Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
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Compound
Target Concepts:
Gene/Protein
Disease
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Drug
Enzyme
Compound
Query: UNIPROT:Q3SYG4 (
C18
)
23,707
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Three groups of diesters have been isolated and identified in the lipids of steer meibomian glands. The first group, designated as alpha Type I, with the abbreviated formula FA-alpha OHFA-FAlc, consisted of alpha-hydroxy fatty acids esterified to fatty acids and fatty alcohols in the approximate molar ratio 1:1:1. The second group, designated as omega Type I-St, with the abbreviated formula FA-omega OHFA-St, consisted of omega-hydroxy fatty acids esterified to fatty acids and sterols in the approximate molar ratio 1:1:1. The third group, designated as alpha, omega Type II, with the abbreviated formula FA-alpha, omega diol-FA, consisted of alpha, omega-diols esterified to 2 moles of fatty acids. The sum of the different diesters comprised about 9% of total steer meibomian lipids. Capillary GLC of the fatty acids of alpha Type I diesters showed the fatty acids to be a family with a two-cluster profile, one at C12 to C20 and the other at C21 to
C31
, with anteiso chains predominating. Fatty acids from omega Type I-St and alpha, omega Type II diesters gave mainly a one-cluster profile in the short chain region with prominent anteiso and
C18
:1 peaks. Fatty alcohols of alpha Type I diesters were mainly long chain, C23 to C30, with anteiso chains predominating, while the alpha-hydroxy fatty acids were short chain C13 to
C18
acids with C16 predominating. The sterols in diesters omega Type I-St were cholesterol (approximately 60%), delta 7 cholestenol (approximately 35%) and an unidentified compound (approximately 5%) with a GLC retention time slightly longer than delta 7 cholestenol on SE-30 phase. The omega-hydroxy fatty acids and alpha, omega-diols both were of exceedingly long chain lengths, C29-C38, and showed similar GLC profiles. Two types of triesters comprising approximately 1% of total steer meibomian lipids have been isolated but incompletely characterized. In terms of molar ratios, one group of triesters gave fatty acids:omega-hydroxy fatty acids:alpha-hydroxy fatty acids:sterols + fatty alcohols as approximately 1:1:1:1. The other contained fatty acids, alpha-hydroxy fatty acids and alpha, omega-diols in what appears to be a complex mixture of several triesters. Diesters omega Type I and alpha, omega Type II also were found in human meibum. Hitherto these two diesters have not been found in any animal tissue.
...
PMID:The di- and triesters of the lipids of steer and human meibomian glands. 403 65
Simple surgery gave whole meibomian glands of steer yielding approximately 47 mg of lipid per pair of lids. This lipid gave a thin-layer chromatography pattern similar to that of steer or human excreta. Column chromatography of pooled steer gland lipids and pooled human lipid (excreta) gave 0.06% and 7.54% hydrocarbons, respectively, containing no squalene. Excluding human hydrocarbons (as exogenous material) the percentage composition of steer and human lipids were, respectively, sterol esters 31.7 and 29.5; wax esters 31.2 and 35.0; material in the diester region 11.4 and 8.4; triacyl glycerols 1.6 and 4.0; material in the post-triacyl glycerol region 2.8 and 3.2; free sterols 3.0 and 1.8; free fatty acids 5.1 and 2.1; and polar lipids 13.3 and 16.0. Glass capillary gas-liquid chromatography revealed the following: a series of normal odd- and even-chain hydrocarbons (C16 to C32) for the steer and a complex pattern for the human samples; unsubstituted fatty acids in total lipids and various lipid classes ranging from C12 to
C31
with n-even, n-odd, iso-even and iso-odd, and anteiso-odd chains for both samples; and fatty alcohols in total lipids and wax esters ranging from
C18
to
C31
. Anteiso structures predominated in the steer, and iso structures in the human samples. Steer fatty acids favored anteiso branching and saturation, whereas human acids favored iso branching and unsaturation. Fatty acids of sterol esters in both samples showed a wider range of chain lengths than did other lipid classes. Similarity of the fatty acid pattern suggests that the free fatty acids are derived from the triacyl glycerols as in human sebum. Identification of saturated fatty acids was confirmed by a gas liquid chromatography--mass spectrometry--data system (GLC-MS-DS). We define "meibum" and "meibocyte" as the meibomian gland equivalent of sebum and sebocyte.
