基于广泛靶向脂质组学与近红外技术的高低油酸花生鉴评

[目的]探索一种能鉴定花生品种与评价品质的新型检测方法,筛选高油酸花生特异性脂质生物标志物.[方法]采用超高效液相色谱-串联质谱(UPLC-MS/MS)技术,对2个油酸含量差异显著的花生品种,即高油酸品种开农1715(KN1715)和低油酸品种冀花7号(JH7H)进行农艺性状考察、近红外分析(Near infrared spectroscopy,NIRS)与广泛靶向脂质组学(Widely targeted lipidomics,WTL)研究.[结果]农艺性状测定结果表明,高油酸花生品种KN1715的主茎、第一侧枝长度比JH7H分别高11.72％和33.74％,差异显著;而单株荚果数、单株饱果率、百果重、百仁重、出仁率分别低46.23％、5.02％、5.35％、11.68％、17.17％,差异显著.品质性状检测结果表明,KN1715的油酸、硬脂酸、花生酸、蛋白质、氨基酸、缬氨酸、蛋氨酸、异亮氨酸、亮氨酸、苯丙氨酸、组氨酸、精氨酸、脯氨酸含量均显著高于JH7H,亚油酸、棕榈酸、山嵛酸、二十四烷酸含量则相反;广泛靶向脂质组代谢物分析表明,高、低油酸品种间存在较大的脂质代谢物差异,共筛选到16类295种脂质分子,进而通过对差异代谢物多元统计分析,最终筛选到3类31种核心差异脂质分子.结合核心差异脂质代谢物与品质指标,通过聚类与相关性分析,得到可视化表型与脂质代谢物特征图谱.[结论]该方法基于广泛靶向脂质组学与近红外技术,可以很好地实现从表型与脂质分子层面对花生品种进行品种与品质鉴评.     

Current Progress in Lipidomics of Marine Invertebrates

Marine invertebrates are a paraphyletic group that comprises more than 90% of all marine animal species. Lipids form the structural basis of cell membranes, are utilized as an energy reserve by all marine invertebrates, and are, therefore, considered important indicators of their ecology and biochemistry. The nutritional value of commercial invertebrates directly depends on their lipid composition. The lipid classes and fatty acids of marine invertebrates have been studied in detail, but data on their lipidomes (the profiles of all lipid molecules) remain very limited. To date, lipidomes or their parts are known only for a few species of mollusks, coral polyps, ascidians, jellyfish, sea anemones, sponges, sea stars, sea urchins, sea cucumbers, crabs, copepods, shrimp, and squid. This paper reviews various features of the lipid molecular species of these animals. The results of the application of the lipidomic approach in ecology, embryology, physiology, lipid biosynthesis, and in studies on the nutritional value of marine invertebrates are also discussed. The possible applications of lipidomics in the study of marine invertebrates are considered.     

水产加工副产物中磷脂和鱼油的分离及脂质组学研究

为更好地对水产加工副产物进行加工利用,本实验建立了从水产加工副产物中同时提取制备磷脂和鱼油的方法,并分别利用多维度串联质谱鸟枪法和气相色谱法对样品的磷脂和鱼油的脂肪酸化合物进行脂质组学研究。利用改进Folch法和丙酮沉淀法制备得到副产物中的磷脂和鱼油,比较了5种不同萃取液的提取效率,其中CH2Cl2-Me OH(1∶2,V/V)混合液同时提取磷脂和鱼油效果最佳,提取率分别为0.97%和28.05%。鱼油经甲酯化反应,以正己烷为溶剂直接进样,利用气相色谱法分析脂肪酸甲酯成分,磷脂样品采用流动注射直接进样,经三重四级杆质谱母离子扫描(Pre IS)和中性质量丢失扫描(NLS)对磷脂分子实现源内分离鉴定和定量分析。结果显示,鱼油中主要含有油酸、亚油酸、棕榈酸等23种脂肪酸,其中不饱和脂肪酸占75.97%;磷脂样品中共检出磷脂酰胆碱、磷脂酰乙醇胺、磷脂酰肌醇和磷脂酰丝氨酸4类共69种磷脂分子,并测出了许多含有DHA、EPA链的磷脂,如16∶0/20∶5、16∶0/22∶6、18∶1/22∶6、18∶0/22∶6、20∶0/22∶6等。研究表明,该方法能同时提取磷脂和鱼油,并且前处理简单、提取效率高,能够实现对资源的合理利用。     

Advances on Current Techniques and Methodologies in Milk Lipidomics

Milk is a complex biological fluid containing lipids, proteins, carbohydrates and minerals, which are essential for infant growth. While the lipid portion constitutes only 3％-5％ of the total milk composition, it accounts for over 50％ of the infant's daily energy intake. The dominant portion (approximately 98％) is in the form of triacylglycerols and polar lipids, such as glycerophospholipids and sphingolipids, forming minor components. Recently, with the development of lipidomics, important progresses have been made in milk lipidomics, and the identification and quantification of several milk lipids at the group and molecular species level has become a reality, thereby providing useful information for the infant formula industry. In this review, an overview of the separation of the main components of milk lipids was presented, including glycerolipids, phospholipids and sphingolipids. The analytical methods and strategies for milk lipidomics, including gas chromatography-mass spectrometry (MS), capillary electrophoresis MS, nuclear magnetic resonance, matrix-assisted laser desorption ionization-MS, electrospray ionization-MS, shotgun lipidomics and liquid chromatography-MS, were reviewed. Additionally, the bioinformatics of lipidomics for milk lipid determination, including lipid classification, lipid databases and lipid analysis software, were investigated. This review would aid future investigations of the nutrition of milk lipids and refined researches on formula milk powder.     

