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Lipidomics insight on differences in lipid profiles and phytosterol compositions of coconut oils extracted by classical and green solvents

Cui J, Yang Z, Xu Y, Tan CP, Zhang W

Food Res Int, 2023 Dec;174(Pt 2):113653.
PMID: 37981374 DOI: 10.1016/j.foodres.2023.113653

Searching for green and ecofriendly solvents to replace classical solvents for industrial scale extraction of coconut oil is of great interest. To explore these possibilities, this study performed comprehensive comparative analyses of lipid profiles and phytosterol compositions in coconut oils obtained by extraction with n-hexane, absolute ethyl alcohol, deep eutectic solvent/n-hexane, dimethyl carbonate (DME) and cyclopentyl methyl ether (CPME) using a foodomics approach. Results indicated that CPME (64.23 g/100 g dry matter) and DME (65.64 g/100 g dry matter) showed comparable capacity for total lipid extraction of total lipids to classical solvents (63.5-65.66 g/100 g dry matter). Considering the phytosterol yield, CPME (644.26 mg/kg) exhibited higher selectivity than other solvents (535.64-622.13 mg/kg). No significant difference was observed in the fatty acid composition of coconut oil by the different solvents assayed. Additionally, total 468 lipid molecules were identified in the samples. For glycerolipid and sphingolipid, the five solvents showed comparable extraction capabilities. However, CPME exhibited higher extraction efficiency of polar lipids (glycerophospholipid and saccharolipid) than other solvents. Overall, these results may be a useful guide for the application of green solvents in industrial production of coconut oil.

Matched MeSH terms: Methyl Ethers*
Selective homogeneous synthesis of dimethyl ether from methanol

Atkins MP, Earle MJ, Seddon KR, Swadźba-Kwaśny M, Vanoye L

Chem Commun (Camb), 2010 Mar 14;46(10):1745-7.
PMID: 20177636 DOI: 10.1039/b923250h

Selected Brønsted acidic ionic liquids were tested as homogeneous catalysts for the dehydration of methanol to dimethyl ether. Ionic liquids incorporating an alkanesulfonic acid as a part of the cation, a complex acidic anion, [A(2)H](-), or both, proved to be good catalysts for this process, providing high conversions and selectivities. Homogeneous catalysis in the liquid state represents a novel approach to dimethyl ether synthesis.

Matched MeSH terms: Methyl Ethers/chemical synthesis*; Methyl Ethers/chemistry
Potassium Alum [KAl(SO4)2∙12H2O] solid catalyst for effective and selective methoxylation production of alpha-pinene ether products

Wijayati N, Lestari LR, Wulandari LA, Mahatmanti FW, Rakainsa SK, Cahyono E, et al.

Heliyon, 2021 Jan;7(1):e06058.
PMID: 33553744 DOI: 10.1016/j.heliyon.2021.e06058

Methoxylation is a relevant technological process applied in the production of high-value α-pinene derivatives. This report investigates the use of potassium alum [KAl(SO4)2 · 12H2O] as a catalyst in the methoxylation of α-pinene. In this study, the methoxylation reaction was optimized for the highest conversion of α-pinene and selectivity, assessed for the factors, catalyst loading (0.5; 1.0; and 1.5 g), volume ratio of α-pinene: methanol (1:4, 1:7, 1:10), reaction temperature (50, 55, 60 and 65 °C), and reaction time (72, 144, 216, 288, 360 min). The highest selectivity of KAl(SO4)2∙12H2O in the methoxylation of α-pinene was achieved under an optimal condition of 1 g of catalyst loading, volume ratio of 1:10, as well as the reaction temperature and incubation time of 65 °C and 6 h, respectively. GC-MS results revealed the yields of the methoxylated products from the 98.2% conversion of α-pinene, to be 59.6%, 8.9%, and 7.1% for α-terpinyl methyl ether (TME), fenchyl methyl ether (FME), bornyl methyl ether (BME), respectively. It was apparent that a lower KAl(SO4)2∙12H2O loading (0.5-1.5 g) was more economical for the methoxylation reaction. The findings seen here indicated the suitability of the KAl(SO4)2 · 12H2O to catalyze the methoxylation of α-pinene to produce an commercially important ethers.

