Palmitic Acid Methyl Ester Research Articles

Retina evokes biphasic relaxations in retinal artery unrelated to endothelium, K V, K ATP, K Ca channels and methyl palmitate

Retinal relaxing factor (RRF) is suggested to be released from the retina and to contribute in the maintenance of retinal arterial tone. Herein, we aimed to clarify the effects of retinal tissue in isolated bovine retinal arteries in comparison with choroidal tissue and to evaluate the possible role of endothelium and potassium channels. In parallel, the effects of palmitic acid methyl ester (PAME), a putative vasodilator proposed to be released from the retina, was also examined. A piece of bovine retinal or choroidal tissue was placed within a close proximity on top of retinal arteries mounted in a wire myograph and precontracted with noradrenaline, prostaglandin F 2α, endothelin-1, thromboxane A 2 mimetic, U46619 or potassium (K +). To elucidate possible mechanisms in the effects of retinal tissue, retinal arteries were either deendothelized or incubated with inhibitors of endothelial vasodilators, i.e. nitric oxide (NO) and prostaglandins, or K + channels. Unlike the choroid, retinal tissue produced rapid, biphasic and complete relaxations in isolated bovine retinal arteries precontracted with various spasmogens acting on distinct receptors. Endothelium removal or preincubation of retinal arteries with inhibitors of NO synthase; L-NOARG (10 − 4 M), guanylate cyclase; ODQ (10 − 5 M) and cyclooxygenase; indomethacin (10 − 5 M), did not cause a significant difference in the relaxation profile. Additionally, retinal relaxations remained unchanged in the presence of respective inhibitors of ATP-sensitive (K ATP) (glibenclamide, 10 − 5 M), voltage-dependent (K V) (4-aminopyridine, 2 × 10 − 3 M), and calcium-activated (K Ca) (tetraethylammonium 10 mM; charybdotoxin, 10 − 7 M; and apamin, 5 × 10 − 7 M) K + channels. Thus, our results provide novel evidence regarding the biphasic relaxing profile of RRF in the retinal artery which was unrelated to endothelium and K + channels (K ATP, K V and K Ca). Interestingly, PAME (10 − 14 –10 − 5 M) did not provoke a relaxation in bovine retinal artery suggesting no association with RRF.

Chlorella sp.: A new strain with highly saturated fatty acids for biodiesel production in bubble-column photobioreactor

The biodiesel production from a naturally isolated strain of Chlorella in 2 L bubble-column photobioreactor was studied. The microalgal strain was isolated from the rice paddy-field soil samples during a screening program. After 17 days, at the end of exponential phase of growth, the total content of the lipids was extracted. The extracted fatty acids were first esterified and then identified using GC/MS analysis. Several types of fatty acid methyl esters (FAMEs) were identified in the isolated microalga and the presence of saturated fatty acids in Chlorella sp. MCCS 040 was approved. The composition of fatty acids in the studied species of microalga was mainly palmitic acid methyl ester, myristic acid methyl ester, stearic acid methyl ester and undecanoic acid methyl ester. This strain because of its highly saturated fatty acids content can be an ideal candidate for biodiesel production.

Cinnamyl alcohols and methyl esters of fatty acids from Wedelia prostrata callus cultures

Two methyl esters of fatty acids, namely octadecanoic acid methyl ester (methyl stearate) (1) and hexadecanoic acid methyl ester (methyl palmitate) (2), in addition to four cinnamyl alcohol derivatives, sinapyl alcohol (3), coniferyl alcohol (4), p-coumaryl alcohol (5) and coniferyl alcohol 4-O-glucoside (coniferin) (6), were isolated from callus cultures of Wedelia prostrata. The structure of coniferin was established by spectroscopic and chemical methods, while the other compounds were identified by gas chromatography–mass spectrometry and thin layer chromatography in comparison with standards.

