Lipase and photodecarboxylase coexpression: A potential strategy for alkane-based biodiesel production from natural triglycerides

Alkane-based biodiesel is considered the next generation of biodiesel owing to its potential environmental benefits and the fact that it exhibits much higher specific caloric values than traditional biodiesel.However,the formidable obstacle impeding the commercialization of this cutting-edge fuel alternative lies in the cost associated with its production.In this study,an engineered strain Escherichia coli(E.coli)showcasing harmonized coexpression of a lipase(from Thermomyces lanuginosus lipase,TLL)and a fatty acid photodecarboxylase(from Chlorella variabilis,CvFAP)was first constructed to transform triglycerides into alkanes.The potential of E.coli BL21(DE3)/pRSFDuet-1-TLL-CvFAP for alkane synthesis was evaluated with tripalmitin as a model substrate under various process conditions.Following a comprehensive examination of the reaction parameters,the scope of the biotransformation was expanded to‘real’substrates(vegetable oils).The results showed that bioderived oils can be transformed into alkanes with high yields(0.80-10.20 mmol·L^(-1))under mild conditions(35℃,pH 8.0,and 36 h)and blue light illumination.The selected processes were performed on an increased lab scale(up to 100 ml)with up to 24.77 mmol·L^(-1) tripalmitin,leading to a yield of 18.89 mmol·L^(-1) pentadecane.With the employment of a method for efficiently producing alkanes under mild conditions and a simple procedure to isolate alkanes from the reaction system,the utilization of sustainable biomass as a fundamental feedstock emerges as the primary solution to lower the cost of alkane-based biodiesel.Thus,this study proposes a readily implementable and highly effective approach for alkane-based biodiesel production.

Carboxyl Ester Lipase Protects Against Metabolic Dysfunction-Associated Steatohepatitis by Binding to Fatty Acid Synthase

Carboxyl ester lipase(CEL),a pivotal enzyme involved in lipid metabolism,is recurrently mutated in obese mice.Here,we aimed to elucidate the functional significance,molecular mechanism,and therapeutic potential of CEL in metabolic dysfunction-associated steatohepatitis(MASH).Hepatocyte-specific carboxyl ester lipase gene(Cel)knockout(Cel^(DHEP))and wildtype(WT)littermates were fed with cholinedeficient high-fat diet(CD-HFD)for 16 weeks,or methionine-and choline-deficient diet(MCD)for three weeks to induce MASH.Liquid chromatography–mass spectrometry and co-immunoprecipitation were employed to identify the downstream targets of CEL.CD-HFD/MCD-fed WT mice received intravenous injections of CEL-adeno-associated viral,serotype 8(AAV8)to induce specific overexpression of CEL in the liver.We observed a decrease in CEL protein levels in MASH induced by CD-HFD or MCD in mice.Cel^(DHEP) mice fed with CD-HFD or MCD exhibited pronounced hepatic steatosis,inflammation,lipid peroxidation,and liver injury compared to WT littermates,accompanied by increased hepatic nuclear factor kappa-light-chain-enhancer of activated B cell(NF-jB)activation.Consistently,Cel knockdown in mouse primary hepatocytes and AML12 cells aggravated lipid accumulation and inflammation,whereas CEL overexpression exerted the opposite effect.Mechanistically,CEL directly bound to fatty acid synthase(FASN),resulting in reduced FASN SUMOylation,which in turn promoted FASN degradation through the proteasome pathway.Furthermore,inhibition of FASN ameliorated hepatocyte lipid accumulation and inflammation induced by Cel knockdown in vivo and in vitro.Hepatocyte-specific CEL overexpression using AAV8-Cel significantly mitigated steatohepatitis in mice fed with CD-HFD or MCD.CEL protects against steatohepatitis development by directly interacting with FASN and suppressing its expression for de novo lipogenesis.CEL overexpression confers a therapeutic benefit in steatohepatitis.

