Search Results (107)

Lipophilicity, commonly described by the n-octanol/water partition coefficient (LogP), is a key physicochemical property influencing the pharmacokinetic behavior of small molecules. Reliable LogP estimation during the early stages of drug discovery is essential to support molecular design and prioritize compounds with favorable ADMET properties. In this work, we report the development of LogPpred, an AI-based predictor of molecular lipophilicity. Starting from a curated dataset of 13,536 molecules with experimentally determined LogP values, multiple machine learning algorithms and molecular representations were systematically evaluated. The best-performing model, based on Gaussian Process Regression and RDKit molecular descriptors, achieved a mean absolute error (MAE) of 0.34 on the independent internal test set. External validation on a fully independent OECD-derived dataset yielded an MAE of 0.84, demonstrating good generalization capability across diverse chemical space. Furthermore, experimental LogP determination of an additional set of independently selected compounds confirmed the predictive reliability of the model, yielding an MAE of 0.66. Comparative analyses showed that LogPpred outperformed several widely used LogP prediction tools. Applicability domain analysis further supported the reliability of the model, with MAE values improving to 0.28 and 0.62 for in-domain compounds in the internal and external validation sets, respectively. Overall, LogPpred represents a robust, accurate, and transparent tool for the early assessment of molecular lipophilicity in medicinal chemistry and drug discovery. Full article

Intravenous lipid therapy (ILE) is used to treat neurotoxicosis in companion animals, but clinical evidence for in vivo xenobiotic partitioning and benefit remains limited. This study evaluated associations between the log n-octanol/water partition coefficient (log P), in vivo plasma partitioning, and early neurological outcome. In this case series from eight veterinary hospitals, dogs and cats with suspected neurotoxicosis received ILE. Blood collected before and at the end of infusion was separated into lipid and aqueous fractions and analyzed by gas chromatography–mass spectrometry. Log P values were retrieved from PubChem. Outcome (improvement vs. no-improvement) was the change from ILE-start to 4–6 h later. Thirty-four cases were analyzed (27 dogs and seven cats; 17 different xenobiotics were identified). At the end of infusion, xenobiotic lipid fraction concentrations exceeded aqueous concentrations in 28/34 cases, and log P did not correlate with the lipid-to-aqueous ratio. Improvement occurred in 14/34 animals and was associated with higher lipid-to-aqueous xenobiotic ratios (geometric mean ratio 5.7; 95% CI 1.73–19.05; p = 0.007). Overall, in vivo lipid sequestration was frequent and was associated with early neurological improvement, whereas log P alone did not predict partitioning or outcome. Full article

With the continuing intensification of modern agriculture, pesticides and antibiotics are extensively used to control pests and diseases, but their improper use and indirect inputs have resulted in widespread contamination of agricultural environments and food products. This review synthesizes how these contaminants enter agroecosystems, their occurrence across soils, waters and agricultural products, and the processes that redistribute residues across air–water–soil interfaces and into the soil–plant continuum. We summarize cross-media transport pathways (e.g., runoff/leaching, volatilization–deposition and irrigation-driven redistribution) and relate environmental exposure to plant uptake using a harmonized indicator set, including the bioconcentration factor (BCF), translocation factor (TF), octanol–water partition coefficient (log Kow) and soil organic carbon–water partition coefficient (Koc). We further discuss key determinants of crop accumulation, including compound-specific properties, soil characteristics and plant physiological traits, and highlight how these factors jointly shape residue profiles in edible tissues. Finally, we outline research priorities for source reduction, standardized multi-matrix surveillance, fate-to-uptake modeling, and microbiome-enabled remediation strategies to support pollution control, food safety and public health. Full article

