scholarly journals Nonacosan-10-ol and n-Alkanes in Leaves of Pinus pinaster

2020 ◽  
Vol 15 (5) ◽  
pp. 1934578X2092607
Author(s):  
Biljana Nikolić ◽  
Marina Todosijević ◽  
Iris Đorđević ◽  
Jovana Stanković ◽  
Zorica S. Mitić ◽  
...  
Keyword(s):  
Chain Length ◽  
Pinus Pinaster ◽  
Cuticular Wax ◽  
Short Chain ◽  
Average Chain Length ◽  
Carbon Preference Index ◽  
Preference Index ◽  
Long Chain

In leaf cuticular wax of Pinus pinaster, content of nonacosan-10-ol is high (77.1% on average). n-Alkanes ranged from C18 to C35 with the most dominant C29 (24.8%). The carbon preference index (CPItotal) ranged from 3.1 to 5.6 (4.0 on average), while the average chain length (ACLtotal) ranged from 14.0 to 17.0 (14.8 on average). Long-chain n-alkanes ( n-C25-35) strongly dominated (80.1%) over middle-chain ( n-C21-24 = 18.9%) and short-chain ( n -C18-20 = 0.9%) n-alkanes.

scholarly journals Nonacosan-10-ol and n-Alkanes in Needles of Pinus halepensis

2020 ◽  
Vol 15 (5) ◽  
pp. 1934578X2092097
Author(s):  
Biljana Nikolić ◽  
Marina Todosijević ◽  
Iris Đorđević ◽  
Jovana Stanković ◽  
Zorica S. Mitić ◽  
...  
Keyword(s):  
Chain Length ◽  
Pinus Halepensis ◽  
Cuticular Wax ◽  
Average Chain Length ◽  
Carbon Preference Index ◽  
Preference Index ◽  
Long Chain

In needle cuticular wax of Pinus halepensis, nonacosan-10-ol is high (77.08% on average). n-Alkanes ranged from C18 to C35 with the most dominant C27 and C29 (32.4% and 25.8%, respectively). The carbon preference index ranged from 3.2 to 5.4 (3.4 on average), while the average chain length ranged from 14.0 to 18.0 (17.2 on average). Long-chain n-alkanes strongly dominated (95.1%).

scholarly journals n-alkanes in needle waxes of Pinus heldreichii var. pancici

2010 ◽  
Vol 75 (10) ◽  
pp. 1337-1346 ◽  
Author(s):  
Biljana Nikolic ◽  
Vele Tesevic ◽  
Iris Djordjevic ◽  
Milka Jadranin ◽  
Marina Todosijevic ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Chain Length ◽  
Gas Chromatography Mass Spectrometry ◽  
Average Chain Length ◽  
Epicuticular Waxes ◽  
Carbon Preference Index ◽  
Preference Index ◽  
Hexane Extracts ◽  
High Level

This is the first report of n-alkanes in needle epicuticular waxes of variety of Bosnian pine, Pinus heldreichii var. pancici. n-Hexane extracts of needle samples, originated from seven isolated localities in Serbia, were analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The results exhibited nalkanes in epicuticular waxes ranging from C18 to C33. The most abundant alkanes were C27, C23, C25 and C29 (12.53 %, 12.46 %, 12.00 % and 10.38 % on average, respectively). The carbon preference index (CPItotal) of Pinus heldreichii var. pancici ranges from 1.1 to 2.1 (1.6 on average), while average chain length (ACLtotal) ranges from 25.0 to 25.8 (25.3 on average). A high level of individual quantitative variation in all of these hydrocarbon parameters was also obtained. The obtained results were compared with the bibliographic references for Pinus heldreichii var. leucodermis and other species of the Pinus genus.

scholarly journals n-Alkane Profile of Argemone mexicana Leaves

2010 ◽  
Vol 65 (9-10) ◽  
pp. 533-536 ◽  
Author(s):  
Indranil Bhattacharjee ◽  
Anupam Ghosh ◽  
Nandita Chowdhury ◽  
Soroj Kumar Chatterjee ◽  
Goutam Chandra ◽  
...  
Keyword(s):  
Carbon Number ◽  
Epicuticular Waxes ◽  
Carbon Preference Index ◽  
Argemone Mexicana ◽  
Mature Leaves ◽  
Preference Index ◽  
Chain Lengths ◽  
First Time ◽  
Long Chain ◽  
Carbon Number Predominance

An n-hexane extract of fresh, mature leaves of Argemone mexicana (Papaveraceae), containing thin-layer epicuticular waxes, has been analysed for the first time by TLC, IR and GLC using standard hydrocarbons. Seventeen long-chain alkanes (n-C18 to n-C34) were identified and quantified. Nonacosane (n-C29) was established as the n-alkane with the highest amount, whilst octadecane (n-C18) was the least abundant component of the extracted wax fraction. The carbon preference index (CPI) calculated for the hydrocarbon sample with the chain lengths between C18 and C34 was 1.2469, showing an odd to even carbon number predominance.