Facile Preparation of Dopamine-Modified Magnetic Zinc Ferrite Immobilized Lipase for Highly Efficient Synthesis of OPO Functional Lipid

1,3-Dioleoyl-2-palmitoylglycerol(OPO)has been a hotspot of functional oils research in recent years,but due to the high cost of sn-1,3 specific lipase in enzymatic synthesis and the lack of biocatalyst stability,large-scale industrial application is difficult.In this study,the prepared magnetic ZnFe_(2)O_(4) was functionalized with dopamine to obtain ZnFe_(2)O_(4)@PDA,and the nano-biocatalyst ZnFe_(2)O_(4)@PDA@RML was prepared by immobilizing sn-1,3 specific lipase of Rhizomucor miehei lipase(RML)via a cross-linking method.The existence of RML on ZnFe_(2)O_(4)@PDA was confirmed by XRD,FTIR,SEM,and TEM.This strategy proved to be simple and effective because the lipase immobilized on magnetic nanoparticles could be quickly recovered using external magnets,enabling reuse of the lipase.The activity,adaptability to a high temperature,pH value,and operational stability of immobilized RML were superior to those of free RML.After optimizing the synthesis conditions,the OPO yield was 42.78%,and the proportion of PA at the sn-2 position(PA-Sn2)was 54.63%.After the first four cycles,the activity of ZnFe_(2)O_(4)@PDA@RML was not significantly affected.The magnetically immobilized lipase has good thermal stability,long-term storage stability,reusability,and high catalytic activity.It can be used as a green and efficient biocatalyst to synthesize the OPO functional lipid.

Conjugation of Candida rugosa lipase with hydrophobic polymer improves esterification activity of vitamin E in nonaqueous solvent

We described a novel polymer-lipase conjugate for high-efficient esterification of vitamin E using vitamin E and succinic anhydride as the substrates in nonaqueous media.In this work,the monomer,N-isopropylacrylamide(NIPAM),was grafted onto Candida rugosa lipase(CRL)to synthesize poly(NIPAM)(pNIPAM)-CRL conjugate by atom transfer radical polymerization via the initiator coupled on the surface of CRL.The result showed that the catalytic efficiencies of pNIPAM-CRL conjugates(19.5-30.3 L·s^(-1)·mmol^(-1))were at least 7 times higher than that of free CRL(2.36 L·s^(-1)·mmol^(-1))in DMSO.It was attributed to a significant increase in Kcat of the conjugates in nonaqueous media.The synthesis catalyzed by pNIPAM-CRL co njugates was influenced by the length and density of the grafted polymer,water content,solvent polarity and molar ratio of the substrates.In the optimal synthesis,the reaction time was shortened at least 7 times,and yields of vitamin E succinate by pNIPAM-g-CRL and free CRL were obtained to be 75.4%and 6.6%at 55℃after the reaction for 1.5 h.The result argued that conjugation with pNIPAM induced conformational change of the lid on CRL based on hydrophobic interaction,thus providing a higher possibility of catalysis-favorable conformation on CRL in nonaqueous media.Moreover,pNIPAM conjugation improved the thermal stability of CRL greatly,and the stability improved further with an increase of chain length of pNIPAM.At the optimal reaction conditions(55℃and 1.5 h),pNIPAM-g-CRL also exhibited good reusability in the enzymatic synthesis of vitamin E succinate and kept~70%of its catalytic activity after ten consecutive cycles.The research demonstrated that pNIPAM-g-CRL was a more competitive biocatalyst in the enzymatic synthesis of vitamin E succinate and exhibited good application potential under harsh industrial conditions.

