Study of the Antioxidative Properties of Several Amino Acid-Type Surfactants and their Synergistic Effect in Mixed Micelle

Cysteine and methionine, two sulfur-containing amino acids (AA), were introduced in their surfactant forms as potential antioxidants. The antioxidative (AOX) properties of lauroyl methionine (C12-Met) and lauroyl cysteine (C12-Cys) was investigated by means of the oxygen radical absorbance capacity assay. Both the surfactants exhibited excellent AOX behavior at the premicellar state and micellar medium. The AOX behavior was found to be comparable for both the surfactants at their premicellar states. However, in micellar medium, C12-Met showed better AOX property than C12-Cys. The AOX power of the surfactants was compared with other previously developed AA-type surfactants. The order of the AOX power was found to be: C12-tryptophan > C12-tyrosine ≈ C12-methionine ≈ C12-cysteine > C12-histidine at the premicellar state and C12-tryptophan > C12-tyrosine > C12-methionine > C12-cysteine > C12-histidine at the micellar state. C12-Cys displayed lower AOX property in micellar medium due to its dimer formation tendency. Based on the HPLC and UPLC-Q-TOF-MS analysis, the dimer formation of C12-Cys was found to be accelerated due to the micellar environment and results into negative synergistic effect on other aromatic AA-type surfactants. However, the presence of C12-His in the micellar solution of C12-Cys resulted no synergistic effect due to stronger H-bonding between the surfactants and resulting less dimer formation.     

A comparison of microstructure and mechanical properties of 12Ce-TZP reinforced with alumina and in situ formed strontium- or lanthanum hexaaluminate precipitates

Composites of 12 mol% Ce-TZP and 30 vol% of alumina 12Ce-30A, strontium hexaaluminate 12Ce-30SA6 and lanthanum hexaaluminate 12 Ce-30LA6 were produced by a mixing and milling method, shaped by slip casting and subsequently sintered in air at 1500–1600 °C. The microstructure, phase composition and mechanical properties of the materials were determined. 12Ce-30A showed the highest hardness, toughness and strength closely followed by the 12Ce-30LA6 composite, the 12Ce-30SA6 showed high toughness at moderate strength and low hardness. Phase analysis hinted at strong differences in the efficiency of transformation toughening. For 12Ce-30A contributions of dilatation and shear were almost fully exploited, 12Ce-30SA6 showed an intermediate efficiency while in 12Ce-30LA6 subcritical transformation was observed. The interaction of cracks with the reinforcement showed specific characteristics for each hexaaluminate. Beside high resistance to subcritical crack growth observed in all materials, 12Ce-30A and 12Ce-30LA6 showed uncommonly high values of crack tip toughness.     

Synthesis of oligoethylene glycol ethers from the seed oil of Vernonia anthelmintica

The seed oil of Vernonia anthelmintica on reaction with diols (mono-, di-, tri-, or tetraethylene glycols) in the presence of boron trifluoride etherate, followed by saponification and esterification (methanol/H⁺), gives the oligoethylene glycol ethers: methyl 12(13)-hydroxy-13(12) [2-hydroxy-ethyl-1-oxy]-octadec-9-enoate; methyl 12(13)-hydroxy-13(12)-[5-hydroxy-3-oxapentyl-1-oxy]-octadec-9-enoate; methyl 12(13)-hydroxy-13(12)-[8-hydroxy-3,6-dioxaoctyl-1-oxy]-octadec-9-enoate; and methyl 12(13)-hydroxy-13(12)-[11-hydroxy-3,6,9-trioxaundecyl-1-oxy]-octadec-9-enoate. Methyl 12,13-dihydroxyoctadec-9-enoate is a co-product in all reactions.     

