Long-chain Compounds Research Articles

Biodiesel production from lipids in wet microalgae with microwave irradiation and bio-crude production from algal residue through hydrothermal liquefaction

A cogeneration process of biodiesel and bio-crude was proposed to make full use of wet microalgae biomass. High-grade biodiesel was first produced from lipids in wet microalgae through extraction and transesterification with microwave irradiation. Then, low-grade bio-crude was produced from proteins and carbohydrates in the algal residue through hydrothermal liquefaction. The total yield (40.19%) and the total energy recovery (67.73%) of the cogenerated biodiesel and bio-crude were almost equal to those of the bio-oil obtained from raw microalgae through direct hydrothermal liquefaction. Upon microwave irradiation, proteins were partially hydrolyzed and the hydrolysates were apt for deaminization under the hydrothermal condition of the algal residue. Hence, the total remaining nitrogen (16.02%) in the cogenerated biodiesel and bio-crude was lower than that (27.06%) in the bio-oil. The cogeneration process prevented lipids and proteins from reacting to produce low-grade amides and other long-chain nitrogen compounds during the direct hydrothermal liquefaction of microalgae.

Relationship between prenatal exposure to perfluorinated compounds and allergic diseases in infants

[Background]Recent studies have shown that prenatal exposure to perfluorinated compounds (PFCs) at general environmental levels has an adverse effect on infants. Immunotoxic effects of PFCs exposure in animal studies include immunosuppression, suppression of IgM antibody production, and increased IgE response in ovalbumin-sensitized mice. However, epidemiological studies investigating the role of PFCs, in particular longer-chain PFCs, are scarce. [Aims]The aim of this study was to investigate the relationship between prenatal exposure to 11 PFCs and infant allergic diseases during the first 12 months of life in a large study population. [Methods]The study population was comprised of mothers and their infants enrolled in a prospective birth cohort study (Hokkaido Study on Environment and Children's Health). Between February 2003 and December 2009, 300 women were randomly selected every year. Eleven PFC compounds were measured in maternal plasma using simultaneous analysis with UPLC-MS/MS. Characteristics of participants and information on infant allergic diseases was obtained from self-administered questionnaires and medical records. Finally, 2,062 mothers and their infants were included in the statistical analysis. [Results]Risk of eczema, wheezing and food allergy during the first 12 months of life was not associated with maternal levels of 11 PFCs, including longer-chain compounds. Odds ratios for eczema and wheezing ranged from 0.66 to 0.73 and from 0.60 to 0.81 for the three higher quartiles of maternal perfluorotridecanoic acid (PFTrDA) levels, compared with the lowest in the adjusted models, but no dose-response pattern was found. [Conclusions]These findings suggest that prenatal exposure to 11 PFCs, including longer-chain compounds, is not associated with risk of infant allergic diseases. Further studies are ongoing to investigate the effects of prenatal exposure to 11 PFCs on cord blood IgE levels, and allergies and infectious diseases at the age of 2 and 4 years.

Advances of chemical constituents and pharmacological activities of Schefflera genus

The genus Schefflera (Araliaceae) consists of 1100 species, 35 of which can be found in China. Some species of the genus have been used in traditional medicine to treat rheumatalgia, trauma, fracture, headache, and so on. Phytochemical studies of the genus have demonstrated the presence of large number of triterpenoids and their saponins, along with some long-chain compounds, steroids and sesquiterpenes. Furthermore, many pharmacological activities of the genus such as anti-inflammatory, anticancer and antiviral activities have been reported. In this article, new development of constituents and biological activities of Schefflera genus is reviewed and summarized for its further development and utilization.

Determination of alcohol sulfates and alcohol ethoxysulfates in marine and river sediments using liquid chromatography–tandem mass spectrometry