Bound lipase:an important form of lipase in rice bran (Oryza sativa)

Rice bran residue possessed a steady lipase activity((26.68 ± 3.69)%)after its endogenous lipase was extracted continuously by phosphate buffer solution(PBS)for 24 h. T herefore, the aim of this research was to explore whether there exist any bound lipases in rice bran(Oryza sativa). Three physical treatments(grinding, homogenizing and ultrasound crush)and 6 enzymatic treatments(cellulase, hemicellulase, pectinase, complex cellulase, glucoamylase and α-amylase)were applied to rice bran in order to investigate this bound lipase. The relative catalytic activities of extraction supernatant and residue for pectinase group were(437.63 ± 22.54)% and(159.26 ± 2.12)%, respectively, which were significantly higher(P < 0.05)than other groups. This phenomenon demonstrated that lipase was the most likely to combine with pectin. Molecular simulation proved that pectin could combine with two rice bran lipases(lipase 315 and lipase 308)and cover the catalytic centers so as to prevent the lipases from encountering the substrate and inhibiting their catalytic activities. During combination, pectin could make the lipases more compact and reduce the solvent accessible surface area of lipases, which would make the lipases inactive to molecular interaction. In summary, part of rice bran lipase was proved to exist in bound form and combined with the pectin.

Novel Lipase from Golden Pompano(Trachinotus ovatus)Viscera:Purification,Characterization,and Application in the Concentrating of n-3 Polyunsaturated Fatty Acids

Lipases have been widely applied in a variety of industrial fields,such as food,pharmaceuticals,biofuels,and biotechnology.Recent years have witnessed a great interest in modifying lipids for the production of triacylglycerols enriched with n-3 polyunsaturated fatty acids(PUFAs).Here,a novel salt-tolerant,organic solvent-stable,and bile salt-activated lipase was purified from golden pompano(Trachinotus ovatus)viscera,which was named as golden pompano lipase(GPL).GPL had a specific activity of 57.2U mg^(-1)with an estimated molecular weight of 14 k Da,exhibited optimal activity at 40℃a nd pH 8.0,and showed K_(m)and V_(max)of 40.16μmol L^(-1)and 769.23μmol L^(-1)min^(-1),respectively.GPL activity was enhanced by Mn^(2+)and sodium deoxycholate.It was active in organic solvents,including methanol,ethanol,chloroform,and hexane.GPL also showed a good salinity tolerance of up to 1 mol L^(-1).n-3PUFA enrichment in the glyceride fraction of golden pompano oil was performed by GPL-catalyzed hydrolysis and yielded a total PUFA concentration of 56.99%.EPA,DHA,and DPA were enriched by 10.4-,3.2-,and 1.8-fold of their initial levels,respectively.This study recognized the industrial applicability of GPL to prepare enriched C_(20-22)n-3 PUFA.

Encapsulation of lipases on coordination polymers and their catalytic performance in glycerolysis and esterification

In this study,lipases of CALB(Candida antarctica lipase B),TLL(Thermomyces lanuginosa lipase),RML(Rhizomucor miehei lipase),CALA(Candida antarctica lipase A)and LU(Lecitase?Ultra)were encapsulated into the nucleotidehybrid metal coordination polymers(CPs)for diacylglyerols(DAG)preparation.Guanosine 5'-monophosphate(GMP)and adenosine 5'-monophosphate(AMP)were used as coordinating molecules,and metal ions of Fe^(3+),Ba^(2+),Mn^(2+),Ni^(2+)and Cr^(3+)were applied to prepare matrix.Results indicated that,besides Ba^(2+)with AMP,all other metal ions can coordinate with AMP and GMP to generate CPs.In addition,the AMP/Ni was amorphous when standing temperature was 4℃,while it was crystalline when standing temperature was from 30 to 180℃.DAG content from 47.55%to 64.99%was obtained from glycerolysis by CALB@GMP/Ba,RML@GMP/Ba,TLL@GMP/Ba,RML@GMP/Mn and TLL@GMP/Mn.Additionally,CALB@GMP/Fe showed selectivity towards DAG formation in the esterification and DAG content up to 61.88%was obtained.

