wax esters
Recently Published Documents


TOTAL DOCUMENTS

385
(FIVE YEARS 41)

H-INDEX

43
(FIVE YEARS 4)

Author(s):  
Henriette Brykczynski ◽  
Till Wettlaufer ◽  
Eckhardt Flöter

Current research on wax-based oleogels indicates wax esters to be the key component in many natural waxes. This necessitates understanding the properties of pure wax esters to unravel the gelling mechanism in wax-based oleogels. Therefore, wax esters with different carbon numbers and symmetries were studied and characterized regarding their thermal (DSC) and viscoelastic (oscillatory rheology) behavior. Pure wax esters and binary mixtures of wax esters were studied as such and in oleogels formed in combination with medium chained triglyceride oil at WE-inclusion levels of 10 % (w/w). Interpretation of the observations was based on detailed analysis of pre-existing data on crystallographic (SAXS) and thermal properties. It is found that all observations concerning single pure WE’s obey a systematic framework linking molecular make up, crystal structure and behavior. The study on the gelling of four different binary mixtures of wax esters revealed that substantial chain length differences do have the expected consequence of separate crystallization. Mixtures of wax esters with only limited chain length difference reconfirmed earlier speculations on mixing and crystal structure. Applying mixtures of wax esters only differing in their position of the ester bond indicated ideal mixing behavior in the solid phase of the gels. Actually, the data revealed that despite these expected observations in both systems, additional thermal events occur at specific mixing ratios. Their supposed relation to compound formation certainly needs further confirmation. Rheological analysis confirmed that sequential crystallization results in highest firmness values for the systems studied.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Katharina Vollheyde ◽  
Ellen Hornung ◽  
Cornelia Herrfurth ◽  
Till Ischebeck ◽  
Ivo Feussner

Abstract Background Wax esters (WE) are neutral lipids that consist of a fatty alcohol esterified to a fatty acid. WE are valuable feedstocks in industry for producing lubricants, coatings, and cosmetics. They can be produced chemically from fossil fuel or plant-derived triacylglycerol. As fossil fuel resources are finite, the synthesis of WE in transgenic plants may serve as an alternative source. As chain length and desaturation of the alcohol and acyl moieties determine the physicochemical properties of WE and their field of application, tightly controlled and tailor-made WE synthesis in plants would be a sustainable, beneficial, and valuable commodity. Here, we report the expression of ten combinations of WE producing transgenes in Arabidopsis thaliana. In order to study their suitability for WE production in planta, we analyzed WE amount and composition in the transgenic plants. Results The transgenes consisted of different combinations of a FATTY ACYL-COA/ACP REDUCTASE (FAR) and two WAX SYNTHASES/ACYL-COA:DIACYLGLYCEROL O-ACYLTRANSFERASES (WSD), namely WSD2 and WSD5 from the bacterium Marinobacter aquaeoleoi. We generated constructs with and without plastidial transit peptides to access distinct alcohol and acyl substrate pools within A. thaliana cells. We observed WE formation with plastid and cytosol-localized FAR and WSD in seeds. A comparative WE analysis revealed the production of shorter and more saturated WE by plastid-localized WE biosynthesis compared to cytosolic WE synthesis. Conclusions A shift of WE formation into seed plastids is a suitable approach for tailor-made WE production and can be used to synthesize WE that are mainly derived from mid- and long-chain saturated and monounsaturated substrates.


Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1471
Author(s):  
Zhenzhen Li ◽  
Wei Liu ◽  
Guolong Yang

Synthesized oleic acid-based wax esters (e.g., cetyl oleate), which can replace spermaceti oil or jojoba oil, have been widely used in the cosmetic, pharmaceutical and other industries. In this work, 4-dodecylbenzenesulfonic acid (DBSA) has been successfully used as an efficient catalyst to synthesize oleic acid-based wax esters through esterification at 40 °C under solvent-free conditions. A 93.6% conversion rate of cetyl alcohol was obtained under optimal conditions: 10 mol% DBSA, a molar ratio of 1.3:1 oleic acid to alcohol, a reaction temperature 40 °C and a reaction time of 4 h. The effect of water content on esterification was investigated, and it was found that the inhibitory effect of water decreased significantly with increasing temperature. Moreover, DBSA-catalyzed esterification could be applied in the production of various oleic acid-based wax esters and excellent conversion (>90%) to esters was obtained under such mild conditions. DBSA-catalyzed low-temperature esterification is an efficient method for the production of liquid wax esters.


Author(s):  
Safal Khanal ◽  
Yuqiang Bai ◽  
William Ngo ◽  
Kelly K. Nichols ◽  
Landon Wilson ◽  
...  

2021 ◽  
Author(s):  
MORITZ GERBAULET ◽  
ANTON MÖLLERKE ◽  
KATHARINA WEISS ◽  
SATYA CHINTA ◽  
JUTTA M. SCHNEIDER ◽  
...  

