Search

Emulsion products with natural antimicrobials are becoming increasingly popular for topical application. Mandelic Acid is interesting in cosmetics due to its potent exfoliating properties, which have driven advancements in skincare technologies. Essential oils have various properties, of which the most useful in cosmetics are those that do not cause irritation, smell pleasant, and have other beneficial properties such as antimicrobial effects. Emulsions with Mandelic Acid and essential oils from Satureja montana, Lemongrass, and Litsea cubeba were formulated and microbiologically tested for their preservative effectiveness. The effect of the treatments on skin condition was monitored by non-invasive diagnostic methods, such as hydration, transepidermal water loss, and pH value. Sensory analysis revealed that the matrix containing Mandelic Acid alone or combined with Litsea Cubeba Oil was the best-performing formulation, consistent with the compliant results of antimicrobial efficacy. The topical form of this cosmetic product has demonstrated excellent preservative activity and desirable biophysical efficacy on the skin. [ABSTRACT FROM AUTHOR]

In line with the comprehensive experimental teaching philosophy of “problem-oriented, interest-driven, and self-directed exploration”, the theory of “chemical transformation-driven impurity separation” has been integrated into organic chemistry laboratory teaching to design innovative comprehensive experiments. Through the utilization of chemical transformations, effective separation of the target molecule to be purified (α-fluorobenzoic acid, abbreviated as “fluorinated mandelic acid”) from impurities (mandelic acid) has been achieved, with product purities reaching 98.7% and 97.0%, respectively. The main chemicals and reagents used throughout the experiment are economically affordable, readily available, and recyclable, fully reflecting the principles of atom economy and green chemistry. Various essential organic chemistry experimental techniques, including vacuum distillation, concentration, recrystallization, and filtration, as well as important analytical methods such as thin-layer chromatography and nuclear magnetic resonance, were employed during the experimental process. Proficiency in these crucial experimental techniques and analytical methods enables the cultivation of students’ abilities to conduct experiments guided by fundamental theories, effectively separate organic compounds with small differences in properties, and analyze experimental phenomena. Furthermore, this enhances undergraduate students’ academic cultivation, scientific literacy, and ability to apply knowledge to solve practical problems. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to develop a novel exfoliating material with high efficacy and low irritation by synthesizing the Mandelic acid_Carnitine ion pairing complex (M_C complex) and evaluating its exfoliating properties. Additionally, the study assessed the skin improvement effects of the M_C complex through clinical evaluations. Methods: The M_C complex was synthesized in a 1:1 molar ratio of Mandelic acid and Carnitine. Structural characterization was performed using dynamic light scattering and Fourier‐transform infrared spectroscopy. Exfoliating efficacy was evaluated on porcine skin, and clinical assessments were conducted on human subjects to measure various skin improvement parameters. Results: The formation of the M_C complex was confirmed through particle size analysis, zeta‐potential measurements, and FT‐IR spectroscopy. The M_C complex demonstrated superior exfoliating efficacy compared to Mandelic acid alone, especially at pH 4.5. Clinical evaluations showed significant improvements in blackheads, whiteheads, pore volume, depth, density, count, and affected area, as well as skin texture. No adverse reactions were observed. Conclusion: The M_C complex exhibits high exfoliating efficacy and minimal irritation, making it a promising cosmetic ingredient for improving skin health. These findings support its potential as a low‐irritation exfoliating material under mildly acidic conditions, contributing to overall skin health enhancement. [ABSTRACT FROM AUTHOR]

Research on titanium-oxo complexes (TOCs) is usually focused on their structure and photocatalytic properties. Findings from these investigations further sparked our interest in exploring their potential biological activities. In this study, we focused on the synthesis and structure of a compound with the general formula [Ti8O2(OiPr)20(man)4] (1), which was isolated from the reaction mixture of titanium(IV) isopropoxide with mandelic acid (Hman) in a molar ratio of 4:1. The structure (1) was determined using single-crystal X-ray diffraction, while spectroscopic studies provided insights into its physicochemical properties. To assess the potential practical applications of (1), its microcrystals were incorporated into a polymethyl methacrylate (PMMA) matrix, yielding composite materials of the type PMMA + (1) (2 wt.%, 5 wt.%, 10 wt.%, and 20 wt.%). The next stage of our research involved the evaluation of the antimicrobial activity of the obtained materials. The investigations performed demonstrated the antimicrobial activity of pure (1) and its composites (PMMA + (1)) against both Gram-positive and Gram-negative strains. Furthermore, MTT tests conducted on the L929 murine fibroblast cell line confirmed the lack of cytotoxicity of these composites. Our study identified (1) as a promising antimicrobial agent, which is also may be use for producing composite coatings. [ABSTRACT FROM AUTHOR]

In the present study, flat cellulose acetate ultrafiltration membranes were prepared first by nonsolvent induced phase separation method. Then chiral membranes for separating the enantiomers were prepared by grafting the ultrafiltration membranes using ethylenediamine‐β‐cyclodextrin as the chiral selector and epichlorohydrin as the spacer arm. The pure water permeability of the ultrafiltration membrane was around 115 L·m−2·h−1·bar−1. The properties of the chiral membranes were characterized using infrared spectroscopy (ATR‐FTIR), X‐ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The chiral membrane performance in enantiomer separation was evaluated with racemates, such as mandelic acid (MA), 2‐chloromandelic acid (2‐ClMA), 4‐chloromandelic acid (4‐ClMA), and methyl mandelate (MM). The influence of feed concentration on the separation efficiency was also investigated. The results indicated that the enantiomeric excess percentages (e.e%) of the racemic mixtures for these four chiral compounds were up to 31.8%, 25.4%, 17.8%, and 32.6%, respectively. The binding free energy of the chiral selector with the (S)‐enantiomer calculated by molecular dynamics simulations was stronger than that with the (R)‐enantiomer, which was consistent with the experimental results (higher concentration of (R)‐enantiomer in the permeate). This supports the affinity absorption‐separation mechanism. [ABSTRACT FROM AUTHOR]

