Monomolecular film viscosities and micromorphologies of fatty acids and their analogues at air/water interfaces: relations to molecular structures

Langmuir ◽  
1990 ◽  
Vol 6 (7) ◽  
pp. 1309-1315 ◽  
Author(s):  
Katsuyuki Naito ◽  
Takano Iwakiri ◽  
Akira Miura ◽  
Makoto Azuma
Keyword(s):  
Fatty Acids ◽  
Molecular Structures ◽  
Monomolecular Film

Surface Film Thicknesses of Polymeric Substances in Relation to Molecular Structure

1946 ◽  
Vol 19 (3) ◽  
pp. 551-551
Author(s):  
Frederick T. Wall ◽  
Murray Zelikoff
Keyword(s):  
Molecular Structure ◽  
Fatty Acids ◽  
Surface Film ◽  
Molecular Structures ◽  
Cellulose Derivatives ◽  
Long Chain Fatty Acids ◽  
Monomolecular Films ◽  
Long Chain ◽  
Chain Fatty Acids

Abstract It is well known that certain compounds, such as long chain fatty acids, can form monomolecular films on water and that the areas of such films can be related to the dimensions of the molecules. Certain polymeric substances, including cellulose derivatives, proteins and the polymer of ω-hydroxydecanoic acid likewise form stable films whose areas can be conveniently measured. At this time we wish to report that we have prepared films of some rubberlike polymers as well, and that the results appear to give useful information about their molecular structures, particularly in relation to branching.

scholarly journals Effects of dietary fatty acids on gut health and function of pigs pre- and post-weaning

2020 ◽  
Vol 98 (4) ◽  
Author(s):  
Charlotte Lauridsen
Keyword(s):  
Oxidative Stress ◽  
Fatty Acids ◽  
Immune Responses ◽  
Molecular Structures ◽  
Epithelial Barrier ◽  
Gut Health ◽  
Inflammatory Reactions ◽  
Epithelial Barrier Function ◽  
Fa Composition ◽  
And Function

Abstract Fatty acids (FA) play a major role in relation to mucosal immune responses, epithelial barrier functions, oxidative stress, and inflammatory reactions. The dietary FA composition and the molecular structures (chain length and number of double bonds) influence digestion, absorption and metabolism, and the bioactivity of the FA. Piglets post-weaning having an immature intestine and not fully formed immune functions are very vulnerable to invading microorganisms. Manipulation of the milk FA composition via sow nutrition, or inclusion of dietary fat sources in the feed for newly weaned pigs, may be used as a strategic tool to enhance pig performance and their gut health and function pre- and post-weaning. Medium-chain fatty acids (MCFA) are absorbed directly into the portal blood and may contribute to immediate energy for the enterocytes. In addition, the MCFA, similarly to the short-chain fatty acids (SCFA), possess antibacterial effects and may thereby prevent overgrowth of pathogenic bacteria in the gastrointestinal tract. The essential FA, linoleic (LA) and α-linolenic (ALA) FA, form the building blocks for the long-chain polyunsaturated n-3 and n-6 FA. The conversion of ALA and LA into n-3 and n-6 eicosanoids, respectively, influences the molecular structures of metabolites and inflammatory reactions and other immune responses upon bacterial challenges. Dietary manipulation of the lactating sow influences the transfer of the n-3 and n-6 polyunsaturated fatty acids (PUFA) from the sow milk to the piglet and the incorporation of the FA into piglet enteric tissues and cell membranes, which exerts bioactivity of importance for immune responses and the epithelial barrier function. Especially, the n-3 PUFA present in fish oil seem to influence the gut health and function of pigs, and this is of importance during the transition periods such as post-weaning in which piglets are prone to inflammation. The proportion of unsaturated FA in the cell membranes influences the susceptibility to oxidative stress. Oxidative stress accompanies infectious diseases, and the development of lipid peroxides and other reactive oxygen products may be harmful to the epithelial barrier function. Fatty acid peroxides from the feed may also be absorbed with other lipid-solubles and thereby harm the intestinal function. Hence, antioxidative protection is important for the enteric cells. In conclusion, manipulation of the dietary FA composition can influence the gut health and function in pigs and may support a normal immune system and modulate resistance to infectious diseases during especially stressful phases of a pig’s life such as post-weaning.

