Pub Date : 2022-07-19DOI: 10.25073/2588-1140/vnunst.5321
N. Dư, Nguyen Thi Ngoc Anh, T. V. Tien, Lê Chí Toàn
Two species of the genus Typhonium are described as the new species for the Flora of Indochina. T. cordifolium was discovered for the first time in Cambodia and Vietnam and T. khonkaenensis was found for the first time in Vientian of Laos. In the paper, the name T. rhizomatosum Galloway & Schmidt is recorded as a new synonym of T. cordifolium S. Y. Hu, while T. khonkaenensis is confirmed as a separated species in the genus Typhonium.
在柬埔寨和越南首次发现T. cordifolium，在老挝万象首次发现T. khonkaenensis。本文将T. rhizomatosum Galloway & Schmidt作为T. cordifolium S. Y. Hu的新同义词记录下来，将T. khonkaenensis确定为Typhonium属的一个分离种。
{"title":"Two New Records of Species and A New Synonym of Genus Typhonium (Araceae) For Flora of Indochina","authors":"N. Dư, Nguyen Thi Ngoc Anh, T. V. Tien, Lê Chí Toàn","doi":"10.25073/2588-1140/vnunst.5321","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5321","url":null,"abstract":"Two species of the genus Typhonium are described as the new species for the Flora of Indochina. T. cordifolium was discovered for the first time in Cambodia and Vietnam and T. khonkaenensis was found for the first time in Vientian of Laos. In the paper, the name T. rhizomatosum Galloway & Schmidt is recorded as a new synonym of T. cordifolium S. Y. Hu, while T. khonkaenensis is confirmed as a separated species in the genus Typhonium.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75286431","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 : 2022-07-19DOI: 10.25073/2588-1140/vnunst.5337
N. M. Linh, Dam Duc Tien, P. V. Quang, Cao Van Luong, Vu Manh Hung
The knowledge of marine algae species composition is imperative not only for understanding the structure, function and biogeographical affinities but also for planning strategies for marine algae conservation and management. This study was carried out to determine the diverse species and evaluate some use-values of green macroalgae from genus Ulva in Hai Phong, where many different habitats such as estuarine floodplains, lagoons or small bays and diverse in the bottom (hard, sandy, sandy-mud bottom). Ulva samples were collected at 11 sites in 5 areas in 2021. Based on the results of species composition, were identified 11 species of the genus Ulva. The species composition of the genus Ulva in Hai Phong accounted for 73.3% of the total species recorded in Vietnam; accounting for 19.6% of the total number of Asian species, and 12.9% of the total number of Ulva species in the world. The Cluster and MDS (Multi-Dimensional Scaling analysis) on the similarity in vertical distribution and geographical distribution among the studied species. Based on the active ingredients and uses value, the studied determined 9 species of genus Ulva in Hai Phong were identified with economic value.
{"title":"Diversity of Green Macroalgae Genus Ulva (Chlorophyta) in Hai Phong and Potential Uses","authors":"N. M. Linh, Dam Duc Tien, P. V. Quang, Cao Van Luong, Vu Manh Hung","doi":"10.25073/2588-1140/vnunst.5337","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5337","url":null,"abstract":"The knowledge of marine algae species composition is imperative not only for understanding the structure, function and biogeographical affinities but also for planning strategies for marine algae conservation and management. This study was carried out to determine the diverse species and evaluate some use-values of green macroalgae from genus Ulva in Hai Phong, where many different habitats such as estuarine floodplains, lagoons or small bays and diverse in the bottom (hard, sandy, sandy-mud bottom). Ulva samples were collected at 11 sites in 5 areas in 2021. Based on the results of species composition, were identified 11 species of the genus Ulva. The species composition of the genus Ulva in Hai Phong accounted for 73.3% of the total species recorded in Vietnam; accounting for 19.6% of the total number of Asian species, and 12.9% of the total number of Ulva species in the world. The Cluster and MDS (Multi-Dimensional Scaling analysis) on the similarity in vertical distribution and geographical distribution among the studied species. Based on the active ingredients and uses value, the studied determined 9 species of genus Ulva in Hai Phong were identified with economic value.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90195740","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 : 2022-07-19DOI: 10.25073/2588-1140/vnunst.5244
D. Xuyen, Ngo Thu Hao, Doan Van Ve, N. Thanh
Scutellaria L. is a genus of flowering plant in the Lamiaceace. The genus includes about 350 species commonly known as skullcaps. Scutellaria is widespread in temperate regions and tropical mountains including Europe, North America and East Asia. 15 species belonging to Scutellaria genus were recorded in Vietnam. The perennial herb Scutellaria tonkinensis Doan is an endemic species of Vietnam and is recorded in Lao Cai and Vinh Phuc provinces. In this study, anatomical charateristics of this species using double-staining method have been investigated. The anatomical characteristics indicate that S. tonkinensis Doan adapt to a habitat with high moisture and intensive insolation.