The presence of corticosteroids (CSs) in aquaculture wastewater poses risks to ecological health and food safety, yet data on their lipophilicity (logK_ow) remain scarce. This study determined the logK_ow of CSs to perform a screening-level in silico environmental risk prioritization. We evaluated nine computational programs (ACD/LogP, ALOGPS 2.1, CLOGP, JChem, KOWWIN, MiLogP, MolLogP, MOSES.logP, and XLOGP3) against experimental data for 50 steroid hormones. Results showed that XLOGP3 demonstrated the highest accuracy (Adjusted R² = 0.9872; SSE = 0.1004), followed by MiLogP, ACD/LogP, and KOWWIN. Structure–lipophilicity analysis revealed that esterification and acetonide formation significantly increase logK_ow, while hydroxylation decreases it. Using the validated XLOGP3, we predicted logK_ow for 32 synthetic CSs and estimated their bioconcentration factor (BCF) and soil organic carbon–water partition coefficient (K_oc). Because experimental logK_ow data for these 32 synthetic compounds are largely unavailable, these estimates should be interpreted as preliminary prioritization indicators rather than experimentally confirmed endpoints. Heavily modified CSs like Ciclesonide and Fluocortolone 21-hexanoate exhibited high logK_ow (>4.5), log BCF (>3.0), and logK_oc (>4.0), indicating their high potential for bioaccumulation and persistent sediment adsorption. This study provides a prioritized list of high-risk CSs, serving as a preliminary tool to identify potential compounds of concern in aquaculture environments. Full article

Steroid hormones (SHs) have a high estrogenic potential, and urban wastewater is one of their main ways into the aquatic environment. Constructed wetlands (CWs) are considered one of the most sustainable alternatives for the treatment of wastewater from small communities. However, the use of gravel and sand implies a significant environmental impact associated with their extraction and transport. A more sustainable alternative is the use of plant residues, as they are abundant, inexpensive, and readily available, and they can improve the efficiency of hormone removal through sorption. Thus, the sorption of 15 SHs was studied on conventional, mineral substrates (gravel, sand, and volcanic ash) and alternative vegetal wastes, i.e., mulches from giant reed, palm tree, balsa wood, and pine needles. These materials were characterized by determining their Point of Zero Charge (pH_PZC), ash content, content of leachable polycyclic aromatic hydrocarbons (PAH) and heavy metals, total surface area (BET), and pore characteristics. Results indicated that SH sorption on the mineral substrates was quite low, in most cases less than 10–15%. However, in the mulches it reached between 50 and 95%, except for corticosteroids (11–43%). The pseudo-second-order kinetics provided the best fit in all cases, with R² values between 0.97 and 0.9999. Experiments with a contact time of 7 days showed that the palm tree was the only substrate that completely removed the three corticosteroids studied (cortisone, prednisone, and prednisolone). Additionally, a significant correlation was observed between removal due to sorption (%) and log octanol–water partition coefficient (log Kow). Freundlich isotherm provided a higher number of best fits than Langmuir. Lastly, to compare sand with palm mulch under more realistic experimental conditions, four lab-scale CWs (two with palm mulch and two with sand, with/without plants) were studied. The sand-based CWs achieved faster SH percentage removals, while after 24 h, SH mass removals were significantly higher in the palm mulch-based CWs. Full article

In industrial settings, one of the key environmental challenges is the remediation of soil contaminated by hydrocarbons. Washing the soil with surfactants mobilises and extracts these compounds, making them easier to treat. As it enables the recovery and reuse of soil within sustainable production processes, this technique is part of the circular economy. Soil-washing experiments using surfactants were carried out to determine whether a mixture of anionic and non-ionic surfactants could improve the remediation of soil contaminated by gasoline and diesel fuel compared to the use of a single surfactant. Four surfactants were used (non-ionic: polyoxyethylene lauryl ether and polyoxyethylene (80) sorbitan monooleate; anionic: sodium dodecylbenzenesulfonate and sodium dodecyl sulfate). The aliphatic and aromatic hydrocarbon fractions (C6–C8, C8–C10, C10–C12, C12–C16, C16–C21 and C21–C35) of gasoline and diesel fuel were analysed. Sodium dodecylbenzenesulfonate was selected for the purpose of preparing mixtures with the other two non-ionic surfactants, polyoxyethylene lauryl ether and polyoxyethylene (80) sorbitan monooleate. These surfactant mixtures demonstrated significantly higher removal rates than sodium dodecylbenzenesulfonate alone. Mixtures of sodium dodecylbenzenesulfonate and polyoxyethylene lauryl ether achieved hydrocarbon extraction of between 61% and 68%, while sodium dodecylbenzenesulfonate-polyoxyethylene (80) sorbitan monooleate mixtures obtained extraction of between 58% and 66%. Analysis of the gasoline and diesel hydrocarbon fractions indicated that smaller molecules desorb more easily than larger ones and that aromatics desorb more easily than aliphatics. Furthermore, the mixtures increased the extraction of both aliphatic and aromatic hydrocarbons, particularly the lighter compounds. The variation on removal rates within the hydrocarbon ranges may be related to the octanol–water partition coefficient (K_ow). These improvements with mixtures of anionic and non-ionic surfactants could be exploited to enhance the effectiveness of surfactant-flushing treatments and optimise the design of soil surfactant treatments. Full article

