基于UPLC-Q-Orbitrap MS/MS研究人参皂苷在发酵过程中的生物转化

应用超高效液相色谱-四极杆-静电场轨道阱串联质谱(UPLC-Q-Orbitrap MS/MS)联用技术分析鉴别人参发酵前后的皂苷类化合物,研究了整体人参皂苷在自然发酵过程中的生物转化规律.通过鉴定45种人参皂苷,比较了生晒参和发酵人参中人参皂苷种类及含量的差异,在发酵人参中检测到20(S)-Rg_3和20(R)-Rg_3,20(S)-Rh_1和20(R)-Rh_1等异构体人参皂苷,其中10余种人参皂苷在自然人参状态下不存在或未被检出.本研究对于人参发酵前后的化学成分变化进行了高通量的精准分析,对同类天然产物发酵研究具有借鉴意义,可指导人参炮制品生晒参和发酵人参的安全有效使用.     

GC–MS法分析茵陈挥发油成分

采用水蒸气蒸馏法提取茵陈中挥发性成分挥发油,用气相色谱–质谱联用技术(GC–MS)对茵陈挥发油成分进行分析鉴定,并采用峰面积归一化法测定其相对含量。共检出52种挥发性成分,鉴定了其中31种主要挥发性成分,含量较高的组分为石竹素(15.27%)、(–)-斯巴醇(6.64%)、石竹烯(4.89%)等。GC–MS法适用于茵陈挥发性成分的定性分析,具有灵敏度高、分析速度快的特点。     

生晒参、全须生晒参中19种有机氯残留农药的毛细管气相色谱测定

建立了生晒参、全须生晒参中19种有机氯农药残留的毛细管气相色谱分析方法。对样品中六六六的4种异构体、滴滴涕的5种异构体、四氯苯胺、六氯苯、五氯硝基苯、七氯、五氯苯胺、艾氏剂、百菌清、环氧七氯、狄氏剂及异狄氏剂共19种有机氯农药的残留量进行了测定。以石油醚-丙酮混合物作为提取剂,样品采用索氏提取,提取液用弗罗里硅土柱层析净化。采用OV-1701石英毛细管气相色谱柱分离样品,ECD检测器进行检测。在3个水平添加时的回收率(n=5)分别为75.7%~96.1%、78.8%~111.6%和81.7%~115·2%;相对标准偏差分别为2.4%~10.6%、2.1%~9.8%和1.4~10.0%。方法用于生晒参和全须生晒参样品中农药残留的测定,结果满意。     

顶空-气相色谱-质谱联用分析桂花和叶中挥发性成分

采用谱库检索结合准确质量测定、保留指数、串联质谱技术的多维定性分析策略鉴定化合物, 能够提高定性分析的效率和准确性. 运用顶空-气相色谱-四极质谱、顶空-气相色谱-飞行时间质谱以及顶空-气相色谱-串联质谱联用技术对桂花样品进行了分析检测, 并采用多维定性分析思路对检出的挥发性成分进行了鉴定. 结果共确认出47种挥发性成分, 其中单萜类和倍半萜类化合物为主要组分. 该定性分析策略准确可靠, 可以广泛应用于复杂样品挥发性成分的定性分析中.     

中国红参中碳、氢、氮元素和蛋白含量的自动分析

人参为五加科植物人参(Panax ginseng C.A.Mey.)的干燥根。红参则是鲜人参洗净后经高温蒸气加热后干燥而制得的产品。有关人参中皂甙、氨基酸、多肽、挥发油、微量元素等成分的研究国内外均有大量的报道。但关于红参中碳、氢、氮元素的研究以及自动定量方法国内外尚未见报道。 1.仪器:1106型元素自动分析仪(意大利)其配套设备包括B-5000型记录仪,微处理机和电子天平。 2.人参样品:1号红参由吉林省抚松县参茸公司提供。2号红参由抚松县漫江参场提供。3号红参为抚松县参场提供。4号红参由延边地区提供。5号红参由集安县新开河参场提供。上述样品均为6年生。     