{"title":"Anatomical Features of Scutellaria tonkinensis Doan in Vietnam","authors":"D. Xuyen, Ngo Thu Hao, Doan Van Ve, N. Thanh","doi":"10.25073/2588-1140/vnunst.5244","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5244","url":null,"abstract":"Scutellaria L. is a genus of flowering plant in the Lamiaceace. The genus includes about 350 species commonly known as skullcaps. Scutellaria is widespread in temperate regions and tropical mountains including Europe, North America and East Asia. 15 species belonging to Scutellaria genus were recorded in Vietnam. The perennial herb Scutellaria tonkinensis Doan is an endemic species of Vietnam and is recorded in Lao Cai and Vinh Phuc provinces. In this study, anatomical charateristics of this species using double-staining method have been investigated. The anatomical characteristics indicate that S. tonkinensis Doan adapt to a habitat with high moisture and intensive insolation.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73347829","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 : 2022-07-19DOI: 10.25073/2588-1140/vnunst.5402
Truong Cong Doanh, Hac Thi Nhung, Nguyen Thi Hanh, N. Hien, Do Tien Dat, Vu Minh Tan, Hoang Mai Ha
The zinc borate nanoparticles (2ZnO.3B2O3.3H2O) were successfully prepared by precipitation reaction in aqueous solutions of borax and zinc sulfate using oleic acid as a surfactant. The structural, morphological characteristics and the wettability of the particle surface were studied through Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and the contact angle. The hydrophobic zinc borate (n-ZB) had nanoplatelet morphology with a diameter of 1.0 - 1.5 µm and thickness of about 90 nm. Nano zinc borate showed a synergistic influence with expandable graphite (EG) and red phosphorus (RP) on the flame retardant properties and thermo-oxidative stability of polypropylene (PP). The nanocomposite 7n-ZB/7RP/7EG/PP achieved the V-1 UL94 verticle burning test with a limited oxygen index of 23.7% and the char yield of 14.67 wt.% at 900 oC. Furthermore, the fire retardant performance and the mechanical properties of the nanocomposites loading ZB nanoparticles were improved compared with the composites employing commercial ZB microparticles.
{"title":"Synthesis of Nanoplatelet Zinc Borate and its Combination with Expandable Graphite and Red Phosphorus as Flame Retardants for Polypropylene","authors":"Truong Cong Doanh, Hac Thi Nhung, Nguyen Thi Hanh, N. Hien, Do Tien Dat, Vu Minh Tan, Hoang Mai Ha","doi":"10.25073/2588-1140/vnunst.5402","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5402","url":null,"abstract":"The zinc borate nanoparticles (2ZnO.3B2O3.3H2O) were successfully prepared by precipitation reaction in aqueous solutions of borax and zinc sulfate using oleic acid as a surfactant. The structural, morphological characteristics and the wettability of the particle surface were studied through Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and the contact angle. The hydrophobic zinc borate (n-ZB) had nanoplatelet morphology with a diameter of 1.0 - 1.5 µm and thickness of about 90 nm. Nano zinc borate showed a synergistic influence with expandable graphite (EG) and red phosphorus (RP) on the flame retardant properties and thermo-oxidative stability of polypropylene (PP). The nanocomposite 7n-ZB/7RP/7EG/PP achieved the V-1 UL94 verticle burning test with a limited oxygen index of 23.7% and the char yield of 14.67 wt.% at 900 oC. Furthermore, the fire retardant performance and the mechanical properties of the nanocomposites loading ZB nanoparticles were improved compared with the composites employing commercial ZB microparticles.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77242778","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 : 2022-07-05DOI: 10.25073/2588-1140/vnunst.5369
Quanh Thi Minh Thu, D. V. Luong, Do Thi Thanh Xuan, Thanh Thi Thu Thuy
In this work, hot water extraction was applied to isolate a polysaccharide from green seaweed Caulerpa torta, the extraction yield was 3.4% of dried seaweed weight. The structural characteristics and cytotoxic effects on three human cancer cell lines of the polysaccharide were investigated. The results showed that the polysaccharide consisted of galactose, glucose, xylose and mannose in a molar ratio of 1.00: 0.74: 0.21: 0.0.21, with a molecular weight of 107 kDa. In addition, it contained sulfate groups, which is approximately 15.34%w. The polysaccharide showed a significant cytotoxic activity against thyroid cancer - 8505C (IC50 55.55±1.84 µg/ml), colon cancer - HT-29 (IC50 57.26±2.06 µg/ml) and cervical cancer - Hela (IC50 54.79 ±3.22 µg/ml).
