JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2018
·Vol. 132
·期 3
·1729-1740
·
IF 2.209
Yuan Jiao-jiao,Tu Jun-ling,Xu Yong-jun,Qin Frank G. F.,Li Bing,Wang Cheng-zhang
Olive leaf extract pretreated by enzymolysis was selected for studying the thermal stability at different heating rates by thermogravimetric coupled with infrared spectroscopy (TG–FTIR) and nonisothermal theoretical analysis, and products analysis by pyrolysis–gas chromatography–mass spectrometry (Py–GC–MS). Results revealed that thermal decomposition of ethyl acetate extract from olive leaf extract pretreated by enzymolysis (EAEEH) consisted of two steps and had a lower thermal stability. The nonisothermal decomposition kinetics mechanism of EAEEH was D3 model (three-dimensional diffusion, Jander equation, the first step) and F3 model (chemical reaction, n = 3, the second step). TG–IR showed –CH 3 , –C=C–, –OH, –C–O were continuously accelerated to produce, and evolved gas were CO 2 , water, CO and CH 4 at the end. In addition, it was found that there were mainly polyphenols with phenolic hydroxyl groups in the pyrolysis products by Py–GC–MS, and it was also explained for the thermal stability results. This will provide a theoretical guidance for thermal application of EAEEH in the safe natural food additives, cosmetic and medicine.
研究领域:
食品科学
·
化学工程
·
植物化学
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DOI
高影响因子
JOURNAL OF FOOD BIOCHEMISTRY
·
2015
·Vol. 39
·期 5
·566-574
·
IF 0.741
Wu Zun-Qiu,Yue Gui-Zhou,Zhu Qing-Ping,Jiang You-Jun,Tang Kai-Yu,Chen Hua-Ping,Yang Ze-Shen,Huang Qian-Ming
Oleuropein was extracted from olive leaves by ultrasonic-assisted method and purified by silica gel column chromatography. The sample was identified as oleuropein by UV, infrared, mass spectroscopy and nuclear magnetic resonance spectroscopy analysis. Oleuropein and total phenolic contents over a year were determined by high-performance liquid chromatography and Folin–Ciocalteu methods. The results showed that 13.52% of pure oleuropein was found with a high purity of 96.54% and purification efficiency of 78.49%. Oleuropein and total phenolic contents of different olive varieties were quite different, but both had similar trends over the year. Five methods, including DPPH (2,2-diphenyl-1-picrylhydrazyl), ABST (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), ferric reducing antioxidant power, total reducing power and nitrite-scavenging ability, were used to evaluate the antioxidant activities of oleuropein, and the IC 50 were 34.54 ± 0.14 μg/mL, 18.79 ± 0.82 μg/mL, 75.32 ± 1.83 μg/mL, 13.80 ± 0.68 μg/mL and 1.00 ± 0.08 mg/mL, respectively. Practical Applications This study provides information on the changes in contents including oleuropein and total phenolics in a year to help understand the relationship between content of oleuropein and various influencing factors. Currently, the metabolic pathways of oleuropein are not clear. These results provide information for the study of the metabolism of phenolic compounds in olive and promote research at the molecular level. Oleuropein occupies a large proportion of total polyphenols in olive and can be to be purified by silica gel column chromatography with high purification efficiency for industrial production and laboratory production. In addition, the comprehensive evaluation of activity in vitro shows that oleuropein is more useful than BHT (2,6-di- tert -butyl-4-methylphenol) for the application in food and human health.