Matched MeSH terms: Methyl Ethers
Effects of sevoflurane increments on left ventricular systolic long-axis performance during sevoflurane-remifentanil anesthesia for cardiovascular surgery

Kwon WK, Sung TY, Yu GY, Sidik H, Kang WS, Lee Y, et al.

J Anesth, 2016 Apr;30(2):223-31.
PMID: 26577248 DOI: 10.1007/s00540-015-2094-9

BACKGROUND: The direct impact of sevoflurane on intraoperative left ventricular (LV) systolic performance during cardiac surgery has not been fully elucidated. Peak systolic tissue Doppler velocities of the lateral mitral annulus (S') have been used to evaluate LV systolic long-axis performance. We hypothesized that incremental sevoflurane concentration (1.0-3.0 inspired-vol%) would dose-dependently reduce S' in patients undergoing cardiac surgery due to mitral or aortic insufficiency.
METHODS: In 20 patients undergoing cardiac surgery in sevoflurane-remifentanil anesthesia, we analyzed intraoperative S' values which were determined after 10 min exposure to sevoflurane at 1.0, 2.0, and 3.0 inspired-vol% (T1, T2, and T3, respectively) with a fixed remifentanil dose (1.0 μg/kg/min) using transesophageal echocardiography.
RESULTS: Linear mixed-effect modeling demonstrated dose-dependent declines in S' according to the end-tidal sevoflurane concentration increments (C(ET)-sevoflurane, p < 0.001): the mean value of S' reduction for each 1.0 vol%-increment of C(ET)-sevoflurane was 1.7 cm/s (95 % confidence interval 1.4-2.1 cm/s). Medians of S' at T1, T2, and T3 (9.6, 8.9, and 7.5 cm/s, respectively) also exhibited significant declines (by 6.6, 15.6, and 21.2 % for T1 vs. T2, T2 vs. T3, and T1 vs. T3, p < 0.001, =0.002, and <0.001 in Friedman pairwise comparisons, respectively).
CONCLUSIONS: Administering sevoflurane as a part of a sevoflurane-remifentanil anesthesia regimen appears to dose-dependently reduce S', indicating LV systolic performance, in patients undergoing cardiac surgery. Further studies may be required to evaluate the clinical implications of these findings.

Matched MeSH terms: Methyl Ethers/administration & dosage*
Fulltext A comparison of the induction and emergence characteristics of sevoflurane and halothane in children

Chiu CL, Chan YK, Ong G, Delilkan AE

Med J Malaysia, 1999 Sep;54(3):346-51.
PMID: 11045061

This open labelled, randomised, controlled study was designed to compare the induction and recovery characteristics of sevoflurane and halothane anaesthesia in children. Forty American Society of Anaesthesiologist (ASA) physical status class 1 or 2 children (aged 1-10 year, weighed less than 25 kg) scheduled for elective urological procedure lasting less than one hour were allocated randomly to receive either sevoflurane (group S, n = 20) or halothane (group H, n = 20). The induction time in children receiving sevoflurane was significantly shorter than in those receiving halothane (mean (SD) 46 (13.6) second vs 69 (19.4) seconds, p < 0.005). The emergence from anaesthesia was also faster in children receiving sevoflurane than in those receiving halothane (mean (SD) 9 min (4.3 min) vs 21 min (8.9 min), p < 0.001). No major adverse effects were encountered in each group. We concluded that sevoflurane is comparable to halothane in Malaysian children.

Matched MeSH terms: Methyl Ethers*
Fulltext Sevoflurane induction in the elderly

Cheong KF, Teh TS

Med J Malaysia, 2001 Dec;56(4):446-50.
PMID: 12014764

The effects of 2% and 4% sevoflurane in oxygen and nitrous oxide for induction of anaesthesia in 60 unpremedicated elderly patients was compared to those obtained during an intravenous Thiopentone induction. Intravenous induction induced anaesthesia in 27 +/- 5 seconds, significantly faster than a 2% or 4% sevoflurane induction (109 +/- 36 and 71 +/- 24 seconds respectively). One patient in both the thiopentone and 2% sevoflurane groups, and 2 patients in the 4% sevoflurane group coughed during induction. The postinduction reduction in mean arterial pressure was greatest in the thiopentone group followed by the 4% and the 2% sevoflurane groups. Heart rate changes were minimal in all groups. We conclude that 2% or 4% sevoflurane offered suitable conditions for induction of anaesthesia in the elderly with minimal cardiovascular derangement.

