C6 Acids Research Articles

Enantioseparation of ofloxacin using a liquid–liquid extraction system based on hydrophobic eutectic solvents

The enantioseparation of chiral drugs is a major challenge for the pharmaceutical industry as the pharmacological activities of the enantiomers may differ, which can lead to severe secondary effects in the treatment of diseases. The aim of this study is to develop an enantioseparation platform for the resolution of ofloxacin (OFX) using enantioselective liquid–liquid extraction (ELLE) based on a hydrophobic eutectic solvent (HES) in conjunction with one chiral selector. β-Cyclodextrin (β-CD) derivatives, including β-CD, hydroxypropyl-β-cyclodextrin (HP-β-CD), carboxymethyl-β-cyclodextrin sodium salt (CM-β-CD), and sulfated-β-cyclodextrin sodium salt (S-β-CD), were investigated as potential chiral selector for the separation of (R/S-OFX), with CM-β-CD proving to be the most promising. The efficiency of the HES-based ELLE system was then studied, and a total of fourteen systems were evaluated using HES from four groups: L-menthol: fatty acid, L-menthol: fatty alcohol, fatty acid: fatty acid, and fatty acid: fatty alcohols. Decanoic acid: dodecanoic acid (C10 acid: C12 acid) in a molar ratio of 2:1 was identified as the optimal HES-based ELLE system for the enantioseparation of R/S-OFX. This selected system was further used to optimize enantioseparation conditions, including pH, HES-water ratio (v/v), and excess of chiral selector (CM-β-CD), using response surface methodology (RSM). Under optimal conditions, i.e., pH 3.6, HES-water ratio (v/v) of 1:2 and a 77-fold molar excess of chiral selector, an OFX selectivity (α) of 3.8 ± 0.3 was achieved in a single-step.

Extraction of ofloxacin from water using hydrophobic eutectic solvents

Wastewater treatment plants do not cope well with emerging micropollutants, such as pharmaceuticals, because they are not effective to remove them. Therefore, this work aims to develop a process for the extraction of ofloxacin (OFX) based on a liquid-liquid extraction using hydrophobic eutectic solvents (HES), coupled with the Conductor-like Screening Model for Real Solvent (COSMO-RS) for solvent screening. First, COSMO-RS was used to predict the partition coefficient of OFX for four HES families: L-menthol: fatty acid, L-menthol: fatty alcohol, fatty acid: fatty acid and fatty acid: fatty alcohols, at three different molar ratios (2:1, 1:1, and 1:2). These results showed that HES formed by fatty acids, especially those with a longer alkyl chain and a higher fatty acid molar ratio, were the most suitable solvents for OFX extraction. Then, the most promising HES to extract OFX was evaluated experimentally. The HES decanoic acid: dodecanoic acid (C10 acid: C12 acid) in a molar ratio of 2:1 being the system with best extraction results of OFX was selected to optimize the extraction conditions of OFX, namely pH, HES: water ratio (v/v), and OFX concentration, using a response surface methodology (RSM). The results obtained showed that at a pH of 5.2, HES-water ratio (v/v) of 1.3, and 2.5 mg/ml of OFX that an extraction efficiency of OFX of (98.8 ± 0.9)% could be achieved. The results show that one-step OFX extraction is possible, but is significantly influenced by both the extraction parameters and the hydrophobic properties of the HES.

Biochar facilitated Biological CO2 conversion to C2-C6 alcohols and fatty acids

Microbial CO2 utilization reduces the carbon footprint, providing economic potential. Biochar, rich in minerals and trace metals, can enhance microbial activity. This study investigates poultry litter and switchgrass biochars produced at 350 and 700 °C (PLB350, PLB700, SGB350 and SGB700, respectively) affect CO2 conversion to C2–C6 alcohols and acids by Clostridium muellerianum P21, C. ragsdalei P11 and C. carboxidivorans P7. Fermentations were in 250-mL bottles containing H2:CO2:N2 (60:20:20) shaken at 125 rpm and 37 °C. SGB350 increased alcohol titers by 1.1–2.1 fold, and PLB350 enhanced acid concentrations by 1.2–1.7 fold compared to the control without biochar. About 2.0–3.3 fold more ethanol was formed by strain P11 compared to strains P7 and P21 with SGB350. However, strain P21 produced 2.4-fold more butanol than strain P7 with SGB350, including unique hexanol production. These results highlight the potential of biochar in enhancing C2–C6 alcohol production from CO2, thereby boosting process feasibility.