研究领域:
植物化学
·
食品科学
·
分子生物学
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产品关联
DOI
高影响因子
MOLECULES
·
2015
·Vol. 20
·期 2
·2903-2921
·
IF 2.416
Jiao-Jiao Yuan,Cheng-Zhang Wang,Jian-Zhong Ye,Ran Tao,Yu-Si Zhang
Oleuropein (OE), the main polyphenol in olive leaf extract, is likely to decompose into hydroxytyrosol (HT) and elenolic acid under the action of light, acid, base, high temperature. In the enzymatic process, the content of OE in olive leaf extract and enzyme are key factors that affect the yield of HT. A selective enzyme was screened from among 10 enzymes with a high OE degradation rate. A single factor (pH, temperature, time, enzyme quantity) optimization process and a Box-Behnken design were studied for the enzymatic hydrolysis of 81.04% OE olive leaf extract. Additionally, enzymatic hydrolysis results with different substrates (38.6% and 81.04% OE) were compared and the DPPH antioxidant properties were also evaluated. The result showed that the performance of hydrolysis treatments was best using hemicellulase as a bio-catalyst, and the high purity of OE in olive extract was beneficial to biotransform OE into HT. The optimal enzymatic conditions for achieving a maximal yield of HT content obtained by the regression were as follows: pH 5, temperature 55 °C and enzyme quantity 55 mg. The experimental result was 11.31% ± 0.15%, and the degradation rate of OE was 98.54%. From the present investigation of the antioxidant activity determined by the DPPH method, the phenol content and radical scavenging effect were both decreased after enzymatic hydrolysis by hemicellulase. However, a high antioxidant activity of the ethyl acetate extract enzymatic hydrolysate (IC50= 41.82 μg/mL) was demonstated. The results presented in this work suggested that hemicellulase has promising and attractive properties for industrial production of HT, and indicated that HT might be a valuable biological component for use in pharmaceutical products and functional foods.Keywords:Olea europeaL.;hydroxytyrosol;oleuropein;enzymatic hydrolysis;hemicellulase
研究领域:
植物化学
·
食品科学
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药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Baoqian Liu,Jianfei Liu,Dongdong Huang,Dong Pei,Jianteng Wei,Duolong Di
Oleuropein is an important natural compound with many biological activities. How to get high purity oleuropein is an urgent issue to be solved. This study provided a method for separating and purifying high purity oleuropein from olive leaves using boric acid affinity resin and a novel solvent system. And the experimental kinetic and adsorption isotherm data of boric acid affinity resin were well–fitted pseudo–first–order kinetic model and Langmuir isotherm model, respectively. The dynamic desorption experiments showed that ethanol was the most efficient eluent while had the lowest oleuropein purity. However, after the novel solvent system treated only one cycle of adsorption and desorption , the purity of oleuropein increased by 5.55 folds from 12.31 ± 0.42% – 68.30 ± 2.08 %. The results can guide the separation and purification of high purity catechol natural products using boric acid affinity resin and mixed solvent systems.
研究领域:
植物化学
·
天然产物分离纯化
·
药用植物研究
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DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2024
·
IF 2.8
Jiaojiao Yuan,Su Tuo,Xiuhong Shi,Junling Tu
Due to three free hydroxyl groups, hydroxytyrosol (HT) presents strong bioactivity and has broad food and drug application prospects. However, there is no good separation and purification technology. In this study, separation and purification technology of HT from the ethyl acetate extraction of enzymatic hydrolysate from olive leaf (EEEH) was investigated with macroporous adsorption resin (MAR) and high-speed counter-current chromatography (HSCCC) and the separation factors were optimized. First, the adsorption properties of eight MARs (AB-8, S-8, D-101, X-5, XAD-1, XAD-5, NKA-Ⅱ, H-103) for HT enrichment were studied. The results showed that H-103 macroporous resin was adsorbent, sample concentration was 1.5 mg/mL, eluent was 30 % ethanol solution, sample loading rate was 3.0 BV/h, elution velocity was 2.0 BV/h, and HT purity of EEEH was increased from 10.23 % to 40.78 %. Then, solvent systems were examined according to partition coefficients of target component and petroleum ether: ethyl acetate: methanol: water (4:6:4:6, v/v) system was chosen. The critical experimental parameters of HSCCC were optimized as following: revolution speed was 1200 rpm and flow rate was 3 mL/min. The HT purity of macroporous resin purified EEEH was increased from 40.78 % to 85.7 %. Therefore, MAR-HSCCC combined technology could be a very effective approach to separate and purify HT from EEEH.