...
PMID:Meibomian gland studies: comparison of steer and human lipids. 719 26
The neutral lipid profiles of nine species of thin trilaminar outer wall (TLS)-containing freshwater and marine microalgae from the class of Chlorophyceae were studied with emphasis on the relationship between the lipid content and the occurrence of insoluble non-hydrolysable biopolymer (i.e. algaenan). All the freshwater microalgae produce a highly aliphatic algaenan. In sharp contrast, no algaenan was isolated from the two marine microalgae, Chlorella marina and Chlorella minutissima marina, supporting the absence of a close relationship between the presence of TLS and the occurrence of algaenan. High molecular weight straight-chain hydrocarbons (C23-C29) were identified in most of the algaenan-producing microalgae and in the algaenan-devoid C. minutissima marina, whereas only low molecular weight hydrocarbons were detected in algaenan-producing Scenedesmus subspicatus and in algaenan-devoid C. marina. Sterols, phytol and fatty alcohols were the major constituents of the polar fraction of the neutral lipids of all the microalgae investigated. High molecular weight saturated or mono-unsaturated alcohols were detected in C. emersonii and in all the microalgae belonging to the genus Scenedesmus. High amounts of saturated C30 and C32 alpha,omega-diols were also detected in S. subspicatus, S. armatus and S. pannonicus. Three classes of lipids were encountered in very small amounts in the medium polarity fraction of the neutral lipids of the microalgae investigated: (i) Monoesters composed predominantly of saturated C16 or
C18
fatty acids and saturated C8, C16 or
C18
alcohols and (ii) long-chain methyl ketones from C25 to
C31
were detected in several species and (iii) methyl esters of fatty acids ranging from C16 to C28 were identified in all the microalgae. Attempts to use the neutral lipid composition and particularly the unusual long-chain lipids, as specific indicators of the occurrence of algaenan in TLS-containing microalgae were unsuccessful.
...
PMID:Comparison of neutral lipid profile of various trilaminar outer cell wall (TLS)-containing microalgae with emphasis on algaenan occurrence. 1089 77
The cuticular surface lipids of the red harvester ant, Pogonomyrmex barbatus, were found to contain minor amounts of novel wax esters, in addition to the major components, hydrocarbons. The wax esters ranged in carbon number from C19 to
C31
and consisted of esters of both odd- and even-numbered alcohols and acids. Each wax ester with a given carbon number eluted at several different retention times indicating possible methyl branching in either the fatty acid or alcohol moiety, or in both moieties. Each eluting peak of wax esters consisted of a mixture of wax esters of the same carbon number in which the fatty acid moiety ranged from C8 to
C18
, and the alcohol moiety ranged from C8 to C17. Some wax esters were largely found on the head indicating they may be of a glandular origin. The hydrocarbons consisted of: n-alkanes, C23 to C33; odd-numbered n-alkenes, C27 to C35; and the major components, methyl-branched alkanes, C26 to over C49. Notable components of the methyl-branched alkanes were 2-methyltriacontane, and the novel trimethylalkanes with a single methylene between the first and second branch points, 13,15,19-trimethylhentriacontane and 13,15,21-trimethyltritriacontane.
...
PMID:Novel wax esters and hydrocarbons in the cuticular surface lipids of the red harvester ant, Pogonomyrmex barbatus. 1125 May 53
The synthesis of the
C18
-
C31
subunit of orevactaene (1) in an enantioselective and convergent manner is reported. Four chiral centers in the structure (i.e., carbons 23, 25, 32, and 33) have unknown configuration; thus, a modular approach has been devised to link the two stereocenter-containing ends of the structure together via a trisubstituted olefin template to ultimately produce all possible diastereomers of the target. Keys to the success of this approach include (i) an efficient synthesis of four diastereomeric hydrophobic tails (C22-C29) of the molecule with two stereogenic centers at C23 and C25; (ii) the synthesis of three stereodefined trisubstituted olefins 37, 38, and 43 using palladium(0)-catalyzed hydrometalation and metallometalation; and (iii) the convergent assembly of the aforementioned sections by a 'one-pot' lithium/halogen exchange, boron/lithium exchange, borate ester saponification, and Suzuki cross-coupling followed by oxidative deprotection. The sequence provided the desired aldehydes 49 and 50 as single isomers in good yields. Compiled spectroscopic data from the literature and present work provides evidence that the relative configuration of the methyl groups in the side chain of orevactaene may be 1,3-syn, which will be confirmed when the total synthesis has been completed. These results have paved the way for a parallel synthesis approach to prepare all 16 possible stereoisomers of orevactaene so that the relative and absolute stereochemistry of this compound can be determined.