A facile method for monitoring sphingomyelin synthase activity in HeLa cells using liquid chromatography/mass spectrometry.

Sphingomyelin synthase (SMS) is a sphingolipid-metabolizing enzyme involved in the de novo synthesis of sphingomyelin (SM) from ceramide (Cer). Recent studies have indicated that SMS is a key therapeutic target for metabolic diseases such as fatty liver, type 2 diabetes, atherosclerosis, and colorectal cancer. However, very few SMS inhibitors have been identified because of the limited sensitivity and selectivity of the current fluorescence-based screening assay. In this study, we developed a simple cell-based assay coupled with liquid chromatography/tandem mass spectrometry (LC-MS/MS) to screen for SMS inhibitors. HeLa cells stably expressing SMS1 or SMS2 were used for the screening. A non-fluorescent unnatural C6-Cer was used as a substrate for SMS to produce C6-SM. C6-Cer and C6-SM levels in the cells were monitored and quantified using LC-MS/MS. The activity of ginkgolic acid C15:1 (GA), a known SMS inhibitor, was measured. GA had half-maximal inhibitory concentrations of 5.5 μM and 3.6 μM for SMS1 and SMS2, respectively. To validate these findings, hSMS1 and hSMS2 proteins were optimized for molecular docking studies. In silico analyses were conducted to assess the interaction of GA with SMS1 and SMS2, and its binding affinity. This study offers an analytical approach for screening novel SMS inhibitors and provides in silico support for the experimental findings.

Characterization of mono‐varietal virgin olive oils obtained from Turkish National Germplasm Bank according to fatty acid composition, volatile profile, and sensory properties

AbstractMono‐varietal virgin olive oils were obtained from Olea europaea L. olives grown in the National Olive Germplasm Bank in the same agronomic conditions for two harvesting years. Samples were characterized according to fatty acid composition, volatile profile, and sensory attributes, and varieties were compared using Pearson correlation, principal component analysis (PCA), and cluster analysis. Odor activity values (OAVs) of the volatiles were calculated to discuss relationships between individual sensory properties and volatiles. Although most of the samples overlapped on the score plots, some samples were located away from the others. The sample groupings on the dendrogram plotted using Ward's linkage were generally suitable with PCA results. Ethanol had a negative correlation with 9 out of 14 pleasant attributes. According to OAVs, trans‐2‐hexenal content had the most important effect on sensory attributes and positively correlated with flower odor, whereas hexenal content contributed to sweet attributes. Similarly, the effect of 1‐hexanol content strengthened the flower attribute but weakened the bitter taste. These findings were also confirmed by separating some varieties rich in those volatiles on the PCA bi‐plot of sensory attributes. Samples were grouped on a dendrogram in accordance with total ester and total C3, C5, and C6 acid contents.Practical Application: Most olive production in Turkey is based on a few varieties, whereas 95 different endemic varieties were registered by Turkish National Germplasm Bank. This study provides information on the volatile composition, sensory profile, and fatty acid composition of virgin olive oils produced from some rare varieties with high oil content. Moreover, relationships and correlations between individual volatiles and sensory attributes were evaluated, and the main differences in fatty acid composition, volatile profile, and sensory attributes of these Turkish virgin olive oils and those produced from well‐known varieties from major producing countries were compared. Thus, data on the main characteristics of extra virgin olive oils produced from Turkish olives were provided to the literature, these varieties were promoted internationally, and their cultivation was encouraged.