From organic waste to biodiesel: Black soldier fly, Hermetiaillucens, makes it feasible

Biodiesel is a renewable and environmentally friendly liquid fuel. However, the feedstock, predominantly crop oil, is a limited and expensive food resource which prevents large scale application of biodiesel. Development of non-food feedstocks are therefore, needed to fully utilize biodiesel’s potential. In this study, the larvae of a high fat containing insect, black soldier fly (Hermetiaillucens) (BSFL), was evaluated for biodiesel production. Specifically, the BSFL was grown on organic wastes for 10days and used for crude fat extraction by petroleum ether. The extracted crude fat was then converted into biodiesel by acid-catalyzed (1% H2SO4) esterification and alkaline-catalyzed (0.8% NaOH) transesterification, resulting in 35.5g, 57.8g and 91.4g of biodiesel being produced from 1000 BSFL growing on 1kg of cattle manure, pig manure and chicken manure, respectively. The major ester components of the resulting biodiesel were lauric acid methyl ester (35.5%), oleinic acid methyl ester (23.6%) and palmitic acid methyl ester (14.8%). Fuel properties of the BSFL fat-based biodiesel, such as density (885kg/m3), viscosity (5.8mm2/s), ester content (97.2%), flash point (123°C), and cetane number (53) were comparable to those of rapeseed-oil-based biodiesel. These results demonstrated that the organic waste-grown BSFL could be a feasible non-food feedstock for biodiesel production.

Composition of the CO2 extract of Eryngium planum

extraction.Table 1 shows that 55 components were observed in the extract. The principal ones were hexadecanoic acid (26.5%),7-(3-carboxybutyl-2-epoxy)coumarin (11.29), hexadecanoic acid methyl ester (8.05), dibutylphthalate (3.80), diisobutylphthalate(3.66), and phytone (3.08).Thus, the component composition of the CO

Ultrasound-Enhanced Subcritical Water Extraction of Volatile Oil from Lithospermum erythrorhizon

An ultrasonic probe was introduced into the kettle of subcritical water extraction device to extract volatile oil from Lithospermum erythrorhizon. The effect of temperature, pressure, ultrasonic power, and frequency on the extraction yield was studied. Gas chromatography-mass spectrometry (GC-MS) was applied to the analysis of the compositions of volatile oil. The mechanism of ultrasonic enhanced subcritical water extraction (USWE) was discussed. The results showed that the ultrasound-assisted enhancement effect of 20 KHz was better than that of 36 KHz and increased with output power (0 ∼ 250 W). The subcritical water extraction yield increased from 1.87% to 2.39% via ultrasonic oscillation (250 W, 20 KHz) at a temperature of 160°C and a pressure of 5 MPa in the 25-minute extraction. Nineteen components were identified chiefly consisting of 18 carbon unsaturated fatty acid methyl esters, hexadecanoic acid methyl ester and pentadecane. Mechanism of USWE was cavitation and mechanical effect.

Blends of biodiesels synthesized from non-edible and edible oils: Influence on the OS (oxidation stability)

Biodiesels jatropha and pongamia synthesized from their respective non-edible seed oils, and PBD (palm biodiesel) synthesized from edible oil were blended with different weight ratios to examine the influence on the OS (oxidation stability). Dependence of the OS on esters of fatty acid composition was also examined. Good correlation between the OS and PAME (palmitic acid methyl ester) was obtained. A correlation between the OS and X (total unsaturated fatty acid methyl ester) was also obtained. Using these correlations, OS of different biodiesel blends can be determined.

