses on a case study describing an experience of our group and emphasizing the dual role of LC in determining Log P.

The theoretical study represents an essential preliminary stage for the start of any industry, as it gives a theoretical description of the properties of compounds (chemical, physical and biological properties) without conducting research to find out about this and the least cost. Through the theoretical study, we extract a clear picture of the chemical compounds before starting to manufacture them to know the extent of their impact on human health and their chemical and biological effectiveness. Using the Density Functional Theory (DFT/B3LYP) with base 6-311G, through Gaussian 09 program, the optimize geometry, (bond lengths, angles bond) and vibrational spectra was calculated of the benzimidazole derivatives [Carbenzim (CZM), Mebendazole (MBZ)]. Through orbital charts of HOMO and LUMO to study electronic properties. The HOMO-LUMO gap was also evaluated for chemical reactivity and determination of global reactivity descriptors (Hardness (h), Softness (S), Electrophilicity (w), Chemicalpotential (m), Electronegativity(χ))] that defines compunds effectiveness and the their biological activities. In addition, (QSAR) data has been used to develop relationships between biological activities and thermophysical properties of chemicals, through the Hyper Chem 8.0 program by using Semi-empirical (SE) method at the (PM3) level. The LOG P value was calculated, binding energy, Polarizability, hydration energy, surface area, and electrostatic potential energy difference of two level. [ABSTRACT FROM AUTHOR]

The dynamic drug release mechanisms from Carbomer 940 (CP) hydrogels have not been systematically explored elsewhere. This study aimed to investigate the quantitative structure−activity relationship of licorice flavonoids (LFs) compounds on their drug release from CP hydrogels based on LFs-CP interactions and drug solubility in the release medium. Ten LFs-CP hydrogels were formulated, and their in vitro release study was conducted. The intermolecular forces of LFs-CP systems were characterized by FTIR, molecular docking and molecular dynamic simulation. Ten LFs compounds were classified into I (high-release capability) LFs and II (low-release capability) LFs according to the different negative correlations between drug release percent at 48 h and intermolecular forces of drugs-CP, respectively. Moreover, high-release LFs possessed significantly lower log P and higher drug solubility in the release medium than low-release LFs. All I LFs release behaviors best followed the first-order equation, while II LFs release characteristics best fitted the zero-order equation except for isoliquiritigenin. Log P mainly affect the hydrogel relaxation process for I drugs release and the drug diffusion process for II drugs release. Higher log P values for LFs resulted in higher intermolecular strength for I drugs-CP systems and lower drug solubility in the release medium for II drugs, which hindered drug release. Hydrophobic association forces in drug-CP hydrogel played a more and more dominant role in hindering I LFs release with increasing release time. On the other hand, lower drug solubility in the release medium restricted II LFs release, and the dominant role of drug solubility in the release medium increased in 24 h followed by a significant decline after 36 h. Collectively, log P of LFs served as a bridge to determine LFs compound release behaviors and classification from CP hydrogels, which provided guidelines for reasonable design of LFs hydrogels in pharmaceutical topical formulations.