scholarly journals Synthesis, Optical, and Geometrical Approaches of New Natural Fatty Acids’ Esters/Schiff Base Liquid Crystals

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4293 ◽  
Author(s):  
Alnoman ◽  
Al-Nazawi ◽  
Ahmed ◽  
Hagar
Keyword(s):  
Fatty Acids ◽  
Schiff Base ◽  
Liquid Crystals ◽  
Density Functional ◽  
Optical Transition ◽  
Molecular Structures ◽  
Frontier Molecular Orbital ◽  
Computational Calculations ◽  
Base Liquid ◽  
Methyl Phenyl

Schiff base liquid crystals, known as [4-(hexyloxy)phenylimino)methyl]phenyl palmitate (IA), [4-(hexyloxy)phenylimino)methyl]phenyl oleate (IIA) and [4-(hexyloxy)phenylimino)methyl]phenyl linoleate (IIIA), were synthesized from palmitic, oleic, and linoleic natural fatty acids. The prepared compounds have been investigated for their thermal and optical behavior as well as phase formation using differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Molecular structures of all studied compounds were confirmed via elemental analysis, FT-IR, 1H NMR, and 13C NMR. Smectic phase is the observed mesophase for all compounds; however, their type and range depend upon the terminal alkanoate chains attached to the phenyl ring. Computational calculations, Density functional theory (DFT), energy difference of the frontier molecular orbital (FMOs), as well as the thermodynamic parameters of different molecular configurations isomers were discussed. It was found that the mesophase behavior and the geometrical characteristics were affected by the degree of unsaturation of fatty terminal chains. Furthermore, the geometrical structure of the CH=N linkage plays an important role in the thermal stability and optical transition temperature.

scholarly journals DIVERSITY OF ANTIBACTERIAL COMPOUNDS FROM EUCHEUMA SERRA, HALIMEDA OPUNTIA, AND HYDROCLATHRUS CLATHRATUS

2016 ◽  
Vol 12 (2) ◽  
pp. 131 ◽  
Author(s):  
Jana Tjahjana Anggadiredja
Keyword(s):  
Fatty Acids ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Bacillus Subtilis ◽  
Brown Seaweed ◽  
Molecular Structures ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Hydroclathrus Clathratus

Fourteen compounds were isolated from acetone extracts of three species of seaweeds (Eucheuma serra, a red seaweed, Halimeda opuntia, a green seaweed, and Hydroclathrus clathratus, a brown seaweed) using bioautographic TLC methods and identified using GC-MS. From Eucheuma serra were isolated 8 compounds (3 fatty acids, 3 steroids, and 2 aldehyds). Only two compounds of fatty acid camefrom Halimeda opuntia, whereas Hydroclathrus clathratus produced 6 compounds (4 fatty acids, one compound each of steroid and ether). All isolated single compoundswere tested for their antibacterial activities by the agar diffusion method against the Gram-positive bacteria Staphylococcus aureus, Bacillus subtilis and Streptococcusfaecalis, and the Gram-negative bacteria Echerichia coli, Pseudomonas aeruginosa and Salmonella typhimurium. All 14 compounds showed activity against Gram-positivebacteria, especially Bacillus subtilis, and only 2 compounds showed activity against Gram-negative bacteria Escherichia coli. Nine compounds showed activity against Staphylococcus aureus, and 4 compounds showed activity against Streptococcusfaecalis. All compounds were not active against Pseudomonas aeruginosa andSalmonella typhimurium bacteria. This study indicated that there is indeed a diversityboth in kinds and in molecular structures of the antibacterial substances.