A novel and successful method has been developed for the identification and quantification of alcohol sulfates (AS) homologues and alcohol ethoxysulfates (AES) ethoxymers in marine and river sediment samples. The method involves the extraction of 5.00g of dry sample with methanol using pressurized liquid extraction (PLE) and liquid chromatography–tandem mass spectrometry (LC–MS/MS). 2-Octylbenzene sulfonic acid sodium salt (2ØC8-LAS) was used as internal standard. The analytical methods were applied to marine sediments collected from the coast of Almeria (South-east Spain) and river sediments collected from the Monachil river (Granada, South-east Spain). For AS homologues, the found limits of detection were 0.04–0.08μgg−1 for marine and river sediments. For AES ethoxymers, the found limits of detection were 0.03–0.09μgg−1 and 0.06–0.22μgg−1 for marine and river sediments, respectively. The highest concentrations of AS and AES were found in river sediment samples. Significant differences were also observed between the behavior of short-chain compounds (C12) and long-chain compounds (C14 to C18). The influence of the physic-chemical properties of water on the occurrence of these compounds was also evaluated, and differences between long- and short-chain compounds were also observed. Additionally, principal components analyses were carried out in order to study the relationship between variables and to evaluate the sources of data variability and behavior patterns. Finally, important conclusions were drawn regarding the environmental behavior of AS and AES.

Two new compounds and other constituents from Cassia fistula root bark

Two new compounds, 4-dodecyl-1,3,8-trihydroxyanthraquinone and hexacosanoyl quinate, along with three long-chain compounds, heptacosyl eicosanoate, palmitic acid, 1-hexacosanol; two sterols, β-sitosterol, β-sitosterol-β-D-glucoside; one triterpene, lupeol; and two anthraquinones, chrysophanol and physcion, were isolated from the root bark of Cassia fistula. The chemical structures of the isolated compounds were elucidated on the basis of their analytical and spectral data.

Identification and characterization of Rv0494: a fatty acid-responsive protein of the GntR/FadR family from Mycobacterium tuberculosis

Escherichia coli FadR, a member of the GntR family of transcription factors, plays dual roles in fatty acid metabolism. FadR-DNA binding is inhibited by fatty acyl-CoAs, and thus FadR acts as a sensor of the fatty acid level in bacteria. We have identified FadR-binding sites in the upstream regions of genes showing altered expression after the disruption of fatty acid biosynthesis in Mycobacterium tuberculosis. A FadR homologue in M. tuberculosis, Rv0494, was identified, which binds to its operator in the upstream region of the kas operon. We have shown that FadRMt (Rv0494) directly binds to long-chain fatty acyl-CoA and that binding quenches the intrinsic fluorescence of the purified protein. FadR-DNA binding can be impaired by long-chain fatty acyl-CoA compounds. Overexpression of Rv0494 in Mycobacterium bovis BCG reduced the basal level expression of kas operon genes, thereby suggesting the repressor nature of this protein in fatty acid synthase II regulation. This is the first report, to the best of our knowledge, of a GntR/FadR family protein acting as a fatty acid-responsive transcriptional regulator in M. tuberculosis, suggesting a possible role for this protein in mycolic acid biosynthesis.

Facile synthesis, characterization, and evaluation of neurotoxicity effect of cerium oxide nanoparticles

Abstract Cerium oxide nanoparticles (CeO 2 -NPs) were synthesized via the sol–gel method in gelatin media. Long-chain gelatin compounds were utilized to terminate the growth of CeO 2 -NPs and stabilize them. The CeO 2 -NPs were characterized by a number of techniques, including X-ray diffraction analysis (XRD), UV–vis spectrophotometry, and high-magnification transmission electron microscopy (TEM). The CeO 2 -NPs calcined at different temperatures exhibited a cubic fluoride structure with sizes less than approximately 10 nm. The influence of the calcination temperature on the morphology of CeO 2 -NPs was also investigated. In vitro cytotoxicity studies on neuro2A cells showed a dose-dependent toxicity with non-toxic effect of concentration below 10 μg/mL. The results indicated that gelatin is an interesting material that can be used as a stabilizer in the sol–gel processes for preparing small CeO 2 -NPs.

New Furanocoumarins and Other Chemical Constituents from Ficus carica Root Heartwood

Two new furanocoumarins, 5-(1",1"-dimethylallyl)-8-methyl psoralen (1) and 2"-O-acetyl oxypeucedanin hydrate-3"-methyl ether (2), were isolated from the root heartwood of Ficus carica Linn. together with three known furanocoumarins, two triterpenoids, two long-chain compounds, and a steroid. Their structures and relative configurations were elucidated by spectroscopic methods (IR, HR-ESI-MS, and NMR) and by comparison of their NMR spectral data with those of related compounds.