Changes in Lipoprotein Lipase in the Heart Following Diabetes Onset

Due to its constant pumping and contraction, the heart requires a substantial amount of energy, with fatty acids (FAs) providing a major part of its adenosine triphosphate (ATP). However, the heart is incapable of making this substrate and attains its FAs from multiple sources, including the action of lipoprotein lipase (LPL). LPL is produced in cardiomyocytes and subsequently secreted to its heparan sulfate proteoglycan (HSPG) binding sites on the plasma membrane. To then move LPL to the endothelial cell (EC) lumen, glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1) attaches to interstitial LPL and transfers it to the vascular lumen, where the LPL is ready to perform its function of breaking down circulating triglycerides (TG) into FAs. The endo-β-glucuronidase heparanase (Hpa) is unique in that it is the only known mammalian enzyme to cleave heparan sulfate (HS), thereby promoting the abovementioned release of LPL from the cardiomyocyte HSPG. In diabetes, it has been suggested that changes in how the heart generates energy are responsible for the development of diabetic cardiomyopathy (DCM). Following moderate diabetes, with the reduction in glucose utilization, the heart increases its LPL activity at the vascular lumen due to an increase in Hpa action. Although this adaptation might be beneficial to compensate for the underutilization of glucose by the heart, it is toxic over the long term, as harmful lipid metabolite accumulation, along with augmented FA oxidation and thus oxidative stress, leads to cell death. This coincides with the loss of a cardioprotective growth factor—namely, vascular endothelial growth factor B (VEGFB). This review discusses interconnections between Hpa, LPL, and VEGFB and their potential implications in DCM. Given that mechanism-based therapeutic care for DCM is unavailable, understanding the pathology of this cardiomyopathy, along with the contribution of LPL, will help us advance its clinical management.

畜禽动物油甘油二酯的酶法制备及应用研究进展

1,3-甘油二酯(diacylglycerol,DAG)是公认的安全食品,在人体中的代谢途径不同于甘油三酯,具有提高人体新陈代谢水平以及预防肥胖和心血管疾病等功效。然而,天然DAG在食用油中的质量分数不及10%,因此,近年来高纯度DAG的制备受到了广泛关注。与化学法相比,酶法因绿色、安全、选择性高等优点成为了油脂工业制备DAG的首选。畜禽动物油具有特殊的风味和一定的营养价值,但其高饱和脂肪、高胆固醇和高熔点等理化特征致使其在食品工业的利用受到了极大限制。鉴于此,合成畜禽动物油DAG成为了实现畜禽动物油高值化利用的一种有效途径。本文综述了酶法制备畜禽动物油DAG的研究现状及其潜在的应用价值,以期为畜禽动物油DAG的酶法加工及高值化利用提供一定的思路。

1株枯草芽胞杆菌的鉴定及其产脂肪酶特性

【目的】对1株产脂肪酶细菌MY016进行鉴定并对其产脂肪酶特性进行研究,为后期规模化发酵生产脂肪酶及其在畜牧业中的实际应用奠定基础。【方法】采用形态学观察、生理生化鉴定、16S rDNA测序分析,对实验室分离保存的1株产脂肪酶细菌MY016进行鉴定;通过菌落和芽胞计数、生长曲线测定,对MY016的生长特性进行分析;通过产脂肪酶量和酶活检测、脂肪酶基因扩增和系统进化分析,对MY016菌株的产脂肪酶特性进行探讨。【结果】产脂肪酶细菌MY016经形态观察、生理生化鉴定和16S rDNA分析,被鉴定为枯草芽胞杆菌。MY016在培养2 h后进入对数生长期,生长迅速;培养10 h其菌液600 nm吸光度最高达到4.7,随后进入稳定期;12 h时活菌数约为5.3×10^(9)CFU/mL;培养22 h后开始二次生长,吸光度最高达5.2;培养46 h后进入衰退期。芽胞观察和计数结果显示,MY016菌株在接种16 h后开始形成芽胞,随着培养时间延长,芽胞形成率逐渐升高,直至72 h完全形成芽胞,芽胞数最高为1.9×10^(9)CFU/mL。产脂肪酶能力检测结果显示,MY016菌株在培养36 h时产酶量达到最大,为246.918 mg/L,然后总酶量逐步降低;48 h时总酶活达到最高,约为281.883 U/L。成功扩增了MY016菌株的脂肪酶基因,并构建系统进化树,结果显示MY016脂肪酶基因与其他芽胞杆菌的脂肪酶基因亲缘关系最近,表明其脂肪酶基因进化保守。【结论】产脂肪酶枯草芽胞杆菌MY016生长迅速、产酶量稳定,总酶活较高,适合后期规模化生产和在畜牧业中推广应用。