The aim of the study was to determine the antioxidant activity and assess the lipophilicity and skin penetration of eugenyl chloroacetate (EChA), eugenyl dichloroacetate (EDChA), and eugenyl trichloroacetate (ETChA). Identification of the obtained products was based on gas chromatography (GC), infrared spectroscopy (FTIR/ATR), gas chromatography coupled with mass spectrometry (GC-MS), and the analysis of 13C-NMR and 1H-NMR spectra. The antioxidative capacity of the derivatives obtained was determined by the DPPH free radical reduction method, while the octanol/water partition coefficient (shake-flask method) was tested to determine the lipophilicity of these compounds. In the next stage of testing EDChA and ETChA–(compounds characterized by the highest degree of free radical scavenging), the penetration of DPPH through pig skin and its accumulation in the skin were evaluated. For comparison, penetration studies of eugenol alone as well as dichloroacetic acid (DChAA) and trichloroacetic acid (TChAA) were also carried out. The antioxidant activity (DPPH, ABTS, and Folin–Ciocalteu methods) of the fluid that penetrated through pig skin was also evaluated. The in vitro pig skin penetration study showed that eugenol derivatives are particularly relevant for topical application. The obtained derivatives were characterized by a high level of antioxidant activity estimated after 24 h of conducting the experiment, which indicates long-term protection against reactive oxygen species (ROS) in the deeper layers of the skin. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to determine the acid dissociation constant (pKa) of piroxicam using high performance liquid chromatography (HPLC) and ultraviolet-visible (UV-Vis) spectrophotometry, and to determine the partition coefficient (Log P), distribution coefficient (Log D), and "Log kw" values of piroxicam using HPLC. Materials and Methods: The HPLC studies were performed on a reversed-phase ACE C18 (150x4.6 mm ID, 5 μm) column at a flow rate of 1.0 mL min-1. The detector was set to 360 nm. Log D at different pH values (3.0-6.5) was examined with a phosphate buffer (20 mM) and acetonitrile (30:70 v/v) mixture as the mobile phase. For pKa determination, HPLC studies were performed with a mixture of phosphate buffer (20 mM) and methanol within the pH range of 3.50-6.00. Log kw measurements were performed with phosphate buffer (20 mM) and MeOH (from 20:80 v/v to 10:90 v/v) mixtures within the pH range of 3.50-6.00. UV-Vis spectrophotometric pKa measurements were performed at 285 nm wavelength. Results: The pKa value of piroxicam was found to be 5.3 by HPLC and 5.7 by UV-Vis spectrophotometry. Log P of piroxicam was determined as 1.58 in our experimental conditions. Log D values were 1.57, 1.57, 1.44, 1.13, and 0.46 for pH values of 3.17, 3.79, 4.44, 5.42, and 6.56, respectively. Conclusion: In the literature, different Log P (3.1, 2.2, and 0.6) and pKa (6.3 and 4.8) values were reported for piroxicam. The Log P (1.58) and pKa (5.3 and 5.7) values obtained for piroxicam in our study were within the range of the literature values. All these results indicate that different experimental approaches used for the determination of physicochemical properties could provide different values. Although UV spectrophotometry is easy to apply, HPLC is a unique technique for simultaneous determination of pKa, Log D, and Log P values of compounds. [ABSTRACT FROM AUTHOR]

Blind predictions of octanol/water partition coefficients at 298 K for 11 kinase inhibitor fragment like compounds were made for the SAMPL6 challenge. We used the conventional, "untrained", free energy based approach wherein the octanol/water partition coefficient was computed directly as the difference in solvation free energy in water and 1-octanol. We additionally proposed and used two different forms of a "trained" approach. Physically, the goal of the trained approach is to relate the partition coefficient computed using pure 1-octanol to that using water-saturated 1-octanol. In the first case, we assumed the partition coefficient using water-saturated 1-octanol and pure 1-octanol are linearly correlated. In the second approach, we assume the solvation free energy in water-saturated 1-octanol can be written as a linear combination of the solvation free energy in pure water and 1-octanol. In all cases here, the solvation free energies were computed using electronic structure calculations in the SM12, SM8, and SMD universal solvent models. In the context of the present study, our results in general do not support the additional effort of the trained approach. [ABSTRACT FROM AUTHOR]