采用热水提取法从绿海藻中分离出一种多糖，其提取率为干海藻重量的3.4%。研究了该多糖的结构特性及其对三种人类癌细胞的细胞毒作用。结果表明，该多糖由半乳糖、葡萄糖、木糖和甘露糖组成，摩尔比为1.00:0.74:0.21:0.0.21，分子量为107 kDa。此外，它还含有硫酸盐基团，约为15.34%w。该多糖对甲状腺癌- 8505C (IC50为55.55±1.84µg/ml)、结肠癌- HT-29 (IC50为57.26±2.06µg/ml)和宫颈癌- Hela (IC50为54.79±3.22µg/ml)具有显著的细胞毒活性。
{"title":"Structural Characteristics and Cytotoxic activity of Polysaccharide Extracted from Green Seaweed Caulerpa torta","authors":"Quanh Thi Minh Thu, D. V. Luong, Do Thi Thanh Xuan, Thanh Thi Thu Thuy","doi":"10.25073/2588-1140/vnunst.5369","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5369","url":null,"abstract":"In this work, hot water extraction was applied to isolate a polysaccharide from green seaweed Caulerpa torta, the extraction yield was 3.4% of dried seaweed weight. The structural characteristics and cytotoxic effects on three human cancer cell lines of the polysaccharide were investigated. The results showed that the polysaccharide consisted of galactose, glucose, xylose and mannose in a molar ratio of 1.00: 0.74: 0.21: 0.0.21, with a molecular weight of 107 kDa. In addition, it contained sulfate groups, which is approximately 15.34%w. The polysaccharide showed a significant cytotoxic activity against thyroid cancer - 8505C (IC50 55.55±1.84 µg/ml), colon cancer - HT-29 (IC50 57.26±2.06 µg/ml) and cervical cancer - Hela (IC50 54.79 ±3.22 µg/ml). ","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85752021","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 : 2022-06-30DOI: 10.25073/2588-1140/vnunst.5370
N. Xuan, Nguyen Hoang Trung Hieu, Taros Ly
While feathers are still commonly regarded in many places as waste, in many developed countries it has been considered a valuable by-product of the poultry industry. The poultry industry of Vietnam has achieved encouraging achievements in the past 10 years. The total flock of poultry from 100 million to now has reached nearly 467 million. Though light as a feather, with the vast quantities of chickens produced annually, the number of feathers produced is considerable. Research has shown that the feathers have hydrophobic properties and can therefore be used to make products that absorb oil. However, the use of large amounts of toxic detergents to clean chicken feathers in reported studies has reduced the environmental significance of agricultural waste reuse. In this study, we evaluated the possibility of replacing toxic cleaning agents with eco-friendly natural cleaners in the handling of chicken feathers. Water-based extracts of soapnuts and bo-ket fruits have been selected for our study due to their high saponin content - an effective cleaning agent, and have been used as a dishwashing liquid or shampoo for a long-time by local housewives. Our study showed that natural detergents derived from soapnuts have been shown the ability to remove lards on the plastic surface, and to clean chicken feathers, thereby increasing their capacity to absorb various oils including cooking oil, used cooking oil, and lubricant oil. We have also created an oil-absorbing pillow containing soapnut extract-treated chicken feathers with a maximum efficiency of 16.8 g/g in absorbing lubricant oil. Our research opens new avenues for the use and treatment of poultry feathers, contributing to the reduction of solid waste from the poultry industry by methods which is friendlier to the environment. The greenness of the created absorber is guaranteed.