Chemical Constituents from Glyphaea brevis and Monodora myristica: Chemotaxonomic Significance

A chemical investigation of the Glyphaea brevis leaves and of the Monodora myristica fruits led to the identification of thirteen compounds, seven linear long-chain aliphatic compounds, 1, 2, 4, 6, and 9-11, three steroids, 3a, 3b, and 7, two triterpenes, 5a and 5b, and one polyol, 8. The compounds 2 and 8, previously mentioned in the literature, are here characterized by their complete (1)H- and (13)C-NMR assignments. This is the first report of a full NMR assignment for linear fatty acid esters of aliphatic primary alcohols and for meso-erythritol. Compound 5b and 8 were isolated for the first time from plant extracts of the Tiliaceae family, and compounds 9-11 from the Annonaceae plant family. Our results constitute the basis for further chemotaxonomic studies on the two species.

Effect of Composition on Structure and Mechanical Properties of Metakaolin Based PSS-Geopolymer

Geopolymer is a type of cross linked long-chain inorganic compound, built in three-dimensional structures and has different attractive properties (thermal, mechanical, chemical, etc). This study elucidated the structure and mechanical properties of PSS type geopolymer obtained by alkaline attack of metakaolin. A systematic investigation was conducted to comprehend the effect of molar ratios Si/Al and Na/Al on the properties of this geopolymer by using 29Si and 27Al magnetic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy, X-Ray diffraction and mechanical measurements. The results indicate that an increase of Si/Al ratio improves the geopolymer mechanical properties due probably to the formation of Si-O-Si bond in the geopolymer at the expense of Si-O-Al one. It was also shown that an introduction of NaOH in the geopolymer composition enhances the mechanical properties until a molar ratio Na/Al=1. Beyond this value, the excess of Na+ cation causes fragility of the geopolymer structure confirmed by a decrease of the mechanical strength.

Dielectric Barrier Discharge Assisted Transformation of Cyclohexane to $\hbox{C}_{1}$ and $ \hbox{C}_{2}$ Hydrocarbons

Efficient transformation of cyclohexaneg to methane, ethylene, and acetylene in argon dielectric barrier discharge is reported. In the absence of another H-atom donating source in the reaction mixture, such products' generation suggests in situ fragmentation of a fraction of parent molecules to C1 and C2 stages, followed by preferential reactions of these fragments with H-atoms freed along. Simultaneous formation of nonvolatile deposits containing diverse oxygenated and nonoxygenated long-chained aliphatic and cyclic compounds also occurred due to the remaining fraction's reactions, including some with the unreacted parent and the adsorbed moisture on dielectric surfaces. The presence of 4% O2 in the gas mixture induced a significant decrease in gas-phase hydrocarbons' yields in addition to a change in the nonvolatile products' nature.

Diversion of phagosome trafficking by pathogenic R hodococcus equi depends on mycolic acid chain length

Rhodococcus equi is a close relative of Mycobacterium spp. and a facultative intracellular pathogen which arrests phagosome maturation in macrophages before the late endocytic stage. We have screened a transposon mutant library of R. equi for mutants with decreased capability to prevent phagolysosome formation. This screen yielded a mutant in the gene for β-ketoacyl-(acyl carrier protein)-synthase A (KasA), a key enzyme of the long-chain mycolic acid synthesizing FAS-II system. The longest kasA mutant mycolic acid chains were 10 carbon units shorter than those of wild-type bacteria. Coating of non-pathogenic E. coli with purified wild-type trehalose dimycolate reduced phagolysosome formation substantially which was not the case with shorter kasA mutant-derived trehalose dimycolate. The mutant was moderately attenuated in macrophages and in a mouse infection model, but was fully cytotoxic.Whereas loss of KasA is lethal in mycobacteria, R. equi kasA mutant multiplication in broth was normal proving that long-chain mycolic acid compounds are not necessarily required for cellular integrity and viability of the bacteria that typically produce them. This study demonstrates a central role of mycolic acid chain length in diversion of trafficking by R. equi.

