Diol Diesters Research Articles

Lipase hydrolysis of mammalian long-chain 1,2-alkanediol diesters. Nonrandom distribution of fatty acids.

Long-chain 1,2-alkanediol diesters were isolated from the total surface lipids of golden Syrian hamsters and Swiss albino mice. Hydrolysis of the diol diester waxes with exocellular lipase from Rhizopus arrhizus delemar or with purified porcine pancreatic lipase produced free fatty acids and 2-acyl diols in about 60--80% yield. Nonrandom distribution of the constituent fatty acids at positions 1 and 2 of the alkanediols was observed. In the diester waxes from the hamster, both straight-chain and branched-chain fatty acids of 14 to 20 carbon atoms predominated at position 1 and those of 22 to 26 carbon atoms at position 2. In contrast, the diester waxes of the mouse contained mainly fatty acids of less than 19 carbon atoms, both saturated and monounsaturated, at position 2 and those of greater chain length (20 to 24 carbon atoms) at position 1. The results of the lipase hydrolysis were confirmed by degradation of the diester waxes with Grignard reagent.

Uropygial gland alkane diol diesters in the Kn mutation of the domestic chicken.

Uropygial glands from chickens which are known to have the Kn gene secrete qualitatively the same types of alkane diol diesters as the normal domestic chicken. However, there are many significant differences in the mole percent of individual fatty acids and diols within the diester between the two genetic types of chickens. In general, the mutant chickens have lesser amounts of the shorter chain fatty acids and diols and greater amounts of the longer chain fatty acids and diols. There is also a gene dosage effect with two mutant genes having a greater effect in many cases than a single mutant gene.

Surface lipids of Sphaerotheca fuliginea spores

The major components (50%) of the surface lipid extract of fungal spores (5.6% of dry spore wt) of Sphaerotheca fuliginea are esters of primary alcohols and fatty acids. Esters (15%) of primary alcohols and a Δ 2 t acid are present. The major acid moieties of the alkyl esters are C 22 and C 24 and of the Δ 2 t alkyl ester is Δ 2 t C 22; for both classes eicosanol is the major primary alcohol. The major ester of each class was concluded to be eicosanyl docosanoate and eicosanyl trans-2-docosenoate. Minor components are saturated and Δ 2 t methyl and diol diesters and free fatty acids. The major acid moieties of the diol diesters are C 22 and C 24 and the major diol is 1,12-dodecanediol.

Skin surface lipids of the dog.

The skin surface lipid of the dog has been reported to contain a high proportion of diol diesters having a lower mobility on thin layer chromatography than diesters from other species in spite of containing similar fatty acid and diol components. In the present study, dog skin surface lipid was separated by preparative thin layer chromatography into sterol esters (42%), wax diesters (32%), free sterols (9%), polar lipids (7%), and unidentified components (10%). The diesters contained 1,2-diols, each estrified with one long chain fatty acid and one isovaleric acid moiety. The diols were principally branched chain C21 and C22 compounds while the long chain fatty acids esterified with them were mainly C20 and C21 branched compounds. The fatty acids from the sterol esters were mostly saturated, branched chain C19 TO C23, together with 7% of straight chain monoenoic acids, principally C21 and C22. There were only trace amounts of free sterols other than cholesterol, while the esterified sterols contained 96% cholesterol and 4% lathosterol.

Antimicrobial properties of some mixed diesters of aliphatic diols.

AbstractTwenty compounds, diesters of ethylene glycol, diethylene glycol, orcis‐2‐butene‐1,4‐diol, were screened for antimicrobial activity against a grampositive bacterium,Staphylococcus aureus; a gramnegative bacterium,Escherichia coli; a mold, eitherAspergillus flavus orA. species; and a yeast, eitherCandida albicans orTorula species. All of the compounds were inhibitory against two or more of the test organisms, and eight mixed diesters were inhibitory against all four types of organisms. Each of these eight compounds had a benzoate group at one ester function and an acyl group other than benzoyl, mostly fatty acyl groups of 12–22 carbons, at the other.

Preparation of some mixed diesters of aliphatic diols and their evaluation as plasticizers

AbstractMixed diesters of three diols‐ethylene glycol, diethylene glycol, and 2‐butene‐1,4‐diol—were prepared wherein one of the ester moieties was benzoate. The laurates were shown to be excellent plasticizers for polyvinyl chloride (PVC) resin. Diesters containing two aroyl groups, or benzoyl and a short branched‐chain alkanoyl group were also shown to be compatible plasticizers for PVC resin. Longer chain acids, including oleic and erucic, gave incompatible plasticizers. Benzoyloxyethoxyethyl laurate plasticized PVC had low temperature properties, volatility, and thermal stability superior to PVC plasticized with di‐2‐ethylhexyl phthalate.