With mandelic acid (MA) as the chiral core, two series of non-symmetric liquid crystal (LC) dimers have been synthesised by changing the rigidity of the side-arms, namely the DBM-nC2B series and the DBBM-nC2B series. In the DBM-nC2B series, one side-arm is the same, while the length of the flexible tail of the other side-arm increases from 0 to 4. The same is true of the DBBM-nC2B series. Chemical structures and LC properties of the two series LC dimers were characterised by FT-IR, 1H NMR, 13C NMR, DSC, TGA and POM. The results show that the DBM-nC2B series LC dimers display the nematic phase (N), and the DBBM-nC2B series LC dimers exhibit the chiral nematic phase (N*). It shows that the side-arm should have sufficient rigidity for MA to induce the N* phase. In the same series, when the length of the flexible tails of the side-arm increases from 0 to 4, it does not change the mesophase, while it has some effect on the melting temperature (Tm), the clearing temperature (TN(*)I), and mesophase range of the dimers. The molecular length-width ratio (l/w) and dipole moment (μ) were used to explain the variation of Tm and (TN(*)I) of LC dimer. [ABSTRACT FROM AUTHOR]

Emulsion products with natural antimicrobials are becoming increasingly popular for topical application. Mandelic Acid is interesting in cosmetics due to its potent exfoliating properties, which have driven advancements in skincare technologies. Essential oils have various properties, of which the most useful in cosmetics are those that do not cause irritation, smell pleasant, and have other beneficial properties such as antimicrobial effects. Emulsions with Mandelic Acid and essential oils from Satureja montana, Lemongrass, and Litsea cubeba were formulated and microbiologically tested for their preservative effectiveness. The effect of the treatments on skin condition was monitored by non-invasive diagnostic methods, such as hydration, transepidermal water loss, and pH value. Sensory analysis revealed that the matrix containing Mandelic Acid alone or combined with Litsea Cubeba Oil was the best-performing formulation, consistent with the compliant results of antimicrobial efficacy. The topical form of this cosmetic product has demonstrated excellent preservative activity and desirable biophysical efficacy on the skin.

Chiral N‐substituted secondary 1,2‐aminoalcohols have been developed for the enantioseparation of ortho‐halomandelic acids (o‐X‐MAs) via diastereomeric salt formation. Two structural isomers, N‐methyl‐2‐amino‐1,2‐diphenylethanol and N‐benzyl‐2‐amino‐2‐phenylethanol, showed high separation abilities for o‐X‐MAs (X = Cl, Br, I). The chiral recognition mechanism was elucidated by crystallographic analysis of the less‐soluble salts. The substituents on the nitrogen atom of the resolving agents and the inclusion of the crystallization solvent stabilized the salt and enhanced their separation ability. [ABSTRACT FROM AUTHOR]

Introduction: In the shipbuilding industry, workers are exposed to a variety of dangerous chemicals, styrene being one of them. The International Agency for Research on Cancer classified styrene as a chemical belonging to group 2A, which means it is probably carcinogenic to humans. This study aimed at evaluating the oxidative stress effects due to occupational exposure to styrene and other chemicals. Materials and methods: Styrene urinary metabolites, such as mandelic acid and phenylglyoxylic acid, and the urinary biomarkers of oxidative stress, i.e., oxidation products of DNA and RNA and of proteins, were measured in a group of 17 workers and compared to the concentrations found in a group of 17 healthy volunteers who had not been exposed to chemicals. Results and discussion: Statistically significant differences were found for 8-oxo-7,8-dihydroguanine (8-oxoGua) and 8-oxo-7,8-dihydro-2'-deoxiguanosine (8-oxodGuo) concentrations that are higher in workers than in the control group. The workers performing the tasks of painting are the most exposed to styrene and show higher concentrations of 8-oxo-7,8-dihydroguanosine (8-oxoGuo). Workers performing the tasks of wood refining and welding are less exposed to styrene but have higher concentrations of 8-oxoGua and 8-oxodGuo. Conclusion: The exposure scenario in shipbuilding is a complex one, in which different xenobiotics are simultaneously present. The oxidative stress effect biomarkers, obtained from the oxidation product of RNA and DNA, are promising, sensitive, but not specific. [ABSTRACT FROM AUTHOR]

Research on titanium-oxo complexes (TOCs) is usually focused on their structure and photocatalytic properties. Findings from these investigations further sparked our interest in exploring their potential biological activities. In this study, we focused on the synthesis and structure of a compound with the general formula [Ti8O2(OiPr)20(man)4] (1), which was isolated from the reaction mixture of titanium(IV) isopropoxide with mandelic acid (Hman) in a molar ratio of 4:1. The structure (1) was determined using single-crystal X-ray diffraction, while spectroscopic studies provided insights into its physicochemical properties. To assess the potential practical applications of (1), its microcrystals were incorporated into a polymethyl methacrylate (PMMA) matrix, yielding composite materials of the type PMMA + (1) (2 wt.%, 5 wt.%, 10 wt.%, and 20 wt.%). The next stage of our research involved the evaluation of the antimicrobial activity of the obtained materials. The investigations performed demonstrated the antimicrobial activity of pure (1) and its composites (PMMA + (1)) against both Gram-positive and Gram-negative strains. Furthermore, MTT tests conducted on the L929 murine fibroblast cell line confirmed the lack of cytotoxicity of these composites. Our study identified (1) as a promising antimicrobial agent, which is also may be use for producing composite coatings.