气相色谱-四极杆飞行时间串联质谱在加拿大一枝黄花挥发性成分检测中的应用

采用气相色谱-四极杆飞行时间串联质谱(GC-QTOF MS)对加拿大一枝黄花中的挥发性成分进行检测。利用气相色谱的保留指数、四极杆飞行时间串联质谱的高分辨多级质谱数据以及谱库检索等对该植物的叶、茎、根三个部位中的挥发性成分进行结构鉴定。共鉴别出挥发性成分54种,其中叶47种、茎35种、根32种。主要成分均为蒎烯、表双环倍半水芹烯、柠檬烯等萜烯类化合物。结果表明,气相色谱的高分离度和四极杆飞行时间串联质谱的高分辨率可以有效地对复杂样品中的挥发性成分进行检测,结合多维数据定性技术能够显著提高未知成分鉴别的准确性。     

超高效液相色谱-轨道阱高分辨质谱法对人参寡糖提取物与蓖麻凝集素120相互作用的研究

利用超高效液相色谱-轨道阱高分辨质谱(UHPLC-Orbitrap-MS)结合链霉亲和素包被的96孔板的方法筛选人参复杂体系中蓖麻凝集素120 (RCA 120)的寡糖结合剂。将RCA 120修饰的96孔板与溶菌酶修饰的96孔板分别与寡糖标准品孵育,对未结合的寡糖利用UHPLC-Orbitrap-MS进行分析,利用峰面积的变化表征寡糖是否与RCA 120发生相互作用。对影响亲和力的因素包括孵育时间、孵育温度和缓冲液等进行了优化。在优化条件下,对生晒参、红参和西洋参的寡糖提取物进行RCA 120结合剂的筛选,从生晒参中筛选出3种二糖化合物和2种三糖化合物,从西洋参中筛选出2种二糖化合物和2种三糖化合物,发现生晒参和西洋参中具有相同单糖残基的寡糖与RCA 120的结合强度均具有显著性差异。但是,从红参中未筛选到RCA 120结合剂,推测这是由红参炮制工艺导致的差异。本方法简单、快速、准确,可高通量地识别和筛选复杂体系中多个糖类组分与蛋白质的相互作用,为糖和蛋白质相互作用的研究提供了新方法。     

顶空-固相微萃取-气相色谱-质谱法测定烟气中挥发性和半挥发性成分

提出了顶空-固相微萃取-气相色谱-质谱法测定烟气中挥发性和半挥发性成分。结合信息量最大的原则,确定了固相微萃取时萃取纤维头为碳分子筛/聚二甲基硅烷萃取纤维头,萃取温度为70℃,萃取时间为60min。在气相色谱分离中用Agilent DB-1色谱柱为固定相,在质谱分析中采用全扫描模式。结果表明:共鉴定出107种成分,含量最大的成分是烟碱(18.07%),其次是新植二烯(11.46%),主要的3类挥发性和半挥发性成分依次为苯系物、酮类以及杂环类。     

RRLC-Q-TOF-MS研究人参二醇型皂苷Rb_1,Rb_2和Rc的化学转化

将高分离快速液相色谱-四极杆-飞行时间质谱(RRLC-Q-TOF-MS)联用技术用于人参二醇型(PPD)皂苷Rb_1,Rb_2和Rc在酸性条件下的化学转化研究,并对人参炮制过程中人参二醇型皂苷Rb_1,Rb_2和Rc及其转化产物的相对含量进行了分析.利用RRLC-Q-TOF-MS联用和串联质谱(MS/MS)技术对化合物的保留时间、精确分子量及串联质谱碎片信息进行分析,以鉴定化合物的结构.研究结果表明,人参二醇型皂苷在酸性条件下的化学转化包括:取代糖基的水解反应、Δ20(21)或Δ20(22)位的脱水反应和C24,C25位的水合加成反应.在MS/MS分析中,质谱峰m/z 459,477和441分别为人参二醇苷元、C24,C25位水合人参二醇苷元和Δ20(21)或Δ20(22)位脱水人参二醇型苷元的特征离子,这为人参二醇型皂苷及其转化产物的结构鉴定提供了依据,并以此总结了人参二醇型皂苷的化学转化途径.还利用所建立的方法研究了生晒参和红参(100和120℃)中PPD人参皂苷在炮制过程中的变化.     