酶制剂对大米面包品质的改良作用研究

该试验以小麦粉和大米粉为主要原料制备大米面包,研究由葡萄糖氧化酶(glucose oxidase, GOD)、α-淀粉酶(α-amylase, AM)和脂肪酶(lipase, LIP)制备的复配酶制剂对大米面包品质的改良作用。以面包的质构特性、比容、高度、感官评分为评价指标,最终得到3种酶以GOD 25 mg/kg、AM 15 mg/kg、LIP 50 mg/kg复配时,大米面包的硬度和咀嚼性分别为88.71 g和93.12 g,与空白组比较分别减少了51.3%和55.2%;大米面包的弹性、比容、高度、感官评分分别为0.92、4.57 (mL/g)、6.02 cm和80分,与空白组比较分别增加了17.9%、27.3%、32.8%和11.1%。复配酶制剂对大米面包具有良好的改良效果。

肉源性芽孢杆菌致腐性能异质性研究

为评估芽孢杆菌的致腐潜能异质性,本研究以从腐败低温香肠中分离出来的6株芽孢杆菌为研究对象,探究其在20℃(常温)和37℃(最适生长温度)条件下的致腐性能。试验分别测定了6株芽孢杆菌的生长曲线、产酸能力、产气能力、蛋白酶活力、脂肪酶活力和淀粉酶活力。结果表明,蜡样芽孢杆菌(C)的产酸能力较强,在37℃条件下培养48 h,pH较空白组下降0.71;解淀粉芽孢杆菌(G)的产蛋白酶和淀粉酶的能力更强,其蛋白酶活力高达7.17 U/mL,37℃条件下培养至5 d的淀粉分解圈面积为16.53 cm^(2);蜡样芽孢杆菌(C)的综合腐败能力最弱,具体表现为其蛋白酶活力为2.63 U/mL,37℃条件下培养5 d的淀粉分解圈面积为7.55 cm^(2)。同时发现生长温度对菌株致腐性能有较大影响。研究结果说明芽孢杆菌菌株的致腐性能存在显著的异质性,在探究其腐败特性时,应充分考虑菌株的异质性。

内皮脂肪酶和脂蛋白酶在冠状动脉粥样硬化发生及发展中的作用研究进展

冠心病是主要由冠状动脉粥样硬化导致的心肌缺血性病变。动脉壁僵硬、脂质代谢异常导致动脉内膜脂质类物质聚集、纤维组织增生和钙质沉积,斑块形成,从而影响血液运输。内皮脂肪酶(EL)是一种磷脂酶,可水解血浆高密度脂蛋白胆固醇,具有促进脂肪分解代谢的作用。脂蛋白酶(LPL)是溶解脂蛋白的关键酶,其特定的酶分子结构可水解甘油三酯,参与人体内脂蛋白代谢。因此,了解EL、LPL在冠状动脉粥样硬化发生及发展中的作用对早期防治冠心病至关重要。现对EL和LPL的结构、生物学特点以及在冠状动脉粥样硬化形成中的作用进行综述。

红小豆提取物对α-葡萄糖苷酶和胰脂肪酶的抑制作用

采用体积分数70%乙醇对红小豆进行提取,提取物经水混旋,然后依次采用石油醚、乙酸乙酯、正丁醇溶剂萃取。正丁醇萃取相浓缩干燥后经AB-8大孔树脂吸附,以不同体积分数乙醇洗脱,测定洗脱相浓缩液中总三萜皂苷和总黄酮的含量,并探究洗脱相浓缩液对α-葡萄糖苷酶和胰脂肪酶的抑制作用。结果显示:体积分数70%和95%乙醇洗脱组分中的总三萜皂苷含量高于其他组分,且体积分数70%乙醇洗脱组分的总黄酮含量最高,为(181.83±3.09)mg/g;体积分数95%、70%、50%乙醇洗脱组分对α-葡萄糖苷酶和胰脂肪酶均具有较好的抑制活性;体积分数95%乙醇洗脱组分对2种酶的抑制类型均为混合型抑制。

