Physicochemical Aspects Research Articles

Understanding of Polydopamine Formulation for Oral Therapeutic Delivery in Ulcerative Colitis Treatment

AbstractOral therapeutic delivery remains challenged by gastrointestinal tract (GI) barriers, which hinders the successful transition of therapeutic candidates into clinical treatments. Polydopamine (PDA), with its versatile ability to overcome GI barriers, offers a promising drug formulation technology to address the challenge. Nevertheless, many critical questions remain unanswered regarding the practicality of PDA‐based formulations. Building on the previous research, which tackled multiple physicochemical aspects, the current study aims to address another three outstanding issues, including the quantification of residual dopamine (DA) in PDA‐based formulations, the examination of these formulations stimulatory effects on colon tissue, and the potential anti‐inflammatory properties. To facilitate this investigation, a curcumin‐containing nanomedicine (CP@CCS) is prepared as a representative PDA‐based formulation. The results reveal a marked decrease of residual DA within the formulation. In the treatment of ulcerative colitis (UC), the formulation do not provoke the substantial contractions in colon tissue typically induced by DA. Furthermore, in vivo evaluation verified the supplementary anti‐UC benefits of PDA. These outcomes add evidence for the practicality of PDA‐based formulations in terms of safety and therapeutic efficacy. Finally, a conceptual framework is proposed for understanding the role of PDA in oral therapeutic delivery, thereby providing insightful directions for subsequent research.

Preparation of Bi2CrO6/CuO heterostructure nanocomposite to increase methylene blue decomposition under visible light irradiation

In this study, the Bi2CrO6/CuO nanocomposite was used for the photocatalytic degradation of methylene blue (MB) under visible light. Nanocomposites with different ratios (1:1, 1:2, 2:1) were synthesized under hydrothermal conditions and investigated for MB removal. Various characterization techniques, including XRD, FT-IR, FE-SEM, BET, DRS, PL, and EDS, were employed to elucidate the physicochemical aspects of the catalysts. The 2:1 nanocomposite ratio was selected as the photocatalyst with the highest removal efficiency (85 %). Four main factors, including initial concentration, solution pH, catalyst dose, and light intensity, were studied using the response surface methodology (RSM) and the Box-Behnken model. Under optimal conditions, the MB removal efficiency reached 90.06 %. Additionally, the effect of oxidizing agents (H2O2) on the enhanced removal of MB was investigated. The improved photocatalytic performance of the Bi2CrO6/CuO (2:1) nanocomposite is attributed to visible light absorption, the formation of a p-n heterostructure, efficient charge separation via the S-scheme mechanism, and increased charge carrier lifetime. Moreover, economic calculations showed that the estimated costs for the photocatalytic removal of MB from wastewater are cost-effective.

Characterization of 'borde': A traditional ethiopian cereal-based fermented beverage - Microbial analysis, rheological profiling, and functional attributes

The study focused on the characterization of an Ethiopian traditional beverage, borde, produced by lactic acid bacteria (LAB) and yeast through natural fermentation. Samples were collected from three distinct locations in Ethiopia and subjected to analyses encompassing microbiological, antioxidant, enzyme inhibition, rheological and physicochemical aspects. The early stages of fermentation exhibited prevalence of Enterobacteriaceae and aerobic mesophilic bacteria. Towards the end of fermentation, yeast (6.07–6.72) and LAB (6.52–7.12) (log CFU mL−1) dominated the microbiological profile of all borde samples. Significant difference (P < 0.05) in the number of microorganisms were noted between the samples. Antioxidant activities, assessed through DPPH and ABTS values, ranged between 51.5 and 64.6 % and 47.4–62.9.1 %, respectively. The average value of α-glucosidase and pancreatic lipase inhibition for borde samples were ranged from 36.56 to 43.23 % and 31.08–40.19 %, respectively. Rheological investigations indicated pseudoplastic fluid behavior, as evidenced by the decreasing apparent viscosity values with shear rate. Moreover, the samples displayed solid-like structures, with lower loss modulus (G″) values compared to storage modulus (G′). The shared physicochemical characteristics and the dominance of specific microbial groups suggest the potential for developing a direct fermentation system for this traditional cereal-based beverage. Overall, these findings contribute valuable insights into the multifaceted nature of borde, paving the way for further advancements in its production and quality control.