热脱附-气相色谱-质谱法测定聚氨酯发泡床垫中12种挥发性有机化合物北大核心CSCD

采用热脱附-气相色谱-质谱法测定聚氨酯发泡床垫中12种挥发性有机化合物的含量。采用挥发性有机化合物的环境气候箱模拟室内环境,用含有Tenax TA的吸附管收集释放出的挥发性有机化合物。在气相色谱分离中采用DB-5MS毛细管色谱柱,在质谱分析中采用全扫描模式。12种挥发性有机化合物的质量在一定范围内与其对应的峰面积呈线性关系,方法的检出限(3S/N)为1.0μg·m^(-3)。加标回收率为84.3%～106%,测定值的相对标准偏差(n=6)为8.0%～9.8%。     

Determination of volatile organic compounds generated from fresh, white and red Panax ginseng (C. A. Meyer) using a direct sample injection technique

Ginsenosides are regarded as the main active, non-volatile components of Panax ginseng (C. A. Meyer). However, throughout the long history of ginseng research, there has been virtually no report describing its volatile flavor compounds. A solvent-free procedure for the determination of volatile flavor compounds generated from fresh, white and red Panax ginseng (C. A. Meyer) using solvent-free solid injection (SFSI) coupled with gas chromatography-mass spectrometry (GC-MS) detection is described here. At no point in the SFSI technique were the extraction conditions optimized. Rather, the experimental variables including various sample preparations (fresh, oven-dried and freeze-dried), injector temperatures (100, 150, 200, 250 and 300 degrees C), and preheating times (3, 5, 7, 10 and 15 min), were predicated on the experience of the authors. A total of 47 compounds were identified in various forms of ginseng. Among the compounds identified in the sample, fresh ginseng was characterized by a high proportion of 3-acetyl-1-(3,4-dimethoxyphenyl)-5-ethyl-4,5-dihydro-7,8-dimethoxy-4-methylene-3H-2,3-benzodiazepine (64.24%) and 23,24-dinor-3-oxolean-4,12-dien-28-oic acid (21.42%); 2-furanmethanol (20.26%) and 3-hydroxy-2-methyl-4H-pyran-4-one (17.95%) were detected as the major components in white ginseng while the main components of the red ginseng were found to be 1,2-benzenedicarboxylic acid dibutyl ester (16.27%) and 2-furanmethanol (13.82%). SFSI is a solvent-free, rapid and simple sample preparation technique based on direct vaporization. There is no dilution or contamination with solvent or its impurities and no loss of quickly eluted components was observed in the solvent peak.     

中国雪参挥发油成分的色谱-质谱分析

本文测定了中国雪参根中人参挥发油的含量,并用色谱-质谱联用仪分析了化学成分及百分含量。从中分离出132种化合物,初步鉴定出49种,占挥发油总量的87.73％,有28种化合物尚未见报道。     

Identification of volatile markers for the detection of adulterants in red ginseng (Panax ginseng) juice using headspace stir‐bar sorptive extraction coupled with gas chromatography and mass spectrometry

Red ginseng (Panax ginseng) products are frequently adulterated by manufacturers with cheaper medicinal plant products including deodeok (Codonopsis lanceolata) and doraji (Platycodon grandiflorum) to increase profits. To identify possible volatile markers for the adulteration of red ginseng juices with deodeok or doraji, a headspace stir‐bar sorptive extraction method was developed. Gas chromatography with mass spectrometry and untargeted metabolomics analysis revealed that 1‐hexanol, cis‐3‐hexen‐1‐ol, and trans‐2‐hexen‐1‐ol are abundantly present in deodeok and doraji but not red ginseng. The peak area ratios in gas chromatograms of these compounds in red ginseng juices mixed with deodeok or doraji indicate that these volatile chemicals can be used as markers to detect the adulteration of red ginseng juice.     

