Chemical data on the lichen Usnea baileyi are scarce. The current investigation reports the extraction, isolation and characterization of depsidones from this lichen collected in Lam Dong Province. Eight depsidones were isolated and elucidated, including methylstictic acid (1), stictic acid (2), cryptostictic acid (3), 8’-O-methylmenegazziaic acid (4), menegazziaic acid (5), 8’- O-methylconstictic acid (6), constictic acid (7), and hypoconstictic acid (8). Multi chromatographic methods comprising normal phase silica gel column chromatography and thin layer chromatography were applied to the crude acetone extract to isolate and purify compounds 1-8. Their chemical structures were elucidated by spectroscopic analysis as well as comparing their data with ones in the literature.
地衣Usnea baileyi的化学数据很少。本研究报道了从林东地衣中提取、分离和鉴定地衣中地油酮的方法。分离并鉴定了8种去酮类化合物，分别为甲基胶酸(1)、胶酸(2)、隐胶酸(3)、8′- o -甲基甲氧基甲酸(4)、甲氧基甲酸(5)、8′- o -甲基聚乳酸(6)、聚乳酸(7)和次聚乳酸(8)。采用正相硅胶柱层析和薄层色谱对粗丙酮提取物进行分离纯化，分离得到化合物1 ~ 8。通过光谱分析和与文献数据的比较，对它们的化学结构进行了鉴定。
{"title":"Extraction, isolation and characterization of depsidones from Usnea baileyi (Stirt.) Zahlbr collected from tree barks in Tam Bo Mountain of Di Linh, Lam Dong Province, Viet Nam","authors":"K. Nguyen, H. Dương","doi":"10.32508/STDJ.V21I1.422","DOIUrl":"https://doi.org/10.32508/STDJ.V21I1.422","url":null,"abstract":"Chemical data on the lichen Usnea baileyi are scarce. The current investigation reports the extraction, isolation and characterization of depsidones from this lichen collected in Lam Dong Province. Eight depsidones were isolated and elucidated, including methylstictic acid (1), stictic acid (2), cryptostictic acid (3), 8’-O-methylmenegazziaic acid (4), menegazziaic acid (5), 8’- O-methylconstictic acid (6), constictic acid (7), and hypoconstictic acid (8). Multi chromatographic methods comprising normal phase silica gel column chromatography and thin layer chromatography were applied to the crude acetone extract to isolate and purify compounds 1-8. Their chemical structures were elucidated by spectroscopic analysis as well as comparing their data with ones in the literature.","PeriodicalId":285953,"journal":{"name":"Science and Technology Development Journal","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133577340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This research aims to develop a new type of electrolyte for dye-sensitized solar cells (DSCs) which can be produced in cost-effective and large scale. DSCs using deep eutectic solvents (DESs) mixed with ethanol (50% w/w DES content), as an electrolyte medium, was studied herein for the first time. Ten types of DESs were synthesized and three among them were potential candidates for DSC electrolytes. Compared to toxic and volatile organic solvents, this mixed solvent is more eco-friendly and inexpensive. According to J-V curve measurements, DSCs that used DES-ethanol medium showed promising photovoltaic performance.
{"title":"Dye-sensitized solar cells using deep eutectic solvents mixed with ethanol as an effective electrolyte medium","authors":"T. Nguyen, P. T. Nguyen, P. Tran","doi":"10.32508/STDJ.V21I1.424","DOIUrl":"https://doi.org/10.32508/STDJ.V21I1.424","url":null,"abstract":"This research aims to develop a new type of electrolyte for dye-sensitized solar cells (DSCs) which can be produced in cost-effective and large scale. DSCs using deep eutectic solvents (DESs) mixed with ethanol (50% w/w DES content), as an electrolyte medium, was studied herein for the first time. Ten types of DESs were synthesized and three among them were potential candidates for DSC electrolytes. Compared to toxic and volatile organic solvents, this mixed solvent is more eco-friendly and inexpensive. According to J-V curve measurements, DSCs that used DES-ethanol medium showed promising photovoltaic performance.","PeriodicalId":285953,"journal":{"name":"Science and Technology Development Journal","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117205980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.32508/stdj.v25i4.4036
{"title":"The relationship between autophagy and multidrug resistance in cancer stem cells","authors":"","doi":"10.32508/stdj.v25i4.4036","DOIUrl":"https://doi.org/10.32508/stdj.v25i4.4036","url":null,"abstract":"","PeriodicalId":285953,"journal":{"name":"Science and Technology Development Journal","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122483496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.32508/stdj.v25i4.4000
{"title":"Studying the inhibition mechanism of human acetyl-CoA carboxylase by aromatic ligands in the treatment of fatty acid metabolic syndrome using computational chemistry methods","authors":"","doi":"10.32508/stdj.v25i4.4000","DOIUrl":"https://doi.org/10.32508/stdj.v25i4.4000","url":null,"abstract":"","PeriodicalId":285953,"journal":{"name":"Science and Technology Development Journal","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123945398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.32508/stdj.v26i1.4030