scholarly journals Leaf wax composition and distribution of Tillandsia landbeckii reflects moisture gradient across the hyperarid Atacama Desert

2022 ◽  
Vol 308 (1) ◽  
Author(s):  
Sergio Contreras ◽  
Manlio Landahur ◽  
Karla García ◽  
Claudio Latorre ◽  
Mark Reyers ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Atacama Desert ◽  
Average Chain Length ◽  
Carbon Preference Index ◽  
Leaf Wax ◽  
Preference Index ◽  
Lipid Biomarker ◽  
Northern Zone ◽  
Structural Adaptations ◽  
Total Average

AbstractIn the hyperarid Atacama Desert, water availability plays a crucial role in allowing plant survival. Along with scant rainfall, marine advective fog frequently occurs along the coastal escarpment fueling isolated mono-specific patches of Tillandsia vegetation. In this study, we investigate the lipid biomarker composition of the bromeliad Tillandsia landbeckii (CAM plant) to assess structural adaptations at the molecular level as a response to extremely arid conditions. We analyzed long-chain n-alkanes and fatty acids in living specimens (n = 59) collected from the main Tillandsia dune ecosystems across a 350 km coastal transect. We found that the leaf wax composition was dominated by n-alkanes with concentrations (total average 160.8 ± 91.4 µg/g) up to three times higher than fatty acids (66.7 ± 40.7 µg/g), likely as an adaptation to the hyperarid environment. Significant differences were found in leaf wax distribution (Average Chain Length [ACL] and Carbon Preference Index [CPI]) in the northern zone relative to the central and southern zones. We found strong negative correlations between fatty acid CPI and n-alkane ACL with precipitation and surface evaporation pointing at fine-scale adaptations to low moisture availability along the coastal transect. Moreover, our data indicate that the predominance of n-alkanes is reflecting the function of the wax in preventing water loss from the leaves. The hyperarid conditions and good preservation potential of both n-alkanes and fatty acids make them ideal tracers to study late Holocene climate change in the Atacama Desert.

Acyl-CoA dehydrogenase activity in pea cotyledon tissue during germination and initial growth

2000 ◽  
Vol 28 (6) ◽  
pp. 760-762 ◽  
Author(s):  
C. Masterson ◽  
A. Blackburn ◽  
C. Wood
Keyword(s):  
Dehydrogenase Activity ◽  
Chain Length ◽  
Root Formation ◽  
Short Chain ◽  
Initial Growth ◽  
Chain Acyl ◽  
Pea Seeds ◽  
Acyl Coa Dehydrogenases ◽  
Hydroponically Grown ◽  
Long Chain

Acyl-CoA dehydrogenase activity has been measured in homogenates of post-imbibition to 14-day-old hydroponically grown pea seeds at daily intervals, using C4, C12 and C16 acyl-CoA substrates. The activity peaks of the different chain-length acyl-CoA dehydrogenases did not transpose at all points and the ratios of the chain-length activities were not constant. It therefore has to be concluded that more than one dehydrogenase is present in pea mitochondria. There was a post-imbibition initial surge of activity with short- and mid-chain-length substrates. The C16- handling enzyme first peaked at 3–4 days, which coincided with the onset of plumule unfurling and greening. Further peaks were observed with all three substrates, coinciding with secondary root formation and leaf enlargement and later with cotyledon degeneration. Overall activity showed that the long-chain acyl-CoA dehydrogenase was much more active than the short-chain acyl-CoA dehydrogenase.

Holocene vegetation signals in the Alashan Desert of northwest China revealed by lipid molecular proxies from calcareous root tubes

2017 ◽  
Vol 88 (1) ◽  
pp. 60-70 ◽  
Author(s):  
Zhuolun Li ◽  
Youhong Gao ◽  
Lang Han
Keyword(s):  
Higher Plants ◽  
Relative Concentration ◽  
Northwest China ◽  
Pollen Concentration ◽  
Carbon Preference Index ◽  
Effective Moisture ◽  
Preference Index ◽  
Desert Regions ◽  
Root Tube ◽  
Long Chain

AbstractIn the hinterland of deserts, it is difficult to reconstruct paleovegetation using fossil pollen because of the low pollen concentration. Therefore, an efficient method is needed to reconstruct the paleovegetation of desert regions. In this study, 34 Holocene calcareous root tube (CRT) samples were collected from the Alashan Desert in northwest China, and lipid molecular proxies from CRTs were selected to address this deficiency. The results show that n-alkanes mainly maximized at C27, C29, and C16, and that the carbon preference index is close to 1. Thus, the sources of n-alkanes from CRTs were the roots of higher plants and microorganisms, and thus changes in n-alkanes from CRTs could reveal variations in vegetation cover. The n-alkane Cmax of long-chain n-alkanes (C>25) in CRTs, maximizing at C27, indicated that vegetation in the Alashan Desert was characterized by shrub vegetation during the Holocene. Changes in the ratio of (C27+C29)/(C31+C33) indicated that the biomass of shrub vegetation increased during the period 7–2 cal ka BP. Moreover, the relative concentration of short-chain to long-chain n-alkanes decreased from 7 to 2 cal ka BP, suggesting that the effective moisture decreased during that period.