顶空进样GC-MS结合保留指数分析墨旱莲挥发性成分

采用顶空-气相色谱-质谱法(HS-GC-MS)对墨旱莲的挥发性成分进行检测,并结合保留指数对其分析鉴定。结果检测到60个组分,鉴定出33个可能的组分,占挥发性成分的70.0%。该研究为墨旱莲药材挥发性成分的指纹图谱研究奠定了基础。     

177 Saponins,Including 11 New Compounds in Wild Ginseng Tentatively Identified via HPLC-IT-TOF-MSn,and Differences among Wild Ginseng,Ginseng under Forest,and Cultivated Ginseng

Wild ginseng (W-GS), ginseng under forest (F-GS, planted in mountain forest and growing in natural environment), and cultivated ginseng (C-GS) were compared via HPLC-DAD and HPLC-IT-TOF-MSⁿ. A total of 199 saponins, including 16 potential new compounds, were tentatively identified from 100 mg W-GS (177 saponins in W-GS with 11 new compounds), F-GS (56 saponins with 1 new compound), and C-GS (60 saponins with 6 new compounds). There were 21 saponins detected from all the W-GS, F-GS, and C-GS. Fifty saponins were only detected from W-GS, including 23 saponins found in ginseng for the first time. Contents of ginsenosides Re (12.36–13.91 mg/g), Rh₁ (7.46–7.65 mg/g), Rd (12.94–12.98 mg/g), and the total contents (50.52–55.51 mg/g) of Rg₁, Re, Rf, Rb₁, Rg₂, Rh₁, and Rd in W-GS were remarkably higher than those in F-GS (Re 1.22–3.50 mg/g, Rh₁ 0.15–1.49 mg/g, Rd 0.19–1.49 mg/g, total 5.69–18.74 mg/g), and C-GS (Re 0.30–3.45 mg/g, Rh₁ 0.05–3.42 mg/g, Rd 0.17–1.68 mg/g, total 2.99–19.55 mg/g). Contents of Re and Rf were significantly higher in F-GS than those in C-GS (p < 0.05). Using the contents of Re, Rf, or Rb₁, approximately a half number of cultivated ginseng samples could be identified from ginseng under forest. Contents of Rg₁, Re, Rg₂, Rh₁, as well as the total contents of the seven ginsenosides were highest in ginseng older than 15 years, middle–high in ginseng between 10 to 15 years old, and lowest in ginseng younger than 10 years. Contents of Rg₁, Re, Rf, Rb₁, Rg₂, and the total of seven ginsenosides were significantly related to the growing ages of ginseng (p < 0.10). Similarities of chromatographic fingerprints to W-GS were significantly higher (p < 0.05) for F-GS (median: 0.824) than C-GS (median: 0.745). A characteristic peak pattern in fingerprint was also discovered for distinguishing three types of ginseng. Conclusively, wild ginseng was remarkably superior to ginseng under forest and cultivated ginseng, with ginseng under forest slightly closer to wild ginseng than cultivated ginseng. The differences among wild ginseng, ginseng under forest, and cultivated ginseng in saponin compositions and contents of ginsenosides were mainly attributed to their growing ages.     

Comparative Analysis of the Volatile Components in the Fresh Roots and Rhizomes of Curcuma wenyujin by Static Headspace Gas Chromatography Mass Spectrometry

Static headspace GC-MS method coupled with H/D exchange was firstly developed to determine and identifythe volatile components in the fresh root and rhizome of Curcuma wenyujin.The TIC chromatograms of 3 batchesof fresh roots harvested at different time showed significant difference in the volatile components:the constitutionwas the same but the content of them was different.More than 60 volatile components in fresh roots(Root of C.wenyujin)and rhizomes(Rhizome of C.wenyujin)of C.wenyujin were detected,of which 51 and 48 volatile com-ponents were identified respectively.The fresh roots and rhizomes of C.wenyujin were found to have the similarvolatile components.The contents of these components were calibrated by the response of β-elemene.In addition,the principal active component,β-elemene,was further confirmed and relatively quantified by its standard.γ-terpinene showed obvious allylic hydrogen/deuterium exchange using deuterium oxide which gave a new methodto identify some compounds containing allylic hydrogen.At the same time,the active hydrogen compounds werealso further confirmed.The results show that HS-GC-MS method is a fast,simple and efficient way for the analysisof volatile components from medical plants.     

