Tran Nhat Thang (K18 HL) (original) (raw)

Papers by Tran Nhat Thang (K18 HL)

Intelligent Systems and Networks, 2021

Mặc dù đã có rất nhiều hỗ trợ từ nhà nước và chính quyền địa phương để giảm bớt mức độ phụ thuộc ... more Mặc dù đã có rất nhiều hỗ trợ từ nhà nước và chính quyền địa phương để giảm bớt mức độ phụ thuộc vào tài nguyên rừng. Nhưng thực trạng về săn bắt động vật hoang dã làm thức ăn và bán lấy tiền để tăng thu nhập vẫn khá phổ biến ở các cộng đồng ở vùng sâu vùng xa của tỉnh Thừa Thiên Huế. Nghiên cứu này nhằm đánh giá hiện trạng và biến động trong săn bắt động vật hoang dã tại Khu Bảo tồn Sao la Thừa Thiên Huế. Nghiên cứu sử dụng kết hợp hoạt động phỏng vấn hộ gia đình, thảo luận nhóm, phỏng vấn chuyên gia, kế thừa kết quả điều tra giám sát đa dạng sinh học, dữ liệu từ hệ thống bẫy ảnh… để đánh giá đánh giá mức độ phụ thuộc vào tài nguyên rừng, sự thay đổi trong hoạt động săn bắt động vật hoang dã, mối tương quan giữa các khu vực giàu tài nguyên động vật hoang dã và hệ thống bẫy bắt động vật hoang dã của người dân địa phương các xã vùng đệm của Khu Bảo tồn Sao la Thừa Thiên Huế, ở 2 huyện Nam Đông và A Lưới, tỉnh Thừa Thiên Huế. Nghiên cứu chỉ ra mức độ phụ thuộc giảm dần đối với tài ngu...

Intelligent Systems Reference Library, 2021

Infection, Genetics and Evolution, 2021

The adult stage of Explanatum explanatum has economic importance in the production of ruminants, ... more The adult stage of Explanatum explanatum has economic importance in the production of ruminants, especially water buffaloes. This species has been widely reported in the Indian sub-continent. Recently, molecular analyses to reveal the dispersal route of this species were performed in Bangladesh, Nepal, and India. In the present study, we focused on E. explanatum distributed in Sri Lanka. A total of 52 flukes were collected from water buffaloes in Sri Lanka and identified as E. explanatum based on the internal transcribed spacer 2 (ITS2) region of nuclear ribosomal DNA. Analysis of the mitochondrial NADH dehydrogenase subunit 1 (nad1) gene from DNA samples detected 18 haplotypes, and five of them were identical to those from the Indian E. explanatum. The pairwise fixation index value indicated that the Sri Lankan population had a comparatively closer relationship with the Indian population than with the Bangladeshi or Nepalese populations. The Sri Lankan population showed significantly lower genetic variability than the Indian population, suggesting that the Indian population was the ancestor of the Sri Lankan population. The movement of host ruminants, including water buffaloes, was probably involved in the introduction of the fluke into Sri Lanka. The results of our study provide useful information for elucidating the geographic origin of E. explanatum distributed in the Indian subcontinent.

Parasitology International, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Journal of Intelligent & Fuzzy Systems, 2020

In this article, we use the monotonic optimization approach to propose an outcome-space outer app... more In this article, we use the monotonic optimization approach to propose an outcome-space outer approximation by copolyblocks for solving strictly quasiconvex multiobjective programming problems and especially in the case that the objective functions are nonlinear fractional. After the algorithm is terminated, with any given tolerance, we obtain an approximation of the weakly efficient solution set, that contains the whole weakly efficient solution set of the problem. The algorithm is proved to be convergent and it is suitable to be implemented in parallel using standard convex programming tools. Some computational experiments are reported to show the accuracy and efficiency of the proposed algorithm.