Catalytic pyrolysis of rice husk by mixing with zinc oxide: Characterization of bio-oil and its rheological behavior

The experiments on the rice husk pyrolysis were performed in a fixed-bed reactor to produce bio-oil. The effects of the different operation factors such as pyrolysis temperature、sweeping gas (N2) flow rates and ZnO catalyst on the yields of three products and the characteristics of bio-oil were investigated. The maximum bio-oil yield of 49.91% was obtained at 550°C pyrolysis temperature with a heating rate of 25°C/min and nitrogen flow rate of 150mL/min. The bio-oils yielded with and without a catalyst were characterized by FT-IR and GC/MS. The results showed that the main identified compounds of bio-oils were phenols, phenol derivatives and long-chain aliphatic compounds. It was observed that the use of catalyst decreased the bio-oil yields, but enhanced the small molecular compound yields and decreased the amount of oxygenated groups in bio-oils. A series of rheological tests were performed for the two kinds of bio-oil with cone and plate rheometer. The results indicated that both types of bio-oil were typical non-Newtonian and strongly shear thinning liquids in the flow behavior. The viscosity of the ZnO-treated bio-oil was significantly lower than that of the bio-oil without any catalyst.

New long-chain aliphatic compounds from Peperomia dindygulensis

Three long-chain aliphatic compounds, including one new polyketide derivative, dindygulerione C (1), one new octaketide derivative, dindygulerione D (2) and one new acylresorcinol derivative dindyguleranone (3) were isolated from the whole plant of the Chinese anticancer folk medicine Peperomia dindygulensis Miq. (Piperaceae). Dindygulerione C is an unprecedented example of a N-containing polyketide. The chemical structures and configurations of 1–3 were elucidated as (−)-(4S)-2-[(Z)-1′-(6″,7″-dihydroxyphenethyl-amino)octadec-11′-enylidene]-4-hydroxycyclohexane-1,3-dione (1), (+)-2-heptadecyl-4-hydroxy-3,4,7,8-tetrahydro-2H-chromen-5(6H)-one (2) and 2-(1,3-dihydroxyphenyl)-octacosan-1′-one (3), respectively, by comparing with the literature data and extensive spectroscopic methods, including 2-D NMR and circular dichroism spectroscopic analysis. The cytotoxicity of 1–3 was evaluated against Hep3B and HepG2 liver cancer cell lines.

The insecticidal, molting disruption and insect growth inhibitory activity of extracts from Condalia microphylla Cav. (Rhamnaceae)

Extracts obtained from a common shrub that occurs as part of vegetative species growing on arid lands of North-Central Chile and adjacent central Argentina known as “piquilin”Condalia microphylla (Rhamnaceae) showed insect growth inhibitory activity against the fall armyworm Spodoptera frugiperda, yellow meal worm Tenebrio molitor and fruit fly Drosophila melanogaster larvae in artificial diet feeding assays. The effects of these extracts on mortality, antifeedancy and growth inhibition were examined. The phytochemical profile of the most active extract was examined with conventional chromatographic and spectroscopic procedures. This n-hexane extract showed a high percentage of hentriacontane and triacontane. The observed mortality strongly correlates with the contents of these long-chain n-alkanes compounds, the LD50 for n-hexane, ethyl acetate and methanol extracts against S. frugiperda, were 3.89, 9.4, and 9.7ppm; against T. molitor 5.2, 14.2, and 20.4ppm, and against D. melanogaster 3.23, 7.65 and 17.9ppm, respectively.

Laboratory spectroscopic analyses of electron irradiated alkanes and alkenes in solar system ices

We report results from laboratory experiments of 10 keV electron irradiation of thin ice films of water and short‐chain hydrocarbons at ∼10−8 Torr and temperatures ranging from 70–100 K. Hydrocarbon mixtures include water with C3H8, C3H6, C4H10 (butane and isobutane), and C4H8, (1‐butene and cis/trans‐2‐butene). The double bonds of the alkenes in our initial mixtures were rapidly destroyed or converted to single carbon bonds, covalent bonds with hydrogen, bonds with −OH (hydroxyl), bonds with oxygen (C‐O), or double bonds with oxygen (carbonyl). Spectra resulting from irradiation of alkane and alkene ices are largely indistinguishable; the initial differences in film composition are destroyed and the resulting mixture includes long‐chain, branched aliphatics, aldehydes, ketones, esters, and alcohols. Methane was observed as a product during radiolysis but CO was largely absent. We find that while some of the carbon is oxidized and lost to CO2 formation, some carbon is sequestered into highly refractory, long‐chain aliphatic compounds that remain as a thin residue even after the ice film has been raised to standard temperature and pressure. We conclude that the high availability of hydrogen in our experiments leads to the formation of the formyl radical which then serves as the precursor for formaldehyde and polymerization of longer hydrocarbon chains.

