Phytyl-diphosphate, which provides phytyl moieties as a common substrate in both tocopherol and phyllo- quinone biosynthesis, derives from de novo isoprenoid biosynthesis or a salvage pathway via phytol phos- phorylat...Phytyl-diphosphate, which provides phytyl moieties as a common substrate in both tocopherol and phyllo- quinone biosynthesis, derives from de novo isoprenoid biosynthesis or a salvage pathway via phytol phos- phorylation. However, very little is known about the role and origin of the phytyl moiety for phylloquinone biosynthesis. Since VTE6, a phytyl-phosphate kinase, is a key enzyme for phytol phosphorylation, we char- acterized Arabidopsis vte6 mutants to gain insight into the roles of phytyl moieties in phylloquinone biosyn- thesis and of phylloquinone in photosystem I （PSI） biogenesis. The VTE6 knockout mutants vte6-1 and vte6-2 lacked detectable phylloquinone, whereas the phylloquinone content in the VTE6 knockdown mutant vte6-3 was 90% lower than that in wild-type. In vte6 mutants, PSI function was impaired and accu- mulation of the PSI complex was defective. The PSI core subunits PsaA/B were efficiently synthesized and assembled into the PSI complex in vte6-3. However, the degradation rate of PSI subunits in the assembled PSI complex was more rapid in vte6-3 than in wild-type. In vte6-3, PSI was more susceptible to high-light damage than in wild-type. Our results provide the first genetic evidence that the phytol phosphorylation pathway is essential for phylloquinone biosynthesis, and that phylloquinone is required for PSI complex stability.展开更多
The development of sericultural industry in the Pearl River Delta has contributed greatly to good ecological environment and economic prosperity of the people’s livelihood.Comprehensive utilization of sericulture res...The development of sericultural industry in the Pearl River Delta has contributed greatly to good ecological environment and economic prosperity of the people’s livelihood.Comprehensive utilization of sericulture resources can turn waste into valuable resources and expand the development approaches of sericultural industry.For example,using abundant silkworm excrement to produce chlorophyll is one of the good practices in comprehensive utilization of sericulture resources,which has leading technologies and good economic benefits.In addition to chlorophyll,the products produced from silkworm excrement can be used as the main raw materials of medicine,food,plant growth regulator and cosmetics.For instances,phytol,the important raw material for synthesis of vitamin E and vitamin K,was extracted from silkworm excrement,enabling China to become an important production base of vitamin E and vitamin K.Triacontanol extracted from silkworm excrement is a new crop growth regulator,which can increase the yield of rice and vegetable.Pectin,dietary fiber and carotenoid extracted from silkworm excrement as well can be used as natural raw material in many fields.China is the biggest manufacturer and supplier of silkworm excrement products in the world,which has a development history of about 50 years and generated high export revenue.It is believed that close combination of academic research and industry development is the only way to promote the industrial development of silkworm excrement resources.展开更多
The genus Schinus(Anacardiaceae)comprises about 29 species that are utilized in both traditional and current medicine to alleviate various disorders such as rheumatism,bronchial infections,stomach upset,menstrual dist...The genus Schinus(Anacardiaceae)comprises about 29 species that are utilized in both traditional and current medicine to alleviate various disorders such as rheumatism,bronchial infections,stomach upset,menstrual disturbance,bronchitis,and conjunctivitis.In this study we aimed to investigate the chemical composition of hexane extracts obtained from Schinus polygamous and Schinus terebinthifolius leaves as well as their cytotoxic and anti-arthritic activities.The GC-MS analysis of S.polygamus leaves revealed identification of fifty-five components:being betulin(6.54%),phytol acetate(5.27%),lupeol(3.96%),palmitic acid methyl ester(3.58%)and heptacosane(3.25%).While,seventeen compounds were identified in S.terebinthifolius leaves,predominately characterized by phytol(14.70%),lupeol(13.33%),linolenic acid methyl ester(11.17%),palmitic acid methyl ester(7.74%),and 28-oxours-12-en-3-yl acetate(7.44%).Both extracts showed moderate cytotoxic activities against hepatocellular carcinoma cells with IC_(50) values of 102.65 and 65.55μg/mL,respectively.While colorectal carcinoma cell line presented IC_(50) values of 217.78 and 83.55μg/mL,respectively.Further,both extracts provided moderate anti-arthritic effects(IC_(50):80.12 and 63.09μg/mL,respectively)using protein denaturation test,compared to diclofenac sodium(IC_(50)=15.12μg/mL).展开更多
This study presents the volatile constituents from leaves of Trifolium alexandrinum from Pakistan.The dried leaves were subjected to hydrodistillation for extraction and extracted volatile oil was subsequently charact...This study presents the volatile constituents from leaves of Trifolium alexandrinum from Pakistan.The dried leaves were subjected to hydrodistillation for extraction and extracted volatile oil was subsequently characterized by gas chromatography-mass spectrometry technique.A total of 22 compounds were identified where the most dominant constituents were:phytol(46.00%),palmitic acid(9.26%),phytol acetate(6.44%),and linolenic acid(3.47%).Most of these are well-known constituents to exhibit antibacterial,antioxidant,antitumor,and anti-inflammatory activities.展开更多
Chemical investigation on leaves oil of Hoslundia opposita, aromatic plant used in traditional medicine, harvested from 20 localities of C?te d’Ivoire was realized by GC and GC/MS. In total, 101 compounds were identi...Chemical investigation on leaves oil of Hoslundia opposita, aromatic plant used in traditional medicine, harvested from 20 localities of C?te d’Ivoire was realized by GC and GC/MS. In total, 101 compounds were identified accounting to 92% - 99%, aromatic compounds such benzyl benzoate and sesquiterpenes namely germacrene D, β-caryophyllene and α-humulene hydroxyl were found as the major constituents. As regard, the chemical profiles of our samples, it was found a great chemical variability suggesting a high polymorphism degree. In order to study this chemical variability, the results were submitted to the principal components and cluster analysis which allowed distinguishing two main groups of essential oils with respect to sampling site. The cluster I was dominated by benzyl benzoate (15%) and thymol (7.4%) comprising 6 localities, cluster II was characterized by phytol (8.5%) and α-humulene (7%) and constituted by 14 localities.展开更多