Human Caspase 12 Enhances NF-κB Activity through Activation of IKK in Nasopharyngeal Carcinoma Cells

Human nasopharyngeal carcinoma (NPC) is a highly invasive cancer associated with proinflammation. Caspase-12 (Casp12), an inflammatory caspase, is implicated in the regulation of NF-κB-mediated cellular invasion via the modulation of the IκBα protein in NPC cells. However, the effect mechanisms of Casp12 need to be elucidated. NPC cells were transfected with the full length of human Casp12 cDNA (pC12) and the effect of human Casp12 (hCasp12) on the NF-κB activity was investigated. We found ectopic expression of hCasp12 increased the NF-κB activity accompanied by an increased p-IκBα expression and a decreased IκBα expression. Treatment of BMS, a specific IKK inhibitor, and pC12-transfected cells markedly decreased the NF-κB activity and ameliorated the expression level of IκBα reduced by hCasp12. Co-immunoprecipitation assays validated the physical interaction of hCasp12 with IKKα/β, but not with NEMO. Furthermore, the NF-κB activity of ΔCasp12-Q (a mutated catalytic of hCasp12) transfected cells was concentration-dependently induced, but lower than that of hCasp12-transfected cells. Importantly, the hCasp12-mediated NF-kB activity was enhanced by TNFα stimulation. That indicated a role of the catalytic motif of hCasp12 in the regulation of the NF-κB activity. This study indicated hCasp12 activated the NF-κB pathway through the activation of IKK in human NPC cells.     

Rheological Properties of Quaternary Ammonium Gemini Surfactants in Aqueous Solution

The rheological properties and time effect of a quaternary ammonium salt gemini surfactant C_n‐s‐C_n?2Br solution were measured. The rheological properties were markedly different at various concentrations of the surfactant C₁₂‐2‐C₁₂?2Br solutions. When the alkyl chain of C_n‐2‐C_n?2Br solution is 14 or 16, the rheological properties of the solution exhibit fluid dilatancy very similar to C₁₂‐2‐C₁₂?2Br solutions. However, when the length of the spacer is four or six, C₁₂‐s‐C₁₂?2Br solutions exhibit Newtonian fluid behavior and are quite different from the C₁₂‐2‐C₁₂?2Br solution. A C₁₂‐2‐C₁₂?2Br solution at a high concentration shows negative thixotropy and time dependency.     

Reactive compatibilization of polyamide-12/poly(butylene terephthalate) blends with hyperbranched PEI-g-PA12: Morphology and thermal properties

Thermal and morphology properties of polyamide-12 (PA12)/poly(butylene terephthalate) (PBT) blends with hyperbranched poly(ethyleneimine)-g-polyamide-12 (PEI-g-PA12) as reactive compatibilizer were studied by a combination of Optical Microscopy, DSC and ¹³C NMR. This compatibilizer was synthesized by simple amidation reactions. The addition of PEI-g-PA12 greatly modified the morphology of PA12/PBT blends, which were originally an incompatible polymer pair. At the beginning of the addition of compatibilizers, the sizes of PA12 and PBT rich phases decreased and the blends dispersed better. Then the phase structures became more diffused with time. At last, bi-phase morphology disappeared totally and one homogeneous structure was obtained at 260 °C. The higher the PEI-g-PA12 compatibilizer content was, the faster the morphology changed. Our DSC measurements provided a consistent picture of the crystallization behavior of PA12 and PBT components. The comparison of ¹³C NMR spectrums between PA12/PBT and PA12/PBT/PEI-g-PA12 undergoing the same thermal treatment indicated that compatibilization was originated from the formation of hyperbranched PBT-co-PEI-co-PA12 copolymers.     

Isolation and Structural Elucidation of Antiproliferative Compounds of Lipidic Fractions from White Shrimp Muscle (Litopenaeus vannamei)