Matched MeSH terms: Methyl Ethers/pharmacology*
Sevoflurane induction in acute airway obstruction

Chiu CL, Delilkan AE

Hosp Med, 1998 Oct;59(10):828.
PMID: 9850310
Matched MeSH terms: Methyl Ethers*
Fulltext A comparison of the maintenance and recovery charcateristic of sevoflurane-nitrous oxide against isoflurane-nitrous oxide anaesthesia

Chiu CL, Chan YK, Ong GS, Delilkan AE

Singapore Med J, 2000 Nov;41(11):530-3.
PMID: 11284610

To compare the maintenance and recovery characteristics of sevoflurane and isoflurane anaesthesia in Malaysian patients.

Matched MeSH terms: Methyl Ethers/pharmacology; Methyl Ethers/therapeutic use*
Fulltext Anesthesia for massive retrosternal goiter with severe intrathoracic tracheal narrowing: the challenges imposed -A case report-

Tan PC, Esa N

Korean J Anesthesiol, 2012 May;62(5):474-8.
PMID: 22679546 DOI: 10.4097/kjae.2012.62.5.474

Anesthetic management of patients with mediastinal masses remains challenging as acute cardiorespiratory decompensation may follow induction of anesthesia. We describe a 57 year old lady with massive retrosternal goiter and severe intrathoracic tracheal compression who had a total thyroidectomy. Comprehensive contingency plans were an essential prerequisite for successful management of difficult airway, including multidisciplinary involvement of otorhinolaryngologic and cardiothoracic surgeons preparing for rigid bronchoscopy and cardiopulmonary bypass. Awake oral fiberoptic intubation was performed under dexmedetomidine sedation. Severe tracheal narrowing necessitated usage of a 5.0 mm uncuffed flexometallic endotracheal tube. Anesthesia was maintained with sevoflurane and dexmedetomidine infusion with target controlled infusion of remifentanil as analgesia. No muscle relaxant was given. Surgical manipulation led to intermittent total tracheal compression and inadequate ventilation. The tumor was successfully removed via the cervical approach. A close working relationship between anesthesiologists and surgeons was the key to the safe use of anesthesia and uneventful recovery of this patient.

Matched MeSH terms: Methyl Ethers
Fulltext Comparison of cardiovascular responses between remifentanil and fentanyl on laryngoscopy and tracheal intubation in patients undergoing elective surgery

Lai, S.C., Choy, Y.C.

Journal of Surgical Academia, 2014;4(1):20-25.
MyJurnal

This was a prospective, randomized, double-blind study comparing the effect of remifentanil and fentanyl on cardiovascular responses from laryngoscopy and tracheal intubation. Forty-four ASA I or II patients aged between 18-65 yrs scheduled for elective surgery under general anaesthesia, were recruited and randomized into two groups. Each patient in Group R received remifentanil of 0.5 mcg/kg bolus over 30 seconds followed by an infusion of 0.25 mcg/kg/min and each patient in Group F received fentanyl of 2 mcg/kg bolus over 30 seconds followed by an infusion of normal saline. Anaesthesia was then induced with propofol, rocuronium and 2% sevoflurane with 100% oxygen. Cardiovascular changes were recorded every minute for 3 minutes after induction and 5 minutes after tracheal intubation. The heart rate remained stable throughout the induction and intubation period in both groups. None of the patients in the remifentanil group develop bradycardia. Systolic blood pressure (SBP) and mean arterial pressure (MAP) were significantly lower in the fentanyl group at the 3rd minute post-induction and 5th minute post- intubation (p < 0.05). Diastolic blood pressure (DBP) in the fentanyl group was significantly lower at the 2nd and 3rd minute post-induction and 4th and 5th minute post-intubation (p < 0.05). The blood pressure remained stable for the remifentanil group throughout the induction and intubation period. Six patients (27.2%) in the fentanyl group and one patient (4.5%) in the remifentanil group experienced hypertension. Three patients (13.7%) from each group experienced hypotensive episodes. In conclusion, remifentanil 0.5 mcg/kg bolus followed by 0.25 mcg/kg/min infusion resulted in SBP, MAP and DBP remained slightly lower than baseline throughout the whole period but still consider stable, as these changes were not statistically significant.

