Safety Assessment of Glycerin as Used in Cosmetics.

This is a safety assessment of glycerin as used in cosmetics. Glycerin functions as a denaturant, fragrance ingredient, hair conditioning agent, humectant, oral care agent, oral health-care drug, skin protectant, skin conditioning agent-humectant, and viscosity-decreasing agent. The Cosmetic Ingredient Review Expert Panel (Panel) reviewed relevant animal and human data. The Panel concluded that glycerin is safe as a cosmetic ingredient in the practices of use and concentration described in this safety assessment.

Antiproliferative Acylated Glycerols from New Zealand Propolis.

Previous work has shown that a number of phenolic components of NZ propolis possess antiproliferative activity against certain human gastrointestinal cancer cell lines. Here we report on a series of acylglycerols isolated from the nonpolar fraction of propolis resin, which represent further bioactive constituents unrelated to the more usual phenolic compounds generally found in propolis. NZ propolis is sourced from poplar trees, and the acylglycerols have been shown to be present in the leaves and buds of some common poplars. The compounds are a series of monoglycerides containing 3,8-dihydroxy fatty acids, many of which are further acylated with acetic acid residues. The dihydroxy fatty acids are C18 to C24, with the most abundant being C20 and C22. These acylglycerols were found to have strong antiproliferative activity against three human gastrointestinal cell lines, particularly gastric cancer cell line NCI-N87, where one example shows an IC50 of less than 50 µM.

Potential of Fatty Oils from Traditional Chinese Medicine in Cancer Therapy: A Review for Phytochemical, Pharmacological and Clinical Studies.

Cancer management is a worldwide challenge. In addition to effective cancer therapies like chemotherapy, radiotherapy and surgery, treatment based on traditional Chinese medicine (TCM) and combined TCM with western medicine has gradually gained attention in Oriental countries. One potential TCM approach using extracted fatty oils, containing fatty acids which are important active ingredients with a variety of pharmacological activities, makes significant contributions to cancer treatment. The strategies of treating cancer with the fatty oils of TCM were classified into "Fuzheng", which usually associates with improving immunity, represented by coix seed oil. The other classification is "Quxie", which relates to inducing apoptosis of cancer cells, and is represented by Brucea javanica oil. Compared with other active substances, the literature about anticancer fatty oils is relatively limited, and most of them focus on the composition and other biological activities without a systematic review. Therefore, based on the theories of "Fuzheng" and "Quxie" in TCM, in this paper, the anticancer effects of fatty oils have been reviewed. The chemical composition, anticancer mechanism, listed drugs, studying dosage form and clinical application of fatty oils have also been discussed. In summary, since there are different types and abundance of fatty oils among botanicals, anticancer effects of fatty oils can be achieved through two TCM theory-based strategies. We hoped that this review paper can reveal the anticancer potential of fatty oils and provide a reference for future related studies.

Study on the adsorption behavior of glycerin from fatty acid methyl esters by a tertiary amine-type anion exchange resin.

A weakly basic anion exchange resin with hydroxylated tertiary amine groups was successfully synthesized and used for the first time in an adsorption study for glycerin in fatty acid methyl esters (FAME). A kinetic study of glycerin adsorption on the resin demonstrated that the resin exhibited a rapid initial adsorption behavior, and the correlation coefficients (r22) of the pseudo-second order reaction model were all greater than 0.98, which indicated the existence of hydrogen bonds through sharing electrons between glycerin and active sites on the resin. The whole process of glycerin adsorption onto the resin was a combination mechanism involving hydrogen bond sorption and intraparticle diffusion. The thermodynamic experiments showed that the glycerin adsorption onto the resin was a spontaneous exothermic process accompanied with a gradual decrease in entropy. In addition to intraparticle diffusion, the adsorption behaviors of the resin for glycerin also involved hydrogen bond forces between the OH in the glycerin molecule and N atom in the N(CH3)2 group, glycerin intermolecular hydrogen bond attraction, the dipole bond forces between glycerin and the N(CH3)2 group (90.96%) in the resin, and the dipole bond forces between glycerin and several of the N(CH3)3+ groups (9.04%) in the resin.

p-Toluenesulfonic Acid-based Deep Eutectic Solvent as Transesterification Catalyst for Biodiesel Production.