Recent Advances in Cyclodextrin-Based Nanoscale Drug Delivery Systems.

Cyclodextrins (CDs) belong to a class of cyclic oligosaccharides characterized by their toroidal shape consisting of glucose units linked via α-1,4-glycosidic bonds. This distinctive toroidal shape exhibits a dual nature, comprising a hydrophobic interior and a hydrophilic exterior, making CDs highly versatile in various pharmaceutical products. They serve multiple roles: they act as solubilizers, stabilizers, controlled release promoters, enhancers of drug bioavailability, and effective means of masking undesirable tastes and odors. Taking advantage of these inherent benefits, CDs have been integrated into numerous nanoscale drug delivery systems. The resulting nanomaterials exploit the exceptional properties of CDs, including their ability to solubilize hydrophobic drugs for substantial drug loading, engage in supramolecular complexation for engineered nanomaterials, increase bioavailability for improved therapeutic efficacy, stabilize labile drugs, and exhibit biocompatibility and versatility. This paper compiles recent studies on CD functional nanoscale drug delivery platforms. First, we described the physicochemical and toxicological aspects of CDs, CD/drug inclusion complexation, and their impact on improving drug bioavailability. We then summarized applications for CD-functional nano delivery systems based on polymeric, hybrid, lipid-based nanoparticles, and CD-based nanofibers. Particular interest was in the targeted applications and the function of the CD molecules used. In most applications, CD molecules were used for drug solubilization and loading, while in some studies, CD molecules were employed for supramolecular complexation to construct nanoscale drug delivery systems. Finally, the review concludes with a thoughtful consideration of the current challenges and outlook.

Numerical and experimental study on corrosion mechanism of the water-oil two-phase flow in the atmospheric tower top system

The atmospheric tower is the main component of the crude oil refining units and is a critical area of concern due to the risk of corrosion failure. Research on the corrosion mechanism and risk protection of atmospheric tower top systems plays a vital role in the safe operation of refineries. In this paper, the water-oil two phase process flow of the atmospheric tower top system was simulated by Aspen software. A corresponding flow corrosion simulation experiment was designed according to the main characteristic parameters of the simulated stream. The experimental results under varying temperature and impact angle conditions were analyzed by using microanalysis technology and CFD simulation methods. The process and mechanism of corrosion failure of tower top system under ammonia salt and dew point corrosion environment are revealed in physicochemical aspects. The results show that the corrosion rate was highest at the dew point temperature, but as the temperature decreases, the corrosion products adsorbed and accumulated on the surface are more difficult to remove from the surface, which slows down the corrosion rate. When the impact angle increased from 0° to 60°, the increment of the surface fluid impact force and turbulence intensity makes the corrosion products easier to be stripped off, which enhances the mass transfer efficiency between the corrosive medium and the surface to accelerate the corrosion rate. Different phase states and flow modes affected the morphology of corrosion pits on the surface. The depth and size of the pits in only water phase corrosion were larger than those in the two-phase flow corrosion, Additionally, as the impact angle increased from 0°, the morphology of pits changes from a relatively flat pattern to a more undulating shape. The research results reveal the characteristics of the main corrosion types occurring in the atmospheric tower top system of the oil refining industry, and provide a reference for corrosion risk protection methods.

A critical review on approaches to generate and validate virtual population for physiologically based pharmacokinetic models: Methodologies, case studies and way forward.

In silico modeling and simulation techniques such as physiologically based pharmacokinetic (PBPK) and physiologically based biopharmaceutics modeling (PBBM) have demonstrated various applications in drug discovery and development. Virtual bioequivalence leverages these computation tools to predict bioequivalence between reference and test formulations thereby demonstrating possibilities to reduce human studies. A pre-requisite for virtual bioequivalence is development of validated virtual population that depicts the same variability as that of observed in clinic. This development, validation and optimization of virtual population is a key attribute of virtual bioequivalence based on which conclusion of bioequivalence is made. Various strategies for optimization of virtual population based on appropriate considerations of physicochemical, physiological and disposition aspects are demonstrated with the help of six diverse case studies of immediate and modified release formulations. Once the virtual population is optimized to match in vivo variability, it can be used for various applications such as biowaivers, dissolution specification justification, f2 mismatch, establishing dissolution safe space, etc. In this review article, we attempted to describe various methodologies and approaches for optimization of virtual population using Gastroplus. Strategies based on optimization of virtual population with emphasis on specific and sensitive parameters were portrayed. We have further elucidated considerations related to study design, in vivo variability, sample size for optimization of virtual population from Gastroplus perspective. We believe that this review article provides a step-by-step process for virtual population optimization for interest of biopharmaceutics modeling scientists in order to ensure reliable and credible physiological models.