Die Strukturen der essentiellen ungesättigten Fettsäuren, Kristallstruktur der Linolsäure sowie Hinweise auf die Kristallstrukturen der α-Linolensäure und der Arachidonsäure / The Structures of the Essential Unsaturated Fatty Acids. Crystal Structure of Linoleic Acid and Evidence for the Crystal Structures of α-Linolenic Acid and Arachidonic Acid

1979 ◽  
Vol 34 (5) ◽  
pp. 706-711 ◽  
Author(s):  
Josef Ernst ◽  
William S. Sheldrick ◽  
Jürgen-Hinrich Fuhrhop
Keyword(s):  
Fatty Acids ◽  
Arachidonic Acid ◽  
Linoleic Acid ◽  
Linolenic Acid ◽  
Unsaturated Fatty Acids ◽  
Essential Fatty Acids ◽  
Molecular Structures ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
First Time

Abstract The essential fatty acids linoleic, α-linolenic and arachidonic acid have been crystallized for the first time. The crystal and molecular structures have been elucidated by X-ray analysis. Linoleic acid crystallizes monoclinic P21/c with a = 4298(3), b = 463.2(3), c = 937.7(6) pm, β = 109.38(8)°, Z = 4. The closely packed molecules are stretched with a tttttts̄CssCs̄tt conformationa. By comparison of the unit-cell constants and calculated densities of the unsaturated fatty acids it may be shown that both α-linolenic acid and arachidonic acid also possess stretched structures in the crystal lattice, α-linolenic acid must display a tttttts̄CssCs̄s̄Cs and arachidonic acid a tts̄CssCs̄s̄CssCs̄ttt conformation.

Electron Microscopy in Molecular Biology

1967 ◽  
Vol 25 ◽  
pp. 2-3
Author(s):  
Cecil E. Hall
Keyword(s):  
Electron Microscopy ◽  
Molecular Biology ◽  
Noise Level ◽  
Molecular Structures ◽  
Material Structure ◽  
The Arts ◽  
Shadow Casting ◽  
Electron Image ◽  
High Degree ◽  
Very High

The visualization of organic macromolecules such as proteins, nucleic acids, viruses and virus components has reached its high degree of effectiveness owing to refinements and reliability of instruments and to the invention of methods for enhancing the structure of these materials within the electron image. The latter techniques have been most important because what can be seen depends upon the molecular and atomic character of the object as modified which is rarely evident in the pristine material. Structure may thus be displayed by the arts of positive and negative staining, shadow casting, replication and other techniques. Enhancement of contrast, which delineates bounds of isolated macromolecules has been effected progressively over the years as illustrated in Figs. 1, 2, 3 and 4 by these methods. We now look to the future wondering what other visions are waiting to be seen. The instrument designers will need to exact from the arts of fabrication the performance that theory has prescribed as well as methods for phase and interference contrast with explorations of the potentialities of very high and very low voltages. Chemistry must play an increasingly important part in future progress by providing specific stain molecules of high visibility, substrates of vanishing “noise” level and means for preservation of molecular structures that usually exist in a solvated condition.

Scanning tunneling microscopy (STM) of DNA and RNA

1989 ◽  
Vol 47 ◽  
pp. 34-35
Author(s):  
Patricia G. Arscott ◽  
Gil Lee ◽  
Victor A. Bloomfield ◽  
D. Fennell Evans
Keyword(s):  
Molecular Structures ◽  
Inorganic Materials ◽  
Resolving Power ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Form And Function ◽  
Dna And Rna ◽  
Calf Thymus ◽  
And Function ◽  
The Relationship

STM is one of the most promising techniques available for visualizing the fine details of biomolecular structure. It has been used to map the surface topography of inorganic materials in atomic dimensions, and thus has the resolving power not only to determine the conformation of small molecules but to distinguish site-specific features within a molecule. That level of detail is of critical importance in understanding the relationship between form and function in biological systems. The size, shape, and accessibility of molecular structures can be determined much more accurately by STM than by electron microscopy since no staining, shadowing or labeling with heavy metals is required, and there is no exposure to damaging radiation by electrons. Crystallography and most other physical techniques do not give information about individual molecules.We have obtained striking images of DNA and RNA, using calf thymus DNA and two synthetic polynucleotides, poly(dG-me5dC)·poly(dG-me5dC) and poly(rA)·poly(rU).

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