In this study, acidic deep eutectic solvents (DESs) have been studied as catalyst in transesterification of soybean oil with methanol to produce biodiesel. p-Toluenesulfonic acid-based deep eutectic solvent (P-DES), composed of p-toluenesulfonic acid and choline chloride (1:3, mol/mol), was found to be an efficient transesterification catalyst for biodiesel production. The optimum conditions for the transesterification process were as follows: 8% P-DES catalyst, 8:1 molar ratio of methanol to oil, reaction temperature of 110°C and 2 h reaction time. The transesterification yield could reach 98.66±0.17%. And the P-DES exhibited as a heterogeneous catalyst after the reaction, which could be separated easily. And P-DES could remove the trace amount of by-product (glycerol) in the final biodiesel product, making this process more simple and cleaner.

Lipase catalysed biodiesel synthesis with integrated glycerol separation in continuously operated microchips connected in series.

Although the application of microreactors in different processes has been extensively explored in recent decades, microreactors continue to be underexplored in the context of the enzyme-catalysed process for biodiesel production. Due to their numerous advantages, microreactors could become the next step in the development of a biodiesel production process characterised by sustainability, cost-effectiveness and energy efficiency. In this investigation, biodiesel production was catalysed by lipase from Thermomyces lanuginosus (Lipolase L100). Edible sunflower oil was used as a model substrate in order to investigate the process. After optimal process conditions had been determined, waste-cooking oil was used for biodiesel production to make the production process more sustainable. Three different substrate-feeding strategies were investigated and finally an optimal strategy was proposed. In all the investigated systems, fatty acids methyl esters (FAME) content was higher than 95% and obtained in a significantly shorter time (less than 2 h) compared to the batch process in which biodiesel production was catalysed by lipase (C = 95%, t = 96 h). After the optimal biodiesel production system had been proposed, an integrated system with two microchips connected in series was developed. The first microchip was used for biodiesel production and the second for simultaneous purification i.e. glycerol separation. Finally, purified biodiesel was produced with glycerol content below the detection limit.

Cycloartane-type triterpene glycosides anopanins A-C with monoacyldigalactosylglycerols from Anodendron paniculatum.

Three cycloartane-type triterpene glycosides (anopanins A-C), together with three known monoacyldigalactosylglycerols gingerglycolipids A-C and (2S)-1-O-palmitoyl-3-O-[α-d-galactopyranosyl-(1→6)-ß-d-galactopyranosyl]-sn-glycerol, were isolated from the aerial parts of Anodendron paniculatum collected in Viet Nam. The chemical structures of the present compounds were elucidated by means of 1D and 2D NMR and HRESIMS spectroscopy, and by comparing to the reported data in the literature. These compounds did not show significant growth inhibitory activities (IC50 > 100 µg/mL) against the tested cancer cell lines LU-1 (lung adenocarcinoma), KB (epidermoid carcinoma), Hep-G2 (hepatoma cancer), MKN-7 (stomach cancer), and SW-480 (colon adenocarcinoma).

Bioanode with alcohol dehydrogenase undergoing a direct electron transfer on functionalized gold nanoparticles for an application in biofuel cells for glycerol conversion.

In this paper we designed and investigated bioanode with alcohol dehydrogenase (ADH) catalysing oxidation of glycerol and glyceraldehyde. The most effective bioanode was fabricated when ADH was immobilized on gold nanoparticles (AuNPs) modified with 4-aminothiophenol. This electrode catalysed the oxidation of both glycerol and glyceraldehyde thus demonstrating a consecutive two-step process. The bioanode generated the current density of 510µAcm-2 at pH 7.0 and 0V vs. SCE. It was demonstrated that the electrode acted effectively due to the direct electron exchange between heme of ADH and modified AuNPs. The reversible oxidation and reduction of ADH heme proceeded at around -0.05V vs. SCE. The turnover number of the immobilized enzyme was estimated to be 65s-1 which is the same as the catalytic number of the enzyme in solution. To the best of our knowledge those parameters are the highest currently reported for the alcohol dehydrogenase bioanodes operating utilizing a direct electron transfer. As a proof of biofuels cell conception, the bioanode was combined with AuNPs-laccase biocathode. The biofuel cell generated maximum power output of 130µWcm-2 at 0.5V and pH 7.0.

E-cigarette liquids: Constancy of content across batches and accuracy of labeling.