...
PMID:Approach toward the total synthesis of orevactaene. 2. Convergent and stereoselective synthesis of the C18-C31 domain of orevactaene. Evidence for the relative configuration of the side chain. 1212 3
The booklouse, Liposcelis bostrychophila, is an increasingly common pest of stored food products worldwide. We report here the cuticular lipid composition of this pest (the first report of the hydrocarbons of any member of the Order Psocoptera and the first report of fatty acid amides as cuticular components for any insect). No unsaturated hydrocarbons were present. A homologous series of n-alkanes (C21-C34), monomethyl alkanes (3-, 4-, 5-, 7-, 9-, 11-, 12-, 13- and 15-methyl-) with a carbon chain range of C28-C42, and dimethyl alkanes (3, 7-; 9, 13-; 11, 15-; 13, 17-; 9, 21-; 11, 19-; and 13, 21-) with a carbon number range of
C31
-C41 were identified. The relative abundances of these hydrocarbons were low, comprising approximately 0.0125% of total biomass. The amides were a homologous series (C16-C22 in chain length), with the major amide being stearoyl amide. In addition to the amides, free fatty acids (C16:1, C16:0,
C18
:2,
C18
:1, and
C18
:0 in chain length) and three straight chain aldehydes (C15, C16, and C17:1 in chain length) also occurred as cuticular components. These findings are discussed in terms of the chemical and physiological ecology of this species.
...
PMID:Cuticular lipids of the booklouse, Liposcelis bostrychophila: hydrocarbons, aldehydes, fatty acids, and fatty acid amides. 1275 23
The accumulation of
beta-amyloid peptide
(Abeta) in the human brain is known to be the major cause that drives Alzheimer's disease pathogenesis. Abeta, a 39-42 amino acid peptide, is the cleavage product of
amyloid precursor protein
in the hydrophobic transmembrane region. The present study employs a two-dimensional (2D) approach. Two synthetic peptidolipids,
C18
-IIGLM-OH and
C18
-IIGLM-NH2, are selected based on the fragment 31-35 of Abeta which is recognized as one of the determining segments that induces formation of amyloid fibril plaques. The aliphatic hydrocarbon chain
C18
is attached to the N-terminal of the fragment 31-35 to facilitate the 2D study at the air-water interface. The aggregation process is observed by two measurements: (1) surface pressure-area and surface dipole moment-area isotherms and (2) epifluorescence microscopy of the Langmuir films to investigate the topography of the amyloid-like formation.
...
PMID:Amyloid-like formation by self-assembly of peptidolipids in two dimensions. 1537 86
Bignoniaceae, Newbouldia laevis, Markhamia acuminata, Spathodea campanulata and Kigelia africana were analysed by GC-MS. The principal constituents were represented by a homologous series of n-alkanes (C23-C33), n-alcohols (
C18
-C30) and related carboxylic acids (C16-C36). For N. laevis and M. acuminata, ursolic and oleanolic acid were the most abundant wax components (52 and 60%, respectively), followed by the C29, the
C31
and the C33 n-alkanes. The predominant components of S. campanulata were n-alcohols (35%), with octacosanol and triacontanol as the most abundant ones, while K. africana is distinguished from these three members by the conspicuous absence of triterpenoic acids and the predominance of n-alkanes (70%) with hentriacontane and tritriacontane as the main representatives. Other notable constituents were sterols, albeit present in trace amounts. The wax profiles are discussed in terms of taxonomic characters.
...
