Alpha-hydroxylated Acids Research Articles

Alpha Hydroxyl Acids from Mume Fructus and Schisandrae Chinensis Fructus Prevent Obesity by Inhibiting Intestinal Lipase in Diet-Induced Obese Mice.

Restriction of lipid uptake and absorption from the diet is regarded as an efficient strategy for the management of obesity, while lipase inhibition could successfully block the digestion of dietary lipids. Mume Fructus (MF) and Schisandrae Chinensis Fructus (SCF) were used as fruits, the biological effect of which on obesity desired more attention. Herein, the extracts of MF and SCF displayed significant efficacy in managing obesity in mice fed with a high-fat diet, via the inhibition of hydrolase activity of lipase in the digestive tract. Using the bioactivity guidance strategy, citric acid and malic acid were identified as the major lipase inhibitors from MF and SCF, respectively, which could prevent body weight gain, along with adipose tissue formation, and alleviate hyperlipidemia and hepatic steatosis in obese mice. Above all, MF and SCF could be used for the management of obesity via the lipase inhibition by citric acid and malic acid, displaying potential applications in healthy foods, nutritional supplements, and pharmaceutical materials.

Synthesis of Terpineol from Alpha-Pinene Catalyzed by α-Hydroxy Acids.

We report the use of five alpha-hydroxy acids (citric, tartaric, mandelic, lactic and glycolic acids) as catalysts in the synthesis of terpineol from alpha-pinene. The study found that the hydration rate of pinene was slow when only catalyzed by alpha-hydroxyl acids. Ternary composite catalysts, composed of AHAs, phosphoric acid, and acetic acid, had a good catalytic performance. The reaction step was hydrolysis of the intermediate terpinyl acetate, which yielded terpineol. The optimal reaction conditions were as follows: alpha-pinene, acetic acid, water, citric acid, and phosphoric acid, at a mass ratio of 1:2.5:1:(0.1–0.05):0.05, a reaction temperature of 70 °C, and a reaction time of 12–15 h. The conversion of alpha-pinene was 96%, the content of alpha-terpineol was 46.9%, and the selectivity of alpha-terpineol was 48.1%. In addition, the catalytic performance of monolayer graphene oxide and its composite catalyst with citric acid was studied, with acetic acid used as an additive.

Extremophilic Exopolysaccharides: Biotechnologies and Wastewater Remediation.

Various microorganisms thrive under extreme environments, like hot springs, hydrothermal vents, deep marine ecosystems, hyperacid lakes, acid mine drainage, high UV exposure, and more. To survive against the deleterious effect of these extreme circumstances, they form a network of biofilm where exopolysaccharides (EPSs) comprise a substantial part. The EPSs are often polyanionic due to different functional groups in their structural backbone, including uronic acids, sulfated units, and phosphate groups. Altogether, these chemical groups provide EPSs with a negative charge allowing them to (a) act as ligands toward dissolved cations as well as trace, and toxic metals; (b) be tolerant to the presence of salts, surfactants, and alpha-hydroxyl acids; and (c) interface the solubilization of hydrocarbons. Owing to their unique structural and functional characteristics, EPSs are anticipated to be utilized industrially to remediation of metals, crude oil, and hydrocarbons from contaminated wastewaters, mines, and oil spills. The biotechnological advantages of extremophilic EPSs are more diverse than traditional biopolymers. The present review aims at discussing the mechanisms and strategies for using EPSs from extremophiles in industries and environment bioremediation. Additionally, the potential of EPSs as fascinating biomaterials to mediate biogenic nanoparticles synthesis and treat multicomponent water contaminants is discussed.

Effect of Dispersants on Photochromic Behavior of Tungsten Oxide Nanoparticles in Methylcellulose.

Tungsten oxide-based photochromic films that change reversibly in air between colorless-transparent in the dark and dark blue under UV irradiation were prepared by using methylcellulose as a film matrix and various dispersants. Alpha-hydroxyl acid such as glycolic acid (GA) or glyceric acid (GlyA) is the best dispersant because it can make the film transparent by adding a small quantity much less than that of 3-hydroxypropionic acid or ethylene glycol. Fourier-transform infrared spectra and Raman spectra indicate that a strong interaction exists between WO3 and GA or GlyA. The coloration and bleaching processes of the prepared films were investigated to clarify the effect of the dispersants and the moisture contents. The bleaching rate remarkably decreased in the films containing GA or GlyA but accelerated by increasing the contact with O2. Measurements of electron-spin resonance reveals that GA and GlyA as dispersants stabilize the W5+ state. This paper shows that the coloring rate and the period for keeping the blue-colored state are tunable by changing the dispersants. The photochromic films containing α-hydroxyl acid as the dispersant have the potential for application as rewritable film on which information displayed with blue-colored state can be clearly readable for longer times compared with other dispersants.