脂代谢相关蛋白在恶性肿瘤中的表达及关系研究

脂代谢紊乱和肥胖是乳腺癌、结直肠癌、卵巢癌等多种恶性肿瘤的高危因素。脂质能为癌细胞的增殖、迁移及侵袭提供生物膜合成的原料、营养成分、信号分子、能量支持。脂代谢过程中关键酶表达异常,是脂代谢重编程的主要表现。本文综述脂肪酸从头合成相关酶、脂肪酸摄取转运蛋白、脂质水解和动员相关酶及脂肪酸氧化相关酶的临床研究进展,从代谢层面探索恶性肿瘤的发病机制、寻找治疗新靶点。

麦角甾醇酯的酶促合成及对非酒精性脂肪肝的预防作用

探究了麦角甾醇亚油酸酯(简称麦角甾醇酯)的酶促合成及对非酒精性脂肪肝的预防作用。将30只雄性昆明小鼠分为四组:空白组(n=6)、高脂组(n=8)、麦角甾醇组(n=8)和麦角甾醇亚油酸酯组(n=8),持续喂养6周。测定血浆总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)和高密度脂蛋白胆固醇(HDL-C)水平,计算LDL-C/HDL-C比值,检测肝脏和粪便脂质水平,并分析肝脏脂肪变性程度。结果显示,以Candida sp.99-125脂肪酶为催化剂可以成功合成麦角甾醇亚油酸酯。麦角甾醇酯使得肝脏总脂肪酸含量降低35.3%(P<0.05),可以有效预防高脂膳食诱导肝脏脂肪变性,并导致粪便总脂肪酸水平增加74.8%(P<0.05)。同时,麦角甾醇酯降低了血浆LDL-C水平和LDL-C/HDL-C比值分别为24.3%(P<0.05)和36.5%(P<0.05),引起血浆HDL-C水平提高52.0%(P<0.05)。以上结果表明,麦角甾醇酯能够有效预防高脂膳食诱导的非酒精性脂肪肝。该文为非酒精性脂肪肝的预防提供了一种新的干预策略。

樟树5种化学型精油组成及其胰脂肪酶抑制活性研究

采用GC和GC-MS方法分析确定了樟树5种精油化学成分组成,进一步研究了5种不同类型精油的胰脂肪酶抑制活性。结果表明:5种精油主成分分别为:芳樟醇(91.98%)、樟脑(81.25%)、龙脑(91.88%)、反式-橙花叔醇(52.63%)和桉叶油素(57.73%)。精油的胰脂肪酶抑制活性顺序为:反式-橙花叔醇型>桉叶油素型>芳樟醇型>樟脑型>龙脑型。其中反式-橙花叔醇型精油IC50为(20.02±3.27)mg/mL,当其精油浓度为100 mg/mL时,胰脂肪酶抑制率达90.17%±1.56%。

凝胶涂层包覆大孔树脂固定化脂肪酶的制备及在风味酯合成中的应用

风味酯是一种重要的香料化合物,在食品、化妆品和制药等行业具有重大的应用价值。酶法合成风味酯具有反应条件温和、选择性高以及污染少等优点,但在有机溶剂中,游离脂肪酶的活性会有极大的损失。为了提高脂肪酶的稳定性,该研究首先使用大孔树脂通过吸附作用固定化脂肪酶,然后对酶蛋白表面进行丙烯酰化修饰和聚合反应,在固定化脂肪酶的表面形成凝胶涂层的包覆。此种方式制备的固定化脂肪酶稳定性有了较大提高。利用该固定化酶分别通过酯化反应合成乙酸丁酯和转酯反应合成乙酸异戊酯,结果显示,以正庚烷为溶剂,乙酸和丁醇浓度均为0.1 mol/L,并添加1 g固定化酶,在45℃经过12 h的反应,乙酸丁酯的合成率达到93.05%,重复利用4次后仍然有70.83%的酯合成率;在3 mL乙酸乙烯酯溶液中加入0.8 mol/L异戊醇和0.5 g固定化酶,在45℃经过14 h的反应,乙酸异戊酯的合成率达到92.35%,重复利用4次后仍然有84.80%的酯合成率,研究建立了一种固定化脂肪酶的新方法,并为风味酯的制备奠定了基础。。