Methyl Palmitate: A Potent Vasodilator Released in the Retina

To determine whether palmitic acid methyl ester (PAME) or methyl palmitate is the retina-derived relaxing factor (RRF). A superfusion bioassay cascade technique was used with rat isolated retina as donor tissue and rat aortic ring as detector tissue. The superfusate was analyzed with gas chromatography/mass spectrometry (GC/MS). The biochemical and pharmacologic characteristics of RRF and PAME were compared. The authors demonstrated that the retina on superfusion with Krebs solution spontaneously released RRF (indicated by aortic ring relaxation) and PAME (measured by GC/MS). The release of RRF and PAME was calcium dependent because the release was abolished when the retinas were superfused with calcium-free Krebs solution. Furthermore, aortic relaxations induced by RRF and PAME were not affected after heating their solutions at 70 degrees C for 1 hour, suggesting that both are heat stable. Exogenous PAME concentration dependently induced aortic relaxation with EC50 of 0.82+/-0.75 pM. The aortic relaxations induced by RRF and exogenous PAME were inhibited by 4-aminopyridine (2 mM) and tetraethylammonium (TEA, 10 mM) but were not affected by TEA at 1 mM or 3 mM, glibenclamide (3 microM), or iberiotoxin (100 nM). The vasodilator activity of Krebs solution containing RRF or exogenous PAME was greatly attenuated after hexane extraction. RRF and PAME share similar biochemical properties and react similarly to all pharmacologic inhibitors examined. Both act primarily on the voltage-dependent K+ (Kv) channel of aortic smooth muscle cells, causing aortic relaxation. These results suggest that PAME is the hydrophobic RRF.

Blends of Biodiesels Synthesized from Non-edible and Edible Oils: Effects on the Cold Filter Plugging Point

To minimize use of biodiesels synthesized from edible oils, such as palm oil, because of the raising food versus fuel issue, palm biodiesel (PBD) was blended in different weight ratios with biodiesels synthesized from tree-borne non-edible oil seeds, jatropha and pongamia, to examine the effects on the cold filter plugging point (CFPP) of PBD. The CFPP of PBD improved significantly after blending with jatropha biodiesel (JBD) and pongamia biodiesel (PoBD). The dependence of CFPP upon the esters of fatty acid composition was also examined. Good correlations between the CFPP and palmitic acid methyl ester (PAME) were obtained. A correlation between CFPP and total unsaturated fatty acid methyl ester (X) was also determined. Using these two correlations, the CFPP of different biodiesel blends can be determined.

Pyrolysis of fermented mass containing microbial oil in a fixed-bed reactor for production of biodiesel

In our previous work, steam-exploded wheat straw has been used to produce microbial oil by solid-state fermentation for the purpose of exploring a potential oil resource for the production of biodiesel. After solid-state fermentation the oil content of the dry fermented mass was 10.2%. In the present work, this dry fermented mass was pyrolyzed in a fixed-bed reactor in order to convert the microbial oil to biodiesel. The maximum liquid product yield of 43.2% was obtained at the conditions of final temperature of 500 °C, heating rate of 40 °C/min and sweep gas flow rate of 40 cm 3/min (N 2). The liquid product was extracted with n-hexane and separated to n-hexane soluble fraction and n-hexane insoluble fraction. The two fractions were analyzed using GC/MS, respectively. The main compositions of n-hexane insoluble fraction were water, methanol, 1-hydroxy-2-propanone, furfural and acetic acid. The main compounds of the n-hexane soluble fraction were n-hexadecanoic acid, hexadecanoic acid methyl ester, 9-octadecenoic acid methyl ester, phenol and 4-methyl-phenol. The conversion rates of hexadecanoic acid methyl ester and 9-octadecenoic acid methyl ester can be increased by pyrolysis with catalyst permutit, the former increased from 6.3 to 30.0% and the latter increased from 4.2 to 10.3% with a catalyst ratio of 20% (w/w). It can be speculated that during pyrolysis, the fatty acid methyl esters were produced by transesterification of microbial oil with methanol which was another pyrolysis product of the fermented mass. This research found that the fatty acid methyl esters, which are used as biodiesel, can be produced by pyrolysis of the oleaginous materials for the first time, hence providing a potential way for the production of biodiesel by pyrolysis instead of the traditional processing of oil extraction and transesterification.