Introduction: In the shipbuilding industry, workers are exposed to a variety of dangerous chemicals, styrene being one of them. The International Agency for Research on Cancer classified styrene as a chemical belonging to group 2A, which means it is probably carcinogenic to humans. This study aimed at evaluating the oxidative stress effects due to occupational exposure to styrene and other chemicals.Materials and methods: Styrene urinary metabolites, such as mandelic acid and phenylglyoxylic acid, and the urinary biomarkers of oxidative stress, i.e., oxidation products of DNA and RNA and of proteins, were measured in a group of 17 workers and compared to the concentrations found in a group of 17 healthy volunteers who had not been exposed to chemicals.Results and discussion: Statistically significant differences were found for 8-oxo-7,8-dihydroguanine (8-oxoGua) and 8-oxo-7,8-dihydro-2′-deoxiguanosine (8-oxodGuo) concentrations that are higher in workers than in the control group. The workers performing the tasks of painting are the most exposed to styrene and show higher concentrations of 8-oxo-7,8-dihydroguanosine (8-oxoGuo). Workers performing the tasks of wood refining and welding are less exposed to styrene but have higher concentrations of 8-oxoGua and 8-oxodGuo.Conclusion: The exposure scenario in shipbuilding is a complex one, in which different xenobiotics are simultaneously present. The oxidative stress effect biomarkers, obtained from the oxidation product of RNA and DNA, are promising, sensitive, but not specific.

The development of new and efficient chiral extractants has always been the research hotspot and difficulty in the field of chiral extraction. Josiphos, a famous ferrocene derivative catalyst, is employed as a chiral extractant in enantioseparation of amino acid and mandelic acid enantiomers. The influences of metal ions, organic solvents, pH of the aqueous solution, extractant concentrations, and extraction temperature on enantioselectivities are systematically studied. The result reveals that Josiphos‐Pd has good capabilities to enantioseparate 4‐nitro‐phenylalanine (Nphe), 3‐chloro‐phenylglycine (Cpheg), and mandelic acid (MA) with separation factors (α) of 3.30, 2.65, and 2.18, respectively. The pH of the aqueous phase and Josiphos‐Pd concentration affect the extraction significantly, whereas extraction temperature shows little influence. After optimizing by response surface method, the mathematical models for extractions are established. And the highest experimental performance factors (pf) for Nphe, Cpheg, and MA are 0.1843, 0.1335, and 0.08884, respectively. [ABSTRACT FROM AUTHOR]

Background: Chemical peel is a cosmetic procedure that is becoming a popular modality in treating acne vulgaris (AV). Mandelic acid (MA) is an upcoming peeling agent for AV due to its anti-inflammatory and antibacterial traits. Hence, it is worthwhile to appraise this newer agent's effectiveness and safety profile and compare it with a more traditional and established peeling agent, salicylic acid (SA), in the treatment of AV. Aims: The aim of this study was to compare the efficacy of 40% MA with 30% SA peels in south Indian patients suffering from mild-to-moderate facial AV. Materials and Methods: One hundred patients suffering from mild-to-moderate facial AV were distributed randomly into two groups of 50 each, with group A receiving 40% MA peel and group B receiving 30% SA peel at an interval of two weeks for six sessions. The duration of the study was twelve weeks. Clinical pictures and Michaelsson acne scores (MAS) were used to evaluate the effectiveness of treatment objectively. Adverse effects of both the peeling agents were also noted. Statistical Analysis Used: A value of P ≤ 0.05 was considered significant. Results: Overall, there was no significant difference in the efficacy between the two peels. However, adverse effects were slightly higher with SA peel. Conclusions: The 40% MA peel was equally effective as 30% SA peel in mild-to-moderate facial AV. However, safety profile and tolerability were better in the MA peel group than the SA peel group. [ABSTRACT FROM AUTHOR]

The mandelic acid oxidation has been carried out by benzimidazolium fluorochromate (BIFC), morpholinium fluorochromate (MFC), benzimidazolium dichromate (BIDC), morpholinium chlorochromate (MCC) and tetraethylammonium chlorochromate (TEACC) using different solvents as dimethyl sulphoxide (DMSO), dimethyl formamide (DMF), chloroform (CF), acetone, dichloromethane (DCM) and 1,2-dichloroethane (DCE) at 308K, which results in the corresponding oxoacids formation. By using the TOPSIS method, we analysed the solvent effect and found the order by the solvent's performance score for the reaction as DMSO>DMF>DCE>ACETONE>DCM>CF. The oxidation with all the oxidants resulted in the formation of corresponding oxo acid. The mechanism involved the construction of a cyclic chromate ester in a fast pre-equilibrium and then the decomposition of the ester in a subsequent slow step via a cyclic concerted symmetrical transition state leading to the formation of corresponding oxo acid in all the cases. [ABSTRACT FROM AUTHOR]

To discover highly efficient and novel lead compounds against Thanatephorus cucumeris, a series of novel mandelic acid derivatives containing 1,3,4-thiadiazole thioether was designed and synthesized. The bioassay results revealed that target compound F10 exhibited excellent antifungal activity against T. cucumeris with EC50 value of 9.7 μg/mL. Further studies found that F10 not only significantly inhibited the growth of T. cucumeris mycelia but also effectively inhibited the formation of sclerotia, and exhibited significant in vivo protective (61.1%) and curative (67.9%) activities at 200 μg/mL. Mechanism studies demonstrated that F10 can damage the integrity of the cell membrane structure, resulting in increased permeability of the cell membrane, releasing the intracellular electrolyte and inhibiting the growth of fungi. In general, this work is helpful for managing the formation and diffusion of the infection source and provides an effective method to control rice sheath blight disease infected with sclerotia of T. cucumeris.