Oleanolic acid (OA) is a natural pentacyclic triterpenoid with reported hypoglycemic, hepatoprotective, antidiabetic, and anti-inflammatory activities. However, its limited aqueous solubility restricts its formulation and potential biomedical applications. To address this limitation, we designed a hydrophilic OA derivative, 1a, by introducing an amino acid fragment at the C-28 position. We established a reverse-phase high-performance liquid chromatography (HPLC)-based method to measure the octanol–water partition coefficient (Log P_ow) of OA and 1a. Under neutral conditions, 1a showed a markedly reduced Log P_ow value (2.91 ± 0.02) compared with OA (4.30 ± 0.01), confirming substantially improved hydrophilicity. The biological compatibility of OA and 1a was further evaluated using in vitro human islet cultures. Both compounds maintained high islet viability (approximately 90%). In addition, islets pre-treated with 1a exhibited viability, purity, and insulin expression levels comparable to those observed with OA treatment, indicating that the C-28 modification preserved OA’s biological properties while improving solubility. Overall, this proof-of-concept study demonstrates that C-28 amino-functionalization can improve the physicochemical properties of OA without compromising its compatibility with human islets. The HPLC-based Log P_ow method established here provides a practical analytical tool for future structure–activity investigations of OA derivatives, and the improved solubility of 1a may facilitate its use in human islet preparation workflows. Full article

Pharmaceutically active compounds (PhACs), pesticides, and poly- and perfluoroalkyl substances (PFAS) are increasingly detected in surface waters at trace concentrations, raising concerns for both aquatic systems and, consequently, human health. Conventional solutions are insufficient to achieve complete removal at trace compound concentrations, highlighting the need for advanced separation technologies. This study aims to comprehensively analyze rejection and removal mechanisms of selected PhACs, pesticides, and PFAS present in water solutions at reported environmentally relevant concentrations (300 ng L⁻¹), using two nanofiltration (NF) and one reverse osmosis (RO) polyamide membrane. PhACs, pesticides, and PFAS were selected to cover a broad range of physicochemical properties, specifically molecular mass (MM), dissociation constant (pKa), and octanol–water partition coefficient (logK_o/w). Rejection values ranged from 42.1% (acetaminophen) to apparent 100% (for multiple compounds), depending on water pH, solute properties, and membrane characteristics. Size exclusion and electrostatic interactions were identified as the primary removal mechanisms, with hydrophobic interactions having a lower impact, particularly for carbamazepine, bezafibrate, and perfluorooctane sulfonic acid (PFOS). Addition of sodium chloride (3 g L⁻¹) decreased rejection of most negatively charged compounds due to suppression of membrane surface charge, although clarithromycin and ofloxacin exhibited improved rejection. Presented results provide fundamental insight into compound-specific membrane rejection and highlight the importance of membrane–solute interactions under environmentally realistic conditions. The results support further optimization of NF and RO for targeted compound rejection and provide a baseline for data-driven membrane process modeling. Full article

This study developed a QSPR model to predict the n-octanol/water partition coefficient (log Kow) of 56 pesticides. Molecular descriptors were calculated using Dragon software. A genetic algorithm and variable subset selection identified key descriptors. The model, built by multiple linear regression, showed strong performance (R² = 0.9322, Q²_LOO = 0.9089, Q²_ext = 0.9277). The dataset was split using the Kennard-Stone algorithm to ensure representative sampling. Internal and external validations confirmed robustness and predictive power. This model offers a reliable tool for estimating log Kow, supporting environmental risk assessment and the evaluation of pesticide behavior and toxicity. Full article