Preliminary Study on The Characteristics of Effluent From A Cachoeiro de Itapemirim – ES and Analysis of Possible Biotechnological Treatments

Purpose: The objective of this research was to organize and evaluate physical-chemical parameters of the industrial dairy effluent and to propose viable alternative treatments using biotechnological methods, aiming not only to prepare the effluent for disposal but also to generate value-added products Theoretical framework: With the growth of the population, the food industry sector expands exponentially. Brazil ranks among the top five milk producers globally, with the dairy industry being a significant producer of effluent, generating between 1.1 m³ and 6.8 m³ of effluent per cubic meter of processed milk. Dairy wastewater carries a high pollutant load and requires treatment prior to discharge into water bodies. There is an increasing demand for converting waste into raw materials, prompting research into biotechnological treatments that not only prepare effluent for disposal but also yield products from such waste. Method/design/approach: The data on wastewater characteristics were provided by the dairy itself, and the physicochemical aspects of the effluents over 19 months were interpreted, establishing relationships among key parameters, as well as the ratios BOD/COD, BOD: N and COD: N. The survey of biotechnological treatments was conducted through bibliographic research on Google Scholar, Scielo, Web of Science, and Scopus databases. Results and conclusion: Through the analysis and correlations of the physicochemical characteristics of effluents from the Cachoeiro dairy, it is evident that this type of effluent is rich in low biodegradability organic matter, as the BOD5/COD ratio was less than 0.15 in over 79% of the samples, indicating that physical-chemical treatment is the most appropriate approach for this effluent. The linear correlation coefficient between BOD5 and COD was 0.6, suggesting a weak correlation that does not allow one parameter to be accurately predicted from the other. According to the literature, it is possible to derive biofuels, bioplastics, single cell protein, organic acids, polysaccharides, biosurfactants, and other products from dairy effluent, while also meeting environmental requirements Research implications: Evaluation of optimal treatments based on effluent characteristics and suggestion of alternative treatments aiming to utilize wastewater as a raw material for obtaining secondary products complementary to the industry's focus, in addition to compliance with current disposal regulations. Originality/value: Development of relationships to assist in evaluating effluent treatments and identification of treatments that can reuse this substantial volume of generated waste.

Repurposing doxycycline for Alzheimer's treatment: Challenges from a nano-based drug delivery perspective

Drug repurposing, also known as drug repositioning, involves identifying new applications for drugs whose effects in a disease are already established. Doxycycline, a broad-spectrum antibiotic belonging to the tetracycline class, has demonstrated potential activity against neurodegenerative diseases like Alzheimer's and Parkinson's. However, despite its promise, the repurposed use of doxycycline encounters challenges in reaching the brain in adequate concentrations to exert its effects. To address this issue, nanostructured systems offer an innovative approach that can enhance brain targeting and the desired therapeutic outcomes. This review discusses the advances in doxycycline repurposing for Alzheimer's disease, presenting physicochemical and biological aspects that permeate doxycycline's repositioning and its application in nano-based delivery systems.

MgFeO3 perovskite nanostructures: A New Frontier in photoelectrochemical water splitting

The process of transforming solar power into hydrogen fuel through photoelectrochemical water splitting is a highly viable strategy for producing hydrogen in an environmentally friendly and sustainable manner, offering a long-term solution to the worldwide energy crisis. Therefore, the need for high-performance photoelectrodes is critical for optimizing the transformation of solar energy into hydrogen fuel. Herein, a simple citrate sol-gel technique was employed to fabricate magnesium iron oxide (MgFeO3) for its potential use in photoelectrochemical water splitting. A detailed analysis was undertaken using techniques such as XRD, FESEM, XPS, PL, EDX, and UV–Vis spectrophotometry to uncover the fundamental physicochemical and optoelectronic aspects of the MgFeO3 perovskite material. The MgFeO3 photoelectrode manifests superior PEC characteristics as evidenced by the optimal photocurrent density of 4.5 mA cm−2 achieved at a potential of 1.2 V vs. RHE, and a commendable solar-to-hydrogen conversion efficiency of 0.97%. EIS studies provided evidence of improved charge transfer kinetics and decreased recombination rates in the MgFeO3 photoelectrode. In addition, extended reliability evaluations utilizing chronoamperometry verified consistent operation for 10 h at a photocurrent density of 3.5 mA cm−2, demonstrating the long-term durability of MgFeO3 in PEC water splitting. These results emphasize the considerable promise of MgFeO3 perovskite as a proficient and robust photoelectrode substance for PEC water-splitting applications.

