The carotenoid-derived volatileβ-ionone makes an important contribution to tea fragrance.Here,we qualitatively and quantitatively analysed 15 carotenoids in tea leaves of 13 cultivars by UHPLC-APCI-MS/MS.The 13 culti...The carotenoid-derived volatileβ-ionone makes an important contribution to tea fragrance.Here,we qualitatively and quantitatively analysed 15 carotenoids in tea leaves of 13 cultivars by UHPLC-APCI-MS/MS.The 13 cultivars were divided into two groups by PCA(Principal Component Analysis)clustering analysis of their carotenoid content,and OPLS-DA(Orthogonal projections to latent structures)indicated that the levels ofβ-carotene(VIP=2.89)and lutein(VIP=2.30)were responsible for much of the variation between the two groups.Interestingly,theβ-carotene toβ-ionone conversion rates in Group 1 were higher than in Group 2,while theβ-carotene content was significantly lower in Group 1 than in Group 2.Theβ-ionone content was significantly higher in Group 1.Pearson Correlation Coefficient calculation between the transcription level of candidate genes(CsCCD1 and CsCCD4)and the accumulation ofβ-ionone indicated that CsCCD1 may involve in the formation ofβ-ionone in 13 cultivars.Prokaryotic expression and in vitro enzyme activity assays showed that‘Chuanhuang 1’had an amino acid mutation in carotenoid cleavage dioxygenases 1(CsCCD1)compared with‘Shuchazao’,resulting in a significantly higherβ-ionone content in‘Chuanhuang 1’.Sequence analysis showed that‘Chuanhuang 1’and‘Huangdan’had different CsCCD1 promoter sequences,leading to significantly higher CsCCD1 expression andβ-ionone accumulation in‘Chuanhuang 1’.These results indicated that the promoter and coding sequence diversity of CsCCD1 might contribute to the differential accumulation ofβ-ionone in different tea cultivars.展开更多
A simple and rapid technique based on liquid-liquid extraction coupled to gas chromatography-mass spectrometric detection(LLE-GC-MS) was developed for analysis of taste and odour compound β-ionone in water. Instrumen...A simple and rapid technique based on liquid-liquid extraction coupled to gas chromatography-mass spectrometric detection(LLE-GC-MS) was developed for analysis of taste and odour compound β-ionone in water. Instrument parameters including programmed oven temperature, injection temperature and ion source temperature were evaluated and optimized. Effects of extraction time, ionic strength and p H on the detection efficiency were investigated and optimum conditions were 8 min of extraction time, without Na Cl addition at p H=9. Good linearity(R2=0.9997) was obtained when the linear range was 10-500 μg/L. The recoveries of β-ionone in ultrapure water and tap water samples were 88%-95% and 110%-114%, respectively. The relative standard deviations(RSD) were less than 10%. The method detection limit(MDL) and rejection quality level(RQL) were achieved at1.98 μg/L and 6.53 μg/L, respectively. LLE-GC-MS was demonstrated to be a rapid and convenient method for the determination ofβ-ionone in water samples.展开更多
The expression of ectopic olfactory receptors （ORs） in melanized cells, such as the human brain nigrostri- atal dopaminergic neurons and skin melanocytes, is here pointed out. ORs are recognized to regulate skin mel...The expression of ectopic olfactory receptors （ORs） in melanized cells, such as the human brain nigrostri- atal dopaminergic neurons and skin melanocytes, is here pointed out. ORs are recognized to regulate skin melanogenesis, whereas OR expression in the dopaminergic neurons, characterized by accumulation of pigment neuromelanin, is downregulated in Parkinson＇s disease. Furthermore, the correlation between the pigmentation process and the dopamine pathway through ct-synuclein expression is also highlighted. Purposely, these ORs are suggested as therapeutic target for neurodegenerative diseases related to the pig- mentation disorders. Based on this evidence, a possible way of turning odorants into drugs, acting on three specific olfactory receptors, OR51E2, OR2AT4 and VN1R1, is thus introduced. Various odorous molecules are shown to interact with these ORs and their therapeutic potential against melanogenic and neurodegen- erative dysfunctions, including melanoma and Parkinson＇s disease, is suggested. Finally, a direct functional link between olfactory and endocrine systems in human brain through VNIR1 is proposed, helping to counteract female susceptibility to Parkinson＇s disease in quiescent life.展开更多
Terpenoids have tremendous biological activities and are widely employed in food,healthcare and pharmaceutical industries.Using synthetic biology to product terpenoids from microbial cell factories presents a promisin...Terpenoids have tremendous biological activities and are widely employed in food,healthcare and pharmaceutical industries.Using synthetic biology to product terpenoids from microbial cell factories presents a promising alternative route compared to conventional methods such as chemical synthesis or phytoextraction.The red yeast Rhodotorula mucilaginosa has been widely studied due to its natural production capacity of carotenoid and lipids,indicating a strong endogenous isoprene pathway with readily available metabolic intermediates.This study constructed several engineered strains of R.mucilaginosa with the aim of producing different terpenoids.Monoterpeneα-terpineol was produced by expressing theα-terpineol synthase from Vitis vinifera.The titer ofα-terpineol was further enhanced to 0.39 mg/L by overexpressing the endogenous rate-limiting gene of the MVA pathway.Overexpression ofα-farnesene synthase from Malus domestica,in combination with MVA pathway rate-limiting gene resulted in significant increase inα-farnesene production,reaching a titer of 822 mg/L.The carotenoid degradation productβ-ionone was produced at a titer of 0.87 mg/L by expressing theβ-ionone synthase from Petunia hybrida.This study demonstrates the potential of R.mucilaginosa as a platform host for the direct biosynthesis of various terpenoids and provides insights for further development of such platforms.展开更多
基金financially supported by National Natural Science Foundation of China(Grant Nos.31961133030,31870678,32022076)Science Fund for Distinguished Young Scientists of Anhui Province(Grant No.1908085J12).