Shrimp is one of the most popular seafood items worldwide, and has been reported as a source of chemopreventive compounds. In this study, shrimp lipids were separated by solvent partition and further fractionated by semi-preparative RP-HPLC and finally by open column chromatography in order to obtain isolated antiproliferative compounds. Antiproliferative activity was assessed by inhibition of M12.C3.F6 murine cell growth using the MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assay. The methanolic fraction showed the highest antiproliferative activity; this fraction was separated into 15 different sub-fractions (M1–M15). Fractions M8, M9, M10, M12, and M13 were antiproliferative at 100 µg/mL and they were further tested at lower concentrations. Fractions M12 and M13 exerted the highest growth inhibition with an IC₅₀ of 19.5 ± 8.6 and 34.9 ± 7.3 µg/mL, respectively. Fraction M12 was further fractionated in three sub-fractions M12a, M12b, and M12c. Fraction M12a was identified as di-ethyl-hexyl-phthalate, fraction M12b as a triglyceride substituted by at least two fatty acids (predominantly oleic acid accompanied with eicosapentaenoic acid) and fraction M12c as another triglyceride substituted with eicosapentaenoic acid and saturated fatty acids. Bioactive triglyceride contained in M12c exerted the highest antiproliferative activity with an IC₅₀ of 11.33 ± 5.6 µg/mL. Biological activity in shrimp had been previously attributed to astaxanthin; this study demonstrated that polyunsaturated fatty acids are the main compounds responsible for antiproliferative activity.     

Effect of ball milling and solid solution treatment on the microstructure and interfacial behaviors of ZrMgMo3O12p/2024Al composites

ZrMgMo₃O₁₂ is a negative expansion material, while 2024Al alloy is a positive expansion material. The difference in thermal expansion coefficients between them will cause thermal mismatch stress at the interface in ZrMgMo₃O_12p/2024Al composites. Therefore, the interface behaviors of ZrMgMo₃O₁₂–Al determine the properties of ZrMgMo₃O_12p/2024Al composites to a great extent. The effects of ball milling and solid solution treatment on the microstructure and interface behaviors of 10 vol% ZrMgMo₃O_12p/2024Al composites were studied to improve the reticular microstructure of ZrMgMo₃O₁₂ distributed at the grain boundary of the α-Al matrix. The results showed that with increasing milling energy, the microstructure of the composites changed from reticular to equiaxed, and the distribution of ZrMgMo₃O₁₂ reinforcements in the matrix was more uniform. The content and size of the primary phase Al₂Cu decreased with increasing solid solution treatment time. In addition, only ZrMgMo₃O₁₂–Al, Al₂Cu–Al₁₂Mo and Al–Al₁₂Mo interfaces can be observed, but it is difficult to observe the interfaces of ZrMgMo₃O₁₂–Al₁₂Mo in the composites milled for 12 h and solution treated for 24 h, which is related to the decomposition mechanism of ZrMgMo₃O₁₂. The decomposition mechanism is as follows: Al atoms from the α-Al matrix captured O atoms from ZrMgMo₃O₁₂ to form Al₂O₃. ZrMgMo₃O₁₂ simultaneously released Mo, Zr and Mg atoms. Mo atoms were enriched and nucleated in situ and precipitated with Al atoms to form the intermetallic compound Al₁₂Mo, while Zr and Mg atoms entered the α-Al matrix to form a solid solution.     

Preparation and Physicochemical Properties of Lauroyl-Glutamyl-Lysil-Lauroyl-Glutamate Vesicles

We investigate the compositions of vesicle formulation by assembling phase diagrams of the ternary components of lauroyl‐glutamyl‐lysil‐lauroyl‐glutamate (C₁₂‐GLG‐C₁₂) peptide‐based gemini‐type amphiphile/citric acid/water using visual and microscopic observations. To clarify interactions between C₁₂‐GLG‐C₁₂ and citric acid, turbidity and zeta potential of the mixtures were investigated. To improve the stability of metastable vesicles, appropriate additives were examined by measuring particle size and zeta potential, visual observation and transmission electron microscopy. The turbidity increased and the absolute value of zeta potential decreased with increasing citric acid concentration in C₁₂‐GLG‐C₁₂/citric acid solutions. Then, a metastable γ region having vesicles was formed. The stability of vesicles increased with increasing cholesterol concentrations. This result suggests that a coacervation has occurred due to the effective cross‐sectional area decreasing with increasing C₁₂‐GLG‐C₁₂ hydrophobicity, which was derived from inhibition of the carboxyl group dissociation. Furthermore, we hypothesized that the orientation of cholesterol between vesicle membranes is a contributing factor to improve the vesicle stability. From transmission electron microscopic observations, it was made clear that the vesicles consisting of cholesterol and C₁₂‐GLG‐C₁₂ at a molar ratio of 2:1 showed multilayered structures. The vesicles consisting of C₁₂‐GLG‐C₁₂, cholesterol and citric acid are expected to be used as transdermal drug delivery system carriers, as they can be easily prepared using biocompatible compounds without the use of organic solvents such as chloroform.     