Antimicrobial hand gels have become extremely popular in recent years due to the COVID-19 pandemic. Frequent use of hand sanitising gel can lead to dryness and irritation of the skin. This work focuses on the preparation of antimicrobial acrylic acid (Carbomer)-based gels enhanced by non-traditional compounds—mandelic acid and essential oils—as a substitute for irritating ethanol. Physicochemical properties (pH and viscosity), stability and sensory attributes of the prepared gels were investigated. Antimicrobial activity against representative Gram-positive and Gram-negative bacteria and yeasts was determined. The prepared gels with mandelic acid and essential oil (cinnamon, clove, lemon, and thyme) proved to have antimicrobial activity and even better organoleptic properties than commercial ethanol-based antimicrobial gel. Further, results confirmed that the addition of mandelic acid had a desirable effect on gel properties (antimicrobial, consistency, stability). It has been shown that the essential oil/mandelic acid combination can be a dermatologically beneficial hand sanitiser compared to commercial products. Thus, the produced gels can be used as a natural alternative to alcohol-based daily hand hygiene sanitisers. [ABSTRACT FROM AUTHOR]

This article investigated the structure, and the spectroscopic and antimicrobial properties of mandelic acid and its alkali metal salts. The electron charge distribution and aromaticity in the analyzed molecules were investigated using molecular spectroscopy methods (FT-IR, FT-Raman, 1H NMR, and 13C NMR) and theoretical calculations (structure, NBO, HOMO, LUMO, energy descriptors, and theoretical IR and NMR spectra). The B3LYP/6-311++G(d,p) method was used in the calculations. The antimicrobial activities of mandelic acid and its salt were tested against six bacteria: Gram-positive Listeria monocytogenes ATCC 13932, Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633, and Loigolactobacillus backii KKP 3566; Gram-negative Escherichia coli ATCC 25922 and Salmonella Typhimurium ATCC 14028, as well as two yeast species, Rhodotorulla mucilaginosa KKP 3560 and Candida albicans ATCC 10231. [ABSTRACT FROM AUTHOR]

Background: Actually, the use of chemical peels in cosmetics and dermatology continues to grow due to their versatility, clinical endpoint–directed predictability, and favorable risk profile in comparison to lasers. The chemical peel is a generally safe method for treatment of some skin disorders and to refresh and rejuvenate the skin. The major challenge of chemical peels is the tolerability, that is because of sensitive skin which is one of the most common skin disorders. Aim: The aim of this study was to evaluate the effectiveness of the new Miamo Renewal Peel Serum formulated with a pool of new generation acids (ELPA25™) on sensitive skin with respect to mandelic acid serum only and with respect to placebo comparison. Materials and Methods: The "in vivo" study following the half‐face experimental protocol active versus placebo involved 30 healthy Caucasian female volunteers between 25 and 64 years, with sensitive skin, who were divided into two different groups. ELPA25™ serum was applied in one group three times a week for 8 weeks. The other group, with the same protocol, applied an active serum containing mandelic acid, as control, versus placebo. In particular, skin moisturizing, skin viscoelastic properties, skin surface smoothness, wrinkle reduction, and stratum corneum renewal were evaluated. Results: Renewal Peel Serum was very well tolerated from sensitive skin. A significant decrease in skin roughness and wrinkle breadth, and an improvement in firmness and in skin elasticity, was observed after 2 months of treatment with respect both to mandelic acid serum and to placebo comparison. Conclusions: Scientific protocol using self‐controlled study methodology and noninvasive skin bioengineering techniques with adequate statistical methods were able to evaluate both the safety and the efficacy of the new Miamo Renewal Peel Serum. This study highlighted that the Miamo Renewal Peel Serum formulated with a patent‐pending mixture of new generation acids (ELPA25™) exerts many beneficial effects and it can be successfully employed for sensitive skin. [ABSTRACT FROM AUTHOR]

[Display omitted] • First photocatalytic synthesis of α-hydroxy acids from reductive carboxylation of aldehydes with CO 2. • Efficient heterostructured composites made up of titanium-based MOF (MIL-125-NH 2) and g-C 3 N 4 for CO 2 activation and conversion using renewable light energy. • The synergistic effect of both components in heterostructured composite played crucial role that facilitated the charge separation and mobility to the photogenerated electrons on the surface. • Highly stable, reusable and visible light active photocatalyst for CO2 activation under mild conditions. The present work described an efficient photoredox-mediated synthesis of α-hydroxy acids from reductive carboxylation of aryl aldehydes with CO 2 using heterostructures made up of titanium-based MOF (MIL-125-NH 2) and g-C 3 N 4 under visible illuminance. The developed protocol worked well for a number of aryl aldehydes having electron-donating substituents and afforded moderate to higher yields of the desired carboxylated products. The substrates having electron-withdrawing groups remained inefficient for the present transformation. The key advantages of the developed methodology include the utilization of CO 2 at room temperature, higher product selectivity, and a highly stable and recyclable photocatalyst. Moreover, blank experiments support that the reaction is truly photocatalytic and light irradiation played a crucial role. [ABSTRACT FROM AUTHOR]

