Jove
Visualize
联系我们
JoVE
x logofacebook logolinkedin logoyoutube logo
关于 JoVE
概览领导团队博客JoVE 帮助中心
作者
出版流程编辑委员会范围与政策同行评审常见问题投稿
图书馆员
用户评价订阅访问资源图书馆顾问委员会常见问题
研究
JoVE JournalMethods CollectionsJoVE Encyclopedia of Experiments存档
教育
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab Manual教师资源中心教师网站
使用条款与条件
隐私政策
政策

相关概念视频

Mass Spectrum: Interpretation01:24

Mass Spectrum: Interpretation

1.2K
An unknown compound can be established by identifying the molecular ion peak in the mass spectrum. The molecular ion peak is often weak or absent due to the predominance of fragmentation in high-energy electron beams. In such cases, a low-energy electron beam can be used to scan the spectrum to enhance the intensity of the molecular ion peak. Additionally, chemical ionization, field ionization, and desorption ionization spectra are used to obtain a relatively intense molecular ion peak.
To...
1.2K
Mass Spectrum01:23

Mass Spectrum

1.9K
A mass spectrum is the graphical representation of the relative abundance of the charged fragments in an analyte plotted against their mass-to-charge ratio (m/z). The plot's x axis represents the ratio of the mass of the charged fragment to the elementary charge it carries. The y axis of the plot represents the relative abundance of each charged species. The relative abundance is calculated from the signal intensity of each charged species recorded at the detector. The most intense signal...
1.9K
Mass Spectrometry: Isotope Effect01:13

Mass Spectrometry: Isotope Effect

2.0K
Most elements exist in nature as a mixture of isotopes. The isotopes differ in weight due to their respective number of neutrons. The molecular weight of a molecule is different depending on the specific isotope of its elements involved. As a result, the mass spectrum of the molecule exhibits peaks from the same fragment at multiple positions. The positions of these mass signals depend on the difference between the molecular mass. Furthermore, the intensity of these signals is dependent on the...
2.0K
Mass Spectrometry: Carboxylic Acid, Ester, and Amide Fragmentation01:01

Mass Spectrometry: Carboxylic Acid, Ester, and Amide Fragmentation

1.3K
The fragmentation patterns observed for compounds such as carboxylic acids, esters, and amides in the mass spectra include ⍺-cleavage and McLafferty rearrangement. Fragmentation by ⍺-cleavage preferentially occurs at the carbon-carbon bond at the ⍺-position next to the carboxylic group to generate a neutral radical and a cation. Long chain compounds with hydrogen at their γ-carbon undergo McLafferty rearrangement to give a radical cation and a neutral alkene.
For example,...
1.3K
Mass Spectrometry: Alcohol Fragmentation01:03

Mass Spectrometry: Alcohol Fragmentation

3.5K
Alcohols (R-OH) ionize to lose one non-bonded electron from the oxygen atom, forming molecular ions. Due to their tendency to fragment rapidly, the intensity of the molecular ion peak in the mass spectrum is weak or sometimes absent. The fragmentation patterns for alcohols occur in two ways, i.e. ⍺-cleavage and dehydration. During ⍺-cleavage, the bond at the ⍺-position adjacent to the hydroxyl group cleaves to give a resonance-stabilized cation and a radical. However,...
3.5K
Mass Spectrometry: Molecular Fragmentation Overview01:20

Mass Spectrometry: Molecular Fragmentation Overview

3.1K
The ionization of a molecule into a molecular ion inside the mass spectrometer causes instability in the molecule's structure due to the loss of an electron. This eventually leads to the fragmentation or breaking of some bonds in the molecule. The fragmentation occurs predominantly at specific bonds to yield relatively stable fragments.
One type of fragmentation pattern is the cleavage of a single bond in the molecular ion. The cleavage leads to a radical and a cation. The cleavage can...
3.1K

您也可能阅读

相关文章

通过共同作者、期刊和引用图与本文相关的文章。

排序
Same author

Geographical origin modulates the gastrointestinal release pathway of bovine β-casomorphin-7 from Colombian commercial milk.

Journal of dairy science·2026
Same author

Volatile and Nonvolatile Contributors to Lager Beer Acceptability in High-Flavor-Liking Consumers.

Journal of agricultural and food chemistry·2026
Same author

Many ligands and states of bitter taste GPCRs.

Nature structural & molecular biology·2026
Same author

Intracellular and dual-site inhibition of a bitter taste GPCR.