Partition coefficients describe the equilibrium partitioning of a single, defined charge state of a solute between two liquid phases in contact, typically a neutral solute. Octanol–water partition coefficients ( K ow ), or their logarithms (log P), are frequently used as a measure of lipophilicity in drug discovery. The partition coefficient is a physicochemical property that captures the thermodynamics of relative solvation between aqueous and nonpolar phases, and therefore provides an excellent test for physics-based computational models that predict properties of pharmaceutical relevance such as protein-ligand binding affinities or hydration/solvation free energies. The SAMPL6 Part II octanol–water partition coefficient prediction challenge used a subset of kinase inhibitor fragment-like compounds from the SAMPL6 p K a prediction challenge in a blind experimental benchmark. Following experimental data collection, the partition coefficient dataset was kept blinded until all predictions were collected from participating computational chemistry groups. A total of 91 submissions were received from 27 participating research groups. This paper presents the octanol–water log P dataset for this SAMPL6 Part II partition coefficient challenge, which consisted of 11 compounds (six 4-aminoquinazolines, two benzimidazole, one pyrazolo[3,4-d]pyrimidine, one pyridine, one 2-oxoquinoline substructure containing compounds) with log P values in the range of 1.95–4.09. We describe the potentiometric log P measurement protocol used to collect this dataset using a Sirius T3, discuss the limitations of this experimental approach, and share suggestions for future log P data collection efforts for the evaluation of computational methods. [ABSTRACT FROM AUTHOR]

The SAMPL Challenges aim to focus the biomolecular and physical modeling community on issues that limit the accuracy of predictive modeling of protein-ligand binding for rational drug design. In the SAMPL5 log D Challenge, designed to benchmark the accuracy of methods for predicting drug-like small molecule transfer free energies from aqueous to nonpolar phases, participants found it difficult to make accurate predictions due to the complexity of protonation state issues. In the SAMPL6 log P Challenge, we asked participants to make blind predictions of the octanol–water partition coefficients of neutral species of 11 compounds and assessed how well these methods performed absent the complication of protonation state effects. This challenge builds on the SAMPL6 p K a Challenge, which asked participants to predict p K a values of a superset of the compounds considered in this log P challenge. Blind prediction sets of 91 prediction methods were collected from 27 research groups, spanning a variety of quantum mechanics (QM) or molecular mechanics (MM)-based physical methods, knowledge-based empirical methods, and mixed approaches. There was a 50% increase in the number of participating groups and a 20% increase in the number of submissions compared to the SAMPL5 log D Challenge. Overall, the accuracy of octanol–water log P predictions in SAMPL6 Challenge was higher than cyclohexane–water log D predictions in SAMPL5, likely because modeling only the neutral species was necessary for log P and several categories of method benefited from the vast amounts of experimental octanol–water log P data. There were many highly accurate methods: 10 diverse methods achieved RMSE less than 0.5 log P units. These included QM-based methods, empirical methods, and mixed methods with physical modeling supported with empirical corrections. A comparison of physical modeling methods showed that QM-based methods outperformed MM-based methods. The average RMSE of the most accurate five MM-based, QM-based, empirical, and mixed approach methods based on RMSE were 0.92 ± 0.13, 0.48 ± 0.06, 0.47 ± 0.05, and 0.50 ± 0.06, respectively. [ABSTRACT FROM AUTHOR]

Results are reported for octanol–water partition coefficients (log P) of the neutral states of drug-like molecules provided during the SAMPL6 (Statistical Assessment of Modeling of Proteins and Ligands) blind prediction challenge from applying the "embedded cluster reference interaction site model" (EC-RISM) as a solvation model for quantum-chemical calculations. Following the strategy outlined during earlier SAMPL challenges we first train 1- and 2-parameter water-free ("dry") and water-saturated ("wet") models for n-octanol solvation Gibbs energies with respect to experimental values from the "Minnesota Solvation Database" (MNSOL), yielding a root mean square error (RMSE) of 1.5 kcal mol−1 for the best-performing 2-parameter wet model, while the optimal water model developed for the pKa part of the SAMPL6 challenge is kept unchanged (RMSE 1.6 kcal mol−1 for neutral compounds from a model trained on both neutral and ionic species). Applying these models to the blind prediction set yields a log P RMSE of less than 0.5 for our best model (2-parameters, wet). Further analysis of our results reveals that a single compound is responsible for most of the error, SM15, without which the RMSE drops to 0.2. Since this is the only compound in the challenge dataset with a hydroxyl group we investigate other alcohols for which Gibbs energy of solvation data for both water and n-octanol are available in the MNSOL database to demonstrate a systematic cause of error and to discuss strategies for improvement. [ABSTRACT FROM AUTHOR]

