Citrus aurantium L. essential oil is commonly used as a flavouring agent. In the present study, the essential oil of fresh Citrus aurantium L. (CaEO) flowers cultivated in North East of Tunisia (Nabeul) was analyzed by GC-FID and GC-MS. 33 compounds were identified, representing 99% of the total oil. Limonene (27.5%) was the main component followed by E-nerolidol (17.5%), α-terpineol (14%), α-terpinyl acetate (11.7%) and E. E-farnesol (8%). The antimicrobial activity of the CaEO was evaluated against a panel of 13 bacteria and 8 fungal strains using agar diffusion and broth microdilution methods. Results have shown that the CaEO exhibited moderate to strong antimicrobial activity against the tested species. The investigation of the mode of action of the CaEO by the time-kill curve showed a drastic bactericidal effect after 5 min using a concentration of 624 μg/ml. The antioxidant activities of the CaEO were assayed by DPPH and beta carotene tests. Results showed that CaEO displayed an excellent DPPH scavenging ability with an IC50 of 1.8 μg/ml and a strong Beta-carotene bleaching inhibition after 120 min of incubation with an IC50 of 15.3 μg/ml. The results suggested that the CaEO possesses antimicrobial and antioxidant properties, and is therefore a potential source of active ingredients for food and pharmaceutical industry.
Chlorella contains a high amount of carotenoids, especially lutein, and has received attention as a possible dietary source for improving carotenoid levels in human blood. In the present study, we performed a 2-month single arm human study, and investigated the efficacy of Chlorella supplementation (9 g Chlorella/day; equivalent to 32 mg lutein/day) on lutein and other carotenoid concentrations in plasma as well as erythrocytes of 12 healthy subjects. Following Chlorella supplementation, lutein was the predominant carotenoid in erythrocytes, showing a 4-fold increase (from 14 to 54 pmol/mL packed cells). After the one month without Chlorella ingestion, erythrocyte lutein then decreased to a basal level (17 pmol/mL packed cells). Erythrocyte carotenoid (lutein, zeaxanthin, α-carotene, and β-carotene) levels were proportional to plasma carotenoid levels. The results suggest the transfer of Chlorella carotenoids, especially lutein, from plasma lipoprotein particles to the erythrocyte membrane. Chlorella intake would be effective for improving and maintaining lutein concentrations in human erythrocytes.
The gas chromatography–flame ionization detector equipped with a higher polarity column (i.e., SP-2560) has often been used for the quantification of trans-fatty acids in food. In particular, AOCS Ce 1h-05, the official method of the American Oil Chemists’ Society (AOCS), is a highly effective method to separate the isomers of trans-fatty acids. In this study, the resolution behavior and the response factors of cis- and trans-octadecenoic acid methyl ester (C18:1-ME) isomers separated by the AOCS Ce 1h-05 method were investigated, and the contents of each cis- and trans-C18:1-ME isomer in partially hydrogenated vegetable oil (PHVO) and milk fat were quantified by using the calibration curves obtained for the respective isomers. The relative response factors for the trans- and cis-C18:1-ME isomers against the internal standard heneicosanoic acid methyl ester (C21:0-ME) were 1.031 ± 0.040 (mean ± SD) and 0.990 ± 0.032, respectively. The relative response factors of trans-isomers tend to be higher than those of cis-C18:1-ME isomers. The peaks of cis-4-C18:1-ME, cis-5-C18:1-ME, cis-6-C18:1-ME, cis-7-C18:1-ME, cis-8-C18:1-ME, and cis-9-C18:1-ME isomers overlapped with those of trans-C18:1-ME isomers. Both PHVO and milk fat contained many types of cis- and trans-C18:1 isomers, and the total contents of the trans-C18:1 isomer in PHVO and milk fat were 28.01 g and 3.62 g per 100 g oil, respectively. When the trans-C18:1-ME isomer was separated from the cis-C18:1-ME by using a silver-ion cartridge column before the analyses, the total contents of the trans-C18:1 isomer in PHVO and milk fat were 23.03 g and 2.78 g per 100 g oil, respectively. The difference in the trans-C18:1 isomer content between the two methods was ascribed to the partial overlapping of cis-isomer peaks with the peaks of trans-C18:1-ME isomers, in the chromatogram.
Triacylglycerol (TAG) molecular species were quantified through high-performance liquid chromatography (HPLC) equipped with a nano quantity analyte detector (NQAD). TAG standard compounds, i.e., 1,3-dipalmitoyl-2-oleoylglycerol (β-POP), 1-palmitoyl-2-oleoyl-3-stearoyl-rac-glycerol (β-POS), and 1,3-distearoyl-2-oleoylglycerol (β-SOS), and natural cocoa butter were used for analyses. NQAD gave the first order equation passing through the origin for all TAG standard compounds. TAG molecular species in cocoa butter were quantified using the calibration curves and the obtained values were almost the same as the reported ones of conventional cocoa butter. Furthermore, a recovery test was also carried out and the values were almost 100. Therefore, HPLC-NQAD can be successfully used for the quantification of TAG molecular species in natural fats and oils.