文摘The carotenoid-derived volatileβ-ionone makes an important contribution to tea fragrance.Here,we qualitatively and quantitatively analysed 15 carotenoids in tea leaves of 13 cultivars by UHPLC-APCI-MS/MS.The 13 cultivars were divided into two groups by PCA(Principal Component Analysis)clustering analysis of their carotenoid content,and OPLS-DA(Orthogonal projections to latent structures)indicated that the levels ofβ-carotene(VIP=2.89)and lutein(VIP=2.30)were responsible for much of the variation between the two groups.Interestingly,theβ-carotene toβ-ionone conversion rates in Group 1 were higher than in Group 2,while theβ-carotene content was significantly lower in Group 1 than in Group 2.Theβ-ionone content was significantly higher in Group 1.Pearson Correlation Coefficient calculation between the transcription level of candidate genes(CsCCD1 and CsCCD4)and the accumulation ofβ-ionone indicated that CsCCD1 may involve in the formation ofβ-ionone in 13 cultivars.Prokaryotic expression and in vitro enzyme activity assays showed that‘Chuanhuang 1’had an amino acid mutation in carotenoid cleavage dioxygenases 1(CsCCD1)compared with‘Shuchazao’,resulting in a significantly higherβ-ionone content in‘Chuanhuang 1’.Sequence analysis showed that‘Chuanhuang 1’and‘Huangdan’had different CsCCD1 promoter sequences,leading to significantly higher CsCCD1 expression andβ-ionone accumulation in‘Chuanhuang 1’.These results indicated that the promoter and coding sequence diversity of CsCCD1 might contribute to the differential accumulation ofβ-ionone in different tea cultivars.
基金Project(51178321)supported by the National Natural Science Foundation of ChinaProject(2012ZX07403-001)supported by the National Science and Technology Major Project,ChinaProject(20120072110050)supported by the Research Fund for the Doctoral Program of Higher Education of China
文摘A simple and rapid technique based on liquid-liquid extraction coupled to gas chromatography-mass spectrometric detection(LLE-GC-MS) was developed for analysis of taste and odour compound β-ionone in water. Instrument parameters including programmed oven temperature, injection temperature and ion source temperature were evaluated and optimized. Effects of extraction time, ionic strength and p H on the detection efficiency were investigated and optimum conditions were 8 min of extraction time, without Na Cl addition at p H=9. Good linearity(R2=0.9997) was obtained when the linear range was 10-500 μg/L. The recoveries of β-ionone in ultrapure water and tap water samples were 88%-95% and 110%-114%, respectively. The relative standard deviations(RSD) were less than 10%. The method detection limit(MDL) and rejection quality level(RQL) were achieved at1.98 μg/L and 6.53 μg/L, respectively. LLE-GC-MS was demonstrated to be a rapid and convenient method for the determination ofβ-ionone in water samples.
基金supported by the University of Ferrara(F72I15000470005)in the frame of the project FAR2014
文摘The expression of ectopic olfactory receptors （ORs） in melanized cells, such as the human brain nigrostri- atal dopaminergic neurons and skin melanocytes, is here pointed out. ORs are recognized to regulate skin melanogenesis, whereas OR expression in the dopaminergic neurons, characterized by accumulation of pigment neuromelanin, is downregulated in Parkinson＇s disease. Furthermore, the correlation between the pigmentation process and the dopamine pathway through ct-synuclein expression is also highlighted. Purposely, these ORs are suggested as therapeutic target for neurodegenerative diseases related to the pig- mentation disorders. Based on this evidence, a possible way of turning odorants into drugs, acting on three specific olfactory receptors, OR51E2, OR2AT4 and VN1R1, is thus introduced. Various odorous molecules are shown to interact with these ORs and their therapeutic potential against melanogenic and neurodegen- erative dysfunctions, including melanoma and Parkinson＇s disease, is suggested. Finally, a direct functional link between olfactory and endocrine systems in human brain through VNIR1 is proposed, helping to counteract female susceptibility to Parkinson＇s disease in quiescent life.
基金National Key Research and Development Program of China(2021YFA0910600)National Natural Science Foundation of China(22308350,22238010)+1 种基金Liaoning Revitalization Talents Program(XLYC2002089)Science and Technology Bureau of Dalian City(2021RT04).
文摘Terpenoids have tremendous biological activities and are widely employed in food,healthcare and pharmaceutical industries.Using synthetic biology to product terpenoids from microbial cell factories presents a promising alternative route compared to conventional methods such as chemical synthesis or phytoextraction.The red yeast Rhodotorula mucilaginosa has been widely studied due to its natural production capacity of carotenoid and lipids,indicating a strong endogenous isoprene pathway with readily available metabolic intermediates.This study constructed several engineered strains of R.mucilaginosa with the aim of producing different terpenoids.Monoterpeneα-terpineol was produced by expressing theα-terpineol synthase from Vitis vinifera.The titer ofα-terpineol was further enhanced to 0.39 mg/L by overexpressing the endogenous rate-limiting gene of the MVA pathway.Overexpression ofα-farnesene synthase from Malus domestica,in combination with MVA pathway rate-limiting gene resulted in significant increase inα-farnesene production,reaching a titer of 822 mg/L.The carotenoid degradation productβ-ionone was produced at a titer of 0.87 mg/L by expressing theβ-ionone synthase from Petunia hybrida.This study demonstrates the potential of R.mucilaginosa as a platform host for the direct biosynthesis of various terpenoids and provides insights for further development of such platforms.