Ethnobotanical survey and cytotoxicity testing of plants of South-western Nigeria used to treat cancer, with isolation of cytotoxic constituents from Cajanus cajan Millsp. leaves

There is only scant literature on the anticancer components of medicinal plants from Nigeria, yet traditional healers in the area under study claim to have been managing the disease in their patients with some success using the species studied. To document plants commonly used to treat cancer in South-western Nigeria and to test the scientific basis of the claims using in vitro cytotoxicity tests. Structured questionnaires were used to explore the ethnobotanical practices amongst the traditional healers. Methanol extracts of the most common species cited were screened for cytotoxicity using the sulforhodamine B (SRB) assay in both exposure and recovery experiments. Three cancer cell lines (human breast adenocarcinoma cell line MCF-7, human large cell lung carcinoma cell line COR-L23 and human amelanotic melanoma C32) and one normal cell line (normal human keratinocytes SVK-14) were used for the screening of the extracts and the fractions obtained. The extract of Cajanus cajan showed considerable activity and was further partitioned and the dichloromethane fraction was subjected to preparative chomatography to yield six compounds: hexadecanoic acid methyl ester, alpha-amyrin, beta-sitosterol, pinostrobin, longistylin A and longistylin C. Pinostrobin and longistylins A and C were tested for cytotoxicity on the cancer cell lines. In addition, an adriamycin-sensitive acute T-lymphoblastic leukaemia cell line (CCRF-CEM) and its multidrug-resistant sub-line (CEM/ADR5000) were used in an XTT assay to evaluate the activity of the pure compounds obtained. A total of 30 healers from S W Nigeria were involved in the study. 45 species were recorded with their local names with parts used in the traditional therapeutic preparations. Cytotoxicity (IC(50) values less than 50 microg/mL) was observed in 5 species (Acanthospermum hispidum, Cajanus cajan, Morinda lucida, Nymphaea lotus and Pycnanthus angolensis). Acanthospermum hispidum and Cajanus cajan were the most active. The dichloromethane fraction of Cajanus cajan had IC(50) value 5-10 microg/mL, with the two constituent stilbenes, longistylins A and C, being primarily responsible, with IC(50) values of 0.7-14.7 microM against the range of cancer cell lines. Most of the species tested had some cytotoxic effect on the cancer cell lines, which to some extent supports their traditional inclusion in herbal preparations for treatment of cancer. However, little selectivity for cancer cells was observed, which raises concerns over their safety and efficacy in traditional treatment. The longistylins A and C appear to be responsible for much of the activity of Cajanus cajan extract.

Bio-oil production from sub- and supercritical water liquefaction of microalgae Dunaliella tertiolecta and related properties

Microalgae Dunaliella tertiolecta were studied for production of bio-oil through a sub- and supercritical water liquefaction process. The effects of liquefaction temperature, holding time, and feedstock ratio on the yields of the products were investigated. The maximum bio-oil yield is about 36.9%, obtained at a reaction temperature of 360 °C and a holding time of 30 min, with a feedstock ratio of materials to water of 1 : 10. The various physical and chemical characteristics of bio-oil obtained under the most suitable conditions were determined, and detailed chemical compositional analysis of bio-oil was performed using an elemental analyzer, Fourier transform infrared spectroscopy, and gas chromatography–mass spectrometry. The empirical formula of bio-oil with a heating value of 26.62 MJ kg−1 was established as CH1.38O0.43N0.07, and bio-oil was composed of hexadecanoic acid, palmitamide, and fatty acid methyl ester. Overall, the bio-oil obtained from microalgae Dunaliella tertiolecta were presented as a potentially valuable and environmentally friendly feedstock candidate for biofuels and chemicals.

Chlamydomonas as a “new” organism for biodiesel production

The production of biodiesel from a naturally isolated strain of Chlamydomonas was investigated. The microalgal strain was isolated from the rice paddy-field soil samples during a screening program. The identification was done using physiological and molecular approaches. After reaching the stationary phase of growth, the total content of the lipids was extracted. The extracted fatty acids were primarily esterified and then identified through TLC and GC/MS analysis. Several types of fatty acid methyl esters (FAMEs) were identified in the isolated microalga and the presence of at least nine FAMEs in Chlamydomonas sp. MCCS 026 was shown. The total fatty acid content of the isolated strain was 25%. The composition of fatty acids in the studied species of microalga was mainly docosanoic acid methyl ester, tetradecanoic acid methyl ester, hexadecanoic acid methyl ester and nonanoic acid methyl ester.