The Rapid Determination of Three Toxic Ginkgolic Acids in the Decolorized Process of Ginkgo Ketone Ester Based on Raman Spectroscopy and ResNeXt50 Deep Neural Network

The decolorization process plays a pivotal role in refining Ginkgo ketone ester by primarily eliminating ginkgolic acids, a toxic component. Presently, the conventional testing method involves sending samples for analysis, causing delays that impact formulation production. Hence, the development of a rapid process control method becomes imperative. This study introduces a swift detection approach for three ginkgolic acids during Ginkgo ketone ester’s decolorization. Initially, an ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method assessed ginkgolic acid C13:0, ginkgolic acid C15:1, and ginkgolic acid C17:1 concentrations in 91 decolorized solution samples, establishing reference values. Subsequently, using a portable Raman spectrometer, Raman spectra of the decolorized liquid within the 3200–200 cm−1 wavelength range were collected. Ultimately, employing partial least squares regression (PLSR) and ResNeXt50 deep learning algorithms, two quantitative calibration models correlated the ginkgolic acid content to Raman spectral data. Both models exhibited high predictive accuracy, with the ResNeXt50 model demonstrating superior performance. The prediction set correlation coefficients (Rp2) for ginkgolic acid C13:0, ginkgolic acid C15:1, and ginkgolic acid C17:1 were 0.9962, 0.9971, and 0.9974, respectively, with root mean square error of prediction (RMSEP) values of 0.0144, 0.0130, and 0.0122 μg/mL. In contrast, the PLSR model yielded Rp2 values of 0.9862, 0.9839, and 0.9480, with RMSEP values of 0.0273, 0.0305, and 0.0545 μg/mL for the three ginkgolic acids. The ResNeXt50 model not only showcased higher precision but also enhanced interpretability, as analyzed through gradient-weighted class activation mapping (Grad-CAM). The integration of Raman spectroscopy and the ResNeXt50 quantitative calibration model furnishes a real-time and precise approach to monitor ginkgolic acid content in the decolorized solution during Ginkgo ketone ester preparation. This significant advancement establishes a robust framework for implementing quality control measures in the decolorization process.

In Vitro, In Vivo, and In Silico Activities of Ginkgolic Acid C15:1 against Streptococcus agalactiae Clinical Isolates.

Streptococcus agalactiae is the major cause of invasive neonatal infections and is a recognized pathogen associated with various diseases in nonpregnant adults. The emergence and spread of antibiotic-resistant S. agalactiae necessitate the development of a novel antibacterial agent. Here, the potential antibacterial activities and mechanisms of ginkgolic acid C15:1 (GA (15:1)) from Ginkgo biloba against clinical S. agalactiae are characterized. The MIC50 and MIC90 values for GA (15:1) against 72 clinical S. agalactiae isolates were 6.25 and 12.5 μM, respectively. GA (15:1) showed a strong bactericidal effect against both planktonic bacteria and bacteria embedded in biofilms as well as significant effectiveness in suppressing the growth of S. agalactiae biofilms. Moreover, GA (15:1) possesses intracellular antibacterial activity and could significantly decrease the bacterial burden in the intraperitoneal infection model of S. agalactiae. Mechanistic studies showed that GA (15:1) triggers membrane damage of S. agalactiae through a unique dual-targeting mechanism of action (MoA). First, GA (15:1) targets phospholipids in the bacterial cytoplasmic membrane. Second, by using mass-spectrometry-based drug affinity responsive target stability (DARTS) and molecular docking, lipoprotein signaling peptidase II (lspA) was identified as a target protein of GA (15:1), whose role is crucial for maintaining bacterial membrane depolarization and permeabilization. Our findings suggest a potential therapeutic strategy for developing GA (15:1) to combat S. agalactiae infections.

The technology of high-power ultrasound and its effect on the color and aroma of rosé wines.

The application of high-power ultrasound (US) has been studied extensively to obtain value-added red wines using short maceration times. It is a technique of wide interest for the extraction of aromatic compounds and compounds responsible for color, so it could also be an important tool to use in the elaboration process of rosé wines. Thus, this study focused on the effect of the application of US on the phenolic, aromatic, and sensorial profile of rosé wines. For this, three different types of rosé wine were produced: a control with direct pressing after crushing, another wine obtained from a 4 h macerated must, and a wine whose crushed and destemmed grape was sonicated and subsequently pressed. The results showed a higher color intensity and a higher total polyphenol and anthocyanin content in the wine obtained from sonicated grape compared to both control wine and that obtained from grape macerated for 4 h. Ultrasound treatment enhanced the extraction of varietal volatile compounds in must, especially the free faction of terpenes and norisoprenoids. It also gave rise to wines with a higher concentration of C6 alcohols and other compounds such as guaiacol and 4-vinylguaiacol, but led to fewer fatty acids, especially C6, C4 and C8 acids. Sensorially these wines showed intense aromas of red fruits and flowers, while no defects in aroma or astringency were found. The color and sensory profile of the resulting wines indicate that the US may be an interesting tool for obtaining quality rosé wines, replacing the maceration stage and reducing potential oxidation problems. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Natural Product-Based Screening for Lead Compounds Targeting SARS CoV-2 Mpro.