Cellular and molecular life sciences : CMLS·2026
Same author

Correction: Analytical approaches to flavor research and discovery: from sensory‑guided techniques to flavoromics methods.

Food science and biotechnology·2026
Same author

Aroma, Flavor, and Textural Drivers of Acceptance in Unflavored Pea Protein Isolates.

Journal of food science·2026

相关实验视频

Updated: Jun 27, 2025

PTR-ToF-MS Coupled with an Automated Sampling System and Tailored Data Analysis for Food Studies: Bioprocess Monitoring, Screening and Nose-space Analysis
08:43

PTR-ToF-MS Coupled with an Automated Sampling System and Tailored Data Analysis for Food Studies: Bioprocess Monitoring, Screening and Nose-space Analysis

Published on: May 11, 2017

12.4K

BitterMasS:从质谱中预测痛苦

Evgenii Ziaikin1, Edisson Tello2, Devin G Peterson2

  • 1Food Science and Nutrition, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Institute of Biochemistry, Food and Nutrition, The Hebrew University of Jerusalem, 76100 Rehovot, Israel.

Journal of agricultural and food chemistry
|April 30, 2024
PubMed
概括

BitterMasS使用质谱来预测苦味化合物,而不是化学结构. 这种机器学习方法有助于识别代谢组内的未知苦分子.

关键词:
这是一种苦,苦.分类器分类器是分类器.机器学习是机器学习.质谱质谱的质谱.代谢组代谢组的代谢自然产品是自然产品的产品.味道 味道 味道 味道 味道

更多相关视频

Determination of the Gas-phase Acidities of Oligopeptides
11:00

Determination of the Gas-phase Acidities of Oligopeptides

Published on: June 24, 2013

11.1K
Analyzing Large Protein Complexes by Structural Mass Spectrometry
15:35

Analyzing Large Protein Complexes by Structural Mass Spectrometry

Published on: June 19, 2010

24.2K

相关实验视频

Last Updated: Jun 27, 2025

PTR-ToF-MS Coupled with an Automated Sampling System and Tailored Data Analysis for Food Studies: Bioprocess Monitoring, Screening and Nose-space Analysis
08:43

PTR-ToF-MS Coupled with an Automated Sampling System and Tailored Data Analysis for Food Studies: Bioprocess Monitoring, Screening and Nose-space Analysis

Published on: May 11, 2017

12.4K
Determination of the Gas-phase Acidities of Oligopeptides
11:00

Determination of the Gas-phase Acidities of Oligopeptides

Published on: June 24, 2013

11.1K
Analyzing Large Protein Complexes by Structural Mass Spectrometry
15:35

Analyzing Large Protein Complexes by Structural Mass Spectrometry

Published on: June 19, 2010

24.2K

科学领域:

  • 分析化学 分析化学
  • 计算化学的计算化学
  • 代谢学 代谢学 代谢学

背景情况:

  • 苦味化合物在天然产品和药品中普遍存在.
  • 目前的机器学习模型根据化学结构预测苦味,但大多数代谢物缺乏指定的结构.
  • 代谢组的很大一部分仍然没有表征,限制了苦味的预测.

研究的目的:

  • 开发一个机器学习模型,BitterMasS,直接从实验性质谱中预测苦味.
  • 与基于结构的方法相比,评估基于频谱的苦味预测策略的性能.
  • 为了在没有先前的结构阐明的情况下,在复杂混合物中识别苦味化合物.

主要方法:

  • 一个随机森林分类器 (BitterMasS) 在 5414 种苦和非苦化合物的实验质谱上受过训练.
  • 使用内部和外部测试集,包括新获取的光谱数据来评估模型的性能.
  • 频谱苦味预测与频谱结构苦味预测策略的比较.

主要成果:

  • 在内部测试套件上,BitterMasS实现了高精度 (0.83) 和回忆 (0.90).
  • 外部验证显示了良好的性能:67%的精度和93%的回忆对于文献频谱,58%的精度和99%的回忆对于新测量的频谱.
  • 频谱苦度方法在有效性和复合覆盖率方面超过了基于结构的方法.

结论:

  • BitterMasS有效地从质谱中预测痛苦,克服了基于结构的预测的局限性.
  • 这种方法可以识别"黑暗"代谢中的苦味化合物.
  • 应用包括代谢学,比较苦味分析和随着时间的推移监测苦味.