Analysis of the geometric isomers of methyl linoleate by gas chromatography

The four geometric isomers of methyl linoleate have been quantitatively determined by gas chromatography on Apiezon L and DEGS polyester capillary columns. Three peaks were eluted from the Apiezon L column: (a) the 9-cis, 12-cis isomer; (b) the 9-cis, 12-trans isomer; and (c) the 9-trans, 12-cis and 9-trans, 12-trans isomers combined. The DEGS polyester column also resolved three peaks: (a) the 9-trans, 12-trans isomer; (b) the 9-cis, 12-cis and 9-cis, 12-trans isomers combined; and (c) the 9-trans, 12-cis isomer. Since the separation of isomers was different on each column, the content of each of the four isomers could be determined from the combined results. Quantitative results agreed closely with the per centtrans bonds as determined by infrared analysis. Presented at the fall meeting of the American Oil Chemists' Society, Chicago, Illinois, October 30-November 1, 1961. Supported in part by a grant from Cargill, Ineorporated.     

Preparation and characterization of derivatives of isoricinoleic acid and their antimicrobial activity

Methylisoricinoleate (methyl-9-hydroxy-cis-12-octadecenoate) (I) has been derivatized to yield new fatty acid derivatives analogous to those obtained from the ricinoleic acid of castor oil. These derivatives include 1,9-dihydroxy-12-octadecene (II); 1,9-diacetoxy-12-octadecene (III); 12,13-epoxy-1,9-diacetoxyoctadecane (IV); 9-cyanoethoxy-1-hydroxy-12-octadecene (V); 1-morpholine-9-hydroxy-12-octadecene (VI), and 1-morpholine-9-cyanoethoxy-12-octadecene (VII). Structures of these compounds were established by chemical and spectral data. The compounds V, VI and VII showed antifungal activity againstAlternaria sp.,Helminthosporium sp.,Penicillium citrinum, Fusarium oxysporum, Aspergillus ochraceous, A. flavus, A. niger, Actinomyces sp. andCladosporium harbarum.     

Involvement of Oxidative and Endoplasmic Reticulum Stress in RDH12-Related Retinopathies

Retinol dehydrogenase 12 (RDH12) is expressed in photoreceptor inner segments and catalyses the reduction of all-trans retinal (atRAL) to all-trans retinol (atROL), as part of the visual cycle. Mutations in RDH12 are primarily associated with autosomal recessive Leber congenital amaurosis. To further our understanding of the disease mechanisms, HEK-293 cell lines expressing wildtype (WT) and mutant RDH12 were created. The WT cells afforded protection from atRAL-induced toxicity and oxidative stress. Mutant RDH12 cells displayed reduced protein expression and activity, with an inability to protect cells from atRAL toxicity, inducing oxidative and endoplasmic reticulum (ER) stress, with upregulation of sXBP1, CHOP, and ATF4. Pregabalin, a retinal scavenger, attenuated atRAL-induced ER stress in the mutant RDH12 cell lines. A zebrafish rdh12 mutant model (rdh12^u533 c.17_23del; p.(Val6AlafsTer5)) was generated through CRISPR-Cas9 gene editing. Mutant fish showed disrupted phagocytosis through transmission electron microscopy, with increased phagosome size at 12 months post-fertilisation. Rhodopsin mislocalisation and reduced expression of atg12 and sod2 indicated early signs of a rod-predominant degeneration. A lack of functional RDH12 results in ER and oxidative stress representing key pathways to be targeted for potential therapeutics.     