Noscapine is an isolated compound from the opium poppy, with distinctive chiral structure and chemistry, interacts with other compounds due to having multiple π‐acceptors, hydrogen bond acceptors, and ionic sites. Therefore, it has promising applicability for the enantioselective separation of a wide range of polar, acidic, basic, and neutral compounds. A new noscapine derivative chiral stationary phase (ND‐CSP) has been synthesized by consecutive N‐demethylation, reduction, and N‐propargylation of noscapine followed by attachment of a solid epoxy‐functionalized silica bed through the 1,3‐dipolar Huisgen cycloaddition. The noscapine derivative‐based stationary phase provides a considerable surface coverage, which is greater than some commercial CSPs and can validate better enantioresolution performance. The major advantages inherent to this chiral selector are stability, reproducibility after more than 200 tests, and substantial loading capacity. The characterization by Fourier transform infrared (FTIR) spectroscopy and elemental analysis indicated successful functionalization of the silica surface. Chromatographic method conditions like flow rate and mobile phase composition for enantioseparation of various compounds such as warfarin, propranolol, mandelic acid, and a sulfanilamide derivative were optimized. Comparing the experimental results with docking data revealed a clear correlation between the calculated binding energy of ND‐CSP and each enantiomer with the resolution of enantiomer peaks. [ABSTRACT FROM AUTHOR]

We reviewed the toxicokinetics of styrene to introduce reliable surrogates for the biological monitoring of styrene workers. We have also discussed the extraction techniques and analytical methods of styrene and its metabolites. Sample preparation is the main bottleneck of the analytical techniques for styrene and its metabolites. Although some microextraction methods have been developed to overcome such disadvantages, some still have limitations such as long extraction time, fiber swelling and breakage, and the cost and the limited lifetime of the fiber. Among all, microextraction by packed sorbents, coupled with HPLC with ultraviolet detection (MEPS‐HPLC‐UV), can be the method of choice for determining styrene metabolites. Few studies investigated unchanged styrene in breath samples. Chemical determination of styrene in exhaled breath provides new insights into organ toxicity in workers with inhalation exposures and can be considered a fascinating tool in risk assessment strategies. Taking blood samples is invasive and less accepted by workers. In contrast, breath analysis is the most attractive method for workers because breath samples are easy to collect and non‐invasive, and sample collection does not require the transfer of workers to health facilities. Therefore, developing selective and sensitive methods for determining styrene in breath samples is recommended for future studies. [ABSTRACT FROM AUTHOR]

Mandelic acid is a valuable chemical that is commonly used in the synthesis of various drugs, in antibacterial products, and as a skin care agent in cosmetics. As it is an important chemical, various methods are used to synthesize and extract this compound. However, the yields of the used processes is not significant. A dilute aqueous solution is obtained when using several production methods, such as a fermentation, etc. In this study, the reactive extraction of mandelic acid from aqueous solutions using tri-n-octylamine extractant at 298.15 K was investigated. Dimethyl phthalate (DMP), methyl isobutyl ketone (MIBK), 2-octanone, 1-octanol, n-pentane, octyl acetate, and toluene were used as diluents. The batch extraction results of the mandelic acid experiments were obtained for the development of a process design. Calculations of the loading factor (Z), distribution coefficient (D), and extraction efficiency (E%) were based on the experimental data. The highest separation yield was obtained as 98.13% for 0.458 mol.L−1 of tri-n-octylamine concentration in DMP. The overall extraction constants were analyzed for the complex of acid-amine by the Bizek approach, including K11, K12, and K23. [ABSTRACT FROM AUTHOR]

In this paper, Garphos with different substituents were employed as chiral extractants to enantioseparate racemic amino acid and mandelic acid. The influences of metal precursors, pH of aqueous solution, Garphos‐metal concentration, extraction temperature, and substituent effect on extraction were investigated. The results indicated that the substituent groups significantly affected the π‐π interaction between extractant and substrate. And the separation factors (α) for Garphos could be remarkably improved by regulating substituent groups. Garphos‐II‐Pd, Garphos‐VI‐Pd, Garphos‐III‐Pd, Garphos‐I‐Cu, Garphos‐VI‐Cu, and Garphos‐V‐Pd were the most efficient extractants for phenylalanine (Phe), homophenylalanine (Hphe), 4‐nitrophenylalanine (Nphe), 3‐chlorophenylglycine (Cpheg), mandelic acid (MA), and 2‐chlormandelic acid (CMA) with α values of 2.40, 2.37, 5.37, 1.59, 5.98, and 3.69, respectively. This work provided an important reference for the design of efficient chiral extractants in future work. [ABSTRACT FROM AUTHOR]

The following article discusses the antioxidant properties of mandelic acid and its hydroxy and methoxy derivatives. The antioxidant capacity of these compounds is determined by DPPH, FRAP, CUPRAC and ABTS. The mechanisms underlying the antioxidant properties are described by BDE, IP, PDE, ETE and PA calculation method values and referenced to experimental data. Thermochemistry, HOMO/LUMO energies, dipole moments, charge distribution, IR, RAMAN, NMR frequencies, binding lengths and angles were calculated using the B3LYP method and the 6-311++G(d,p) basis set. The structure of mandelic acid and its derivatives was determined experimentally using IR and RAMAN spectroscopy. [ABSTRACT FROM AUTHOR]

In our pursuit to discover new anticancer agents, we have synthesized a new series of 2-aryl-1,3- thiazolidin-4-one derivatives carrying a mandelic acid part. Compounds 3a-h and 4a-j have been synthesized with the cyclization of mandelic acid-derived Schiff bases, their structures have been elucidated with spectral methods (1H-NMR, 13C-NMR, and LC/MS-APCI) and elemental analyzes (C, H, N). Five compounds 3d, 3e, 4e, 4f, and 4g chosen as prototypes were evaluated against the full panel of 58 human tumor cell lines in the National Cancer Institute's in vitro primary cytotoxicity assay (Bethesda, Maryland). Among the tested compound, 3e showed good cytotoxic effects against melanoma cell line UACC-62. Compounds 3d, 4e, 4f, and 4g showed moderate cytotoxic effects, especially against leukemia cell line, RPMI-8226, non-small cell lung cancer cell lines NCI-H23 and HOP-92, central nervous system (CNS) cancer cell lines SF-295 and SNB-75, melanoma cell line UACC-62, and ovarian cancer cell line IGROV1. It is considered that the in vitro test results of selected compounds are promising and an additional mandelic acid moiety to core structure 2-aryl-1,3-thiazolidin-4-one and different modifications may result in effective agents in anticancer treatment. [ABSTRACT FROM AUTHOR]