Effect of blends of Palm-Jatropha-Pongamia biodiesels on cloud point and pour point

To minimize use of biodiesels synthesized from edible oils like Palm due to raising food versus fuel issue, Palm biodiesel (PBD) was blended with biodiesels derived from tree borne non-edible oil seeds Jatropha, and Pongamia to examine the effect on cloud point (CP) and pour point (PP) of PBD. Dependence of CP and PP on esters of fatty acid composition was also examined. Good correlations between CP and palmitic acid methyl ester (PAME) and between PP and PAME were obtained. A correlation between CP and total unsaturated fatty acid methyl ester (X) was also obtained and correlation between PP and X was also determined. Using these four correlations, cloud and pour points of different biodiesel blends can be determined.

Comparative analysis of essential oils from eight herbal medicines with pungent flavor and cool nature by GC–MS and chemometric resolution methods

Systematic comparative research was conducted on essential oils from eight traditional Chinese medicines (TCM) of pungent flavor and cool nature because the essential oils are the main active ingredients of herbs of this kind. The work was based on their component analysis by gas chromatography-mass spectrometry (GC-MS), on their retention indices, as well as on chemometric resolution methods. A total of 144 compounds were tentatively identified, accounting for 69.0% to 91.8% of the total essential oils. It is worth noting that there are 67 compounds in at least three of these eight essential oils. Moreover, many biologically active compounds, such as hexanal, alpha-pinene, camphene, beta-pinene, p-cymene, limonene, eucalyptol, (Z)-ocimene, gamma-terpinene, camphor, p-menthone, 4-terpineol, alpha-terpineol, carvone, eugenol, caryophyllene, beta-farnesene, alpha-curcumene, beta-selinene, delta-cadinene, caryophyllene oxide, cedrol, n-hexadecanoic acid, benzaldehyde, benzeneacetaldehyde, phthalic acid diisobutyl ester, linoleic acid, tetradecanoic acid, (Z,Z,Z)-9,12,15-octadecatrienoic acid, eucalyptol, pentadecanoic acid, hexadecanoic acid methyl ester, linoleic acid methyl ester, exist in at least four of the eight essential oils. These results might help us to understand why the eight herbs are all of pungent flavor and cool nature according to the theory of TCM, and may provide a useful chemical basis for future research on herbs of this kind.

Lotus (Nelumbo nuficera) flower essential oil increased melanogenesis in normal human melanocytes

In this study, the essential oil from lotus flower extract, including petals and stamens, was assessed with regard to its effects on melanogenesis in human melanocytes. The lotus flower essential oil was shown to stimulate melanin synthesis and tyrosinase activity in a dose-dependent manner. The lotus flower essential oil induced the expression of tyrosinase, microphthalmia-associated transcription factor M (MITF-M), and tyrosinase-related proten-2 (TRP-2) proteins, but not tyrosinase mRNA. Moreover, it increased the phosphorylation of ERK and cAMP response element binding protein (CREB). In order to verify the effective components of the lotus flower oil, its lipid composition was assessed. It was found to be comprised of palmitic acid methyl ester (22.66%), linoleic acid methyl ester (11.16%), palmitoleic acid methyl ester (7.55%) and linolenic acid methyl ester (5.16%). Among these components, palmitic acid methyl ester clearly induced melanogenesis as the result of increased tyrosinase expression, thereby indicating that it may play a role in the regulation of melanin content. Thus, our results indicate that lotus flower oil may prove useful in the development of gray hair prevention agents or tanning reagents.