两种季铵盐Gemini表面活性剂的合成及其表征

合成了两种联结基团为含羟基亚甲基链的季铵盐Gemini表面活性剂,即C12-3(OH)-C12·2C1及C12- 4(OH)-C12·2Cl,用红外光谱、核磁共振及元素分析对它们的结构进行了鉴定,并对影响反应的因素进行了讨论,得出了合成C12-3(OH)-C12·2Cl的最佳条件为:n(十二叔胺):n(十二叔胺盐酸盐):n(环氧氯丙烷)=2．0 :1.0:1．0,以正丙醇为溶剂,在回流温度下反应3 h,产率可达94．5％以上;合成C12-4(OH)-C12·2Cl的最佳条件为:n(十二叔胺):n(1,4-二氯-2-丁醇)=2．2:1．0,以正丙醇为溶剂,回流反应24 h,产率可达70％。     

High-Throughput Profiling of Cas12a Orthologues and Engineered Variants for Enhanced Genome Editing Activity

CRISPR/Cas12a (formerly Cpf1), an RNA-guided endonuclease of the Class II Type V-A CRISPR system, provides a promising tool for genome engineering. Over 10 Cas12a orthologues have been identified and employed for gene editing in human cells. However, the functional diversity among emerging Cas12a orthologues remains poorly explored. Here, we report a high-throughput comparative profiling of editing activities across 16 Cas12a orthologues in human cells by constructing genome-integrated, self-cleaving, paired crRNA–target libraries containing >40,000 guide RNAs. Three Cas12a candidates exhibited promising potential owing to their compact structures and editing efficiency comparable with those of AsCas12a and LbCas12a, which are well characterized. We generated three arginine substitution variants (3Rv) via structure-guided protein engineering: BsCas12a-3Rv (K155R/N512R/K518R), PrCas12a-3Rv (E162R/N519R/K525R), and Mb3Cas12a-3Rv (D180R/N581R/K587R). All three Cas12a variants showed enhanced editing activities and expanded targeting ranges (NTTV, NTCV, and TRTV) compared with the wild-type Cas12a effectors. The base preference analysis among the three Cas12a variants revealed that PrCas12a-3Rv shows the highest activity at target sites with canonical PAM TTTV and non-canonical PAM TTCV, while Mb3Cas12a-3Rv exhibits recognition features distinct from the others by accommodating for more nucleotide A at position −3 for PAM TATV and at position −4 for PAM ATCV. Thus, the expanded Cas12a toolbox and an improved understanding of Cas12a activities should facilitate their use in genome engineering.     

Sex Attractant Pheromone of Saturniid Moth Coloradia velda

The female-produced sex attractant pheromone of Coloradia velda has been identified by a combination of analytical methods and field tests as a blend of (10E,12Z)-hexadecadien-1-yl acetate (10E,12Z–16:Ac), (10E,12E)-hexadecadien-1-yl acetate (10E,12E–16:Ac), and (10E,12Z)-hexadecadien-1-ol (10E,12Z–16:OH) in a 10:1:0.33 ratio, respectively. The corresponding aldehyde (10E,12Z–16:Ald) was also found in extracts of female pheromone glands, but in blends with 10E,12Z–16:Ac and 10E,12E–16:Ac at low doses did not significantly increase the attractiveness of baits to male moths.     

Sex Pheromone of Nuttall's Sheep Moth, Hemileuca nuttalli, from the Eastern Sierra Nevada Mountains of California

The sex attractant pheromone blend of Hemileuca nuttalli (Lepidoptera: Saturniidae) from the eastern slope of the Sierra Nevada Mountains in California was determined to be a combination of E10,Z12-hexadeca-10,12-dien-1-yl acetate (E10,Z12–16:Ac) and E10,E12-hexadeca-10,12-dien-1-yl acetate (E10,E12–16:Ac). Ratios of the compounds in extracts of female pheromone glands varied around a mean of 100:48, although the ratio was not critical in field trials. Blends of synthetic E10,Z12–16:Ac and E10,E12–16:Ac in 100:50, 50:100, and 100:100 ratios attracted equal numbers of male moths. Field trials also indicated that E10,Z12–hexadeca-10,12-dien-1-ol (E10,Z12–16:OH) and E10,Z12-hexadeca-10,12-dienal (E10,Z12–16:Ald) were antagonistic at rates of 3.3% and 10%, respectively, of the E10,Z12–16:Ac, despite being found in female moth extracts. E10,E12–16:Ac, E10,Z12–16:OH, and E10,Z12–16:Ald all appear to have roles in maintenance of reproductive isolation between H. nuttalli and H. eglanterina.     