AIMS: To assess whether bottles of refill liquids for e-cigarettes were filled true to label, whether their content was constant across two production batches, and whether they contained impurities. METHODS: In 2013, we purchased on the Internet 18 models from 11 brands of e-liquids. We purchased a second sample of the same models 4months later. We analyzed their content in nicotine, anabasine, propylene glycol, glycerol, ethylene glycol and diethylene glycol, and tested their pH. RESULTS: The median difference between the nicotine value on the labels and the nicotine content in the bottles was 0.3mg/mL (range -5.4 to +3.5mg/mL, i.e. -8% to +30%). For 82% of the samples, the actual nicotine content was within 10% of the value on the labels. All models contained glycerol (median 407mg/mL), and all but three models contained propylene glycol (median 650mg/mL). For all samples, levels of anabasine, ethylene glycol and diethylene glycol were below our limits of detection. The pH of all the e-liquids was alkaline (median pH=9.1; range 8.1 to 9.9). The measured content of two batches of the same model varied by a median of 0% across batches for propylene glycol, 1% for glycerol, 0% for pH, and 0.5% for nicotine (range -15% to +21%; 5th and 95th percentiles: -15% and +10%). CONCLUSIONS: The nicotine content of these e-liquids matched the labels on the bottles, and was relatively constant across production batches. The content of propylene glycol and glycerol was also stable across batches, as was the pH.

Unloading of cryoprotectants from cryoprotectant-loaded cells on a microfluidic platform.

In this paper, a multistep dilution-filtration microdevice (MDFD) is developed for unloading cryoprotectants from cryoprotectant-loaded cells. The MDFD contained a diluent producing region, a dilution-filtration execution region, and a filtrate collection region. It was made of two patterned PMMA stamps with four pieces of sandwiched PVDF membranes. Firstly, the performances of the mixers that were used in the diluent producing region and the dilution-filtration execution region were assessed using fluorescence experiments. Then, the effect of the MDFD structure on the loss of cells was investigated by applying the MDFD to unload glycerin from glycerin-loaded porcine red blood cells. Finally, the effects of the cell density, glycerin concentration, and membrane pore size on the clearance efficiency of glycerin (C G ), the survival rate of cells (S C ) and the recovery rate of cells (R C ) have been studied. Under the designed conditions, C G achieved ~80% and S C reached ~90%. However, R C was only ~40%, mainly resulting from the cells detained on the membrane surface and squeezed through the membrane pores into the filtrate. Increasing the membrane pore size caused high C G and S C , but low R C . For a low glycerin concentration, C G , S C , and R C were all high. For a high cell density, C G was high, but both S C and R C were low. This work is of significance to develop a microfluidic chip for unloading cryoprotectants from a small amount of cryopreserved cell samples.

Chemical constituents of the aerial part of Taraxacum mongolicum and their chemotaxonomic significance.

A phytochemical investigation of Taraxacum mongolicum led to the isolation of 24 compounds, including six flavonoids (1-6), four sesquiterpenes (7-10), two sphingolipids (11 and 12), six glycerols (13-18) and six triterpenoids and sterols (19-24). The structures of these compounds were identified by spectroscopic methods, and their data compared with those reported in the literature. This is the first report of compounds 11-19 from T. mongolicum and the genus Taraxacum, and compounds 11, 12, 15, 16, 18 and 19 from the Asteraceae family. The chemotaxonomic relationship between T. mongolicum and other Taraxacum species is also discussed.

New mono-ether of glycerol and triterpenes with DPPH radical scavenging activity from Cameroonian propolis.

The extracts of some propolis samples were analysed by GC-MS and then purified by column chromatography. The latter led to the isolation of a new mono-ether of glycerol, 1'-O-eicosanyl glycerol and a new triterpene, methyl-3ß,27-dihydroxycycloart-24-en-26-oate together with known triterpenoids namely betulin, 3ß-hydroxylanostan-9,24-dien-21-oic acid, mangiferonic acid, a mixture of ambolic acid and ß-sitosterol, 3ß-hydroxycycloartan-12,24(25)-diene and 27-hydroxymangiferonic acid. The DPPH radical scavenging potential of some extracts and compounds were measured. The radical scavenging activity varied from Hexane extract of Foumban propolis (IC50 = 5.6 mg/mL) to Methanol extract of Foumban propolis (IC50 = 1.07 mg/mL) for the extracts and from 3ß-hydroxylanostan-9,24-dien-21-oic acid (IC50 = 1.22 mg/mL) to 1'-O-eicosanyl glycerol (IC50 = 0.93 mg/mL) for the compounds. Activities of samples were moderate as they remained closer to those of the standard antioxidants Gallic acid (IC50 = 0.30 mg/mL) and vitamin C (IC50 = 0.80 mg/mL), especially 1'-O-eicosanyl glycerol, the most active compound.