研究领域:
食品科学
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药物化学
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分离技术
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产品关联
DOI
PubMed
高影响因子
EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY
·
2018
·Vol. 120
·期 5
·1700471
·
IF 2.2
Lingyi Liu,Zhou Jin,Min Wang,Wangyang Shen,Zhenzhou Zhu,Zhan Wang,Lianliang Liu
Natural phenolic compounds have been drawn a wide attention to replace the synthesis antioxidants due to the food safety issues, while, natural phenolic compounds are usually polyhydroxy derivatives which exhibit hydrophilic capacity, limiting their applications directly in lipid systems. In this work, olive leaf phenolics (OLP) are extracted by ultrasound from five cultivars and the optimal cultivar is chosen to prepare W/O nano-emulsions of Sacha Inchi oil (SIO, containing more than 90% polyunsaturated fatty acids). The droplet size could reach 2.15 ± 0.13 nm and remaines stable without phase separation during 30-day storage. Oxidative stabilities of SIO containing 0.02%, 0.05%, and 0.1% OLP (w/w) are evaluated by Rancimat test and accelerated storage test. The release of OLP by preparation of W/O nano-emulsions is capable of controlling the oxidative progress of SIO, by prolonging the induction time, preventing the production of primary and secondary oxidative products and also the deterioration of polyunsaturated fatty acids and tocopherols. Practical Applications : Sacha Inchi oil (SIO) contains approximately 90% of polyunsaturated fatty acids (PUFAs) associated with poor oxidative stability. Olive leaf phenolics (OLP) are considered as a great and cheap source of natural phenolic compounds. This study aimes to select the optimum source of OLP from five cultivars and to prepare a W/O nano-emulsion of OLP. By diluting the W/O nano-emulsion of OLP into SIO, effect of different concentrations OLP on the oxidative stability of SIO is evaluated through thermal oxidative stability and storage oxidative stability in an accelerated storage test. Results indicate that the capacity of OLP to retard the SIO oxidation depends on the incorporated concentration, which means that it is doable to adopt OLP, an abundant and cheap material, to improve the stability of edible oil with high PUFAs in the industry. Olive leaf phenolics are extracted and detected to prepare an efficient and stable W/O nano-emulsion; By diluting W/O nano-emulsion into Sacha Inchi oil, oxidative stability of the high content PUFAs oil is improved.
研究领域:
食品科学
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植物化学
·
抗氧化研究
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2021
·
IF 3.383
Qianqian Yu,Hongxia Gan,Nan Feng,Yuanfei Li,Yongping Han
As a by-product of Chinese olive , an important economic tree, Chinese olive leaves have a large amount of hydroxytyrosol and other ingredients with high biological activity . At present, Chinese olive leaves can only be treated as waste and animal feed, causing a lot of waste of resources and pollution to the environment . Magnetic molecularly imprinted polymers using hydroxytyrosol as a template molecule were synthesized by surface imprinting molecular technology. Several ways, such as X-ray diffraction, Fourier transform infrared spectroscopy , scanning electron microscope and vibrating sample magnetometer, were used to perform physicochemical characterization of Fe 3 O 4 @MIPs. The results of the kinetic and static adsorption experiments showed that adsorption equilibrium could be reached within 45 min, with a maximum adsorption capacity of 36.27 mg g -1 . Fe 3 O 4 @MIPs had good selectivity and specificity for hydroxytyrosol. Under the optimum conditions, an efficient method based upon MISPE combined with high-performance liquid chromatography (HPLC) was developed for the determination of hydroxytyrosol in Chinese olive leaves with the high recovery rate (96.71–98.06%) and relative standard deviations of 2.35–3.27%. Therefore, this research provided a new method for the separation, purification and determination of hydroxytyrosol from Chinese olive leaves, improved the resource utilization of Chinese olive leaves, and protected the environment.