血清淀粉酶、脂肪酶及C-反应蛋白在急性胰腺炎患者中的应用价值

目的探讨血清淀粉酶、脂肪酶及C-反应蛋白联合检验对诊断急性胰腺炎的临床价值。方法选取2020年4月—2022年5月甘肃省天水市第一人民医院收治的50例急性胰腺炎患者为研究组,包括30例轻型急性胰腺炎患者及20例重型急性胰腺炎患者;同时选择50例非急性胰腺炎急腹症患者作为A1组,50例健康体检人员作为A2组;对所有研究对象均展开血清淀粉酶水平检测、脂肪酶水平检测以及C反应蛋白检测,比较3组的血清淀粉酶水平、脂肪酶水平以及C反应蛋白检测结果,比较轻型、重型急性胰腺炎患者指标测定结果,并进行相关性分析。结果研究组血清淀粉酶水平、血清脂肪酶水平及C反应蛋白水平均高于A2组和A1组,差异有统计学意义(P均<0.05);重型急性胰腺炎患者血清淀粉酶水平为(768.49±43.22)U/L、血清脂肪酶水平为(1694.88±300.15)mg/L、C反应蛋白水平为(137.49±13.35)mg/L,高于轻型急性胰腺炎患者的(591.85±48.22)U/L、(1232.49±300.13)mg/L、(26.25±4.13)mg/L,差异有统计学意义(t=19.288、7.702、56.288,P均<0.05)。随着急性胰腺炎病情的严重,患者的血清淀粉酶水平、血清脂肪酶水平以及C反应蛋白水平呈现出显著提升(r=0.128、0.139、0.137,P均<0.05)。结论临床对急性胰腺炎患者在开展早期诊断工作期间,合理展开血清淀粉酶水平、血清脂肪酶水平以及C反应蛋白水平检测工作,可为疾病顺利诊断提供一定依据,发现随着急性胰腺炎病情的严重,患者的血清淀粉酶水平、血清脂肪酶水平以及C反应蛋白水平呈现出显著提升对于疾病的有效治疗可以奠定基础。

牛蒡根中多酚成分对脂肪酶的抑制作用

为明确牛蒡根中多酚成分对脂肪酶的抑制作用,本文提取并富集牛蒡根中的多酚成分,采用福林-西奥卡特(Folin-Ciocalteu)法测定总酚含量;HPLC-UV法测定多酚部位中指标性成分的含量;对硝基苯基丁酸酯(p-NPB)法测定牛蒡根多酚和其指标性成分对脂肪酶的抑制效果、抑制类型,采用等效线图解法和药物联合指数(CI)测定牛蒡根中的多酚单体化合物联合使用时的抑制作用。结果表明,富集后的牛蒡根多酚部位的总多酚含量达到51.23%,5种指标性成分的含量占纯化后牛蒡根多酚含量的12.87%,牛蒡根多酚对脂肪酶半数抑制浓度IC_(50)值为1.706 mg/mL,抑制类型为可逆性竞争型抑制。新绿原酸、隐绿原酸、咖啡酸、绿原酸和异绿原酸A对脂肪酶的IC_(50)值分别为0.872、0.910、0.280、0.847、0.244 mg/mL。绿原酸和异绿原酸A浓度比为1:2.15时,CI值为0.549,咖啡酸和异绿原酸A浓度比为1:0.87时,CI值为0.282,对脂肪酶具有协同抑制作用。本研究为探究牛蒡根降脂功效的物质基础及其降脂的机制提供了实验依据,为牛蒡根的开发奠定基础。