The crystal of spiculisporic acid, [4S, 5S-(4,5-dicarboxy-4-pentadecanolide)], is orthorhombic, and the space group is P21 21 21 with Z = 4 at 23°C. The cell dimensions are as follows, a = 43.82 (1) Å, b = 7.540 (2) Å, c = 5.579 (2) Å, V = 1843 (1) Å3. The molecules form intermolecular networks linked by hydrogen bonds around their polar carboxylic moieties. The hydrophobicity of the lactone ring (γ-butanolide) was evaluated at ca. 4 methylene linkages of n-alkyl chain from both of the molecular alignmental data and the surface active properties of sodium spiculisporates. Then, it was made clear that sodium spiculisporates, anionic polyfunctional biosurfactants, exerted a distinctive characteristic of lower critical micelle concentration (cmc) and γcmc (surface tension at the cmc), simultaneously, through their properties. On the other hand, sodium salts of the lactone-cleaved derivative of spiculisporic acid (O-acid), showed large dispersing and calcium ion sequestration properties due to their plural polar heads.
Phase behaviors in water/poly(oxyethylene) dodecyl ether (C12EOn, n = 4, 6, 8)/cetyl isooctanoate (CIO) systems were studied. In the C12EO6 and C12EO8 systems, self-assembled structures with positive curvatures, such as O/W microemulsions, and micellar cubic and hexagonal phases, were observed. A wider region of a lamellar liquid-crystalline phase, which included a narrow microemulsion region joined by a miscibility gap, was observed in the C12EO4 system. The structure of the microemulsion phase in the C12EO4 system was characterized by pulsed-field-gradient NMR (PFG-NMR) and small angle X-ray scattering (SAXS) techniques. PFG-NMR measurements indicated that the structure of the microemulsion was bicontinuous; both water and oil phases were continuous within the microemulsion. Pair-distance distribution function, p (r), and structure factors obtained by Generalized Indirect Fourier Transformation (GIFT) analysis of the SAXS data showed that the microemulsion domain sizes decreased with an increase in the oil content. The structure of the bicontinuous microemulsion was consistent with the results of a detergency test, in which the microemulsion samples were applied to lipstick dirt on an artificial skin plate. Detergency was observed to be better for the microemulsion at lower oil contents because of the larger oil domain size at these low concentrations.
The miscibility behavior of palmitoyl sphingomyelin (PSM) with phytosterol derivatives of β-sitosterol (SITO), β-sitosteryl glucoside (SG), and β-sitosteryl glucoside palmitate (SGP) was systematically investigated using Langmuir monolayers. The surface pressure (π)–molecular area (A) and surface potential (ΔV)–A isotherms for binary PSM/SITO, PSM/SG, and PSM/SGP systems on 0.02 M Tris buffer with 0.13 M NaCl (pH 7.4) were measured as a function of the molar fraction of PSM (XPSM). The surface potentials (ΔV) of the pure components were analyzed using the three-layer model proposed by Demchak and Fort [J. Colloid Interface Sci. 46 (1974) 191–203]. The contributions of the hydrophilic D-glucose moiety, hydrophobic palmitoyl group, and sphingomyelin group to the vertical component of the dipole moment (μ⊥) were evaluated. The thermodynamic quantities, based on the π–A isotherms, revealed that PSM interacts attractively with all three phytosterol derivatives in the following order: SITO > SGP > SG. In addition, the two-dimensional phase diagram constructed based on the phase transition pressure (πeq), from a liquid-expanded to liquid-condensed state, and collapse (πc) pressure shows that the two-component systems are all miscible with each other. The manner of miscibility between PSM/SG and PSM/SGP systems is found to be opposite in the large XPSM region. The interaction between the same molecules (PSM–PSM or SG–SG) is stronger than that of the different molecules (PSM–SG) in the PSM/SG system, and vice versa in the PSM/SGP system. These results suggest that the incorporation of a D-glucose and palmitoyl group to a SITO molecule dramatically changes the miscibility behavior with PSM. Observations using fluorescence microscopy imaging also provide insights into miscibility behavior in the monolayer state.