Endogenous methyl palmitate modulates nicotinic receptor-mediated transmission in the superior cervical ganglion

Nitric oxide (NO) is identified as the endothelium-derived relaxing factor and a neurotransmitter with a superfusion bioassay cascade technique. By using a similar technique with rat superior cervical ganglion (SCG) as donor tissue and rabbit endothelium-denuded aortic ring as detector tissue, we report here that a vasodilator, which is more potent than NO, is released in the SCG upon field electrical stimulation (FES) or addition of nicotine. Release of this vasodilator was enhanced by arginine analogs, including N(omega)-nitro-l-arginine (a NO synthase inhibitor), suggesting that it is not NO. Analysis by gas chromatography/mass spectrometry identified 2 saturated fatty acids, palmitic acid methyl ester (PAME) and stearic acid methyl ester (SAME), being released from the SCG upon FES in the presence of arginine analogs. Exogenous PAME but not SAME induced significant aortic dilation (EC(50) = 0.19 nM), indicating that PAME is the potent vasodilator. Release of PAME and SAME was significantly diminished in chronically decentralized SCG but not denervated SCG, suggesting the preganglionic origin. Furthermore, release of both fatty acids was calcium- and myosin light chain kinase-dependent, suggesting that both were released from axoplasmic vesicular stores. Electrophysiological studies further demonstrated that PAME but not SAME inhibited nicotine-induced inward currents in cultured SCG and the alpha7-nicotinic acetylcholine receptor-expressing Xenopus oocytes. Endogenous PAME appears to play a role in modulation of the autonomic ganglionic transmission and to complement the vasodilator effect of NO.

Performance of Φ‐Sulfo Fatty Methyl Ester Sulfonate Versus Linear Alkylbenzene Sulfonate, Secondary Alkane Sulfonate and α‐Sulfo Fatty Methyl Ester Sulfonate

AbstractSulfoxidation of fatty acid methyl esters with SO2, O2 and ultraviolet light of appropriate wavelength, has led to the synthesis of methyl esters sulfonates or sulfoxylates, known as Φ‐MES, because of the possible random position of SO3 group in the alkyl chain. Aqueous solutions based on the sulfoxylated methyl ester of palmitic acid (Φ‐MES C16) have been studied and compared to the leading types of surfactants used today: linear alkylbenzene sulfonate (LAS) secondary alkane sulfonate (SAS) and α‐sulfo fatty methyl ester sulfonate (α‐MES) with regard to solubility, performance and skin compatibility. The experimental results obtained indicate that Φ‐MES C16 can be regarded as a potential component of detergent formulations and most likely also of body care products.

Effect of fatty acid methyl esters from plastrum testudinis on proliferation of rat bone mesenchymal stem cells

The ointment of plastrum testudinis was extracted using petroleum ether, ether and dichloromethane sequentially and the extracts were methyl-esterified. The effects on the proliferation of bone marrow mesenchymal stem cells (bMMSCs) were examined by MTT[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay and flow cytometry analysis. The volatile components of the samples were studied by gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography (HPLC). The results show that the methyl-esterified parts can promote the proliferation of stem cells and they all contain palmitic acid methyl ester. Palmitic acid methyl ester can promote proliferation when the concentration was 0.15 μg/μL. It may be concluded that the palmitic acid methyl ester is important for the methyl-esterified parts that have effects on proliferation.

Characterization of chemical components in extracts from Si-wu decoction with proliferation-promoting effects on rat mesenchymal stem cells

Si-wu decoction (SDE), a classic prescription in Traditional Chinese Medicine, has been used for the treatment of a variety of anaemia in China for centuries. In order to explore the scientific basis of the formula, we investigated the relationship between its chemical components and proliferation-promoting effects on rat marrow-derived mesenchymal stem cells (MSCs). Twenty (F-1–F-20) components were obtained and their proliferation-promoting effects on MSCs were investigated. The results showed that F-4, F-7, F-10, and F-11 stimulated the proliferation of the MSCs. The chemical components with proliferation-promoting effects on the MSCs were further identified by GC–MS, HPLC, LC–MS, and other spectra. Ligustilide (F-4) isolated from SDE showed the best proliferation-promoting effect. Palmitic acid methyl ester and stearic acid ethyl identified from F-7 and F-10 by HPLC were also confirmed to be responsible for stimulating MSC proliferation. A novel compound, 6,7-dihydroxy-3-(-prop-1-enyl)isobenzofuran-1(3H)-one, was found in the SDE for the first time by LC–MS n, whose structure was similar to ligustilide.