Ethanol Extraction of Polar Lipids from Nannochloropsis oceanica for Food,Feed, and Biotechnology Applications Evaluated Using Lipidomic Approaches

Nannochloropsis oceanica can accumulate lipids and is a good source of polar lipids, which are emerging as new value-added compounds with high commercial value for the food, nutraceutical, and pharmaceutical industries. Some applications may limit the extraction solvents, such as food applications that require safe food-grade solvents, such as ethanol. However, the effect of using ethanol as an extraction solvent on the quality of the extracted polar lipidome, compared to other more traditional methods, is not yet well established. In this study, the polar lipid profile of N. oceanica extracts was obtained using different solvents, including chloroform/methanol (CM), dichloromethane/methanol (DM), dichloromethane/ethanol (DE), and ethanol (E), and evaluated by modern lipidomic methods using LC-MS/MS. Ultrasonic bath (E + USB)- and ultrasonic probe (E + USP)-assisted methodologies were implemented to increase the lipid extraction yields using ethanol. The polar lipid signature and antioxidant activity of DM, E + USB, and E + USP resemble conventional CM, demonstrating a similar extraction efficiency, while the DE and ethanol extracts were significantly different. Our results showed the impact of different extraction solvents in the polar lipid composition of the final extracts and demonstrated the feasibility of E + USB and E + USP as safe and food-grade sources of polar lipids, with the potential for high-added-value biotechnological applications.     

Comparative Lipid Profile Analysis of Hermetia illucens Larvae Fed Food Waste at Different Days of Age Using an LC-MS-Based Lipidomics Approach

A lipidomics approach based on liquid chromatography–tandem mass spectrometry (LC-MS) was applied to analyze the molecular-level mechanism of lipid deposition in Hermetia illucens (H. illucens) larvae fed food waste (FW) at different days of age. The H. illucens larvae reared on FW substrates generally became larger, heavier, and fatter at 5–15 d of age. A large amount of glycerolipids (GL) were deposited, while glycerophospholipids (GP), sphingolipids, and derivatized lipids became relatively less abundant during the growth stage of the larvae. Forty-three subclasses of 3,205 lipid molecules were identified in larvae, and 139 lipids (79 upregulated and 60 downregulated during larval growth and development) were identified as potential biomarkers (variable importance in projection > 1; P < 0.05). The differential lipids were mainly enriched in 19 metabolic pathways, of which 9 metabolic pathways related to lipids, including GL and GP metabolisms. The results demonstrate that the lipid composition and mechanisms changed during the growth and development stage of H. illucens larvae. To the best of our knowledge, this is the first work exploring the molecular-level mechanism of lipid deposition during the growth and development stage of H. illucens larvae. The findings provide novel information for determining and utilizing the nutritional value of H. illucens larvae.     

基于液相色谱-串联质谱法分析不同植物油经加热处理前后氧化脂肪酸的变化

植物油中的氧化脂肪酸主要是亚油酸(linoleic acid, LA)和亚麻酸(linolenic acid, ALA)等多不饱和脂肪酸在酶、光照、加热等条件下产生的过氧化羟基脂肪酸(hydroperoxyl fatty acid)、羟基脂肪酸(hydroxy fatty acids)和环氧基脂肪酸(epoxy fatty acid)等。这些氧化脂肪酸的变化在一定程度上反映了油脂本身的氧化稳定性和氧化初期的变化,可作为植物油氧化初级阶段标志物。本研究基于高效液相色谱-三重四极杆质谱(high performance liquid chromatography triple quadrupole mass spectrometry,HPLC-Qq Q-MS/MS)联用技术,对室温和180℃加热处理30min后的菜籽油、葵花油、紫苏油、亚麻籽油中氧化脂肪酸进行了定性和定量分析。结果表明,相比于室温,经180℃加热处理30min,4种植物油中的LA、ALA等多不饱和脂肪酸含量下降;大部分LA、ALA类氧化脂肪酸的含量明显提高。经主成分分析(Principal component analysis, PCA),不同种类和处理下的植物油样本聚类明显,差异显著;经偏最小二乘法判别分析(Partial least squares discriminant analysis,PLS-DA),发现了植物油加热氧化初期的13-HODE、13-oxo-ODE、12,13-Ep OME、9,10-Ep ODE、12,13-Ep ODE、15,16-Ep ODE六种潜在的标志物,本研究对植物油氧化初期的评价以及植物油氧化初级阶段机制的深入研究具有一定的指导意义。     