A Flux Capacitor for Moth Pheromones

In this issue of Chemical Senses, Baker et al. propose a provocative and intriguing explanation for a commonly observed phenomenon in moth chemocommunication. Sex pheromones in moths typically consist of mixtures of long-chain unsaturated compounds in specific ratios. These ratios are correspondingly detected by male moths using separate olfactory sensory neurons for each pheromone component housed singly or multiply in long trichoid sensilla on the antennal surface. These neurons are often present in different proportions, typically with the neuron responding to the highest ratio component present in greatest abundance or with the largest dendritic diameter. In their article, Baker et al. postulate that these physical differences in neuron magnitudes arise to compensate for the higher molecular flux present with the most abundant pheromone components. Such a suggestion raises several questions concerning the physiological and behavioral nature of pheromone communication. Specifically, is the flux in a natural pheromone plume high enough to warrant increased flux detection for the most abundant components? Second, how can changes in neuronal number or size lead to increased flux detection? And finally, how would this increased flux detection be accomplished at molecular, cellular, and ultimately network scales? We address each of these questions and propose future experiments that could offer insight into the stimulating proposition raised by Baker et al.

Mammalian-Specific OR37 Receptors Are Differentially Activated by Distinct Odorous Fatty Aldehydes

The capacity of the mammalian olfactory system to detect an enormous collection of different chemical compounds is based on a large repertoire of odorant receptors (ORs). A small group of these ORs, the OR37 family, is unique due to a variety of special features. Members of this subfamily are exclusively found in mammals, they share a high degree of sequence homology and are highly conserved during evolution. It is still elusive which odorants may activate these atypical receptors. We have reasoned that compounds from skin, hairs, or skin glands might be potential candidates. We have exposed mice to such compounds and monitored activation of glomeruli through the expression of the activity marker c-fos in juxtaglomerular cells surrounding ventrally positioned glomeruli in the olfactory bulb (OB). Employing this methodology it was found that stimulation with long-chain alkanes elicits activation in the ventral part of the OB, however, none of the OR37 glomeruli. Analyses of long-chain hydrocarbon compounds with different functional groups revealed that long-chain aliphatic aldehydes elicited an activation of defined OR37 glomeruli, each of them responding preferentially to an aldehyde with different chain lengths. These results indicate that OR37 receptors may be tuned to distinct fatty aldehydes with a significant degree of ligand specificity.

Morphological Transition from Nanosheet to Nanosphere of Ternary Comb Copolymers with Carbazole Rings Induced by an Increase in Surface Pressure

Fax: +81-48-858-3503, e-mail: fujimori@fms.saitama-u.ac.jp Transition behavior from a monolayer on the water surface to a single particle layer of a ternary comb copolymer containing carbazole rings have been investigated by surface pressure-area isotherm, atomic force microscopy, X-ray diffraction. This polymer monolayer is able to form the “polymer nanosheet” with amorphous layers and strong interaction between main-chains prepared by the Langmuir-Blodgett (LB) technique. Further, the single particle layer is able to form the multi-particle layered organization of “polymer nanosphere” by the LB technique. This ternary comb copolymers were synthesized by radical copolymerization with hydrogenated and fluorinated long-chain vinyl compounds. Poly(N-vinylcarbazole) homopolymer formed a single particle layer on the water surface immediately after spreading. Spontaneous “particulation” behavior is accelerated by incorporation of carbazole units in ternary copolymer films. Organized molecular film of these copolymers formed a monolayer on the water surface below 10 m Nm

A review: Ethnobotanical survey of genus Leucas.

Plants of genus Leucas (Lamiaceae) are widely distributed throughout Asia, Africa, and India. The plant is used in traditional medicine to cure many diseases such as cough, cold, diarrhea, and inflammatory skin disorder. A variety of phytoconstituents have been isolated from the Leucas species, which include lignans, flavonoids, coumarins, steroids, terpenes, fatty acids, and aliphatic long-chain compounds. Anti-inflammatory, analgesic, anti-diarrheal, antimicrobial, antioxidant, and insecticidal activities have been reported in the extracts of these plants and their phytoconstituents. An overview of the ethnobotanical, phytochemical, and pharmacological investigations on the Leucas species is presented in this review.