研究领域:
植物化学
·
环境科学
·
分析化学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 35
·16168-16178
·
IF 3.591
Kunjie Wang,Lei Liang,Yi Zheng,Hongxia Li,Xiaohui Niu,Deyi Zhang,Haiyan Fan
Using olive leaves as the carbon source, carbon quantum dots (CQDs) with up-conversion luminescence were prepared via a reflux method. Through a hydrothermal treatment, CQDs were loaded on the surface of TiO2 to form a CQDs/TiO2 composite that exhibited photocatalytic properties. The morphology, size and composition of the as-prepared composite were characterized using XRD, SEM, TEM and XPS. Excited at the wavelength range from 560 nm to 740 nm, CQDs exhibited a significant multi-photon-based up-conversion luminescence property. This property of CQDs endowed CQDs/TiO2 composites with great photocatalytic efficiency. The performance of CQDs/TiO2 composites was tested in the degradation of tetracycline (TC) and rhodamine B (RhB). Irradiated under visible light for 10 min and 70 min, the degradation rates of 5% CQDs/TiO2 reached 81% and 92% for TC and RhB, respectively. Photocurrent and PL tests indicated that the loading of CQDs significantly improved the separation efficiency of TiO2-photogenerated charge carriers. Taking advantage of the up-conversion luminescence property of CQDs, the harvesting efficiency of visible light by CQDs/TiO2 composites was greatly enhanced.
研究领域:
环境科学
·
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Bio
·
2024
·
IF 8.7
Zhenzhen Wang,Jumao Yuan,Yan Xu,Nuo Shi,Lin Lin,Ruirui Wang,Rong Dai,Lin Xu,Ning Hao,Qianyi Li
Photoaging, primarily caused by ultraviolet (UV) light, is the major factor in extrinsic skin aging. Existing anti-photoaging strategies mainly focus on early sun protection or repairing damaged skin, lacking a comprehensive treatment strategy. Therefore, this study developed a dressing that actively shields against UV radiation and repairs photoaged skin, offering double protection. This study utilized exosome-like nanovesicles derived from Olea europaea leaves (OLELNVs), enhancing them into a potent core biomaterial with high-dose effects and skin-friendly, non-cytotoxic inhibition of cell aging. These nanovesicles were incorporated into a cross-linked hyaluronic acid (HA) and tannic acid (TA) hydrogel with strong UV-absorbing properties, creating the OLELNVs@HA/TA hydrogel system. In vitro and in vivo experiments demonstrated that OLELNVs@HA/TA hydrogel can effectively reduce UV-induced skin damage and promote skin repair and regeneration. Additionally, RNA-seq and clustering analysis of miR168a-5p predicted targets revealed significant down-regulation of the NF-κB signaling pathway, mediating inflammatory aging responses. Overall, the OLELNVs@HA/TA hydrogel represents a novel dual-strategy approach for clinical application in combating photoaging.
研究领域:
皮肤病学
·
药学
·
生物技术
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Biomedical Research
·
2018
·
IF 0
Li-xing Wu,Yu-yu Xu,Zhi-jian Yang,Qing Feng
Myocardial infarction triggers massive biochemical changes, even cardiac cell death. Endoplasmic reticulum stress is involved in the pathology of myocardial infarction-mediated apoptosis. In the present study, myocardial cell line H9c2 cells were treated with cobalt chloride (CoCl 2 ) to induce hypoxia. Isoproterenol was used for two successive days to induce myocardial infarction in SD rats. The cardioprotective effect of olive leaf extract (OLE) and its main constituent hydroxytyrosol and the underlying mechanisms were evaluated. The results showed that hydroxytyrosol markedly protected H9c2 cells against CoCl 2 -induced apoptosis. Hydroxytyrosol could reduce the mRNA and protein expression of GRP78 and CHOP induced by CoCl 2 in vitro . In vivo , the decreased ejection fraction and fractional shortening, increased heart weight/body ratio, the formation of infarction, disordered cardiac muscle fibers and infiltration of inflammatory cells induced by isoproterenol could be significantly ameliorated by pretreatment with OLE for a month. Similarly, OLE could also reverse the increase of GRP78 and CHOP expression induced by isoproterenol. Therefore, OLE and hydroxytyrosol exert a cardioprotective effect through endoplasmic reticulum stress, which could be a new target for the prevention and treatment of cardiovascular diseases.
研究领域:
心脏病学
·
药理学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
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