Parasitology International, 2019

Recently, phosphoenol pyruvate carboxykinase (pepck) and DNA polymerase delta (pold) were establi... more Recently, phosphoenol pyruvate carboxykinase (pepck) and DNA polymerase delta (pold) were established as reliable nuclear markers for species identification of Fasciola spp. in multiplex polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism-based assays, respectively. Currently, little is known about Fasciola species distribution in Central Asia. Therefore, the objective of the present study was to perform precise molecular species identification of liver flukes from Afghanistan and to reveal their dispersal route(s) via phylogenetic analysis based on mitochondrial nad1 haplotypes. Ninety-two Fasciolaflukes collected from sheep in Kabul, Afghanistan, were identified as F. hepatica based on pepck and pold screening. Although the pepck fragment pattern obtained via multiplex PCR analysis could not distinguish the species of the seven Fasciola flukes, the pepck nucleotide sequence data confirmed that they were F. hepatica.The 20 nad1 haplotypes detected among the Afghani liver flukes were closely related to those from China and Egypt, with the F ST value (−0.003, P = .41) between the F. hepatica populations from Afghanistan and China confirming a very close relationship. Nucleotide diversity was greater in the population from Afghanistan compared with that from China, indicating that the Afghani population was older, and that the dispersal direction of F. hepatica was from Afghanistan to China. The results of the present study contribute to our understanding of the dispersal of F. hepatica from its predicted origin, the Fertile Crescent.

2013 Asia-Pacific Symposium on Electromagnetic Compatibility (APEMC), 2013

ABSTRACT

Electric Power Systems Research, 2015

ABSTRACT In this paper, a simplified model of corona discharge for the finite-difference time-dom... more ABSTRACT In this paper, a simplified model of corona discharge for the finite-difference time-domain (FDTD) computations has been applied to analysis of transient voltages at the tower of a transmission line caused by direct lightning strikes to an upper phase conductor. In the simulations, three 40-m towers, separated by 300 m, with one overhead ground wire and three phase conductors are employed. Corona is assumed to occur only on the upper phase conductor struck by lightning. The progression of corona streamers from the conductor is represented as the radial expansion of cylindrical conducting region around the conductor. The reduction of transient-voltage peak due to corona is not very significant, so that the voltage at the nearest tower exceeds the insulation level of 66/77 kV power line considered in this paper. For a 10-kA peak current, the upper-phase-conductor voltage peaks are reduced by 26% and 21% for a positive stroke with 1-us and 3-us-risetime currents, respectively, and those for negative-stroke case are reduced by 18% and 13%, respectively. For a 20-kA peak current, the corresponding upper-phase-voltage peaks are reduced by 32% and 25% for the positive-stroke case, and those for the negative-stroke case are reduced by 22% and 15%.

Journal of Essential Oil Bearing Plants, 2014

ABSTRACT Essential oil obtained by hydrodistillation from the leaf of Amomum aculeatum Roxb. grow... more ABSTRACT Essential oil obtained by hydrodistillation from the leaf of Amomum aculeatum Roxb. grown in Vietnam were analysed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS). Monoterpene hydrocarbons (57.4 %) and sesquiterpene hydrocarbons (30.1 %) were the main class of compounds present in the oil. The main compounds were identified to be limonene (20.8 %), valencene (18.0 %), α-phellandrene (8.7 %), α-pinene (6.9 %) and bsequiphellandrene (6.1 %). The volatile oil contents were being reported for the first time.

Advances in Intelligent Systems and Computing, 2015

The problem of optimizing a real function over the efficient set of a multiple objective programm... more The problem of optimizing a real function over the efficient set of a multiple objective programming problem arises in a variety of applications. Because of its interesting mathematical aspects as well as its wide range of applications, this problem has attracted the attention of many authors. In this article, we propose a branch and bound algorithm in outcome space for minimizing a function \(h(x)=\varphi (f(x))\) over the efficient set \(X_{E}\) of the bi-criteria convex programming problem \(\mathrm{{Vmin}}\{f(x)=(f_{1}(x),f_{2}(x))^{T}|x\in X\}\), where the function \(\varphi \) is a quasi-concave function defined on \(f(X)\). The convergence of the algorithm is established. Preliminary computational results are reported.