Determination of 3-Monochloropropane-1,2-diol and 2-Monochloropropane-1,3-diol (MCPD) Esters and Glycidyl Esters by Microwave Extraction in Different Foodstuffs.

This paper describes a method for the determination of 3-monochloropropane-1,2-diol and 2-monochloropropane-1,3-diol (MCPD) esters and glycidyl esters in various foodstuffs, which are isolated using microwave extraction. The next step is based on alkaline-catalyzed ester cleavage. The released glycidol is transformed into monobromopropanediol (MBPD). All compounds are derivatized in free diols (MCPD and MBPD) with phenylboronic acid and analyzed by gas chromatography-mass spectrometry (GC-MS). The method was validated for oils with a limit of quantitation (LOQ) of 0.1 mg/kg, for chips and crisps with a LOQ of 0.02 mg/kg, and for infant formula with a LOQ of 0.0025 mg/L. Recoveries of each sample were controlled by standard addition on extracts before derivatization. Quantitation was performed by the addition of isotopically labeled glycidyl and 3-monochloropropane-1,2-diol (3-MCPD) esters.

Alkylglycerols reduce serum complement and plasma vascular endothelial growth factor in obese individuals.

Alkylglycerols (AKGs), isolated or present in shark liver oil have anti-inflammatory properties. Complement 3 (C3) and 4 (C4) participate in lipid metabolism and in obesity, contributing to the metabolic syndrome and to the low-grade inflammation associated with obesity. In a randomized, controlled, crossover study, 26 non-diabetes obese individuals were assigned two preparations with low (LAC, 10 mg AKGs) and high (HAC, 20 mg AKGs) AKG content. Intervention periods were of 3 weeks preceded by 2-week washout periods in which shark liver oil was avoided. Cholesterol, C3, C4, and vascular endothelial growth factor (VEGF) decreased in a linear trend (P < 0.01) from baseline (control) to LAC and HAC. Values after HAC were significantly lower (P < 0.05) versus both baseline and after LAC. No adverse effects were observed or reported. Data from this pilot study open a promising field for the study of the beneficial effects of AKGs on cardiovascular risk factors in obese individuals.

1-Acetyl-3-[(3R)-hydroxyfatty acyl]glycerols: Lipid Compounds from Euphrasia rostkoviana Hayne and E. tetraquetra (Bréb.) Arrond.

Five homologous acetylated acylglycerols of 3-hydroxyfatty acids (chain lengths C(14) - C(18)), named euphrasianins A - E, were characterized for the first time in Euphrasia rostkoviana Hayne (Orobanchaceae) by gas chromatography/mass spectrometry (GC/MS) and high-performance liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (HPLC/APCI-MS(n) ). In addition to mass spectrometric data, structures of euphrasianins were verified via a three-step total synthesis of one representative homologue (euphrasianin A). The structure of the latter was confirmed by 1D- and 2D-NMR experiments as well as high-resolution electrospray ionization-mass spectrometry (HR-ESI-MS). The absolute configuration of the 3-hydroxyfatty acid moiety at C(3) was found to be R in the natural euphrasianins, which was determined by alkaline hydrolysis and methylation of a purified fraction, followed by chiral GC analysis. Furthermore, in extracts of Euphrasia tetraquetra (Bréb.) Arrond. euphrasianins C and E were detected exclusively, indicating that this subclass of lipid constituents is possibly valuable for fingerprinting methods.

Value-added processing of crude glycerol into chemicals and polymers.

Crude glycerol is a low-value byproduct which is primarily obtained from the biodiesel production process. Its composition is significantly different from that of pure glycerol. Crude glycerol usually contains various impurities, such as water, methanol, soap, fatty acids, and fatty acid methyl esters. Considerable efforts have been devoted to finding applications for converting crude glycerol into high-value products, such as biofuels, chemicals, polymers, and animal feed, to improve the economic viability of the biodiesel industry and overcome environmental challenges associated with crude glycerol disposal. This article reviews recent advances of biological and chemical technologies for value-added processing of crude glycerol into chemicals and polymers, and provides strategies for addressing production challenges.

Genetic determinants for enhanced glycerol growth of Saccharomyces cerevisiae.