Nickel oxide (NiOx) inverted perovskite solar cells have been witnessed as promising solar cells because of the low cast, easy fabrication and negligible hysteresis. However, the inferior interface feature of the link NiOx and perovskite layer often causes poor device property and repeatability. Here, Mandelic acid (MAD) is introduced to form a modified layer, which could improve the poor interface properties between perovskite layer and NiOx layer. The contact angel images revels MAD could increase the hydrophobicity and facilitate the growth of perovskite crystal. The X‐ray diffraction pattern and Fourier transform infrared spectroscopy have confirmed that the MAD small molecule could interact with residual PbI2 crystal, leading to better interface contact and high crystallinity. This is further demonstrated by the scanning electron microscopy test of NiOx/MAD/MAPbI3 film that average grain size is increased from 201.85 nm to 315.17 nm. The space‐charge limited current measurement proves the introduction of MAD molecule that result in the decreased trap state density from 3.58×1015 cm−3 to 2.721015 cm−3. As a consequence, The power conversion efficiency is significantly improved from 14.9% to 18.42% of MAPbI3‐based devices that retained nearly 80% initial PCE after 50 days in N2 without encapsulation. [ABSTRACT FROM AUTHOR]

Mandelic acid and its derivatives are an excellent source of chirality for the construction of chiral coordination polymers (CPs) and metal-organic frameworks (MOFs) for enantioselective applications. To date, limited reports exist for the incorporation of mandelic acid derivatives with halogen substituents such as fluorine and chlorine despite the extra intermolecular interactions possible. The extra sites for hydrogen and halogen bonding in these mandelic acid derivatives may afford interesting modes of coordination and packing in 3 D space. Six CPs containing mandelic acid and its halogenated analogues, (R)-2-chloromandelic acid, 3,5-difluoromandelic acid, 4-trifluoromethylmandelic acid, together with linear dipyridyl co-ligands are reported. These structures consist of three 2 D sql sheets and three 1 D chains with a range of packing motifs influenced by the differing intermolecular interactions present. [ABSTRACT FROM AUTHOR]

Copyright of China Forest Products Industry is the property of China Forest Products Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract (R)-mandelic acid is an industrially important chemical, especially used for producing antibiotics. Its chemical synthesis often uses highly toxic cyanide to produce its racemic form, followed by kinetic resolution with 50% maximum yield. Here we report a green and sustainable biocatalytic method for producing (R)-mandelic acid from easily available styrene, biobased L-phenylalanine, and renewable feedstocks such as glycerol and glucose, respectively. An epoxidation-hydrolysis-double oxidation artificial enzyme cascade was developed to produce (R)-mandelic acid at 1.52 g/L from styrene with > 99% ee. Incorporation of deamination and decarboxylation into the above cascade enables direct conversion of L-phenylalanine to (R)-mandelic acid at 913 mg/L and > 99% ee. Expressing the five-enzyme cascade in an L-phenylalanine-overproducing E. coli NST74 strain led to the direct synthesis of (R)-mandelic acid from glycerol or glucose, affording 228 or 152 mg/L product via fermentation. Moreover, coupling of E. coli cells expressing L-phenylalanine biosynthesis pathway with E. coli cells expressing the artificial enzyme cascade enabled the production of 760 or 455 mg/L (R)-mandelic acid from glycerol or glucose. These simple, safe, and green methods show great potential in producing (R)-mandelic acid from renewable feedstocks.

Synthesis and enzymatic resolution of a new class of alicyclic and heterocyclic mandelic acid derivatives was described. The method relied on the preparation of cyanohydrins from the commercially available aldehydes followed by hydrolysis to corresponding racemic hydroxy esters that were used in the resolution with the Amano PS enzyme. An alternative approach was proposed for compounds that were not suitable for this procedure. For the selected examples, synthesis of the corresponding mandelic acid analogs using the subsequent hydrolysis of esters followed by enantiomeric enrichment via recrystallization of the diastereomeric salt was performed. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel green chemical mechanical polishing was developed. • Surface roughness Sa of 0.179 nm is achieved. • Chemical mechanical polishing mechanism is elucidated. Traditional chemical mechanical polishing (CMP) normally employs noxious slurries, leading to pollution to the environment. It is a challenge to achieve atomic surfaces of nickel (Ni) alloy using green CMP. To overcome this challenge, a novel green CMP was developed, including composite abrasives of ceria and silica, mandelic acid, hydrogen peroxide and deionized water. Using the developed green CMP, atomic surface with surface roughness Sa of 0.179 nm was achieved, under a scanning area of 50 × 50 μm2. Electrochemical tests indicate that the developed slurry has effective corrosion ability on Ni alloy. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy reveal that the Ni alloy was oxidized by hydrogen peroxide, forming oxides of Ni, chromium (Cr) and molybdenum (Mo). Cr and Mo oxides demonstrated better stability in mandelic acid, while Ni oxides reacted with hydrogen ions and produced Ni2+ and Ni3+ ions. The ions chelated with mandelic acid. Finally, the generated oxides and reaction products were removed by abrasives and a polishing pad under chemical and mechanical balanced functions. The developed green CMP paves a new avenue to obtain atomic surface of a Ni alloy for the possible applications of high-performance components in aerospace industry. [ABSTRACT FROM AUTHOR]