scholarly journals Preparation of Bisphenol-A and Polydimethylsiloxane (PDMS) Block Copolycarbonates by Melt Polycondensation: Effects of PDMS Chain Length on Conversion and Miscibility

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2660
Author(s):  
Zibo Zhou ◽  
Guozhang Wu
Keyword(s):  
Bisphenol A ◽  
Chain Length ◽  
Short Chain ◽  
Side Reactions ◽  
Diphenyl Carbonate ◽  
Key Factors ◽  
Factors Affecting ◽  
Melt Polycondensation ◽  
Chain Lengths ◽  
Long Chain

This study aimed to improve polydimethylsiloxane (PDMS) conversion in the preparation of polycarbonate (PC)–polydimethylsiloxane (PDMS) copolymer through melt polycondensation. We examined the transesterification process of PDMS with diphenyl carbonate (DPC) and its copolymerization products with bisphenol-A (BPA) for different chain lengths of PDMS. The key factors affecting PDMS conversion were investigated. Results showed that long-chain PDMS required a higher critical transesterification level (38.6%) to improve miscibility with DPC. During polycondensation, side reactions were more prone to occur when the equilibrium transesterification level of long-chain PDMS was lower. PDMS conversion was also lower when more short-chain PDMS was fed. Increasing the chain length of PDMS also reduced PDMS conversion. Notably, increasing the amount of KOH can significantly improve PDMS conversion throughout the polycondensation stage by increasing the equilibrium transesterification level of long-chain PDMS, thereby inhibiting the occurrence of side reactions.

scholarly journals The Stiffness-Threshold Conflict in Polymer Networks and a Resolution

2019 ◽  
Vol 87 (3) ◽  
Author(s):  
Yifan Zhou ◽  
Wenlei Zhang ◽  
Jian Hu ◽  
Jingda Tang ◽  
Chenyu Jin ◽  
...  
Keyword(s):  
Chain Length ◽  
Polymer Networks ◽  
Fatigue Threshold ◽  
Short Chain ◽  
High Threshold ◽  
Material Parameters ◽  
High Stiffness ◽  
Load Carrying ◽  
Chain Lengths ◽  
Long Chain

Abstract Stiffness and fatigue threshold are important material parameters in load-carrying applications. However, it is impossible to achieve both high stiffness and high threshold for single-network elastomers and single-network hydrogels. As the polymer chain length increases, the stiffness reduces, but the threshold increases. Here, we show that this stiffness-threshold conflict is resolved in double-network hydrogels, where the stiffness depends on the short-chain network, but the threshold depends on the long-chain network. Experimental data in the literature have shown that the stiffness of the hydrogels is inversely proportional to chain length of the short-chain network. In this paper we measure the threshold of PAAm-PAMPS hydrogels with five different chain lengths of the long-chain network. We find that the threshold is proportional to 1/2 power of the chain length of the long-chain network. The resolution of the conflict enables the design of elastomers and hydrogels to achieve both high stiffness and high threshold.

Effects of fatty acid chain length and saturation on gastric inhibitory polypeptide release in obese hyperglycaemic (ob/ob) mice

1985 ◽  
Vol 5 (8) ◽  
pp. 701-705 ◽  
Author(s):  
Piotr Kwasowski ◽  
Peter R. Flatt ◽  
Clifford J. Bailey ◽  
Vincent Marks
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Chain Length ◽  
Gastric Inhibitory Polypeptide ◽  
Chain Fatty Acid ◽  
Short Chain ◽  
Degree Of Saturation ◽  
Gip Release ◽  
Long Chain ◽  
Chain Fatty Acids

Plasma gastric inhibitory polypeptide (GIP) responses to equimolar intragastrically administered emulsions of fatty acids (2.62 mmol/7.5 ml/kg) were examined in 18 h fasted obese hyperglycaemic (ob/ob) mice. Propionic acid (C3:0), a saturated short-chain fatty acid, and capric acid (C10:0), a saturated medium chain fatty acid, did not signilicantly stimulate GIP release. However, the saturated long-chain fatty acid stearic acid (C18:0), and especially the unsaturated long-chain fatty acids oleic (C18:1), linoleic (C18:2) and linolenic (C18:3) acids produced a marked GIP response. The results show that chain length and to a lesser extent the degree of saturation are important determinants of fatty acid-stimulated GIP release. The GIP-release action of long-chain, but not short-chain, fatty acids may be related to differences in their intracellular handling.

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