甲基化辅助实时直接分析电离的机理研究

实时直接分析电离源(DART)已经广泛应用于固体、液体和气体样品的快速检测. 在使用DART对低挥发性化合物进行分析时, 样品衍生化是十分重要的. 四甲基氢氧化铵(TMAH)是强的瞬时甲基化试剂, 常用于GC-MS的分析中. 以人参皂苷及人参寡糖为例, 研究了它们在TMAH的辅助下在DART中发生甲基化及电离的过程, 并从凝聚相和气相的角度对电离过程中的甲基化机理进行了研究. 人参皂苷主要发生不完全和全甲基化, 人参寡糖的甲基化则随着糖链的增长以及羟基的增多由全甲基化主导转变为过甲基化主导. 结果表明, 凝聚相和气相的共同作用是质谱检测到甲基化及过甲基化样品分子的根本原因.     

Geographical traceability of Italian white truffle (Tuber magnatum Pico) by the analysis of volatile organic compounds

Results are presented that were obtained on the geographic traceability of the white truffle Tuber magnatum Pico. Solid-phase microextraction coupled to gas chromatography/mass spectrometry (SPME-GC/MS) was employed to characterize the volatile profile of T. magnatum white truffle produced in seven geographical areas of Italy. The main components of the volatile fraction were identified using SPME-GC/MS. Significant differences in the proportion of volatile constituents from truffles of different geographical areas were detected. The results suggest that, besides genetic factors, environmental conditions influence the formation of volatile organic compounds. The mass spectra of the volatile fraction of the samples were used as fingerprints to characterize the geographical origin. Next, stepwise factorial discriminant analysis afforded a limited number of characteristic fragment ions that allowed a geographical classification of the truffles studied.     

Identification and Evaluation of a Panel of Ginsenosides from Different Red Ginseng Extracts with Nootropic Effect

Red ginseng has been gradually discovered to have pharmacological and physiological effects. It is well known that the most important bioactive components of ginseng are ginsenosides. The nootropic effect of ginsenosides from nine different red ginseng extracts was evaluated here. Nine groups of mice were perfused with different concentrations of nine red ginseng extracts, respectively, and two groups of mice with distilled water. The nootropic effect of ginsenosides on mice was evaluated with behavior tests and a biochemical indicator study. The extracts were identified by rapid resolution liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry(RRLC-Q-TOF-MS). Furthermore, principal component analysis(PCA) was used to analyze the contribution of chemical components from different ginseng groups. The extracts with the most and the weakest effective nootropic were found. It is notable that extract processing is a very important factor to decide pharmacological functions of ginseng extracts. As a conclusion, the most effective extract method for ginsenosides has been found. A panel of 13 ginsenosides has been screened out as chemical markers with nootropic effect, which include high level ginsenosides Ra0, Rb1, Rc, Rb2, Rb3, Re, Rd, and Rg1 and low level ginsenosides mRb1, mRc, mRb2, mRd, and F2. Low level ginsenosides were first time to be discovered as possible nootropic compounds. This method may shed light on fast discovery of bioactive compounds of medicinal plants with low level compounds.     

Characteristic aroma compounds from different pineapple parts

Characteristic aroma volatile compounds from different parts of cayenne pineapple were analyzed by headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC/MS). The main volatile compounds were esters, terpenes, ketones and aldehydes. The number and content of aroma compounds detected in pulp were higher than those found in core. In pulp, the characteristic aroma compounds were ethyl 2-methylbutanoate, ethyl hexanoate, 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF), decanal, ethyl 3-(methylthio)propionate, ethyl butanoate, and ethyl (E)-3-hexenoate; while in core the main compounds were ethyl 2-methylbutanoate, ethyl hexanoate and DMHF. The highest odor units were found to correspond to ethyl 2-methylbutanoate, followed by ethyl hexanoate and DMHF. The odor units found for pulp were higher than those for core.