2010 Asia-Pacific International Symposium on Electromagnetic Compatibility, 2010

We have modeled corona discharge from an overhead wire struck by lightning for surge and electrom... more We have modeled corona discharge from an overhead wire struck by lightning for surge and electromagnetic-pulse calculations using the finite-difference time-domain (FDTD) method. The radial progression of corona discharge from the wire is represented as the radial expansion of conducting region whose conductivity is several tens of micro Siemens per meter. The critical electric field on the surface of a

Journal of Essential Oil Bearing Plants, 2004

ABSTRACT The volatile oil from the fresh leaves of Canarium bengalense Roxb. was obtained by stea... more ABSTRACT The volatile oil from the fresh leaves of Canarium bengalense Roxb. was obtained by steam distillation. The essential oil was analyzed by the use of Capillary GC and GC/MS. 37 components were identified of which the major components were sabinene (15.9%), caryophyllene (17.5%) and epi-bicyclosesquiterpene (10.4% ). Predominant minor constituents included Δ3-carene (3.6%), p-cymene (3.7%), y-terpinene (6.2%), terpinen -4 -ol (3.7%), a - humulene (3.1%), germacrene B (2.6%), y-elemene (7.3%), and caryophyllene oxide (2.0%). All the other constituents including the unknown were in concentrations of less than 1%.

Journal of Essential Oil Bearing Plants, 2005

ABSTRACT The genus Michelia comprises over 50 species and is distributed in tropical areas and bo... more ABSTRACT The genus Michelia comprises over 50 species and is distributed in tropical areas and both hemisphere. The volatile components of the leaf oil of Michelia balansae (A.DC.) Dandy from the Nghean province, Vietnam were analyzed by Capillary GC, GC/MS as well as by background substraction of coeluting compounds. The major components in the leaf oil were α-pinene (18.41%), (α and β-phellandrene (17.36% and 7.42%), germacrene D (17.98%) and bicyclogermacrene (7.55%). The lesser amounts were β-myrcene (3.88%),δ-elemene (5.11%) and β-caryophyllene (3.47%).

Journal of Essential Oil Bearing Plants, 2013

Abstract The chemical composition of the leaf oil of Lindera rufa Hook. f. grown in Vietnam were ... more Abstract The chemical composition of the leaf oil of Lindera rufa Hook. f. grown in Vietnam were study by GC and GC-MS. The oil yield was 0.9 % on fresh leaves. Thirty-two compounds were identified (97.6% of the total composition), of which the most prominent was camphor (67.5 %).

Journal of Forest and Livelihood, 2013

DOI: http://dx.doi.org/10.3126/jfl.v11i1.8614 Journal of Forestry and Livelihood Vol.11(1) 2013 8... more DOI: http://dx.doi.org/10.3126/jfl.v11i1.8614 Journal of Forestry and Livelihood Vol.11(1) 2013 82-93

Journal of Essential Oil Bearing Plants, 2004

ABSTRACT The composition of the essential oil of Canarium album (Lour.) Raeusch. leaves Vietnam i... more ABSTRACT The composition of the essential oil of Canarium album (Lour.) Raeusch. leaves Vietnam is reported. The essential oil content was 0.1%. More than 50 compounds could be detected of which nearly the same constituents were identified. The main components of the oil obtained from fresh leaves were β-myrcene (23.7%) and β-caryophyllene (15.0%). The olfactorially valuable compounds that were found with concentration higher than 0.1% were: (Z)-3-hexenyl acetate, 1-hexyl acetate, terpinen-4-ol, salicyl methylate, β-ionone, nerolidol, (Z)-3-hexenyl benzoate, linalyl acetate, τ-muurulol, 6,10,14-trimethyl-2-pentadecanone, and phytol.

Phytochemistry, 2012

Glycosides, clausenosides A and B, and carbazole alkaloids, clausenaline A, claulamine A, and cla... more Glycosides, clausenosides A and B, and carbazole alkaloids, clausenaline A, claulamine A, and claulamine B, together with 50 known compounds, were isolated from the stems of Clausena lansium. Their structures were determined by means of spectroscopic methods, including that of CD and 1D/2D NMR analysis. Claulamine A has a 1-oxygenated carbazole skeleton with a rare 2,3-lactone ring, and claulamine B represents an hitherto unknown acetal carbazole alkaloid. Thirty-one of the isolated known compounds were evaluated in various assays for anti-inflammatory activity. Among them, imperatorin, isoheraclenin, and osthol exhibited selective and potent inhibition of formyl-L-methionyl-L-leucyl-L-phenylalanine/cytochalasin B (fMLP/CB)-induced superoxide anion generation, and lansiumarin C also decreased nitric oxide (NO) and tumor necrosis factor-a (TNF-a) production in lipopolysaccharide (LPS)-induced macrophages. In addition, a modified HPLC method of pre-column derivatization was developed that is more practical for simultaneous analysis of aldose enantiomers as compared to the literature method. The absolute configurations of the sugar moieties in clausenosides A and B were determined with this modified method.