{"title":"Using Biosurfactants from Plants to Treat Chicken Feathers into a Green Oil Absorbent Material","authors":"N. Xuan, Nguyen Hoang Trung Hieu, Taros Ly","doi":"10.25073/2588-1140/vnunst.5370","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5370","url":null,"abstract":"While feathers are still commonly regarded in many places as waste, in many developed countries it has been considered a valuable by-product of the poultry industry. The poultry industry of Vietnam has achieved encouraging achievements in the past 10 years. The total flock of poultry from 100 million to now has reached nearly 467 million. Though light as a feather, with the vast quantities of chickens produced annually, the number of feathers produced is considerable. Research has shown that the feathers have hydrophobic properties and can therefore be used to make products that absorb oil. However, the use of large amounts of toxic detergents to clean chicken feathers in reported studies has reduced the environmental significance of agricultural waste reuse. In this study, we evaluated the possibility of replacing toxic cleaning agents with eco-friendly natural cleaners in the handling of chicken feathers. Water-based extracts of soapnuts and bo-ket fruits have been selected for our study due to their high saponin content - an effective cleaning agent, and have been used as a dishwashing liquid or shampoo for a long-time by local housewives. Our study showed that natural detergents derived from soapnuts have been shown the ability to remove lards on the plastic surface, and to clean chicken feathers, thereby increasing their capacity to absorb various oils including cooking oil, used cooking oil, and lubricant oil. We have also created an oil-absorbing pillow containing soapnut extract-treated chicken feathers with a maximum efficiency of 16.8 g/g in absorbing lubricant oil. Our research opens new avenues for the use and treatment of poultry feathers, contributing to the reduction of solid waste from the poultry industry by methods which is friendlier to the environment. The greenness of the created absorber is guaranteed.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90275346","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 : 2022-06-30DOI: 10.25073/2588-1140/vnunst.5399
Thức Ngọc Đinh, Mai Thi Ha Vu, H. Vu, H. Bui
Abelmoschus sagittifolius belongs to the Abelmoschus genus, Malvaceae family. Chemical study on the aerial parts of Abelmoschus sagittifolius collected in Vinh Hung commune, Vinh Loc district, Thanh Hoa province have led to the isolation of six compounds including sitostenone (1), friedelin (2), vomifoliol (3), vanilic acid (4), ketopinoresinol (5) and daucosterol (6). The structures of these compounds have been elucidated by NMR, MS spectroscopic data and comparison with the reported literatures. Compounds 1-2 and 4-5 were isolated for the first time from Abelmoschus sagittifolius.
{"title":"Chemical Consituents from Abelmochus Sagitifolius (Kurz) Merr.","authors":"Thức Ngọc Đinh, Mai Thi Ha Vu, H. Vu, H. Bui","doi":"10.25073/2588-1140/vnunst.5399","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5399","url":null,"abstract":"Abelmoschus sagittifolius belongs to the Abelmoschus genus, Malvaceae family. Chemical study on the aerial parts of Abelmoschus sagittifolius collected in Vinh Hung commune, Vinh Loc district, Thanh Hoa province have led to the isolation of six compounds including sitostenone (1), friedelin (2), vomifoliol (3), vanilic acid (4), ketopinoresinol (5) and daucosterol (6). The structures of these compounds have been elucidated by NMR, MS spectroscopic data and comparison with the reported literatures. Compounds 1-2 and 4-5 were isolated for the first time from Abelmoschus sagittifolius.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80410423","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 : 2022-06-30DOI: 10.25073/2588-1140/vnunst.5375
Ho Cong Hau, L. T. Quyen, Ngo Thi Hong Nhung, Ngo Vuong Hoang, Nguyen Truong An, Nguyen Phi Hung, N. T. Trung
Eight stable structures of nHCHO∙∙∙nH2O (n=1-3) were observed on potential surface energy at the MP2/aug-cc-pVDZ level of theory. All complexes were mainly stabilized by O-H∙∙∙O hydrogen bond and an additional contribution of Csp2-H∙∙∙O one. The larger positive cooperativity when adding H2O as compared to HCHO molecule is the most important factor in complex stabilization. The obtained results show that the O-H∙∙∙O is red-shifting hydrogen bond while Csp2-H∙∙∙O belongs to blue-shifting hydrogen bond. It is remarkable that an addition of H2O/HCHO into the binary system leads a Csp2-H bond contraction and an increase of its stretching frequency in Csp2-H∙∙∙O hydrogen bond, in which the larger marnitude of its blue-shifting enhancement is found as adding H2O molecule. This result is mainly governed by a decrease of electron density at σ*(Csp2-H) orbital and an increase in the s-character percentage of the Csp2 (Csp2-H).