Effects of synergistic application of Viscozyme L–wet ball milling on structural, physicochemical and functional properties of insoluble dietary fiber from ginseng residue

Synergistic effect of Viscozyme L with wet ball milling treatment on structural, physicochemical and functional aspects of insoluble dietary fiber (IDF) from ginseng residue were examined. SEM examination showed that IDF extracted by Viscozyme L in conjunction with wet ball milling (WBE-IDF) exhibited loose microstructural arrangement, and particle size of WBE-IDF was much smaller than that of IDF extracted by Viscozyme L (E-IDF) and along IDF (untreated). The FTIR spectra demonstrated the variations in the peak intensities in three modified ginseng IDFs. Besides, the highest thermal stability and viscosity was displayed by WBE-IDF among examined samples. In addition, WBE-IDF has higher water and oil holding, water swelling, nitrite ion absorption, bile acid absorption, and glucose absorption capacities as compared to that of E-IDF and IDF. Overall results revealed that the Viscozyme L combined with wet ball milling extraction may change ginseng IDF structure, and improve its physicochemical and functional qualities, thereby providing a theoretical basis for food industry to produce good ginseng IDF.

Effects of different types of starches on heat penetration and physicochemical characteristics in alfredo sauce

Corn starch is frequently used as a thickening agent in food products because of its stability under thermal processing conditions. However, with fluctuating raw material costs due to weather conditions, disruptions in supply chains, and geopolitical challenges, there is an increasing need to explore alternative sources of starch. This study examines the effect of retort processing on the heat penetration and physicochemical aspects of modified corn, tapioca, and potato starches in Alfredo sauce. Modified corn starch, commonly used in commercial sauces, was compared with tapioca and potato starches to evaluate their effects on viscosity, color, and processing times required to achieve a F0 = 6 for Clostridium botulinum. Using the reference starch concentration of 1.90%, modified corn starch showed a significant increase in viscosity from 3,328 cP to 13,296 cP with a processing time of 31.33 min. Modified tapioca starch, at the same concentration, increased from 3440 cP to 8176 cP over 38.38 min, indicating superior thermal stability being the longest cooking time evaluated between all samples. For modified potato starch, using the reference concentration, viscosity increased from 1,200 cP to 4,656 cP, with a processing time of 31.93 min. Adjusting the starch concentration to 3% for modified tapioca starch and 2.38% for modified potato starch increased viscosity to 14,400 cP and 16,336 cP, respectively. These adjustments resulted in a darker Alfredo sauce, with the L value decreasing from 92.27 to 83.67 due to the longer cooking time. Heat penetration findings suggest that modified potato starch can replace modified corn starch safely using the reference concentration (1.90%) without altering the process holding time but requiring further adjustments to match commercial viscosity standards, while modified tapioca starch, although requiring higher concentrations and longer processing times, was tested for retention time at 3.00% and to be a feasible alternative. This study offers valuable insights to the food industry in selecting appropriate starches to maintain the quality and safety of thermally processed Alfredo sauce.

Study of Seasonal Variations in the Physical-chemical Features of the Cauvery Estuary, Southeast Coast of India

Water is a vital element of the environment, supporting life on Earth and being necessary for all living creatures to live. Between rivers and the ocean, estuaries are places with distinctive ecological traits, an abundance of flora and fauna, and a crucial role in hydrological processes and biodiversity. The biological and physico-chemical aspects of aquatic habitats are intertwined. Investigating seasonal fluctuations in the physico-chemical characterisation of the east coast Cauvery estuary in Tamil Nadu is the goal of the current study. The Cauvery Estuary’s physical and chemical properties are known and have an effect on the estuary. Seasonal fluctuations in the climatic and physico-chemical parameters pH, DO, ammonium, nitrate, BOD, sodium, chloride, sulfate, and fluoride content were noted in the waters of the Cauvery estuary. In the future, research on the ecology, biodiversity, and cultural aspects of the estuary species, as well as the determination of the permissible limit for fisheries and aquatic life, may benefit greatly from the initial data on the physical and chemical properties of the Cauvery estuary. In order to protect the Cauvery Estuary, conservation initiatives are started in collaboration with local non-governmental organizations after a thorough understanding of the various factors influencing these ecosystems is obtained.