Drugs that cure COVID-19 have been marketed; however, this disease continues to ravage the world without becoming extinct, and thus, drug discoveries are still relevant. Since Mpro has known advantages as a drug target, such as the conserved nature of the active site and the absence of homologous proteins in the body, it receives the attention of many researchers. Meanwhile, the role of traditional Chinese medicine (TCM) in the control of epidemics in China has also led to a focus on natural products, with the hope of finding some promising lead molecules through screening. In this study, we selected a commercial library of 2526 natural products from plants, animals and microorganisms with known biological activity for drug discovery, which had previously been reported for compound screening of the SARS CoV-2 S protein, but had not been tested on Mpro. This library contains compounds from a variety of Chinese herbs, including Lonicerae Japonicae Flos, Forsythiae Fructus and Scutellariae Radix, which are derived from traditional Chinese medicine prescriptions that have been shown to be effective against COVID-19. We used the conventional FRET method for the initial screening. After two rounds of selection, the remaining 86 compounds were divided into flavonoids, lipids, phenylpropanoids, phenols, quinones, alkaloids, terpenoids and steroids according to the skeleton structures, with inhibition rates greater than 70%. The top compounds in each group were selected to test the effective concentration ranges; the IC50 values were as follows: (-)-gallocatechin gallate (1.522 ± 0.126 μM), ginkgolic acid C15:1 (9.352 ± 0.531 μM), hematoxylin (1.025 ± 0.042 μM), fraxetin (2.486 ± 0.178 μM), wedelolactone (1.003 ± 0.238 μM), hydroxytyrosol acetate (3.850 ± 0.576 μM), vanitiolide (2.837 ± 0.225 μM), β,β-dimethylacrylalkannin (2.731 ± 0.308 μM), melanin (7.373 ± 0.368 μM) and cholesteryl sodium sulfate (2.741 ± 0.234μM). In the next step, we employed two biophysical techniques, SPR and nanoDSF, to obtain KD/Kobs values: hematoxylin (0.7 μM), (-)-gallocatechin gallate (126 μM), ginkgolic acid C15:1 (227 μM), wedelolactone (0.9770 μM), β,β-dimethylacrylalkannin (1.9004 μM,), cholesteryl sodium sulfate (7.5950 μM) and melanin (11.5667 μM), which allowed better assessments of the binding levels. Here, seven compounds were the winners. Then, molecular docking experiments were specially performed by AutoDock Vina to analyze the mode of interactions within Mpro and ligands. We finally formulated the present in silico study to predict pharmacokinetic parameters as well as drug-like properties, which is presumably the step that tells humans whether the compounds are drug-like or not. Moreover, hematoxylin, melanin, wedelolactone, β,β-dimethylacrylalkannin and cholesteryl sodium sulfate are in full compliance with the "Lipinski" principle and possess reasonable ADME/T properties, they have a greater potential of being lead compounds. The proposed five compounds are also the first to be found to have potential inhibitory effects on SARS CoV-2 Mpro. We hope that the results in this manuscript may serve as benchmarks for the above potentials.

Microbial Enrichment Techniques on Syngas and CO2 Targeting Production of Higher Acids and Alcohols.