In this study, we examined whether tocotrienol (T3) reduces allergic dermatitis in mice and suppresses degranulation of mast cells. First, allergic dermatitis was examined in the atopic dermatitis model NC/Nga mouse. Allergic dermatitis was induced using picryl chloride in mice with and without administration of T3 (1 mg/day/mouse). Increases in scratching behavior, dermal thickening, and the serum histamine level were greatly reduced in mice treated with T3, indicating that T3 reduces allergic dermatitis in vivo. Next, the effect of T3 on degranulation of mast cells was examined, since these cells release bioactive substances such as histamine. T3 significantly suppressed degranulation of mast cells and significantly reduced histamine release. The effect of T3 on protein kinase C (PKC) activity was also measured, since suppression of this activity may be associated with the mechanism underlying the antidegranulation effect of T3. T3 significantly suppressed PKC activity. Therefore, we conclude that T3 suppresses degranulation of mast cells and reduces allergic dermatitis in mice through reduction of PKC activity.
Some acetic acid bacteria have been shown to produce large amounts of glyceric acid (GA) from glycerol, which is a by-product of biodiesel fuel (BDF) production. Previously, a Gluconobacter strain was found that produced decreased amounts of GA from glycerol in the presence of methanol, a major ingredient of raw glycerol derived from the BDF industry. Thus, a comparative transcriptome analysis of Gluconobacter frateurii NBRC103465 was performed to investigate changes in gene expression during GA production from glycerol in the presence of methanol. Cells grown with methanol showed upregulated expression of a class III alcohol dehydrogenase homolog (adhCGf) and decreased GA production. adhCGf was cloned and expressed heterologously in Escherichia coli, and the presence of an additional protein with an approximate molecular mass of 39 kDa in the cytosol of the recombinant E. coli cells was identified by SDS-PAGE. Activity measurements of the cytosol revealed that the translational product of adhCGf exhibited formaldehyde dehydrogenase activity in the presence of nicotinamide adenine dinucleotide and glutathione. Gluconobacter frateurii cells grown in 1% methanol-containing glycerol were found to have fivefold higher formaldehyde dehydrogenase activity than cells grown without methanol, suggesting that adhCGf in G. frateurii cells functions in the dissimilation of methanol-derived formaldehyde.
Polyalthia is a versatile genus of shrubs and trees found in tropic and sub-tropic regions. In this study, three clerodane diterpenes, kolavenic acid (1), polyalthialdoic acid (2), and 16α-hydroxy-cleroda-3,13(14)Z-dien-15,16-olide (3) isolated from Polyalthia longifolia leaves were evaluated for their apoptotic potential against human leukemia HL-60 cells. Compounds 2 and 3 inhibited cell proliferation with IC50 values of 21.8 and 13.7 μM, respectively. Morphological changes and DNA fragmentation analysis indicated that these diterpenes induce apoptotic cell death in the HL-60 cells. Our results revealed the importance of P. longifolia as a chemopreventive medicinal plant.
A convinent and efficient method was developed for the synthesis of 1,2-azidoalcohols by ring opening of terminal epoxides with sodium azide employing glycerol-based sulphonic acid functionalized carbon as heterogeneous catalyst in aqueous acetonitrile. The reaction is highly regioselective and affords the corresponding products in excellent yields (78-100%) under mild reaction conditions. The catalyst exhibited efficient reusability without loosing its activity even after 5 cycles of azidolysis of methyl 10,11-epoxy undecanoate under optimized conditions within 2 h.
To facilitate the development of bio-based chemicals from renewable and inexpensive natural resources, we sought to produce biosurfactants using non-edible jatropha oil. Twenty yeasts known to produce biosurfactants were tested in this study, and Stamerella bombicola NBRC 10243 was found to use jatropha oil efficiently to produce sophorolipids (SLs) as a mixture of lactone-form SL (L-SL) and acid-form SL (A-SL). Under culture conditions using rice bran as the source of organic nutrients, the yield of SLs reached 122.6 g/L in 5-L jar fermentors after 9 d in culture. HPLC analysis of the culture medium showed that the levels of phorbol esters (PEs), major toxic components of the oil, decreased markedly with an increase in culture time, suggesting that the yeast degrades PEs. Although the SLs obtained by solvent extraction of the culture medium contained a small amount of PEs, the sodium salt of A-SL (A-SL-Na) obtained by alkaline treatment (5N NaOH, 80°C) showed no PE peaks upon HPLC analysis. A-SL-Na had excellent surface activity with low CMC (9.0×10–4 M) and γCMC (29.6 mN/m), which are lower than that of sodium dodecyl sulfate (SDS). The solubilizing ability of A-SL-Na toward for octanoic acid ([octanoic acid]/[A-SL-Na]) was found to be 2.0, which is half that of SDS. Our findings should help improve SL production from non-edible feedstock and broaden the use of promising bio-based surfactants.