{"title":"New model for low-end computers: ResNet and VGG-16","authors":"","doi":"10.32508/stdj.v26i1.4030","DOIUrl":"https://doi.org/10.32508/stdj.v26i1.4030","url":null,"abstract":"","PeriodicalId":285953,"journal":{"name":"Science and Technology Development Journal","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131015391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.32508/stdj.v26i1.4016
Nguyen Xuan Khanh, T. Tan, N. N. Nam, N. Tram, Nguyen Hoang Cam, P. Tung, Le Hoang Khang, N. Phung, D. T. Huy, Huynh Ngoc Vinh
Introduction: The Bazzania genus , a type of liverwort known as a low-level herbaceous organism, comprises approximately 250 species. Only 8 species have been chemically and biologically studied worldwide, and none have been studied in Vietnam. This paper described the isolation and structure elucidation of six compounds isolated from the liverwort Bazzania sp. collected in Lac Duong district, Lam Dong Province, Vietnam, in July 2020. Methods: Phytochemical investigations of the n-hexane and chloroform extracts of Bazzaniasp. led to the isolation of six pure compounds. Their chemical structures were elucidated by HR-ESI-MS, 1D and 2D-NMR spectroscopic analysis and comparison with previously published data. Results: From the studied liverwort Bazzania sp ., six compounds, namely, cycloartenol ( 1 ) and five phenolic derivatives, p-coumaric acid ( 2 ), p-hydroxybenzoic acid ( 3 ), methyl 2,4-dihydroxy-3,6-dimethylbenzoate ( 4 ), barbatic acid ( 5 ), and methyl 2-hydroxy-4-methoxy-6-tetradecylbenzoate ( 6 ), were isolated and structurally elucidated. Conclusions: Although these compounds are known in other species, this is the first time they have been reported in Bazzania sp.
{"title":"One triterpenoid and five phenolic compounds from the liverwort Bazzania sp.","authors":"Nguyen Xuan Khanh, T. Tan, N. N. Nam, N. Tram, Nguyen Hoang Cam, P. Tung, Le Hoang Khang, N. Phung, D. T. Huy, Huynh Ngoc Vinh","doi":"10.32508/stdj.v26i1.4016","DOIUrl":"https://doi.org/10.32508/stdj.v26i1.4016","url":null,"abstract":"Introduction: The Bazzania genus , a type of liverwort known as a low-level herbaceous organism, comprises approximately 250 species. Only 8 species have been chemically and biologically studied worldwide, and none have been studied in Vietnam. This paper described the isolation and structure elucidation of six compounds isolated from the liverwort Bazzania sp. collected in Lac Duong district, Lam Dong Province, Vietnam, in July 2020. Methods: Phytochemical investigations of the n-hexane and chloroform extracts of Bazzaniasp. led to the isolation of six pure compounds. Their chemical structures were elucidated by HR-ESI-MS, 1D and 2D-NMR spectroscopic analysis and comparison with previously published data. Results: From the studied liverwort Bazzania sp ., six compounds, namely, cycloartenol ( 1 ) and five phenolic derivatives, p-coumaric acid ( 2 ), p-hydroxybenzoic acid ( 3 ), methyl 2,4-dihydroxy-3,6-dimethylbenzoate ( 4 ), barbatic acid ( 5 ), and methyl 2-hydroxy-4-methoxy-6-tetradecylbenzoate ( 6 ), were isolated and structurally elucidated. Conclusions: Although these compounds are known in other species, this is the first time they have been reported in Bazzania sp.","PeriodicalId":285953,"journal":{"name":"Science and Technology Development Journal","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124392321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.32508/stdj.v25i4.3960
{"title":"Studying the influence of solvent concentration on the fabrication of PCL membrane for wound dressing applications","authors":"","doi":"10.32508/stdj.v25i4.3960","DOIUrl":"https://doi.org/10.32508/stdj.v25i4.3960","url":null,"abstract":"","PeriodicalId":285953,"journal":{"name":"Science and Technology Development Journal","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124765494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.32508/stdj.v25i3.3935
Thang Minh Bui, Dai Cao Truong, Phung Y Nguyen, A. Pham, Dung V. Hoang, T. H. Nguyen, V. Tran, T. Phan
Introduction: ZnO is a potential semiconductor material for thermoelectric (TE) applications at high temperature. In this study, doping Bi atoms aims to improve the power factor of ZnO ceramic. Based on the analyses of structural and TE properties, the enhancement in Seebeck coefficient proves the benefit of Bi doping. Methods: The ZnO and Bi-doped ZnO (BZO) ceramics were fabricated by solid-state reaction at 1400oC in air. The Seebeck LSR-3 system measured both samples’ TE properties, with a combined Hall effect at room temperature. The crystalline structure was analyzed through the X-ray diffraction (XRD) technique. Results: The XRD patterns show all samples having polycrystalline hexagonal wurtzite structure. Although the crystallinity is enhanced, Bi doping reduces significantly carrier concentration from 3.4×1019 to 1.1×1019 cm-3 at room temperature. As a result at 500oC, the electrical conductivity, Seebeck coefficient, and power factor are 126 Scm-1, -99 µVK-1, and 124 µWm-1K-2 for pure ZnO; and 76 Scm-1, -142 µVK-1, and 165 µWm-1K-2 for BZO ceramic, respectively. Conclusion: The power factor of Bi-doped ZnO is improved by 32% as compared to pure ZnO at 500oC. The raise of Seebeck coefficient is the main reason for the growth of power factor.