Diesters of alkane diols and 2-hydroxy fatty acids: Identification and discrimination of isomers with the aid of NMR spectroscopy

High resolution nuclear magnetic resonance spectroscopy has been shown to be extremely useful for the identification and discrimination of naturally occurring diesters of 1,2- and 2,3-alkanediols as well as for fatty alkyl esters of acylated 2-hydroxy fatty acids. A comparison of 220 MHz spectra of 1,2 and erythro- 2,3-alkanediol diesters exhibits the following distinguishing features: (1) two non-equivalent methylene protons from the glycol group of 1,2-alkanediol diesters resonate at 3.87 ppm and 4.17 ppm respectively while these resonances are completely absent in the spectrum of 2,3-isomer; (2) methylene protons adjacent to ester carbonyl groups appear as two overlapping triplets at 2.22 ppm in 1,2-alkanediol diesters while the corresponding protons in the 2,3-isomer are displayed as two partially overlapping triplets centered at 2.15 ppm and 2.2 ppm respectively; and (3) methyl protons adjacent to glycol group in 2,3-isomer appear as downfield doublet at 1.13 ppm; this downfield doublet is not shown by 1,2-alkanediol diesters. Erythro- and threo-2,3-alkanediol diesters have also been distinguished from each other; two α-methylenes in erythro isomers appear as partially overlapping triplets while these protons in threo isomer display an apparent quartet centered at 2.22 ppm. Fatty alkyl esters of acylated 2-hydroxy fatty acids display a triplet at 4.79 for 2-position methylene proton, a distinguishing feature not shown by diacyl alkanediols. A distinction between diester lipids and other classes of neutral lipids has also been achieved by the study of nuclear magnetic resonance spectra, particularly in the region of 3–6 ppm.

Diol Lipids in the Phospholipid Fraction of Lipomyces starkeyi Grown in the Medium Containing 1, 2-Propanediol

After training for 1, 2-propanediol, a yeast, Lipomyces starkeyi, grew well in the media containing the diol, showing a diauxie-like pattern. The yeast phospholipid was converted into monoacetyl-diglyceride by acetolysis. The presence of monoacetyl-mono fatty acyl esters of the diol in this fraction was found by GC-MS. The data suggested that the diol was present as 2-palmitoyl-ester and 2-oleoyl-ester in the form of phospholipid analogue, in which phosphorus bound in 1-position of the diol. Molecular species of the phospholipid was also deduced from the GC-MS data. Diol diester was not found in the triglyceride fraction of the yeast.

Leaf wax of Triticum aestivum

Leaf waxes from spring wheat varieties Selkirk and Manitou contain hydrocarbons (6%, 10%), long chain esters (14%, 13%), free acids (5%, 8%), free alcohols (19%, 21%), β-diketone (16%, 20%), hydroxy β-diketones (8%, 10%), unidentified gum (29%, 16.5%) and minor amounts of diol diesters, glycerides and aldehydes. The major hydrocarbon is nonacosane and major esters are octacosyl esters of C 14–C 32 acids but C 20 and C 22 alcohol esters of trans 2-docosenoic and tetracosenoic acids are also present (Selkirk 20%, Manitou 10% of total esters). Previously unknown trans 2-docosen-1-ol is present as an ester (Selkirk 5%, Manitou 2.5% of total esters). Free acids are C 14–C 32 acids and trans 2-docosenoic and tetracosenoic acids (Selkirk 30%, Manitou 9% of free acids). Octacosanol is the principal free alcohol. Hentriacontane-14,16-dione is the β-diketone and the hydroxy β-diketones are a 1:1 mixture of 8- and 9- hydroxyhentriacontane-14,16-diones.