Abstract Emerging evidence shows that the cuticular and silk lipids of spiders are structurally more diverse than those of insects, although only a relatively low number of species have been investigated so far. As in insects, such lipids might play a role as signals in various context. The wasp spider Argiope bruennichi has probably the best investigated chemical communication system within spiders, including the known structure of the female sex pheromone. Recently we showed that kin-recognition in A. bruennichi is mediated through the cuticular compounds consisting of hydrocarbons and to a much larger proportion of wax esters. By use of MS and various derivatization methods these esters were identified here to be esters of 2,4-di­methyl­alkanoates with varying chain length and 1-alkanols, such as tetradecyl 2,4‑di­methyl­hepta­decanoate. A representative enantioselectively synthesis to this compound was performed which proved the identifications and allowed to postulate the natural enantiomer to have (2R,4R)-configuration. Cuticular profiles of the silk and cuticula of females were similar, while male cuticular profiles differed quantitatively from those of females. In addition, minor female specific 4-methylalkyl esters were detected.


Nano Letters ◽  
2021 ◽  
Author(s):  
Tuomo Viitaja ◽  
Jukka Moilanen ◽  
Kirsi Johanna Svedström ◽  
Filip S. Ekholm ◽  
Riku O. Paananen

2021 ◽  
Author(s):  
Katharina Vollheyde ◽  
Ellen Hornung ◽  
Cornelia Herrfurth ◽  
Till Ischebeck ◽  
Ivo Feussner

Abstract Background: Wax esters (WE) are neutral lipids that consist of a fatty alcohol esterified to a fatty acid. WE are valuable feedstocks in industry for producing lubricants, coatings and cosmetics. They can be produced chemically from fossil fuel or plant derived triacylglycerol. As fossil fuel resources are finite, the synthesis of WE in transgenic plants may serve as an alternative source. As chain length and desaturation degree of the alcohol and acyl moieties determine the physicochemical properties of WE and their field of application, a tightly controlled tailor-made WE synthesis in plants is aimed for. Here, we report the generation of ten combinations of WE producing transgenes expressed in Arabidopsis thaliana. In order to study their suitability for WE production in planta, we analyzed WE amount and synthesized WE species in the transgenic plants.Results: The transgenes consisted of different combinations of a fatty acyl-CoA/ACP reductase (FAR) and two wax synthases/acyl-CoA:diacylglycerol O-acyltransferases (WSD) namely WSD2 and WSD5 from the bacterium Marinobacter aquaeoleoi. We generated constructs with and without plastidial transit peptides to access diverse alcohol and acyl substrate pools within A. thaliana. We observed WE formation with plastid and cytosol-localized FAR and WSD in seeds. A comparative WE analysis revealed the production of shorter and more saturated WE by plastid-localized WE biosynthesis compared to cytosolic WE synthesis.Conclusions: A shift of WE formation into seed plastids is a suitable approach for tailor-made WE production and can be used to synthesize WE mainly derived from mid and long chain saturated and monounsaturated substrates.


Author(s):  
Ya-Hue Valerie Soong ◽  
Le Zhao ◽  
Na Liu ◽  
Peng Yu ◽  
Carmen Lopez ◽  
...  

2021 ◽  
Author(s):  
Luiz Henrique Sales de Menezes ◽  
Eliezer Luz do Espírito Santo ◽  
Marta Maria Oliveira dos Santos ◽  
Iasnaia Maria de Carvalho Tavares ◽  
Adriano Aguiar Mendes ◽  
...  

Abstract In the present work, Candida rugosa lipase (CRL) was immobilized by physical adsorption in organic medium on Accurel MP 1000 (AMP) with a protein load of 6.5 mg g-1 (mg protein/g support). CRL-AMP was applied with 5 and 10% of catalyst/volume of medium (m v-1) in esterification reactions of stearic acid with lauryl and cetyl alcohols producing the wax esters such as dodecanoyl octadecanoate 1 and hexadecanoyl octadecanoate 2 in a heptane medium. Six reaction cycles were studied to evaluate the stability and recyclability of the prepared biocatalyst. The specific activity (Asp) for CRL-AMP was 200 ± 20 U mg-1. Its catalytic activity was 1300 ± 100 U g-1. CRL-AMP was used in the synthesis of esters in heptane medium with a 1:1 acid:alcohol molar ratio at 45°C and 200 rpm. In synthesis 1, conversion was 62.5 ± 3.9% in 30 min at 10% m v-1 and 56.9 ± 2.8% in 54 min at 5% m v-1, while in synthesis 2, conversion was 79.0 ± 3.9% in 24 min at 10% m v-1, and 46.0 ± 2.4% in 54 min at 5% m v-1. Reuse tests after 6 consecutive cycles of reaction showed that the biocatalyst retained approximately 50% of its original activity for both reaction systems. CRL-AMP showed a high potential in the production of wax esters, since it started from low enzymatic load and high specific activities and conversions were obtained, in addition to allowing an increase in stability and recyclability of the prepared biocatalyst.


Sign in / Sign up

Export Citation Format

Share Document