Potential of different salt forming agents on the formation of chitosan nanoparticles as carriers for protein drug delivery systems

The effects of salt forming agents for chitosan on the potential for nanoparticle formation was investigated. The salt forms were prepared from the amino acid group, including glutamic and aspartic acids, and the alpha hydroxyl acid group, including lactic and glycolic acids. All types of chitosan salt could be used to prepare bovine serum albumin (BSA) loaded nanoparticles. The chitosan salts prepared from the amino acid group showed a higher salt formation ability as demonstrated using FTIR, hence a higher %encapsulation efficiency (%EE) and a reduction in zeta potential were obtained. The difference was due to the different organic acids used giving different polymer conformations and pH values in solution. Chitosan glutamate gave the highest salt formation ability and hence the highest %EE was obtained. The release of protein from all types of chitosan was similar and chitosan glutamate exhibited the highest release. Chitosan salt is therefore a material of choice for protein-loaded nanoparticles and the characteristics of nanoparticles can be readily modulated by different types of salt form.

VITAMIN C, VITAMIN A AND ALPHA HYDROXY ACID IN BENGKOANG (Pachyrhizus Erosus)

Bengkoang or Pachyrhizus erosus has been used as a traditional cosmetic material since many years ago. Until now, many cosmetic preparations using bengkoang as a main material have been produced by cosmetic industries, mainly for skin care, whitening and sunscreen preparation. However, content of vitamin A, vitamin C and alpha hydroxyl acid has not been discovered yet. These compounds are essential in skin care process because of their activities in cell regeneration, antioxidant as well as peeling of dead skin cell layer. The aim of this research is to provide information about the content of three compounds in bengkoang. Vitamin A has been analysed by spectrophotometer, vitamin C analysed using titration method and alpha hydroxyl acid analysed using gas chromatography. The result showed that concentrations of vitamin A and vitamin C are 179.21 ± 8.19 ppm and 0.31 ± 0.06 %, respectively. Meanwhile the content of alpha hydroxyl acid was 0.80 ± 0.01% (measured as glycolic acid).

Impact of Cosmetic Lotions on Nanoparticle Penetration through ex vivo C57BL/6 Hairless Mouse and Human Skin: A Comparison Study.

Understanding the interactions of nanoparticles (NPs) with skin is important from a consumer and occupational health and safety perspective, as well as for the design of effective NP-based transdermal therapeutics. Despite intense efforts to elucidate the conditions that permit NP penetration, there remains a lack of translatable results from animal models to human skin. The objectives of this study are to investigate the impact of common skin lotions on NP penetration and to quantify penetration differences of quantum dot (QD) NPs between freshly excised human and mouse skin. QDs were mixed in 7 different vehicles, including 5 commercial skin lotions. These were topically applied to skin using two exposure methods; a petri dish protocol and a Franz diffusion cell protocol. QD presence in the skin was quantified using Confocal Laser Scanning Microscopy. Results show that the commercial vehicles can significantly impact QD penetration in both mouse and human skin. Lotions that contain alpha hydroxyl acids (AHA) facilitated NP penetration. Lower QD signal was observed in skin studied using a Franz cell. Freshly excised human skin was also studied immediately after the sub-cutaneous fat removal process, then after 24 hours rest ex vivo. Resting human skin 24 hours prior to QD exposure significantly reduced epidermal presence. This study exemplifies how application vehicles, skin processing and the exposure protocol can affect QD penetration results and the conclusions that maybe drawn between skin models.

Polyols from epoxidized soybean oil and alpha hydroxyl acids and their adhesion properties from UV polymerization

Two types of biobased polyols, ESOGA and ESOLA, were synthesized from epoxidized soybean oil (ESO) with glycolic acid (GA) and lactic acid (LA), respectively, using a solvent-free/catalyst-free method. An ESO epoxy conversion rate of over 93% was achieved for both polyols. ESOGA has a weight-/number-average molecular weight (Mw/Mn) of 27,700/3900g/mol and average hydroxyl functionality (fOH) of 12.9, and ESOLA has Mw/Mn of 8800/3000g/mol and fOH of 11.7. The structures of the polyols were further characterized with Fourier transform infrared spectroscopy and 1H-nuclear magnetic resonance. Rheology and thermal properties were studied with a rheometer and a differential scanning calorimeter. The polyols were polymerized with ESO to adhesive polymers using UV light in the presence of cationic photoinitiator. The curing rate decreased as the amount of polyol increased for resins based on ESOGA and ESOLA (EGA and ELA). With the same amount of polyol, ELA resins cured faster than EGA resins. The peel strength and tack of EGA and ELA adhesives increased significantly as the ratio of polyol in the resin increased. ELA exhibited obviously higher peel strength and tack than EGA with the same amount of polyol. All resin tapes exhibited high static shear values (20,000+min). Overall, both ESOGA and ESOLA exhibited great potential as polyols for pressure-sensitive adhesive applications.