Matched MeSH terms: Methyl Ethers
Comparison between the use of LMA™ and SLIPA™ in patients undergoing minor surgeries

Wan Rahiza, W.M., Nurlia, Y., Abd Rahman, I., Esa, K., Nadia, M.N., Raha, A. R.

Journal of Surgical Academia, 2012;2(1):8-13.
MyJurnal

Supraglottic airway devices have been used as safe alternatives to endotracheal intubation in appropriate types of surgery. This was a prospective, randomised, single blind study comparing the use of LMA™ and SLIPA™ in terms of ease of insertion, haemodynamic changes and occurrence of adverse effects (e.g. blood stains on the device upon removal and sore throat). A total of 62 ASA I or II patients, aged between 18 to 70 years were recruited for this study. Patients were randomised into two groups; LMA™ and SLIPA™ group. Following induction of anaesthesia, an appropriate sized LMA™ or SLIPA™ was inserted after ensuring adequate depth of anaesthesia. Anaesthesia was maintained with oxygen, nitrous oxide and sevoflurane. The ease of insertion was graded and haemodynamic changes were recorded at 2 minute intervals up to 10 minutes after insertion of the airway devices. The presence of blood stains upon airway device removal at the end of surgery and incidence of sore throat was also recorded. No difficult insertion was experienced in either of these devices. Insertion was either easy [LMA™ 87.1% versus SLIPA™ 80.6% (p = 0.49)] or moderate [LMA™ 12.9% versus SLIPA™ 19.4% (p = 0.16)]. Throughout the study period, the haemodynamic changes that occurred in both groups were not statistically different. Traces of blood were noted on the surface of the device in 9.7% of patients in the SLIPA™ group versus 6.5% of patients in the LMA™ group. The incidence of sore throat was recorded in 12.9% versus 19.4% of patients in the SLIPA™ and the LMA™ groups respectively. These findings were not statistically significant. In conclusion, this study showed no significant differences between the use of LMA™ and SLIPA™ in terms of ease of insertion, haemodynamic changes and adverse effects in patients undergoing minor surgical procedures.

Matched MeSH terms: Methyl Ethers
Sevoflurane for dental extraction in children with Tetralogy of Fallot

Chiu CL, Wang CY

Paediatr Anaesth, 1999;9(3):268-70.
PMID: 10320610

Two children with Tetralogy of Fallot presented for dental extraction. Anaesthesia was induced rapidly and smoothly by inhalation of sevoflurane. We discussed the advantages of sevoflurane as an induction agent as compared to halothane in these children.

Matched MeSH terms: Methyl Ethers/administration & dosage*
A comparative study of sevoflurane sedation with nitrous oxide sedation for dental surgery

Wang CY, Chiu CL, Har KO, Chan C, Rahman ZA

Int J Oral Maxillofac Surg, 2002 Oct;31(5):506-10.
PMID: 12418566

This study compares the use of inhalation sedation using sevoflurane (group S) with inhalation sedation using nitrous oxide (group N) in patients undergoing bilateral extraction of third molar teeth under local anaesthesia. The study was designed as a cross-over study. Seventeen ASA I, day surgery patients were studied. Patients were randomly allocated to receive either 8 l/min 50% nitrous oxide in oxygen (group N) or same flow of 1% sevoflurane (group S) for the first procedure. Each patient then had the alternate method of sedation for the second procedure. There were no significant differences between the methods in patient co-operation and surgeon's satisfaction with sedation. Psychomotor tests were comparable in both groups. The patients were significantly more sedated in the group S compared to group N (P=0.004). Significantly more patients complained of an unpleasant odour group S (P<0.01) but none withdrew from the study for this reason. No adverse cardiorespiratory effects resulted from sevoflurane or nitrous oxide sedation. Both methods gave good amnesia during the procedure. There was high acceptance of both methods and the patients rated the technique as equally satisfactory. We conclude that inhalation sedation with sevoflurane is a suitable alternative method to nitrous oxide sedation.

Matched MeSH terms: Methyl Ethers/administration & dosage*

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