Short-chain phorbol ester constituents of croton oil

Five phorbol diesters, three 4-deoxy-4α-phorbol diesters, two phorbol monoesters, and one 4-deoxy-4α-phorbol monoester were isolated from a commercial sample of croton oil and characterized spectroscopically. Their purification was achieved using combinations of droplet countercurrent chromatography, low-pressure column chromatography over phase-bonded silica gel, and preparative thin layer chromatography. All of these isolates were shown to possess short-chain ester functionalities, with 12-O-tiglylphorbol-13-isobutyrate, 12-O-(2-methyl)butyrylphorbol-13-isobutyrate, 12-O-(2-methyl)butyrylphorbol-13-acetate, 12-O-tiglyl-4-deoxy-4α-phorbol-13-isobutyrate, 12-O-tiglyl-4-deoxy-4α-phorbol-13-acetate, 12-O-(2-methyl)butyryl-4-deoxy-4α-phorbol-13-acetate, phorbol-12-tiglate and 4-deoxy-4α-phorbol-13-acetate being new compounds. A contribution from the Program for Collaborative Research in the Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago.     

12-tungstophosphoric and 12-tungstosilicicacid supported onto hydrous zirconia for liquid phase tert-butylation of m-cresol

Supported 12-tungstophosphoricacid (12-TPA) and 12-tunstosilicicacid (12-TSA) were used as heterogeneous catalysts for liquid-phase tert-butylation of m-cresol, an industrial important reaction. Alkylation reactions have been carried out with supported 12-TPA by varying different parameters such as % loading of 12-tungstophosphoricacid onto support, mole ratio of alcohol to m-cresol, reaction temperature, amount of the catalyst, reaction time and calcination temperature to optimize the conditions. To see the effect of the acidity on the reaction, the same reaction was studied over supported 12-TSA. Both the catalysts give 100% selectivity for o-isomer with different % conversion. The difference in catalyst performance of both the catalyst was correlated with the value of total acidity as well as Bronsted acidity.     

Influence of powder mixing processes and WC contents on microstructure,shrinkage behavior,and mechanical properties of WC-Si3N4 composites

WC-Si₃N₄ composite structural material with excellent mechanical properties is essential for achieving high-strength connections between WC and Si₃N₄. Proper powder mixing process can significantly improve the mechanical properties of sintered samples. This study investigates the effects of two different ball milling methods: (1) mixing WC powder, Si₃N₄ powder, and sintering aid powders and then ball milling for 24 h (BM24); and (2) ball milling WC powder, Si₃N₄ powder, and sintering aid powders separately for 12 h and then ball milling in same jar for 12 h (BM12 + 12), as well as WC content on sintering shrinkage behavior of mixed powders. Furthermore, the bonding between the layers of one-time sintered sample of the WC-Si₃N₄ composite structure was investigated. The results showed that the microstrains of powders prepared by BM24 mixing process were greater than those of the powders prepared by BM12 + 12 mixing process. Shrinkage displacements and shrinkage rates during sintering of BM12 + 12 powders were greater than those of BM24 powders to varying degrees. Moreover, sintering temperature at which shrinkage rate of composite powders reaches its maximum value gradually increases as WC content decreases, while maximum value of shrinkage rate gradually decreases. Additionally, mechanical properties of all BM12 + 12 samples were better than those of BM24 samples. WC-Si₃N₄ composite structure sample sintered with BM12 + 12 powders had a smooth transition between the layers without any defects.