Atorvastatin calcium (ATV) is an anti-hyperlipidemic agent with poor bioavailability. Several approaches were reported to improve the solubility of ATV. In this study ATV was prepared as a choline salt (ATV-C) and a complex of the prepared salt with hydroxy-propyl-beta-cyclodextrin (HPβCD) (ATV-C-CD) hoping to enhance ATV solubility, decrease the partition coefficient and improve its transdermal permeability. The pharmaceutical properties of the products were investigated. The prepared salts were characterized by FTIR, NMR and DSC, UV and HPLC. 2D NMR was successfully employed to unequivocally assign the protons of ATV, which was essential for better understanding of the structure of the formed salt. ATV-C showed higher solubility in phosphate buffer than ATV. Its log Po/phosphate buffer was found to be 1.1 while that for ATV 1.78. This change had an effect on the transdermal permeation where the ATV-C compound achieved a 4 times greater diffusion compared to ATV. Interestingly, ATV-C seemed to cause a tighter fitting of the drug into the HPβCD cavity leading to higher binding constant. However, the ATV-C-CD complex showed a negative effect on transdermal permeation. [ABSTRACT FROM AUTHOR]

Azo dyes, in addition to showing a wide range of applications in various industries, after releasing into aquatic ecosystems can act as pollutants. The first step in the prediction of possible toxic effects of compounds in the environment includes the estimation of its lipophilicity. Lipophilicity of selected derivatives of azo dyes was examined by thin layer chromatography on a reversed phase (RPTLC18F254s) in t-butanol and N,N-dimethylformamide, as well as by applying appropriate software packages. Relationship between lipophilicity chromatographic parameters (RM0 and m) and values of partition coefficient, log P, as standard measure of lipophilicity was established applying linear regression analysis. Also, relationship between chromatographic parameters (RM0 and m) and computational values of effective concentration, EC50, as a measure of acute toxicity of investigated derivatives for different test organisms was studied. Obtained results show that chromatographic parameters (RM0 and m) could be successfully used for describing lipophilicity (estimation of toxic effects) of examined derivatives of azo dyes.

This study was investigated the effect of adding fat to pork sausage on taste and aroma persistence. Sensory evaluation indicated that increasing fat content intensified umami and saltiness perception, enhancing the mouthfulness and flavor persistence, leading to Koku enhancing effect. Gas chromatography/mass spectrometry (GC/MS) analysis identified aroma compounds such as β-pinene, 3-carene, D-limonene, octanal, nonanal, caryophyllene, and methyl eugenol, which were consistently present regardless of fat content. These aroma compounds were less likely to be released as the fat content increased. Furthermore, the release of these aroma compounds from the sausage with addition of fat was larger than that without addition of fat in the presence of saline, indicating that the added fat retained these aroma compounds and released them in the presence of saline. This suggests that sausages with added fat release more aroma compounds during consumption, resulting in a more intense flavor and flavor persistence of Koku perception. These seven compounds detected in pork sausage were found to be easily retained by cholesterol and lecithin, likely due to differences in their log P values (octanol/water partition coefficients), which were greater than 3.

