Horticultural Plant Journal
·
2024
·
IF 5.7
Sanyan Lai,Ning Yi,Shixin Yin,Yipeng Huang,Tianlin Shen,Qianying Dai,Liping Gao,Xiaolan Jiang,Tao Xia
Tea flavor is a comprehensive representation of its aroma and other characteristics. The formation of volatile odor compounds during tea processing depends on a variety of enzymatic and non-enzymatic activities. ( Z )-3-hexenol is considered the primary source of the green odor and is also the most important component in tea aroma, significantly affecting the overall aroma. However, the biosynthesis and accumulation of ( Z )-3-hexenol during tea processing have not been fully analyzed. In this study, we found that withering treatment at different times and withering plus shaking treatment at different degrees promoted the accumulation of important volatile components of green tea odor, especially ( Z )-3-hexenol by GC-MS. The RNA-seq and qRT-PCR results showed that withering and withering plus shaking treatments enhanced the expression of ( Z )-3-hexenol-related genes in tea leaves, including synthetic pathway 1 genes ( CsLOX3 , CsHPL1 , CsADH4 , and CsAHD1 ), synthetic pathway 2 genes ( CsGLU ), and synthetic pathway 3 genes ( CsCXEs ). Correlation analysis of the key odorants and important genes in the three synthetic pathways revealed that some CsCXEs were positively correlated with green odor compounds. The in vitro enzyme activity results showed that rCsCXE3 (GWHTASIV011658), and rCsCXE6 (GWHTASIV031480) exhibited hydrolytic activity against three tea acetate compounds [hexyl acetate, ( E )-2-hexyl acetate, and ( Z )-3-hexyl acetate], resulting in the production of corresponding alcohol compounds. In summary, withering and shaking treatment during tea processing promoted the expression of CsCXE3 and CsCXE6 , thereby enhancing the production of hexenol compounds. These compounds play a crucial role in increasing the green odor of tea.
研究领域:
植物学
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
PLANT CELL AND ENVIRONMENT
·
2018
·Vol. 42
·期 4
·1352-1367
·
IF 5.415
Tingting Jing,Na Zhang,Ting Gao,Mingyue Zhao,Jieyang Jin,Yongxian Chen,Miaojing Xu,Xiaochun Wan,Wilfried Schwab,Chuankui Song
Plants emit a variety of volatiles in response to herbivore attack, and (Z)-3-hexenol and its glycosides have been shown to function as defence compounds. Although the ability to incorporate and convert (Z)-3-hexenol to glycosides is widely conserved in plants, the enzymes responsible for the glycosylation of (Z)-3-hexenol remained unknown until today. In this study, uridine-diphosphate-dependent glycosyltransferase ( UGT ) candidate genes were selected by correlation analysis and their response to airborne (Z)-3-hexenol, which has been shown to be taken up by the tea plant. The allelic proteins UGT85A53-1 and UGT85A53-2 showed the highest activity towards (Z)-3-hexenol and are distinct from UGT85A53-3, which displayed a similar catalytic efficiency for (Z)-3-hexenol and nerol. A single amino acid exchange E59D enhanced the activity towards (Z)-3-hexenol, whereas a L445M mutation reduced the catalytic activity towards all substrates tested. Transient overexpression of CsUGT85A53-1 in tobacco significantly increased the level of (Z)-3-hexenyl glucoside. The functional characterization of CsUGT85A53 as a (Z)-3-hexenol UGT not only provides the foundation for the biotechnological production of (Z)-3-hexenyl glucoside but also delivers insights for the development of novel insect pest control strategies in tea plant and might be generally applicable to other plants.
研究领域:
植物学
·
分子生物学
·
昆虫学
✓ 已验证
DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2020
·
IF 5.977
Xiaoping Zhang,Xiang Ren,Konstantin Chingin,Jiaquan Xu,Xin Yan,Huanwen Chen
We present an approach for the elucidation of C=C bond position and cis/trans isomers, which is achieved by the reaction of ambient water radical cations and double bonds, followed by the fragmentation of epoxide radical cations to generate diagnostic ions in tandem mass spectrometry . Hexenol double bond positional isomers and cis/trans isomers which exhibit different properties and biological functions are characterized as a proof of concept. The merits of the approach include the simplicity of experimental setup, rapid derivatization (within seconds), the obviation of organic solvents , as well as easy spectral interpretation.
研究领域:
分析化学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 1
·362
·
IF 4.6
Shi-Hui Lu,Hao-Jiang Zuo,Jing Huang,Wei-Neng Li,Jie-Lian Huang,Xiu-Xia Li
The leaves ofLigustrum robustumhave been consumed as Ku-Ding-Cha for clearing heat and removing toxins, and they have been used as a folk medicine for curing hypertension, diabetes, and obesity in China. The phytochemical research on the leaves ofL. robustumled to the isolation and identification of two new hexenol glycosides, two new butenol glycosides, and five new sugar esters, named ligurobustosides X (1a), X1(1b), Y (2a), and Y1(2b) and ligurobustates A (3a), B (3b), C (4b), D (5a), and E (5b), along with seven known compounds (4aand6–10). Compounds1–10were tested for their inhibitory effects on fatty acid synthase (FAS), α-glucosidase, and α-amylase, as well as their antioxidant activities. Compound2showed strong FAS inhibitory activity (IC504.10 ± 0.12 μM) close to that of the positive control orlistat (IC504.46 ± 0.13 μM); compounds7and9revealed moderate α-glucosidase inhibitory activities; compounds1–10showed moderate α-amylase inhibitory activities; and compounds1and10displayed stronger 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) ammonium salt (ABTS) radical scavenging effects (IC503.41 ± 0.08~5.65 ± 0.19 μM) than the positive controll-(+)-ascorbic acid (IC5010.06 ± 0.19 μM). This study provides a theoretical foundation for the leaves ofL. robustumas a functional tea to prevent diabetes and its complications.Keywords:Ligustrum robustum;hexenol glycoside;butenol glycoside;sugar ester;FAS;α-glucosidase;antioxidant;antiobesity;hypoglycemic
研究领域:
植物化学
·
药理学
·
代谢疾病研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Food Bioscience
·
2024
·
IF 4.8
Huiting Wu,Caiyan Sheng,Mingxia Lu,Han Ke,Tiehan Li,Yuming Wei,Shanshan Shen,Xuchao Yin,Chengye Lu,Yujie Wang,Jingming Ning
Sunlight withering (SWT) enhanced the floral aroma of white tea, whereas withering–tank withering (WWT) enriched its grassy aroma. This study investigated the impact of diverse withering methods on white tea aroma, examining aroma formation mechanisms by analyzing changes in essential compounds, their precursors, and enzyme activities during these treatments. Findings revealed that tea at 50% moisture concentration decreased the concentration of isopentenyl pyrophosphate and dimethylallyl pyrophosphate, leading to increased levels of linalool, geraniol, and β -myrcene. Sunlight spurred non-enzymatic reactions, elevating β -ionone concentration. The breakdown of linoleic and linolenic acids increased the hexanal and ( Z )-3-hexenol levels. Enzyme activity analysis indicated that the prominent floral aroma in SWT was linked to heightened geranyl pyrophosphate synthase and alcohol dehydrogenase activity, enriching terpene–catalyzed products and benzeneacetaldehyde concentration, respectively. Elevated levels of lipoxygenase and arogenate dehydratase promoted grassy compounds in WWT. This study underscores how withering methods shape white tea aromas and offers operational insights.
研究领域:
食品科学
·
农学
·
代谢组学
·
植物生物化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）