Chiral coordination polymers constructed from mandelic acid have shown promise in enantioselective recognition and sensing, whereas its methoxy-protected derivative, α-methoxyphenyl acetic acid, is rarely used as a ligand in coordination polymers. In this study, mandelic acid, 3,5-difluoromandelic acid, and α-methoxyphenyl acetic acid were combined with divalent transition metals and bridging dipyridyl co-ligands to obtain a series of six 1D coordination polymers. The coordination polymers of mandelate and 3,5-difluoromandelate possessed densely packed structures stabilised by hydrogen bonding. In contrast, the use of (R)-α-methoxyphenyl acetic acid gave rise to zig-zag chains with significant solvent-accessible void space. (R)-Mandelic acid and its derivatives are useful ligands for the synthesis of chiral coordination polymers. Combining (R)-mandelic acid and 3,5-difluoromandelic acid with first row transition metals and dipyridyl co-ligands gives one-dimensional chains linked by hydrogen bonds into a densely packed structure. In contrast, the methoxy-protected analogue formed an open framework with solvent accessible channels. [ABSTRACT FROM AUTHOR]

A simple and efficient general procedure has been developed for the synthesis of three-component reaction methodology of 2,4,5-trisubstituted imidazoles by using benzil, ammonium acetate and various aromatic aldehydes. In this methodology, mandelic acid is used as a novel and efficient organo-catalyst in catalytic amount under solvent-free conditions for preparation of variety of 2,4,5-trisubstituted imidazoles derivatives in excellent yields. All products have been characterized by ¹H NMR and 13C NMR spectroscopy, IR spectroscopy and mass spectrometry. This method provides versatile advantages of organo-catalyst such as economical, nontoxic, highly stable, readily and easily available as well as solvent-free reaction conditions. [ABSTRACT FROM AUTHOR]

A simple, mild, eco-friendly, general and convenient approach has been developed for the synthesis of various trisubstituted methane derivatives via one-pot pseudo three-component reactions between one equivalent of aromatic aldehydes and two equivalents of 6-amino-uracils or dimedone respectively using a catalytic amount of mandelic acid as a low cost, commercially available, efficient organo-catalyst in aqueous ethanol at room temperature. [ABSTRACT FROM AUTHOR]

The major concern to search for new anti-arthritic drugs is primarily to prevent systemic complications and to maintain quality of life. As these drugs are prescribed for long duration so the objective is to ensure their safety in terms of toxicity. By keeping in view this concept, the present study was investigated to determine new anti-arthritic potential using in-vitro and in-vivo methods. The in-vitro tests comprised of protein denaturation (BSA and egg albumin) and Human Red Blood cell (HRBC) membrane stabilization assays at 50-6400µg/mL, for in-vivo testing, formaldehydeinduced arthritic rats were treated with 40, 80 and 160mg/kg mandelic acid. Mandelic acid (MA) inhibited the protein denaturation and stabilized the membrane of HRBC in a concentration dependent manner. Likewise, mandelic acid exhibited dose dependent reduction in paw volume induced by formaldehyde. For acute and sub-acute treatment, MA did not show any sign of toxicity and mortality in each rat and LD50 might be greater than 2000mg/kg. In addition, histopathological assessment presented slight increased interstitial spaces in the kidney, disorganization of glomerulus, dilated sinusoids at highest dose 800mg/kg which were not observed in sub-chronic therapy. Hence, these results conclude that mandelic acid has the potential to treat rheumatoid arthritis with observed no significant signs of toxicity and should be tested further to determine anti-arthritic mechanism of drug action at cellular level. [ABSTRACT FROM AUTHOR]

Oxidation of biologically important mandelic acid in the presence of Cetyltrimethylammonium bromide (CTAB) and Sodium lauryl sulphate (SDS) has been assessed. The reactions follow differing order kinetics at experimental conditions. In presence of cetyltrimethylammonium bromide, the reaction rate increased, at higher concentration constancy in rate has been observed, whereas presence of SDS slightly retards the reaction rate. Quantitative kinetic analyses of the reaction in the presence of cationic and anionic surfactants have been performed on the basis of pseudo-phase model. Micellar binding constants KS and km were evaluated for the mandelic acid with CTAB micelle and SDS micelle, respectively. Experimental findings help in understanding the mechanistic pathways and better reaction conditions for the synthesis. [ABSTRACT FROM AUTHOR]

The enantioseparation and resolution mechanism of mandelic acid (MA), 4‐methoxymandelic acid (MMA), and 4‐propoxymandelic acid (PMA) were investigated by reversed‐phase high‐performance liquid chromatography (HPLC) with 2‐hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) as a chiral mobile‐phase additive and molecular dynamics simulation. The suitable chromatographic conditions for the enantioseparation of MA, MMA, and PMA were obtained. Under the selected chromatographic conditions, these enantiomers could achieve baseline separation. The results of thermodynamic parameter analysis revealed that the main driven forces for the enantioseparation of MA, MMA, and PMA could be van der Waals forces and hydrogen‐bonding interactions and the chromatographic retention of these chiral compounds was an enthalpy‐driven process. The results of the molecular simulation revealed that their chiral resolution mechanism on HP‐β‐CD was responsible for the formation of inclusion complexes of enantiomers with HP‐β‐CD with different conformations and binding energies. And the binding energy of HP‐β‐CD with (S)‐isomer was larger than that with (R)‐isomer, which is consistent with the experimental results of the first elution of (S)‐isomer. Additionally, it is also confirmed that the interaction energies included the van der Waals energy (∆Evdw), electrostatic energy (∆Eelec), polar solvation energy, and SASA energy (∆Esasa), and the separation factor (α) was closely connected with the disparity in the binding energies of optical isomers and HP‐β‐CD complexes. Meanwhile, from molecular dynamics simulation, it can be found that the ∆(∆Ebinding), (∆(∆Ebinding) = ∆Ebinding,R − ∆Ebinding,S) value was in order of MA–HP‐β‐CD complex > MMA–HP‐β‐CD complex > PMA–HP‐β‐CD complex, which was consistent with the order of Δ(ΔG) values obtained from van't Hoff plot. This indicated that the molecular dynamics simulation has predictive function for chiral resolution. [ABSTRACT FROM AUTHOR]