Background: Metabolic syndrome is one of the major non-communicable global health hazards of the modern world owing to its amplifying prevalence. Acetyl coenzyme-A carboxylase 2 (ACC 2) is one of the most crucial enzymes involved in the manifestation of this disease because of its regulatory role in fatty acid metabolism., Objective: To find novel potent ACC 2 inhibitors as therapeutic potential leads for combating metabolic syndrome., Methods: In the present study, a two-dimensional quantitative structure-activity relationship (2D QSAR) approach was executed on biologically relevant thiazolyl phenyl ether derivatives as ACC 2 inhibitors for structural optimization. The physiochemical descriptors were calculated and thus a correlation was derived between the observed and predicted activity by the regression equation. The significant descriptors i.e. log P (Whole Molecule) and Number of H-bond Donors (Substituent 1) obtained under study were considered for the design of new compounds and their predicted biological activity was calculated from the regression equation of the developed model. The compounds were further validated by docking studies with the prepared ACC 2 receptor., Results: The most promising predicted leads with the absence of an H-bond donor group at the substituted phenyl ether moiety yet increased overall lipophilicity exhibited excellent amino acid binding affinity with the receptor and showed predicted inhibitory activity of 0.0025 μM and 0.0027 μM. The newly designed compounds were checked for their novelty. Lipinski's rule of five was applied to check their druggability and no violation of this rule was observed., Conclusion: The compounds designed in the present study have tremendous potential to yield orally active ACC 2 inhibitors to treat metabolic syndrome., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Novel Triclosan mimic diphenyl ether derivatives 4a–k were designed and synthesized with lipophilicity considerably lesser than that of Triclosan. The binding mode of the compounds at the active site of enoyl-ACP reductase was analysed using docking method. The syntheses were carried out with one-pot reductive amination reaction and were characterized by spectral techniques. The synthesized compounds were evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv strain by Microplate Alamar Blue assay. Compounds 4h and 4j were the most active compounds with MIC equal to 25 μg/mL against M. tuberculosis H37Rv strain. All compounds were also examined for their cytotoxic potential against VERO and HepG2 cell lines and were safe even at 300 μg/mL. Log P of all the synthesized compounds was evaluated by RPHPLC and was significantly lesser than Triclosan. [ABSTRACT FROM AUTHOR]

Hildebrand and Hansen solubility parameters, and log P value are widely used to determine the solubility of polymers in solvents. The models were used to explain the recovery of phytochemical, rosmarinic acid from Orthosiphon aristatus extract in C18 solid phase extraction (SPE) using the eluent consisting of ethyl acetate and chloroform in the decreasing polarity of solvent system. The experimental recovery of rosmarinic acid appeared to be well explained by the Hansen solubility model. The small difference in the Hansen solubility parameters, particularly for dispersion and hydrogen bonding forces, results in a higher polar solvent system for high rosmarinic acid recovery. The results found that the Hansen solubility model fitted well to the recovery of rosmarinic acid from crude extract with high coefficient of determination (R2 > 0.8), low standard error (4.4%), and p < 0.05. Hildebrand solubility is likely to be the second fit model, whereas log P has poor R2 < 0.7 and higher standard error (7.3%). The Hansen solubility model describes the interaction of solute-solvent in three dimensions (dispersion, polar, and hydrogen bonding forces) which can accurately explain the recovery of rosmarinic acid. Therefore, Hansen solubility can be used to predict the recovery of rosmarinic acid from O. aristatus extract using SPE. [ABSTRACT FROM AUTHOR]

The increased risk of illness and disability is related to the age inevitable biological changes. Oxidative stress is a proposed mechanism for many age-related diseases. The crucial importance of polyphenol pharmacophore for aging process is largely described thanks to its effects on concentrations of reactive oxygen species. Resveratrol (3,5,4′-trihydroxy-trans-stilbene, RSV) plays a critical role in slowing the aging process but has a poor bioavailabity after oral intake. In this present work, a series of RSV derivatives was designed, synthesized, and evaluated as potential antioxidant agents. These derivatives contain substituents with different electronic and steric properties in different positions of aromatic rings. This kind of substituents affects the activity and the bioavailability of these compounds compared with RSV used as reference compound. Studies of Log P values demonstrated that the introduction of halogens gives the optimum lipophilicity to be considered promising active agents. Among them, compound 6 showed the higher antioxidant activity than RSV. The presence of trifluoromethyl group together with a chlorine atom increased the antioxidant activity compared to RSV.