Background: We studied in silico models of both organic and inorganic substances. In most cases, these in silico models are used for organic substances only. The following endpoints were taken for the case studies: the octanol–water coefficient (three models), the enthalpies of formation of organometallic compounds, and rat acute toxicity. Methods: The correlation weights were optimized using the Monte Carlo method with two special training and validation sets. The training set was structured into three subsets of active and passive training, as well as a calibration set. The division into these four subsets was carried out using the Las Vegas algorithm. It is assumed that considering groups of different splits into these four subsets is more informative than considering only a single split. Results: Models were built for the octanol–water coefficient for a set containing organic and inorganic substances or for a subset of the original data; other models were developed for a set containing only specially defined inorganic substances for platinum complexes. In addition, models of the enthalpy of formation and for toxicity in rats were built using the same approach for two sets of inorganic substances. Conclusions: A comparison of different methods for the optimization of correlation weights using the Monte Carlo method showed that optimization can be improved using the coefficient of conformism of a correlative prediction (CCCP) or the index of the ideality of correlation (IIC). Optimization with CCCP was the best option for the models of the octanol–water partition coefficient for the set of organic compounds, the octanol–water partition coefficient of the inorganic set, and the enthalpy of formation of the inorganic compounds. However, optimization with IIC was the best option in terms of the toxicity of the inorganic compounds in rats. Full article

The widespread availability and pseudo-persistence of typical psychiatric pharmaceuticals (PDs) can have serious impacts on aquatic ecosystems and even human health. However, the toxicokinetics of typical PDs and the corresponding enzymatic biomarker responses are unclear. In this study, eight typical PDs [carbamazepine (CBZ), citalopram (CIT), sertraline (SER), venlafaxine (VLF), amitriptyline (AMT), chlorpromazine (CPM), quetiapine (QTP) and clozapine (CLZ)] were selected to study the uptake, depuration and biological effects of PDs in Daphnia magna. The results found that the uptake rates (K_u) were in the sequence of VLF < QTP < CBZ < CLZ < CIT < AMT < SER < CPM, while the depuration rates (K_d) were in the order of CLZ < AMT < CIT < SER < QTP < CBZ < CPM < VLF. Correspondingly, the bioconcentration factors (BCFs) followed on as VLF < QTP < CBZ < CIT < AMT < CLZ < SER < CPM. Both pH-dependent octanol–water partition coefficients (log D_ow) and liposome–water partition coefficients (log D_lip-w) exhibited positive correlations with the log BCF of PDs (p < 0.05), indicating the important roles of ionization degree and biological phospholipid contents on bioconcentration. Superoxide dismutase (SOD) activities were evidently induced in the SER and CPM groups, while ethoxyresorufin-O-deethylase (EROD) and glutathione-S-transferase (GST) activities were significantly induced only in the CBZ group. Acetylcholinesterase (AChE) activity was obviously induced by CBZ, SER and AMT, with levels 1.73, 1.62 and 2.44 times that of the control group (p < 0.05). The K_u of PDs, oxidative stress and metabolic level of D. magna combine to affect BCF levels together. In conclusion, this study contributes to a better understanding of the toxicokinetics and biochemical responses of PDs in D. magna and potential mechanisms of action, which may allow for a better assessment of their environmental health risks to aquatic ecosystems. Full article

Marine macroalgae are excellent sources of bioactive compounds recognized by their pharmaceutical and biomedical potential. A subcritical water extraction (SWE) was applied to the macroalga Codium tomentosum, and the extract was used to prepare phytosomes. A Box–Behnken design was applied to optimize the entrapment efficiency. These phytosomes were further modified with DSPE-PEG (2000)-maleimide and apolipoprotein E and characterized by dynamic light scattering, UV spectrophotometry, octanol/water partition coefficient, differential scanning calorimetry, and Fourier transform infrared spectroscopy. As proof of concept, prototypes of functional food tailored to the elderly were produced. Yogurts were fortified with seaweed extract or phytosomes, and physicochemical properties and proximal composition (pH, acidity, syneresis, moisture, peroxides, proteins, total lipids, sugar content, ash, and mineral composition) were analyzed. The antioxidant and the inhibition capacity of two brain enzymes, cholinesterases (AChE and BuChE), involved in the pathogenesis of Alzheimer’s disease, were also evaluated in the final prototypes. Despite their unappealing sensory characteristics, the results are promising for integrating marine extracts with potential neuroprotective effects into functional foods. Full article