The effect of physically applied alpha hydroxyl acids on the skin pore and comedone.

Alpha hydroxy acids (AHA) have been recognized as commonly used therapy for acne. Our studies examined whether an additional effect of physical treatment using chemical peeling combined with negative pressure and compared with AHA treatment only occurs in acne-prone subjects. The chemical peeling agent used 4% of an AHA solution (mixture of 1000mL of carbonated water, 20mL of glycolic acid and 20mL of lactic acid). All subjects' faces were randomly divided into test and control groups. The test group was treated with chemical peeling combined with a physical effect, and the control group applied chemical peeling alone. For the 23 healthy females (average age: 30.17±5.06year), we measured sebum output level by light transmission, pore area and number by optical image analyser, and comedone counting before treatment and at 1, 2 and 4weeks after a single treatment. Compared to the before treatment, whiteheads and blackheads were significantly decreased at 1, 2 and 4weeks in the test group (P<0.05), but for the control group, whiteheads and blackheads showed a tendency to decrease at 1, 2 and 4weeks. Also at 1week, whiteheads and blackheads of the test group significantly decreased compared to the control group (P<0.05). Pore area and number significantly decreased at 1week (P<0.05), and the sebum output level was significantly decreased at 4weeks (P<0.05) only in the test group, which did not show any significant group difference for individual parameters. 4% AHA solution combined with a physical effect had rapidly improving effects on whiteheads and blackheads synergistically. Combined physical therapy may have more impact on pore size and seborrhoea.

Clinical tolerance and efficacy of capryloyl salicylic acid peel compared to a glycolic acid peel in subjects with fine lines/wrinkles and hyperpigmented skin

Several chemical agents are currently used to perform superficial peels of the face to reduce facial hyperpigmentation and fine lines/wrinkles. Some of the most commonly used agents are alpha hydroxyl acids, such as glycolic acid (GA), or beta hydroxy acid, such as salicylic acid. This study aims to compare the efficacy of GA to that of a novel derivative of salicylic acid, capryloyl salicylic acid (LHA). In a split-face study, 50 female volunteers between the ages of 35 and 60 years with mild to moderate facial hyperpigmentation and fine lines/wrinkles were randomized and LHA or GA peel was applied to one side of the face. Increasing peel concentrations were applied (5-10% LHA or 20-50% GA) based on the tolerance level of the subjects and clinical observations of an expert dermatologist for 12 weeks at biweekly intervals. Of the 44 volunteers who completed the study, at 12 weeks 41% of LHA-treated and 30% of GA-treated subjects demonstrated significant reduction of fine lines/wrinkles compared to baseline. Forty-six percent of LHA-treated subjects and 34% of GA-treated subjects showed significant reduction of hyperpigmentation compared to baseline. LHA treatment was better than GA peels, although there were no statistically significant differences between the two groups. Five percent to 10% of LHA peel is generally safe and as effective as 20-50% GA peel in reducing facial hyperpigmentation and fine lines/wrinkles.

Cleansing lotion containing tamarind fruit pulp extract. II. Study of cumulative irritation effects in human

Cleansing lotion containing extract of tamarind fruit pulp was developed to provide skin a lighter effect. Skin irritation may occur due to keratolytic effect of alpha-hydroxyl acids (AHA) in the tamarind fruit pulp extract. To assess the cumulative irritation effect of cleansing lotion containing tamarind fruit extract with 2% (w/w) tartaric acid on human skin compared with placebo product and de-ionized water. The study design was a single-blinded, randomized side of arm, and controlled study. Three samples, including test product, placebo product, and de-ionized water, were repeatedly applied on the inner forearm of 15 healthy females (aged 28.3 +/- 3.1 years) for 30 min daily for 5 days under semi-occlusive patch. Skin irritation was measured by using visual scoring and instruments such as Tewameter and Mexameter. All measurements were done before application of samples every day from day 1 until day 5. Final measurements were done after the last application for 3 days (day 8). The results obtained from the visual scoring scale indicated no irritation signs and symptoms of test product. Mean differences of transepidermal water loss and erythema values between test product and de-ionized water and between test and placebo products were not statistically significant (P > 0.05). These findings indicate a preliminary safety evidence of our developed cleansing lotion containing the natural AHAs and can be used as cumulative evidence for supporting the future home use study of this product in human.