Ten dimeric procyanidin (PC) analogs were hemisynthesized from catechin or epicatechin and from five different aldehydes using the same mechanism that produces the important acetaldehyde-mediated adducts of proanthocyanidins (PAs) and anthocyanins in red wine. Protein precipitation capacity (PPC), octanol-water partition coefficient (log P ) and stability of the PC analogs were determined. The emphasis was on the PPC because it has been shown to correlate with anthelmintic activity against gastrointestinal nematodes in ruminants and with other beneficial bioactivities in animals, as well. The PPC of PC analogs was greatly improved compared to natural PC dimers, but the capacity was not as great as that of a PC trimer or epigallocatechin gallate. The log P of PC analogs varied from hydrophobic to hydrophilic depending on the intramolecular linkage. Great variation was observed in stabilities of PC analogs in phosphate buffered saline, and the mixtures of degradation products were characterized using high-resolution mass spectrometry.

The purpose of this study is to develop high-performance liquid chromatography (HPLC) and ultravioletvisible (UV-Vis) spectrophotometry methods for the determination of pKa, log P, and log D values of phenazopyridine hydrochloride (PHCl). For the HPLC analysis, the pH of the mobile phase was plotted against the capacity factor, and the pKa value was obtained from a sigmoidal relationship. Meanwhile, for the UV-Vis spectrophotometric study, the absorbance of PHCl was plotted against pH at 332 nm to obtain the pKa value. The log P and log D (at pH 2.0) values were then calculated based on the concentration of PHCl in the octanol/water phase. Using the HPLC method, the pKa value was established as 5.05 (± 0.15). Meanwhile, the spectroscopic technique afforded pKa values of 5.20 (± 0.22) and 5.17 (± 0.17) via a classical sigmoidal curve and the Albert and Serjeant method. The log D (at pH 2.0) and log P values of PHCl were 1.61 (± 0.16) and 2.62 (± 0.11), respectively. The obtained results are in good agreement with each other. The pKa, log P, and log D values of PHCl can be determined by HPLC and UV-Vis spectrophotometry with reproducible results. [ABSTRACT FROM AUTHOR]

Although log P is now recognized to be a key factor that determines the bioactivity of a molecule, the focus of medicinal chemists on hydrophobicity and log P started with the quantitative structure-activity relationships (QSAR) publications of Hansch and Fujita. Their original publication represents a dramatic change of focus to incorporate consideration of log P after a decade of work unsuccessfully attempting to use the Hammett equation to explain the structure-activity relationships of plant growth regulators. QSAR allows one to explore the quantitative relationship between log P and biological activity even when other factors also influence potency. In particular, Hansch’s publications of thousands of QSAR equations demonstrate that a relationship of biological activity with log P is indeed a general phenomenon. Hansch’s group also provided data and tools that enable others to explore the relationship between log P and the biological activity of compounds of interest. [ABSTRACT FROM AUTHOR]

A diet rich in phytochemicals confers benefits for health by reducing the risk of chronic diseases via regulation of oxidative stress and inflammation (OSI). For optimal protective bio-efficacy, the time required for phytochemicals and their metabolites to reach maximal plasma concentrations (T max ) should be synchronised with the time of increased OSI. A statistical model has been reported to predict T max of individual phytochemicals based on molecular mass and lipophilicity. We report the application of the model for predicting the absorption profile of an uncharacterised phytochemical mixture, herein referred to as the ‘functional fingerprint’. First, chemical profiles of phytochemical extracts were acquired using liquid chromatography mass spectrometry (LC-MS), then the molecular features for respective components were used to predict their plasma absorption maximum, based on molecular mass and lipophilicity. This method of ‘functional fingerprinting’ of plant extracts represents a novel tool for understanding and optimising the health efficacy of plant extracts. [ABSTRACT FROM AUTHOR]