Mandelic acid is a valuable chemical that is commonly used in the synthesis of various drugs, in antibacterial products, and as a skin care agent in cosmetics. As it is an important chemical, various methods are used to synthesize and extract this compound. However, the yields of the used processes is not significant. A dilute aqueous solution is obtained when using several production methods, such as a fermentation, etc. In this study, the reactive extraction of mandelic acid from aqueous solutions using tri-n-octylamine extractant at 298.15 K was investigated. Dimethyl phthalate (DMP), methyl isobutyl ketone (MIBK), 2-octanone, 1-octanol, n-pentane, octyl acetate, and toluene were used as diluents. The batch extraction results of the mandelic acid experiments were obtained for the development of a process design. Calculations of the loading factor (Z), distribution coefficient (D), and extraction efficiency (E%) were based on the experimental data. The highest separation yield was obtained as 98.13% for 0.458 mol.L−1 of tri-n-octylamine concentration in DMP. The overall extraction constants were analyzed for the complex of acid-amine by the Bizek approach, including K11, K12, and K23.

Mandelic acid was found to be gentle and efficient organocatalyst for the synthesis of diversified secondary amines from aldehydes primary amines via imine using Hantzsch DHP ester which act as a hydrogen source in one-pot manner under mild conditions. The green and inexpensive process described herein requires only catalytic amount of mandelic acid and provides quick access to the structurally diverse amines in high yields under mild conditions. [ABSTRACT FROM AUTHOR]

Enantiopure or enantiomerically enriched chemicals are often used as active pharmaceutical ingredients (APIs). However, API synthesis and purification on a preparative scale is usually costly, time-consuming, and difficult to scale up in conventional batch reactors. To develop an alternative solution, we applied kinetic enantioselective synthesis with simultaneous product separation. More specifically, we constructed a continuously operated packed-bed milli-reactor (PBR) with an orthogonally applied electric field for in situ separation. We tested our concept in the enzymatic production of mandelic acid (MA) enantiomers from racemic methyl mandelate (rMM) by immobilised Aspergillus niger lipase. The electric field selectively extracted the product (mandelate anions) whilst leaving almost 100 % of the electroneutral substrate in the reaction mixture. Such selective product separation significantly enhanced MA formation by shifting the reaction toward product synthesis. The applied electric current efficiently controlled the overall rMM conversion, reaching more than 90 % compared to 30% without current. We identified the electric current providing the highest (R)-(-)-MA to (S)-(+)-MA enantiomeric ratio equals to 5.20. This ratio was above 3.86 achieved in an ordinary PBR, albeit subject to further optimization. Our PBR with in situ product separation provided superior process control and significantly enhanced enantiomerically enriched chemical synthesis. [Display omitted] • Mandelic acid enantiomers are synthetized by lipase in a packed-bed milli-reactor. • Electric field provides in situ product separation and process intensification. • Selective separation of enantiomers shifts the reaction equilibrium. • In situ separation improves (R)-(−) to (S)-(+)-mandelic acid enantiomeric ratio. • Electric current provides superior control of methyl mandelate conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • S-CuO was synthesized by an eco-friendly one-pot hydrothermal method. • S-CuO possesses peroxidase-like activity and chirality. • S-CuO exhibits a different affinity toward S-MA and R-MA. • S-MA and R-MA have different impacts on the peroxidase-like activity of S-CuO. • A S-CuO-based sensor was designed for chiral recognition of S-MA. Chiral copper oxide flowers (S-CuO) with peroxidase-like activity were synthesized by an eco-friendly one-pot method without introducing toxic materials and organic solvents. The chirality of S-CuO arises from the helical arrangement of subnanopetals in a specific pattern rather than any surface modification. S-CuO was found to have a different affinity toward S-mandelic acid (MA) and R-MA, resulting in various impacts on improving the peroxidase-like activity of S-CuO. The mechanism was demonstrated experimentally. Moreover, these findings were used to build a colorimetric sensor for chiral recognition and determination of MA. The utility of the sensor was proved through the detection of MA in acid skincare essences. Additionally, an STM32-based portable device was constructed employing 3D printing technology to achieve on-site determination of MA. Notably, the sensor expands the application of chiral ligand-free materials with chirality in chiral discrimination fields. [ABSTRACT FROM AUTHOR]

The following article discusses the antioxidant properties of mandelic acid and its hydroxy and methoxy derivatives. The antioxidant capacity of these compounds is determined by DPPH, FRAP, CUPRAC and ABTS. The mechanisms underlying the antioxidant properties are described by BDE, IP, PDE, ETE and PA calculation method values and referenced to experimental data. Thermochemistry, HOMO/LUMO energies, dipole moments, charge distribution, IR, RAMAN, NMR frequencies, binding lengths and angles were calculated using the B3LYP method and the 6-311++G(d,p) basis set. The structure of mandelic acid and its derivatives was determined experimentally using IR and RAMAN spectroscopy.