(1) Background: Microbial conversion of gaseous molecules, such as CO2, CO and H2, to valuable compounds, has come to the forefront since the beginning of the 21st century due to increasing environmental concerns and the necessity to develop alternative technologies that contribute to a fast transition to a more sustainable era. Research efforts so far have focused on C1-C2 molecules, i.e., ethanol and methane, while interest in molecules with higher carbon atoms has also started to emerge. Research efforts have already started to pay off, and industrial installments on ethanol production from steel-mill off-gases as well as methane production from the CO2 generated in biogas plants are a reality. (2) Methodology: The present study addresses C4-C6 acids and butanol as target molecules and responds to how the inherent metabolic potential of mixed microbial consortia could be revealed and exploited based on the application of different enrichment methods (3) Results and Conclusions: In most of the enrichment series, the yield of C4-C6 acids was enhanced with supplementation of acetic acid and ethanol together with the gas substrates, resulting in a maximum of 43 and 68% (e-mol basis) for butyric and caproic acid, respectively. Butanol formation was also enhanced, to a lesser degree though and up to 9% (e-mol basis). Furthermore, the microbial community exhibited significant shifts depending on the enrichment conditions applied, implying that a more profound microbial analysis on the species level taxonomy combined with the development of minimal co-cultures could set the basis for discovering new microbial co-cultures and/or co-culturing schemes.

Addressing the Structural Organization of Silicone Alternatives in Formulations by Molecular Dynamics Simulations and a Novel Equilibration Protocol

The world of cosmetics is an always-evolving field with constant updates on its formulation components. The current reality asks for an ever-increasing need for natural and sustainable replacements for synthetic compounds in all fields of modern consumer products. However, the research and development stages of finding these alternatives can be an expensive, time-consuming, and often wasteful process that turns this task into a laborious procedure. This study introduces the development of a computational methodology that will aid the research of silicone alternatives, disclosing their structural performance in a formulation. Additionally, an equilibration protocol was developed to measure the distribution and densities of these silicone alternatives to determine how they behave in relation to their counterparts, using molecular dynamics simulations. Two systems were tested, A and B, where the former is composed of one ester (Dipentaerythrityl Hexa C5 Acid Ester) and the latter by an ester combined with an alkane (Triheptanoin and C13-Isoalkane); all three molecules are commercially available and widely used. Both systems were subjected to a 3-step thermal regulation strategy. The systems went through an initial simulation at 25 °C and at 70 °C, then a temperature switch took place (25 °C « 70 °C), then a shock to 200 °C, and finally a Simulated Annealing protocol reaching 250 °C. In the end, all systems converged towards micelle-like structures. These results come to further ascertain the position of computational chemistry and Molecular Dynamics Simulations as an important part of R&D processes in modern sciences and investigation.

Site-Directed Mutation of Salicylate Decarboxylase Gene and Mechanism of Ginkgo Acid Decarboxylation.

Ginkgo seed is an important Chinese medicine and food resource in China, but the toxicity of ginkgo acid in it limits its application. Previous studies have found that salicylic acid decarboxylase (Sdc) has a decarboxylation degradation effect on ginkgo acid. In order to improve the decarboxylation ability of Sdc to Ginkgo acid, 11 residues of the Sdc around the substrate (salicylic acid) were determined as mutation targets according to the analysis of crystal structure of Sdc (PDB ID:6JQX), from Trichosporon moniliiforme WU-0401, and a total of 30 single point mutant enzymes and one compound mutant enzyme were obtained. With Ginkgo acid C15:1 as the substrate, it was found from activity assay that Sdc-Y64T and Sdc-P191A had higher decarboxylation activity, which increased by 105.18% and 116.74% compared with that of wild type Sdc, respectively. The optimal pH for Sdc Y64T and Sdc-P191A to decarboxylate Ginkgo acid C15:1 was 5.5, which is the same as the wild type Sdc. The optimal temperature of Sdc-P191A was 50°C, which was consistent with that of the wild type Sdc, but the optimal temperature of the mutant Sdc-Y64T was 40°C, which was 10°C lower than that of wild type Sdc.

Coupled Natural Fusion Enzymes in a Novel Biocatalytic Cascade Convert Fatty Acids to Amines.