Enzymatic esterification of alkane-2,3-diols by the microsomes of the uropygial glands of ring-necked pheasants ( Phasianus colchicus)

Extracts of uropygial glands of ring-necked pheasants ( Phasianus colchicus) catalyzed diester formation from tritiated C 18 alkane-2,3-diol. Monoacylated diol was also tentatively identified in the enzymatic product. Subcellular fractionation showed that the esterifying activity was located mainly in the microsomal fraction. ATP and CoA were required for the esterification process, and this reaction was stimulated by Mg 2+. Source of the acyl moieties for esterification was endogenous, and addition of exogenous fatty acid inhibited the reaction. When microsomes were treated with bovine serum albumin (BSA) in order to remove the endogenous source of acyl moieties, palmitoyl-CoA substituted for the ATP and CoA requirement. The pH optimum with ATP and CoA was between 6.0–9.0, while maximal rates of esterification were obtained with palmitoyl-CoA from pH 7.0 to 9.0. Borate ions stimulated esterification. The half maximal velocity was obtained with 2.0 × 10 −4, m diol, and 7.2 × 10 −5, m palmitoyl-CoA. Thiol reagents severely inhibited the esterification reaction with ATP and CoA, while much less inhibition was observed when palmitoyl-CoA was used. It is concluded that a microsomal acyl-CoA-diol transacylase catalyzes stepwise acylation of alkane-2,3-diols to give the diol diester which constitute the major component of the uropygial lipids of ring-necked pheasants.

Diesters of diols in wheat leaf wax

AbstractDiesters have been isolated from the leaf wax of spring wheat,Triticum aestivum, L. (Selkirk variety) by chromatography. The diesters, which form 3% of the wax and which were shown by gas liquid chromatography to be a mixture of C51−C60 esters, consist largely oftrans 2‐docosenoic andtrans 2‐tetracosenoic acid esters of 1,9‐nonanediol, 1,10‐decanediol, 1,11‐undecanediol and 1,12‐dodecanediol. The structures of the components were confirmed by synthesis.

Comparative effects of methylene, ethylene and propylene dimethanesulphonates on the male rat reproductive system.

Summary. Histological changes in the rat testis were correlated with the antifertility effects of injections of three diol diesters of methanesulphonic acid. The compounds are consecutive members of a homologous series each differing by -CH2- from its neighbours. The diester of ethylene glycol (EDS) caused antispermatogenic effects resembling those following hypophysectomy and was associated with involution of prostate and epididymis; spermatocoele formation occurred in the latter organ. Methylene dimethanesulphonate and 1,3-propylene dimethanesulphonate induced changes consistent with spermatogonial damage resembling those produced by Myleran (busulphan).

Fatty acids of the alkane diol diesters of vernix caseosa.

AbstractThe fatty acid monoenes esterified to the alkane diol diesters of vernix caseosa lipid form two patterns of homologues starting from either C16Δ9 or C16Δ6 and adding (or subtracting) an integral number of C2 units at the carboxyl group. Although components of the Δ6 pattern are the predominant monoenes of sebaceous gland ester lipid classes, for these diol diesters Δ9 pattern components are preferentially used.

Mass spectrometric analysis of long-chain esters of diols

Homologous series of synthetic long-chain monoesters and diesters of 1,2-ethanediol were analyzed by mass spectrometry, and the patterns of fragmentation were studied. Under electron impact saturated ethanediol monoesters yielded prominent ions characteristic of the short-chain diol, such as the rearranged ion formed by 2,3-cleavage (m/e 104) and the ion caused by 3,4-cleavage (m/e 117). Fragments characteristic of the constituent long-chain moieties were the acylium ions [RCO](+), [RCO - 1](+), and the ions [RC(OH)(2)](+). The mass spectra of ethanediol diesters exhibited very intense peaks due to the ions formed by loss of the acyloxy group, [M - RCOO](+), or one carboxylic acid, [M - RCOOH](+). These ions are distinctive for diol diesters. Precise mass measurements by high resolution mass spectrometry verified the composition of the ion fragments. Spectral studies of some monoesters and diesters of 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, and also of some monounsaturated homologues, demonstrated that mass spectrometry is very suitable for the identification, distinction, and analysis of diol lipids.

The occurence of diester waxes in human vernix caseosa and in hair lipids of common laboratory animals

1. 1. The hair lipids of rabbit and cat contain diesters of hydroxy fatty acids with aliphatic monohydric alcohols and unsubstituted fatty acids (Type I). 2. 2. The lipids of human vernix caseosa and the hair lipids of mouse and guinea-pig contain diesters of aliphatic diols with unsubstituted fatty acids (Type II). 3. 3. The main fraction of the dog hair lipids gives rise to diols and unsubstituted fatty acids upon hydrolysis, but it is not identical with the Type II diester waxes.