文摘Phytyl-diphosphate, which provides phytyl moieties as a common substrate in both tocopherol and phyllo- quinone biosynthesis, derives from de novo isoprenoid biosynthesis or a salvage pathway via phytol phos- phorylation. However, very little is known about the role and origin of the phytyl moiety for phylloquinone biosynthesis. Since VTE6, a phytyl-phosphate kinase, is a key enzyme for phytol phosphorylation, we char- acterized Arabidopsis vte6 mutants to gain insight into the roles of phytyl moieties in phylloquinone biosyn- thesis and of phylloquinone in photosystem I （PSI） biogenesis. The VTE6 knockout mutants vte6-1 and vte6-2 lacked detectable phylloquinone, whereas the phylloquinone content in the VTE6 knockdown mutant vte6-3 was 90% lower than that in wild-type. In vte6 mutants, PSI function was impaired and accu- mulation of the PSI complex was defective. The PSI core subunits PsaA/B were efficiently synthesized and assembled into the PSI complex in vte6-3. However, the degradation rate of PSI subunits in the assembled PSI complex was more rapid in vte6-3 than in wild-type. In vte6-3, PSI was more susceptible to high-light damage than in wild-type. Our results provide the first genetic evidence that the phytol phosphorylation pathway is essential for phylloquinone biosynthesis, and that phylloquinone is required for PSI complex stability.
文摘The development of sericultural industry in the Pearl River Delta has contributed greatly to good ecological environment and economic prosperity of the people’s livelihood.Comprehensive utilization of sericulture resources can turn waste into valuable resources and expand the development approaches of sericultural industry.For example,using abundant silkworm excrement to produce chlorophyll is one of the good practices in comprehensive utilization of sericulture resources,which has leading technologies and good economic benefits.In addition to chlorophyll,the products produced from silkworm excrement can be used as the main raw materials of medicine,food,plant growth regulator and cosmetics.For instances,phytol,the important raw material for synthesis of vitamin E and vitamin K,was extracted from silkworm excrement,enabling China to become an important production base of vitamin E and vitamin K.Triacontanol extracted from silkworm excrement is a new crop growth regulator,which can increase the yield of rice and vegetable.Pectin,dietary fiber and carotenoid extracted from silkworm excrement as well can be used as natural raw material in many fields.China is the biggest manufacturer and supplier of silkworm excrement products in the world,which has a development history of about 50 years and generated high export revenue.It is believed that close combination of academic research and industry development is the only way to promote the industrial development of silkworm excrement resources.
文摘The genus Schinus(Anacardiaceae)comprises about 29 species that are utilized in both traditional and current medicine to alleviate various disorders such as rheumatism,bronchial infections,stomach upset,menstrual disturbance,bronchitis,and conjunctivitis.In this study we aimed to investigate the chemical composition of hexane extracts obtained from Schinus polygamous and Schinus terebinthifolius leaves as well as their cytotoxic and anti-arthritic activities.The GC-MS analysis of S.polygamus leaves revealed identification of fifty-five components:being betulin(6.54%),phytol acetate(5.27%),lupeol(3.96%),palmitic acid methyl ester(3.58%)and heptacosane(3.25%).While,seventeen compounds were identified in S.terebinthifolius leaves,predominately characterized by phytol(14.70%),lupeol(13.33%),linolenic acid methyl ester(11.17%),palmitic acid methyl ester(7.74%),and 28-oxours-12-en-3-yl acetate(7.44%).Both extracts showed moderate cytotoxic activities against hepatocellular carcinoma cells with IC_(50) values of 102.65 and 65.55μg/mL,respectively.While colorectal carcinoma cell line presented IC_(50) values of 217.78 and 83.55μg/mL,respectively.Further,both extracts provided moderate anti-arthritic effects(IC_(50):80.12 and 63.09μg/mL,respectively)using protein denaturation test,compared to diclofenac sodium(IC_(50)=15.12μg/mL).
文摘This study presents the volatile constituents from leaves of Trifolium alexandrinum from Pakistan.The dried leaves were subjected to hydrodistillation for extraction and extracted volatile oil was subsequently characterized by gas chromatography-mass spectrometry technique.A total of 22 compounds were identified where the most dominant constituents were:phytol(46.00%),palmitic acid(9.26%),phytol acetate(6.44%),and linolenic acid(3.47%).Most of these are well-known constituents to exhibit antibacterial,antioxidant,antitumor,and anti-inflammatory activities.
文摘Chemical investigation on leaves oil of Hoslundia opposita, aromatic plant used in traditional medicine, harvested from 20 localities of C?te d’Ivoire was realized by GC and GC/MS. In total, 101 compounds were identified accounting to 92% - 99%, aromatic compounds such benzyl benzoate and sesquiterpenes namely germacrene D, β-caryophyllene and α-humulene hydroxyl were found as the major constituents. As regard, the chemical profiles of our samples, it was found a great chemical variability suggesting a high polymorphism degree. In order to study this chemical variability, the results were submitted to the principal components and cluster analysis which allowed distinguishing two main groups of essential oils with respect to sampling site. The cluster I was dominated by benzyl benzoate (15%) and thymol (7.4%) comprising 6 localities, cluster II was characterized by phytol (8.5%) and α-humulene (7%) and constituted by 14 localities.