Polar Lipids Composition,Antioxidant and Anti-Inflammatory Activities of the Atlantic Red Seaweed Grateloupia turuturu

Grateloupia turuturu Yamada, 1941, is a red seaweed widely used for food in Japan and Korea which was recorded on the Atlantic Coast of Europe about twenty years ago. This seaweed presents eicosapentaenoic acid (EPA) and other polyunsaturated fatty acids (PUFAs) in its lipid fraction, a feature that sparked the interest on its potential applications. In seaweeds, PUFAs are mostly esterified to polar lipids, emerging as healthy phytochemicals. However, to date, these biomolecules are still unknown for G. turuturu. The present work aimed to identify the polar lipid profile of G. turuturu, using modern lipidomics approaches based on high performance liquid chromatography coupled to high resolution mass spectrometry (LC–MS) and gas chromatography coupled to mass spectrometry (GC–MS). The health benefits of polar lipids were identified by health lipid indices and the assessment of antioxidant and anti-inflammatory activities. The polar lipids profile identified from G. turuturu included 205 lipid species distributed over glycolipids, phospholipids, betaine lipids and phosphosphingolipids, which featured a high number of lipid species with EPA and PUFAs. The nutritional value of G. turuturu has been shown by its protein content, fatty acyl composition and health lipid indices, thus confirming G. turuturu as an alternative source of protein and lipids. Some of the lipid species assigned were associated to biological activity, as polar lipid extracts showed antioxidant activity evidenced by free radical scavenging potential for the 2,2′-azino-bis-3-ethyl benzothiazoline-6-sulfonic acid (ABTS^●+) radical (IC₅₀ ca. 130.4 μg mL⁻¹) and for the 2,2-diphenyl-1-picrylhydrazyl (DPPH^●) radical (IC₂₅ ca. 129.1 μg mL⁻¹) and anti-inflammatory activity by inhibition of the COX-2 enzyme (IC₅₀ ca. 33 µg mL⁻¹). Both antioxidant and anti-inflammatory activities were detected using a low concentration of extracts. This integrative approach contributes to increase the knowledge of G. turuturu as a species capable of providing nutrients and bioactive molecules with potential applications in the nutraceutical, pharmaceutical and cosmeceutical industries.     

基于iKnife智能手术刀质谱技术金枪鱼内脏脂质组学研究

本研究利用iKnife智能手术刀质谱建立了一种金枪鱼内脏组织脂质组学检测新技术,用于对金枪鱼内脏营养价值进行深入研究。iKnife智能手术刀切割组织样品产生含有大量含磷脂离子的气溶胶,经专门的质谱接口装置直接引入质谱进行实时检测。结果显示,金枪鱼内脏中共鉴定出磷脂离子峰41种,质量范围m/z 699.5~911.6,其中信号最强离子峰m/z 790.5经鉴定为[PE 40:6-H]^-(相对丰度10.03%),其次为m/z 745.5([PA 40:7-H]^-,相对丰度9.02%)。该方法选择性强、精密度高、灵敏度好。本研究结果为质谱相关技术发展提供了参考,为金枪鱼副产物中脂质检测与综合利用提供了依据。     

急性冷刺激后巴马猪背膘和腹股沟皮下脂肪组织的脂质组比较

本研究旨在获得巴马猪皮下脂肪组织（包括背膘（backfat）和腹股沟皮下脂肪组织（inguinal subcutaneous white adipose tissue，iWAT））在急性冷刺激（4 ℃、4 h）后其脂质组成应答的差异。正常饲喂的6月龄巴马公猪在急性冷刺激处理后进行屠宰，收集背膘和腹股沟皮下脂肪组织，利用液相二级质谱（LC-MS/MS）高通量脂质组学检测技术分析其脂质组成。结果表明，在巴马猪皮下脂肪组织中，中性脂类、游离脂肪酸、磷脂类和鞘脂类4大类脂质含量差异巨大，其中含量最高的为中性脂类，在腹股沟皮下脂肪组织和背膘中分别占4大脂类总和的97.43%和98.53%；含量最低的为鞘脂类，在腹股沟皮下脂肪组织和背膘中所占比例分别为0.10%和0.07%。在16亚类脂质组成中含量最高的脂质为甘油三酯，在腹股沟皮下脂肪组织和背膘分别占16亚类脂质总和的95.97%和97.33%；含量最低的脂质为磷脂酸，在腹股沟皮下脂肪组织和背膘中所占比例分别为3.98E-04%和1.13E-04%。主成分分析表明，背膘和腹股沟皮下脂肪组织在急性冷刺激后脂质组成存在差异。以∣差异倍数∣>1.5和P<0.05为标准筛选，共获得18种差异显著的脂类，其中16种脂类在背膘中含量显著低于腹股沟皮下脂肪组织，其中包括14种甘油三酯、DAG32：1（16：1/16：0）和PE40：6p；只有2种脂质（CL74：8（18：2）和TAG54：3（16：0））在背膘中的含量显著高于腹股沟皮下。巴马猪皮下脂肪主要脂质组成为甘油三酯；急性冷刺激后，背膘和腹股沟皮下脂肪组织对急性冷刺激存在不同的应答。