Tambjamine YP1 is a pyrrole-containing natural product. Analysis of the enzymes encoded in the Pseudoalteromonas tunicata “tam” biosynthetic gene cluster (BGC) identified a unique di-domain biocatalyst (PtTamH). Sequence and bioinformatic analysis predicts that PtTamH comprises an N-terminal, pyridoxal 5′-phosphate (PLP)-dependent transaminase (TA) domain fused to a NADH-dependent C-terminal thioester reductase (TR) domain. Spectroscopic and chemical analysis revealed that the TA domain binds PLP, utilizes l-Glu as an amine donor, accepts a range of fatty aldehydes (C7–C14 with a preference for C12), and produces the corresponding amines. The previously characterized PtTamA from the “tam” BGC is an ATP-dependent, di-domain enzyme comprising a class I adenylation domain fused to an acyl carrier protein (ACP). Since recombinant PtTamA catalyzes the activation and thioesterification of C12 acid to the holo-ACP domain, we hypothesized that C12 ACP is the natural substrate for PtTamH. PtTamA and PtTamH were successfully coupled together in a biocatalytic cascade that converts fatty acids (FAs) to amines in one pot. Moreover, a structural model of PtTamH provides insights into how the TA and TR domains are organized. This work not only characterizes the formation of the tambjamine YP1 tail but also suggests that PtTamA and PtTamH could be useful biocatalysts for FA to amine functional group conversion.

Characterization and properties of starch-dicarboxylic acid inclusion complexes prepared by excess steam jet cooking

A series of dicarboxylic-amylose inclusion complexes (AIC) were prepared by excess steam jet-cooking high amylose corn starch with linear C10, C12, C14, and C16 dicarboxylic acids to examine the influence of two polar head groups on complex formation. The C12, C14, and C16 dicarboxylic acid AIC were prepared in 48–63 % yields and contained 8.9–11.8 % diacid while the C10 AIC gave 30 % and contained 2.6 % diacid. These AIC had V6 helical amylose structures by XRD and complexation was further confirmed by DSC, FTIR, and TGA. SEM of the C12-C16 AIC revealed micron-sized toroidal spherulites while the C10 AIC was predominantly amorphous. DSC showed two AIC related transitions. This work provides a better understanding of the formation and physicochemical properties of these diacid AIC. Preparation by excess steam jet cooking demonstrates practical and commercial utility to prepare AIC as off-the-shelf materials for food and nonfood applications.

Thermal Stability of Ginkgolic Acids and Thermal Decomposition Kinetics of Ginkgolic Acid C15:1

Thermal Stability of Ginkgolic Acids and Thermal Decomposition Kinetics of Ginkgolic Acid C15:1

Self-assembled nanostructure induced in deep eutectic solvents via an amphiphilic hydrogen bond donor

HypothesisPopular deep eutectic solvents (DESs) typically lack amphiphilic molecules and ions and therefore do not have the useful self-assembled nanostructures prevalent in many ionic liquids. We hypothesise that nanostructure in DESs can be induced via an amphiphilic hydrogen bond donor (HBD), and that nanostructure becomes better defined with HBD chain length. ExperimentsThe structure of DESs formed from choline chloride mixed with either butyric acid (ChCl/BuOOH) or hexanoic acid (ChCl/HeOOH) in a 1:4 M ratio were studied using atomic force microscopy (AFM) imaging, force curves, and friction measurements combined with bulk rheology. FindingsDESs formed with both the C4 and C6 acids are nanostructured. As the length of the acid group is increased from C4 to C6, AFM images reveal the nanostructure becomes larger and better defined due to the longer acid chain, and AFM force curves show the interfacial nanostructure extends further from the surface. Self-assembled nanostructure in these systems is a consequence of choline cations, chloride anions, and acid alcohol groups clustering together due to electrostatic attractions and hydrogen bonding to form polar domains. Acid alkyl chains are solvophobically excluded from the polar domains and aggregate into apolar domains.

Addition of medium chain fatty acid blend impacts Salmonella enteritidis infection in layer hens

Mitigation of food pathogens, such as Salmonella, continues to be a focus in poultry production, whether on shell eggs or meat products. No single mitigation approach is fully capable of eliminating the risk of Salmonella contamination, but rather multicomponent, comprehensive strategies are now used to mitigate the risk. Targeted in-feed additives are a component of a food safety program and may help to reduce Salmonella infection. This study evaluated the efficacy of a medium chain fatty acid ( MCFA ) feed-additive product to reduce Salmonella Enteritidis ( S. E. ) infection in commercial layer hens. One-hundred and forty-four 1-day-old Hy-line pullets were raised on new litter until 10 wk of age when they were moved into individual cages. There were 3 treatments, 1) Control, 2) MCFA given d 0-termination, and 3) MCFA given wk 10-termination. MCFA blend was a mixture of C6, C8, and C10 acids. At 17 wk-of-age each bird was orally challenged with 3 × 10 6 CFU/bird of a nalidixic acid resistant S.E. strain. Seven- and 14-d postchallenge, ceca and ovaries were aseptically collected and cultured for S.E. Significant differences ( P < 0.05) in mean cecal S.E. log 10 MPN/g were observed between 7 d postinfection compared with 14 d postinfection. Fourteen days post infection, MCFA d 0 birds had significantly ( P < 0.05) lower prevalence than the untreated group and the MCFA (wk 10) group did not differ significantly from either of the other 2 groups. No significant differences ( P < 0.05) in prevalence and mean ovary S.E. log10 MPN/g were observed. Inclusion of MCFA d 0-termination resulted in reduction of S.E. infection in ceca's, but this benefit was not seen in ovary S.E. prevalence.