Novel poly(2-ethyl-2-oxazoline) and poly(diallyldimethylammonium chloride) polymer functionalized montmorillonite: Physicochemical aspects and near-IR study of hydration properties

The novel functionalized montmorillonites (Mts) with non-ionic poly(2-ethyl-2-oxazoline) (PEtOx) and cationic poly(diallyldimethylammonium) (PDDA) were created via an intercalation method with different loading ratio of both polymers. A comprehensive investigation into their physicochemical properties was conducted using Carbon analysis (CA), Powder X-ray diffraction (PXRD), Fourier-transform infrared spectroscopy (FTIR), Simultaneous thermal analysis (TGA/DSC) and BET-N2 adsorption analysis. The impact of hydration on PEtOx-Mts and PDDA-Mts was assessed through gravimetric analysis and near-infrared spectroscopy (NIR) spectroscopy. PXRD analysis revealed a significant increase in 001 diffraction of PDDA-Mt corresponding to a PDDA interlayer with a basal spacing ranging from 1.47 to 1.49 nm. Conversely, the basal spacing exceeding 2 nm for PEtOx suggested, that the PEtOx polymer was intercalated in a larger amount and packed in a less compact manner compared to PDDA. After modification of Na-Mt with PEtOx polymer, FTIR spectroscopy confirmed the presence of the carbonyl CO group (3265 and 1641 cm-1) and the stretching (2982, 2942 and 2883 cm-1) and bending (1480–1200 cm-1) vibrations of the CH2 and CH3 groups. The vibrations of CH groups were further verified following PDDA modification. NIR spectroscopy also confirmed the vibrational bands attributed to both modifiers after intercalation of PEtOx and PDDA. The results of BET-N2 adsorption revealed a significant decrease in the specific surface area (SSA) after intercalation with a non-ionic PEtOx polymer. On the contrary, in the case of saturation of Na-Mt with polycation PDDA, SSA increased slightly in two instances. TGA analysis confirmed greater weight loss for PEtOx-Mts compared to PDDA-Mts. Derivative thermogravimetry (DTG) revealed the release of physisorbed bound water around 100 °C, decomposition of the organic phase within the 250–550 °C range and dehydroxylation of OH groups around 550–800 °C in both cases. The results obtained from the gravimetry and NIR analysis indicated a greater hydrophobic nature for PEtOx-Mts compared to PDDA-Mts. These findings hold substantial potential for enhancing the properties of novel organo-montmorillonites, thereby facilitating their application as adsorbents for pollutants, surface coatings, biodegradable materials, fillers in polymer nanocomposites, drug carriers, anticancer agents and various other significant applications.

The effect of organic fruit juices on physicochemical, microbiological and antioxidative aspects of organic goat's and cow's fermented whey beverages produced on laboratory and industrial scale

Fermented milk beverages have been known for years and are characterized by excellent health-promoting properties. Therefore, consumer attention has been drawn to this product type in recent years. In the presented research, the technology of production in laboratory and industrial scale of controlled fermentation of whey beverages containing sweet and sour organic cow's or goat's whey with the addition of organic fruit juices (apple, blackcurrant juice or Kamchatka berry), has been described. Food production on a laboratory scale involves small batch processes designed for experimentation and refinement, often with precise control over variables and conditions. In contrast, industrial-scale food production in enterprises focuses on large volume output with an emphasis on efficiency, consistency, and adherence to regulatory standards for mass consumption. In this study was examined the amino acid content and nutritional value of the obtained products. Tests were carried out on fermented whey drinks' microbiology and antioxidant properties. The significance was determined using an ANOVA (ANOVA)-each prepared drink was characterized by better antioxidant properties and nutritional values compared with product without juice addition. Microbiological examination proved that only one product was not fit for consumption according to the Polish norm. Using whey (goat and cow) as a base for a fermented beverage with enhanced health benefits is a positive step toward using products commonly regarded as waste.