The yeast Saccharomyces cerevisiae generally shows a low natural capability to utilize glycerol as the sole source of carbon, particularly when synthetic medium is used and complex supplements are omitted. Nevertheless, wild type isolates have been identified that show a moderate growth under these conditions. In the current study we made use of intraspecies diversity to identify targets suitable for reverse metabolic engineering of the non-growing laboratory strain CEN.PK113-1A. A genome-wide genetic mapping experiment using pooled-segregant whole-genome sequence analysis was conducted, and one major and several minor genetic loci were identified responsible for the superior glycerol growth phenotype of the previously selected S. cerevisiae strain CBS 6412-13A. Downscaling of the major locus by fine-mapping and reciprocal hemizygosity analysis allowed the parallel identification of two superior alleles (UBR2CBS 6412-13A and SSK1CBS 6412-13A). These alleles together with the previously identified GUT1CBS 6412-13A allele were used to replace the corresponding alleles in the strain CEN.PK113-1A. In this way, glycerol growth could be established reaching a maximum specific growth rate of 0.08h(-1). Further improvement to a maximum specific growth rate of 0.11h(-1) could be achieved by heterologous expression of the glycerol facilitator FPS1 from Cyberlindnera jadinii.

1-Acyl-3-0-[ß-glucopyranosyl-(1"-+ 6')-ß-glucopyranosyl]-glycerols and Cordycedipeptides B and C, New Metabolites from Bacillus pumilus.

Four 1-monoacyl-3-0-[ß-glucopyranosyl-( ->6)-ß-glucopyranosyl]-glycerols (1) and four 1,2-diacyl-3-0-[p-glucopyranosyl-(1->6)-p-glucopyranosyl]- glycerols (2a) with acyl residues consisting of 1:1 mixtures of 1-iso-pentadecanoyl- and 1 -anteiso-pentadecanoyl residues and the respective heptadecanoic acid isomers s as main components, have been characterized in the extracts of Bacillus pumilus strain DKS 1. Twenty-seven further metabolites, among them the diketopiperazines cordycedipeptide A (3), B (4), and C (5), were obtained. All compounds were elucidated by NMR and MS techniques and fully characterized and tested for antimicrobial activity against Legionella pneumophila.

Utilization of Stearic acid Extracted from Olive Pomace for Production of Triazoles, Thiadiazoles and Thiadiazines Derivatives of Potential Biological Activities.

Olive Pomace was firstly dried, then pomace olive oil was extracted, and the obtained oil was hydrolyzed to produce glycerol and mixture of fatty acids. Fatty acids mixture was separated, this mixture was then cooled, where the all saturated fatty acids were solidified, and then they were filtered off. These saturated fatty acids were identified by GC mass after esterification, and were identified as stearic, palmitic and myristic acids. Stearic acid was extracted using supercritical CO2 extractor. The stearic acid was confirmed by means of GC mass after its esterification, and it was used as starting material for preparation of a variety of heterocyclic compounds, which were then tested for their antimicrobial activities. Thus the long-chain fatty acid hydrazide (2) was prepared from the corresponding long-chain fatty ester with hydrazine hydrate. Reacting 2 with phenyl isothiocyanate afforded the corresponding thiosemicarbazide 4. The later 4 underwent intramolecular cyclization in basic medium, and gave the s-triazole derivative 5, which was methylated and afforded 3-heptadecanyl-5-(methylthio)-4-phenyl-4H-1,3,4-triazole (7), which was then treated with hydrazine hydrate and afforded the corresponding 1-(5-heptadecanyl-4-phenyl-4H-1,2,4-triazol-3-yl) hydrazine (8).On the other hand, thiosemicarbazide 4 underwent intramolecular cyclization in acid medium and afforded the corresponding thiadiazole derivative 6.Treatment of thiosemicarbazide 4 with ethyl chloro(arylhydrazono) acetate derivatives 9a-b, furnished a single product 13 (Scheme 6). Similarly, when the thiosemicarbazide 4 was treated with the phenylcarbamoylarylhydrazonyl chloride 10a-c, it afforded (3-Aryl-N-5-(phenylcarbamoyl)-1,3,4-thiadiazol-2(3H)-ylidene)octadecanehydrazide 15a-c (Scheme 7). Also the reaction of thiosemicarbazide 4 with 2-oxo-N-arylpropanehydrazonoyl chlorides 11a-c and N-phenylbenzohydrazonoyl chloride 11d gave the corresponding thiadiazole derivatives 16a-d as shown in Scheme 8. A solution of thiosemicarbazide 4 was treated with the haloketones 17a-c, afforded the thiadiazine derivatives 20a-c, as shown in Scheme 9. Analogously, the thiosemicarbazide 4 was reacted with α-haloketones 21a-b and afforded the corresponding products 22a-b (Scheme 9). The structure elucidation of all synthesized compounds is based on the elemental analysis and spectral data (IR, 1H NMR, 13C NMR and MS).