{"title":"A Study on Structure, Stability, Cooperativity and Hydrogen Bond in the Complexes of nHCHO and nH2O (n=1-3) by Quantum Chemical Method","authors":"Ho Cong Hau, L. T. Quyen, Ngo Thi Hong Nhung, Ngo Vuong Hoang, Nguyen Truong An, Nguyen Phi Hung, N. T. Trung","doi":"10.25073/2588-1140/vnunst.5375","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5375","url":null,"abstract":"Eight stable structures of nHCHO∙∙∙nH2O (n=1-3) were observed on potential surface energy at the MP2/aug-cc-pVDZ level of theory. All complexes were mainly stabilized by O-H∙∙∙O hydrogen bond and an additional contribution of Csp2-H∙∙∙O one. The larger positive cooperativity when adding H2O as compared to HCHO molecule is the most important factor in complex stabilization. The obtained results show that the O-H∙∙∙O is red-shifting hydrogen bond while Csp2-H∙∙∙O belongs to blue-shifting hydrogen bond. It is remarkable that an addition of H2O/HCHO into the binary system leads a Csp2-H bond contraction and an increase of its stretching frequency in Csp2-H∙∙∙O hydrogen bond, in which the larger marnitude of its blue-shifting enhancement is found as adding H2O molecule. This result is mainly governed by a decrease of electron density at σ*(Csp2-H) orbital and an increase in the s-character percentage of the Csp2 (Csp2-H).","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88049700","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 : 2022-06-23DOI: 10.25073/2588-1140/vnunst.5180
N. T. Nghia
CH and C2H5OH are important species in the combustion system. The reaction mechanism between CH and C2H5OH was elucidated at the CCSD(T)//BHandHLYP/6-311+G(3df, 2p) level of theory. The results of quantum chemistry calculation showed that the CH free radical preferentially inserted the O-H and C-H bonds of CH2 and CH3 groups in the C2H5OH molecule. Meanwhile, the insertion of the CH radical into C-O and C-C bonds are much more difficult due to the high energy barriers. The main products of the reaction are: CH3CHCH2 + OH, CH3C(OH)CH2 + H, CH3CHO + CH3, CH3COCH3 + H, C2H4 + CH3O, CH2O + CH3CH2 and C2H4 + CH2OH. The geometries of the species and the heats of reaction at 0 K are in good agreement with the available experimental results. These results can provide guidance for future experimental work.
{"title":"Density Functional Theory Study on the Insertion Reaction Mechanism of Methylidyne with Ethanol","authors":"N. T. Nghia","doi":"10.25073/2588-1140/vnunst.5180","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5180","url":null,"abstract":"CH and C2H5OH are important species in the combustion system. The reaction mechanism between CH and C2H5OH was elucidated at the CCSD(T)//BHandHLYP/6-311+G(3df, 2p) level of theory. The results of quantum chemistry calculation showed that the CH free radical preferentially inserted the O-H and C-H bonds of CH2 and CH3 groups in the C2H5OH molecule. Meanwhile, the insertion of the CH radical into C-O and C-C bonds are much more difficult due to the high energy barriers. The main products of the reaction are: CH3CHCH2 + OH, CH3C(OH)CH2 + H, CH3CHO + CH3, CH3COCH3 + H, C2H4 + CH3O, CH2O + CH3CH2 and C2H4 + CH2OH. The geometries of the species and the heats of reaction at 0 K are in good agreement with the available experimental results. These results can provide guidance for future experimental work.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87211092","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 : 2022-06-23DOI: 10.25073/2588-1140/vnunst.5400
T. Loc, P. T. Ninh, Nguyen Thi Luu, T. Chien, T. Anh, Nguyễn Thị Dung, T. T. Thao
During the screening for biological active compounds from the medicinal plant, a species of Euphorbia hirta L. collected from Dan Phuong-Hanoi was utilized for its phytochemical study. From the n-butanol extract, eight compounds, including nonacosan-1-ol (1); β-sitosterol (2); β-sitosterol glucoside (3); quercetin (4); nicotiflorin (5); rutin (6); afzelin (7) and quercitrin (8) have been isolated. Their structures were determined by analysis of IR, MS and NMR (1D and 2D) spectroscopy as well as by comparison with published data.
{"title":"Chemical Composition of Euphorbia Hirta L. collected in Dan Phuong, Hanoi","authors":"T. Loc, P. T. Ninh, Nguyen Thi Luu, T. Chien, T. Anh, Nguyễn Thị Dung, T. T. Thao","doi":"10.25073/2588-1140/vnunst.5400","DOIUrl":"https://doi.org/10.25073/2588-1140/vnunst.5400","url":null,"abstract":"During the screening for biological active compounds from the medicinal plant, a species of Euphorbia hirta L. collected from Dan Phuong-Hanoi was utilized for its phytochemical study. From the n-butanol extract, eight compounds, including nonacosan-1-ol (1); β-sitosterol (2); β-sitosterol glucoside (3); quercetin (4); nicotiflorin (5); rutin (6); afzelin (7) and quercitrin (8) have been isolated. Their structures were determined by analysis of IR, MS and NMR (1D and 2D) spectroscopy as well as by comparison with published data.","PeriodicalId":23524,"journal":{"name":"VNU Journal of Science: Natural Sciences and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81025285","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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