Fouling, particularly from organic fouling and biofouling, poses a significant challenge in the RO/NF treatment of marginal waters, especially wastewater. Part 1 of this review detailed LMWOC fouling mechanisms. Part 2 focuses on countermeasures and applications. Effective fouling prevention relies on pretreatment, early detection, cleaning, optimized operation, and in situ membrane modification. Accurate fouling prediction is crucial. Preliminary tests using flat-sheet membranes or small-diameter modules are recommended. Currently, no specific fouling index exists for LMWOC fouling. Hydrophobic membranes, such as polyamide, are proposed as alternatives to the standard silt density index (SDI) filter. Once LMWOC fouling potential is assessed, suitable pretreatment methods can be implemented. These include adsorbents, specialized water filters, oxidative decomposition, and antifoulants. In situations where pretreatment is impractical, alternative strategies like high pH operation might be considered. Membrane cleaning becomes necessary upon fouling; however, standard cleaning often fails to fully restore the original flow. Specialized CIP chemicals, including organic solvent-based and oxidative agents, are required. Conversely, LMWOC fouling typically leads to a stabilized flow rate reduction rather than a continuous decline. Aggressive cleaning may be avoided if the resulting operating pressure increase is acceptable. When a significant flow rate drop occurs and LMWOC fouling is suspected, analysis of the fouled membrane is necessary for identification. Standard FT-IR often fails to detect LMWOCs. Solvent extraction followed by GC-MS is required. Pyrolysis GC-MS, which eliminates the extraction step, shows promise. The review concludes by examining how LMWOCs can be strategically utilized to enhance membrane rejection and restore deteriorated membranes. Full article

Background: A total of 348 pesticides from different chemical families (carbamates, organochlorines organophosphorus compounds, pyrethroids, triazines and miscellaneous) were investigated in the context of their cornea permeability and potential to cause eye corrosion. Methods: Multivariate models of cornea permeability based on compounds whose cornea permeability has been determined experimentally were proposed. The models, applicable to compounds across a relatively broad lipophilicity range (e.g., pesticides with octanol–water partition coefficient log P up to ca. 8), assume a reverse-parabolic relationship between cornea permeability and lipophilicity, expressed as XLOGP3; other main descriptors present in the models are log D at pH 7.4 and polar surface area (PSA). Results: It appears that the trans-corneal transport of all studied pesticides is possible to some degree; however, it is more difficult for the majority of highly lipophilic pesticides from the organochlorine and pyrethroid families. The same set of 348 pesticides was also evaluated for their eye-corrosive potential using novel artificial neural network models involving simple physico-chemical properties of the compounds (lipophilicity, aqueous solubility, polar surface area, H-bond donor and acceptor count and the count of atoms such as N, NH, O, P, S and halogens). Conclusions: It was concluded that eye corrosion is an issue, especially among the pesticides from organochlorine and organophosphorus families. Full article

Microplastics can transfer antibiotics in water through adsorption and desorption, causing adverse effects on the water environment. Therefore, understanding the interaction between microplastics and antibiotics is important in order to assess their impact on the environment. In this study, the adsorption–desorption behaviors of two commonly used antibiotics [enrofloxacin (ENR) and trimethoprim (TMP)] in aquaculture and their interactions with three typical microplastics [polystyrene (PS), polyvinyl chloride (PVC), and polyethylene (PE)] were investigated through laboratory experiments. The results showed that the adsorption capacity of the three microplastics was 1.229–1.698 mg/g for ENR and 1.110–1.306 mg/g for TMP, correlating with the octanol–water partition coefficients ($\log {\mathrm{K}}_{ow}$) of antibiotics. Due to the larger specific surface areas and special functional groups of microplastics, the antibiotic adsorption capacity of PS and PVC was higher than that of PE. The adsorption behavior followed pseudo-second-order kinetics and a Freundlich isotherm model, indicating a non-uniform surface with multilayer adsorption. A thermodynamic analysis showed that these were all spontaneous endothermic adsorptions. X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) analyses indicated that the adsorption mechanism was dominated by physical adsorption, involving π–π conjugation, halogen bonds, hydrogen bonding, and electrostatic interactions. High salinity and alkaline environments were conducive to desorption, and the ENR and TMP desorption rates of the microplastics ranged from 20.65% to 24.95%. This indicates that microplastics adsorbed with antibiotics will desorb antibiotics when entering the seawater system, thereby affecting marine ecosystems. These findings reveal the interaction mechanism between microplastics and aquaculture antibiotics in aqueous systems, providing theoretical support for environmental protection and sustainable development. Full article