New Insights Into Application Relevant Properties of Cu2+-Doped Brushite Cements.

Doping of brushite cements with metal ions can entail many positive effects on biological and physicochemical properties. Cu2+ ions are known to exhibit antibacterial properties and can additionally have different positive effects on cells as trace elements, whereas high Cu2+ concentrations are cytotoxic. For therapeutical applications of bone cement, a combination of good biocompatibility and sufficient mechanical properties is required. Therefore, the aim of this study was to investigate different physicochemical and biological aspects, relevant for application, of a brushite cement with Cu2+-doped β-tricalcium phosphate, monocalcium phosphate monohydrate and phytic acid as setting retarder. Additionally, the ion release was compared with a cement with citric acid as setting retarder. The investigated cements showed good injectability coefficients, as well as compressive strength values sufficient for application. Furthermore, no antibacterial effects were detected irrespective of the Cu2+ concentration or the bacterial strain. The cell experiments with eluate samples showed that the viability of MC3T3-E1 cells tended to decrease with increasing Cu2+ concentration in the cement. It is suggested that these biological responses are caused by the difference in the Cu2+ release from the hardened cement depending on the solvent medium. Furthermore, the cements showed a steady release of Cu2+ ions to a lesser extent in comparison with a cement with citric acid as setting retarder, where a burst release of Cu2+ was observed. In conclusion, despite the anticipated antibacterial effect of Cu2+-doped cements was lacking and mammalian cell viability was slightly affected, Cu2+-concentrations maintained the physicochemical properties as well as the compressive strength of cements and the slow ion release from cements produced with phytic acid is considered advantageous compared to citric acid-based formulations.

Synthesis, characterization, and physico-chemical aspects of a new PVC-based quaternary triethanol ammonium chloride anionite for tungsten recovery.

The usability of polyvinyl chloride-based quaternary triethanol ammonium chloride anionite (PVC-TEAC) as a potential extractant for tungstate was investigated to recover tungstate from Gabal Qash Amir, Egypt, assaying 70.91% WO3. Structure elucidation for PVC-TEAC anionite was successfully carried out using several techniques. Experimental measurements, such as pH, agitation time, initial tungsten concentration, anionite dose, co-ions, temperature, and eluting agents, have been optimized. It was found that PVC-TEAC anionite has a maximum capacity of 63 mg per gram. From the distribution isotherm modeling, Langmuir's model fits the experimental results better than Freundlich's, with a theoretical value of 61.728 mg g-1. According to kinetic modeling, the first- and second-order modeling may be regarded as a mixed modeling for a successful adsorption system. Thermodynamic prospects reveal that the adsorption process was predicted as an exothermic, spontaneous, and preferable adsorption at low temperatures. Tungsten ions can be eluted from the loaded anionite, by 1M H2SO4 with a 97% efficiency rate. It was found that PVC-TEAC anionite reveals good separation factor (S.F.) towards most of co-ions. A successful Alkali fusion with NaOH flux followed by tungstate recovery by PVC-TEAC anionite is used to obtain a high-purity tungsten oxide concentrate (WO3), with a tungsten content of 78.3% and a purity of 98.75%.

Synthesis and Cytotoxic Activity of Friedelinyl Esters.

Commonly isolated from plants of Celastraceae family, pentacyclic triterpenoids have a broad spectrum of biological activities, such as antitumor, anti-inflammatory, antinociceptive properties, among others. Structural modifications in these triterpenoids can enhance their biological activity, as well as their selectivity, while improving their physicochemical and pharmacokinetic aspects. In this study, eight novel esters were synthesized: four derivatives of 3α-friedelinol (friedelan-3α-yl p-bromobenzoate (1a); friedelan-3α-yl naproxenate (1b); friedelan-3α-yl pent-4-ynoate (1c); friedelan-3α-yl undec-10-ynoate (1d)) and four derivatives of 3β-friedelinol (friedelan-3β-yl p-bromobenzoate (2a); friedelan-3β-yl naproxenate (2b); friedelan-3β-yl pent-4-ynoate (2c); friedelan-3β-yl undec-10-ynoate (2d)). Overall, 3α-friedelinol showed greater reactivity when compared to the β-epimer. The esters 1b-d and 2b-c were tested for antileukemic activity against THP-1 and K-562 cells but showed low cytotoxicity for both cell lines. The most active against THP-1 cells was friedelan-3β-yl naproxenate (2b, IC50=266±6 μM), and the most active against K-562 cells was friedelan-3α-yl pent-4-ynoate (1c, IC50=267±5 μM).