PMID:Cuticular wax profiles of leaves of some traditionally used African Bignoniaceae. 1554 May 93
We have used a set of synthetic overlapping peptides encompassing the entire heavy (H) chain of botulinum neurotoxin serotype A (BoNT/A) to map, in two mouse strains (BALB/c, H2d, and SJL, H2S), the regions on the H-chain recognized by Abs in the last bleed of non-protective anti-BoNT/A antisera and in the bleed of protective antisera immediately following it in the bleeding schedule. Although the protective antisera bound slightly higher amounts of total (IgG+IgM) Abs, non-protective and protective BALB/c antisera showed similar peptide-binding profiles involving peptides N6/N7, N25, C2/C3, C9/C10/C11, C15,
C18
, C24, C30, and
C31
and, at lower amounts of bound Abs, peptides N19, C6/C7, and C28. IgG+IgM antibodies of the protective SJL antisera recognized peptides N5, N22, and C21, and these peptides were only slightly recognized (N22, C21) or unrecognized (N5) by the non-protective antisera. Additionally, peptides N7/N8, N25, C11, C15, and less so N27/N28 bound two-fold or more Abs from the SJL protective antisera than the non-protective antisera. The Abs bound to peptides C4 and C29 were of relatively lower affinity. Peptides C2/C3, C7,
C18
/C19, C24, C30, and
C31
bound higher amounts of Abs in the SJL protective versus the non-protective antisera, but the differences were less than double. We also mapped the binding profiles of the IgG Abs in these sera. BALB/c and SJL had 13-36-fold higher of IgG Abs that bound to BoNT/A in the protective antisera relative to non-protective antisera. The IgG Abs in the protective antisera of each mouse haplotype bound to the same peptides that bound total Abs in the correlate antiserum. But in both mouse strains, the non-protective Abs showed little or no IgG Abs that bound to these peptides. In the SJL haplotype, the IgG response to peptide N5 was transient, appearing strongly in early protective Abs and disappearing by day 70. It is not clear whether the response to region N5 plays a role in initiating and contributing to the protective activity of the toxin in the SJL strain in the early stages but is not needed in later hyperimmune stages of the Ab response. It is concluded that the switch in BALB/c and SJL mice from non-protective to protective Abs is not associated with major changes in the epitope-recognition profiles. Although some slight differences between non-protective and protective antisera appeared in their levels of Abs that were bound by some peptides, these differences are not sufficient to explain differences in the protection properties. Protection was mostly associated with the immunoglobulin class of the antibodies. IgM antibodies were non-protective, while IgG Abs produced after the switch were protective.
...
PMID:Submolecular recognition profiles in two mouse strains of non-protective and protective antibodies against botulinum neurotoxin A. 1595 Jul 44
The neutralizing activity of three anti-human TNF monoclonal antibodies, designated D2, E6, and F6 were investigated by three experimental systems. The results from the systems showed that all the three mAbs could neutralize TNF-mediated cytotoxicity in L929 cells, TNF-induced NF-kappaB activation in ECV304 cells, and TNF-upregulated ICAM-1 surface expression on ECV304 cells in dose-dependent manners. D2 had the highest neutralizing activity of the three mAbs, and F6 had higher level of neutralizing activity than E6. We also cloned the VH and VL cDNAs and obtained their cDNA sequences. The sequences were used in molecular modeling to establish the complex structures of TNF with variable regions of the three mAbs, respectively. In the structures, the TNF epitopes of D2, E6, and F6 were predicted at amino acids of (A109, A111-A112, C19, C21-C29, C44-C46, C66-C75, C77, C79, C90, C101, C103, C105, C114, C134-C148), (
C18
-C19, C21-C30, C32, C37, C43-C47, C67-C75,
C83
, C105-C106, C131, C135-C141), and (C21-C32, C45-C47, C65, C67-C72, C74, C81,
C83
, C90-C95, C105-C113, C133-C147), respectively, and the affinities of D2, E6, and F6 to TNF were predicted as -252.69, -232.83, and -299.92 kcal, respectively. Moreover, we proved the binding ability of F6 to the epitopes of amino acids of 141-146 in TNF molecule was better than that of E6, and that of D2 was the best of the three mAbs by Western blot and ELISA, in which the mutant TNF deleted the amino acids of 141-146 in TNF molecule was employed. These results make a basic foundation for selecting candidate mAbs for various purposes, such as construction of chimeric or humanized mAbs for therapeutic purpose, establishment of ELISA kits for determination of TNF, and production of affinity columns to purify TNF.
...
PMID:Characterization of the neutralizing activity of three anti-human TNF monoclonal antibodies and prediction of their TNF epitopes by molecular modeling and mutant protein approach. 1623 21
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