{"title":"Structural, electrical and thermoelectric characterizations of bismuth-doped ZnO ceramic material","authors":"Thang Minh Bui, Dai Cao Truong, Phung Y Nguyen, A. Pham, Dung V. Hoang, T. H. Nguyen, V. Tran, T. Phan","doi":"10.32508/stdj.v25i3.3935","DOIUrl":"https://doi.org/10.32508/stdj.v25i3.3935","url":null,"abstract":"Introduction: ZnO is a potential semiconductor material for thermoelectric (TE) applications at high temperature. In this study, doping Bi atoms aims to improve the power factor of ZnO ceramic. Based on the analyses of structural and TE properties, the enhancement in Seebeck coefficient proves the benefit of Bi doping. Methods: The ZnO and Bi-doped ZnO (BZO) ceramics were fabricated by solid-state reaction at 1400oC in air. The Seebeck LSR-3 system measured both samples’ TE properties, with a combined Hall effect at room temperature. The crystalline structure was analyzed through the X-ray diffraction (XRD) technique. Results: The XRD patterns show all samples having polycrystalline hexagonal wurtzite structure. Although the crystallinity is enhanced, Bi doping reduces significantly carrier concentration from 3.4×1019 to 1.1×1019 cm-3 at room temperature. As a result at 500oC, the electrical conductivity, Seebeck coefficient, and power factor are 126 Scm-1, -99 µVK-1, and 124 µWm-1K-2 for pure ZnO; and 76 Scm-1, -142 µVK-1, and 165 µWm-1K-2 for BZO ceramic, respectively. Conclusion: The power factor of Bi-doped ZnO is improved by 32% as compared to pure ZnO at 500oC. The raise of Seebeck coefficient is the main reason for the growth of power factor.","PeriodicalId":285953,"journal":{"name":"Science and Technology Development Journal","volume":"2010 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125605680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.32508/stdj.v25i4.3984
{"title":"Establishment of a fiber optic sensor coupled to the plasmonic effect of silver nanoparticles in glucose concentration monitoring","authors":"","doi":"10.32508/stdj.v25i4.3984","DOIUrl":"https://doi.org/10.32508/stdj.v25i4.3984","url":null,"abstract":"","PeriodicalId":285953,"journal":{"name":"Science and Technology Development Journal","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126381062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.32508/stdj.v26i1.4023
T. T. T. Nguyen, D. T. Dang
Introduction : Alpha-Momorcharin ( a -MMC) is a member of the ribosome-inactivating protein (RIP) family that has been widely used as an antitumor, antiviral and antifungal agent. Methods : In this study, the codons of DNA encoding a -MMC were optimized for expression in E. coli and cloned into the pET-28a(+) vector . The protein was then expressed in E. coli strain BL21 (DE3) and purified by nickel affinity chromatography. Results : Under IPTG induction, a -MMC was expressed at approximately 50% of the total protein, showing high-level recombinant protein expression in E. coli . A high amount of purified a -MMC (70 mg) was isolated from 1 L LB culture medium of E. coli BL21 (DE3) with approximately 95% purity. Interestingly, a -MMC inhibited the mycelial growth of Pyriculariaoryzae in a concentration-dependent manner. Conclusion: Using a microbial system for a -MMC expression provides a promising method for the design of a new agent against pathogens.
{"title":"Molecular cloning and isolation of a recombinant alpha-Momorcharin in E. coli against Pyricularia oryzae","authors":"T. T. T. Nguyen, D. T. Dang","doi":"10.32508/stdj.v26i1.4023","DOIUrl":"https://doi.org/10.32508/stdj.v26i1.4023","url":null,"abstract":"Introduction : Alpha-Momorcharin ( a -MMC) is a member of the ribosome-inactivating protein (RIP) family that has been widely used as an antitumor, antiviral and antifungal agent. Methods : In this study, the codons of DNA encoding a -MMC were optimized for expression in E. coli and cloned into the pET-28a(+) vector . The protein was then expressed in E. coli strain BL21 (DE3) and purified by nickel affinity chromatography. Results : Under IPTG induction, a -MMC was expressed at approximately 50% of the total protein, showing high-level recombinant protein expression in E. coli . A high amount of purified a -MMC (70 mg) was isolated from 1 L LB culture medium of E. coli BL21 (DE3) with approximately 95% purity. Interestingly, a -MMC inhibited the mycelial growth of Pyriculariaoryzae in a concentration-dependent manner. Conclusion: Using a microbial system for a -MMC expression provides a promising method for the design of a new agent against pathogens.","PeriodicalId":285953,"journal":{"name":"Science and Technology Development Journal","volume":"150 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115317933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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