In silico studies on leishmanicide activity of limonoids and fatty acids from Carapa guianensis Aubl.

The oil of Carapa guianensis showed leishmanicidal activity, with its activity being related to limonoids, but fatty acids are the major constituents of this oil. The present study evaluated the physicochemical, pharmacokinetic, and toxicity profiles of limonoids and fatty acids already identified in the species. Based on these results, 2 limonoids (methyl angosinlate, 6-OH-methyl angosinlate) and 2 fatty acids (arachidic acid; myristic acid) were selected for the prediction of possible targets and molecular docking. Included in this study were: Gedunin, 6α-acetoxygedunin, Methyl angosenlato, 7-deacetoxy-7-oxogedunin, Andirobin, 6-hydroxy-angolensate methyl, 17β-hydroxyazadiradione, 1,2-dihydro-3β-hydroxy-7-deacetoxy-7-oxogedunin, xyllocensin k, 11beta-Hydroxygedunin, 6α,11-11β-diacetoxygedunin, Oleic Acid, Palmitic Acid, Stearic Acid, Arachidic Acid, Myristic Acid, Palmitoleic Acid, Linoleic Acid, Linolenic Acid, and Beenic Acid. Regarding physicochemical aspects, fatty acids violated LogP, and only limonoid 11 violated Lipinski's rule. A common pharmacokinetic aspect was that all molecules were well absorbed in the intestine and inhibited CYP. All compounds showed toxicity in some model, with fatty acids being mutagenic and carcinogenic, and limonoids not being mutagenic and carcinogenic at least for rats. In in vivo models, fatty acids were less toxic. Molecular dockings were performed on COX-2 steroids (15 and 16) and hypoxia-inducible factor 1 alpha for limonoids (3,6), with this target being essential for the intracellular development of leishmania. Limonoids 3 and 6 appear to be promising as leishmanicidal agents, and fatty acids are promising as wound healers.

Searching for "Greener" Bioequivalents of CF3 to Lower its Environmental Impact.

Considering the broad use of the trifluoromethyl functional group (-CF3) in medicinal chemistry and taking into account the recent concerns on the negative environmental effects of CF3 containing compounds, we are searching for "greener" alternatives. Thus, different chemical groups (i. e. iodide, fluoride, cyclopropyl, isopropyl, cyclobutyl, 3-oxetyl, 2-oxetyl, methylsulfide, pentafluorosulfide, methylsulfonyl and sulfonamide) have been considered as potential bioequivalents of -CF3 aiming to use them in compounds with therapeutic interest instead of the polyfluoride functionality. Different structural (molecular surface and volume) and physicochemical (electronic and lipophilic) aspects of the bioequivalent functionalities proposed have been theoretically calculated and compared to those of -CF3. Additionally, the corresponding phenyl derivatives carrying these functionalities have been purchased or prepared and their experimental lipophilicity (i. e. LogP) measured using shake-flask experiments and UV-vis spectroscopy.

Physicochemical characteristics of solid-phase reduction of pellets (briquettes) under induction heating

A new method for organizing the solid-phase reduction of pellets (briquettes) using induction heating was proposed, and the physicochemical aspects of the heating and reduction processes were investigated. A thermodynamic analysis of the reactions during solid-phase reduction was carried out; the equilibrium composition of the gaseous phase in the Fe–O–C and Mn–O–C systems was determined, and the thermodynamically permissible temperature of iron oxide reduction initiation at different values of =РСО+РСО2 were established. The results of calculating the rate of heating of coal and ore concentrate by the metallic component of the pellets (briquette) were analyzed both under condition of the flow of chemical reactions and in the absence of chemical transformation. The experiments demonstrated the fundamental possibility of heating and reducing iron oxides inside the volume of the pellet, as well as conducting both solid-phase reduction and melting of the reduced iron to obtain liquid steel under induction furnace melting conditions.