Repellent and acaricidal activity of coconut oil fatty acids and their derivative compounds and catnip oil against Amblyomma sculptum

This study was carried out aiming to evaluate the repellent and acaricidal activity of major ingredient compounds from coconut oil including their methyl ester derivatives and catnip oil against nymphs and larvae of Amblyomma sculptum. Repellent candidates, coconut oil free fatty acids (coconut FFA mainly C12, C10 and C8 acid); lauric acid (C12 acid); capric acid (C10 acid); methyl laurate; methyl caprate and 10 % each of C12, C10 and C8 acid (1:1:1) in lavender oil formulation (CFA in lavender formula) and catnip oil (Nepeta cataria), were screened using a Petri dish bioassay to assess repellency. Catnip oil, methyl caprate, methyl laurate, and CFA in lavender formulation repelled ticks strongly (P < 0.05) at almost all times evaluated, with an average of 77.8–100% repellency. Some candidate repellents with consistent strong repellence observed were selected for further evaluation, with coconut CFA in lavender formula showing a repellency lasted up to 7 days, while those of catnip oil and methyl caprate were active for 4 and 3 days, respectively. For the acaricide test, five concentrations (2.5; 5; 10; 15 and 20 mg/mL) were evaluated using the larval packet test. Only CFA in lavender formula and two methyl esters showed acaricidal activity, with methyl laurate presenting the strongest toxicity at 15 mg/mL concentration, which was effective against more than 93 % of the tested larvae. Catnip oil caused no mortality of A. scultptum larvae in all concentrations tested.

Saturated Vapor Pressures and Enthalpies of Vaporization of Diesters of Neopentyl Glycol and Linear C2–C6 Acids

Saturated Vapor Pressures and Enthalpies of Vaporization of Diesters of Neopentyl Glycol and Linear C2–C6 Acids

Heterogeneous biocatalytical esterification by recombinant Thermomyces lanuginosus lipase immobilized on macroporous carbon aerogel

Heterogeneous biocatalysts prepared by immobilizing recombinant lipases are promising for implementation in organic synthesis of various esters used as fragrances, emollients, emulsifiers, non-ionic surfactants, plasticizers, etc. For this research, the Thermomyces lanuginosus lipase produced by the authoring recombinant Pichia pastoris strain was adsorbed on the authoring macroporous carbon aerogel. The prepared biocatalysts were studied in the periodic processes of enzymatic esterification carried out in nonconventional anhydrous media of organic solvents at ambient conditions (22 ± 2 °C, 1 bar). Biocatalytical activities depended strongly on both the selected pair of lipase substrates (acid and alcohol) involved in reaction and the organic solvent used for esterification. The reaction rates of fatty C7 acid esterification with double and triple bond C3 alcohols, such as allyl and propargyl alcohols, were found to be 2–4 times lower than with aliphatic propanol. Isomerism of an acid (not alcohol) molecule greatly affected the esterification rates. It was observed that isomers of C4 and C5 acids (iso-butyric and iso-valeric) practically did not react with butanol. The esterification rates strongly depended on the polarity of the organic solvent characterized by the parameter logP. With an increase in the solvent polarity from non-polar hexane to polar acetone, the esterification rate decreased by two orders of magnitude. The prepared lipase-active biocatalysts had a sufficiently high operational stability under the chosen optimal reaction conditions; their stationary activity (300 ± 100 U·g–1) did not change in periodic reaction cycles during several tens of hours.