Histopathological and ultrastructural effects of glycolic acid on rat skin

Use of alpha hydroxy acids (AHA) to ameliorate specific dermatological problems with keratinization has become fairly widespread. The aim of this study was to evaluate the effects of the AHA derivative of glycolic acid, applied in different dosages, on rat skin using light and electron microscopy. Skin biopsies were taken from the dorsal side of rats (n=16) and at the end of each week after applying solutions containing AHA: week 1, 8% (n=5); week 2, 50% (n=5); week 3, 70% (n=6). The skin samples were fixed in 10% formalin for histology and 2.5% glutaraldehyde solution for electron microscopy and processed using routine protocols. Histological sections were stained with hematoxylin and eosin (H&E), Masson's trichrome and were also labelled for binding of a primary antibody against collagen I using the avidin-biotin-peroxidase method. The epidermal thicknesses were measured and the fibroblast count of the dermis was taken and the results compared using the statistical ANOVA test. Semi-thin sections were stained with toluidine blue-azure II solution and ultrathin sections were contrasted with uranyl acetate and lead citrate. Histochemical and immunohistochemical observations demonstrated that AHA treatment resulted in statistically significant increased thickness of the epidermis and an increase in numbers of active fibroblasts and in the amount of dense collagen, especially at higher dosages of AHA. Ultrastructural examination of rat skin from AHA-treated groups showed cytoplasmic vacuolization in epidermal keratinocytes, intercellular dysjunctions, and increased quantities of organized bundles of collagen fibers in the dermis. The use of AHA in appropriate dosages has been found to play an important role in the treatment of specific skin disorders, however, the harmful effects of use of AHAs at higher concentrations should not be ignored. We conclude that alpha hydroxyl acids have a wide spectrum of use in the field of dermatology but, due to side-effects, their use, dosage, and time frame should be restricted to the advice of dermatologists.

Mauran, an exopolysaccharide produced by the halophilic bacterium Halomonas maura, with a novel composition and interesting properties for biotechnology.

Mauran is an anionic, sulfated heteropolysaccharide with a high uronic-acid content, synthesized by strain S-30 of the halophilic bacterium Halomonas maura. Under optimum environmental and nutritional conditions, it is capable of producing up to 3.8 g of mauran per liter of medium. Aqueous solutions of mauran are highly viscous and display pseudoplastic, viscoelastic and thixotropic behavior. Its viscosity is stable over a wide pH range (3-11), after freezing-thawing processes, and in the presence of sucrose, salts, surfactants and alpha-hydroxyl acids. It has a high capacity for binding lead and other cations. Its molecular mass when collected from an MY medium supplemented with 2.5% w/v salt during the stationary growth phase is 4.7x10(6) Da.

Biochemical and physicochemical determinations in a premyelin fraction obtained by zonal centrifugation in normal mouse and in dysmyelinating mutants (quaking, shiverer, and myelin-deficient).

Myelin and premyelin material denser than myelin were obtained from quaking (Qk), shiverer (Shi), and myelin-deficient (mld) mutant and control mice, using zonal centrifugation on zonal rotor. On these fractions, we performed biochemical analysis (lipids and fatty acid), and, in parallel, we determined the physical structure of membranes by the spin-label method. The hyperfine splitting constant (2 Tll) was used to determine the order of membranes and their rigidity, and frequency of rotation (Vc) was used to measure fluidity. In control mice, the premyelin material contained a lesser amount of sphingolipids than pure myelin, but the relative proportions between hydroxy- and nonhydroxy-cerebroside and sulfatides were similar in the premyelin material and in pure myelin. The premyelin material contained half the alkanes found in the pure myelin and much less very-long-chain fatty acids. The (2 Tll) was lower in the premyelin material, but the (Vc) was similar in myelin and premyelin material. In mutants, the amount of material recovered in the premyelin fraction was reduced in qk, and increased in both shi and mld. The relative amount of sphingolipids were normal in mld, but not in shi mutants, especially in cerebrosides formed with alpha-hydroxylated fatty acids and sulfatides formed with unsubstituted fatty acids. The absolute amounts of sphingolipids were nearly normal in both shi and mld. In the premyelin fraction from qk mutants, both relative and absolute amounts of sphingolipids were drastically altered. In percentage, cerebrosides and sulfatides formed with nonhydroxyfatty acids were dramatically reduced, and, conversely, cerebrosides and sulfatides formed with hydroxyfatty acids were increased. In terms of absolute amount, only cerebrosides and sulfatides formed with nonhydroxyfatty acids were dramatically reduced. In the premyelin fraction, polyunsaturated fatty acids were increased in shi and mld, but decreased in qk. In this mutant, lignoceric (24:0) and nervonic (24:1) acids were drastically reduced. The amount of alkanes in the premylin material from qk and mld was reduced by 50%. The shi fraction was nearly free of alkanes. The maximal apparent coupling constant (hyperfine splitting constant, 2 Tll) was not affected in the mld and qk mutant, but was reduced in the shi mutant premyelin fraction. The Vc was dramatically increased in the qk, slightly decreased in the shi, and close to control in the mld. This work provides additional data on premyelin material prepared in various neurological mutants using continuous gradients in zonal rotor.(ABSTRACT TRUNCATED AT 400 WORDS)