Natural Product Research, 2013

Essential oils isolated from the air-dried leaves of Alphonsea philastreana and Alphonsea gaudich... more Essential oils isolated from the air-dried leaves of Alphonsea philastreana and Alphonsea gaudichaudiana growing in Vietnam have been studied for their constituents by means of gas chromatography with flame ionization detector and gas chromatography coupled with mass spectrometry. Sesquiterpenes were the most prominent class of compound identified in the oils. The quantitatively significant constituents of the oils were (E)-β-ocimene (6.9% and 8.5%), bicycloelemene (8.9% and 6.3%), β-caryophyllene (5.1% and 5.9%), α-humulene (5.8% and 4.6%), bicyclogermacrene (9.3% and 6.3%), guaiol (9.0% and 5.2%) and α-eudesmol (8.3% and 5.5%), respectively, for A. philastreana and A. gaudichaudiana. This is the first comprehensive report on the volatile oil constituents of the studied species.

Molecules, 2013

In the present study, the chemical investigation of the leaves of Annona reticulata has resulted ... more In the present study, the chemical investigation of the leaves of Annona reticulata has resulted in the identification of nine compounds, including annonaretin A, (1), a new triterpenoid. The purified compounds were subjected to the examination of their effects on NO inhibition in LPS-activated mouse peritoneal macrophages and most of them exhibited significant NO inhibition, with IC 50 values in the range of 48.6 ± 1.2 and 99.8 ± 0.4 μM.

Intelligent Systems and Networks, 2021

Mặc dù đã có rất nhiều hỗ trợ từ nhà nước và chính quyền địa phương để giảm bớt mức độ phụ thuộc ... more Mặc dù đã có rất nhiều hỗ trợ từ nhà nước và chính quyền địa phương để giảm bớt mức độ phụ thuộc vào tài nguyên rừng. Nhưng thực trạng về săn bắt động vật hoang dã làm thức ăn và bán lấy tiền để tăng thu nhập vẫn khá phổ biến ở các cộng đồng ở vùng sâu vùng xa của tỉnh Thừa Thiên Huế. Nghiên cứu này nhằm đánh giá hiện trạng và biến động trong săn bắt động vật hoang dã tại Khu Bảo tồn Sao la Thừa Thiên Huế. Nghiên cứu sử dụng kết hợp hoạt động phỏng vấn hộ gia đình, thảo luận nhóm, phỏng vấn chuyên gia, kế thừa kết quả điều tra giám sát đa dạng sinh học, dữ liệu từ hệ thống bẫy ảnh… để đánh giá đánh giá mức độ phụ thuộc vào tài nguyên rừng, sự thay đổi trong hoạt động săn bắt động vật hoang dã, mối tương quan giữa các khu vực giàu tài nguyên động vật hoang dã và hệ thống bẫy bắt động vật hoang dã của người dân địa phương các xã vùng đệm của Khu Bảo tồn Sao la Thừa Thiên Huế, ở 2 huyện Nam Đông và A Lưới, tỉnh Thừa Thiên Huế. Nghiên cứu chỉ ra mức độ phụ thuộc giảm dần đối với tài ngu...

Intelligent Systems Reference Library, 2021

Infection, Genetics and Evolution, 2021

The adult stage of Explanatum explanatum has economic importance in the production of ruminants, ... more The adult stage of Explanatum explanatum has economic importance in the production of ruminants, especially water buffaloes. This species has been widely reported in the Indian sub-continent. Recently, molecular analyses to reveal the dispersal route of this species were performed in Bangladesh, Nepal, and India. In the present study, we focused on E. explanatum distributed in Sri Lanka. A total of 52 flukes were collected from water buffaloes in Sri Lanka and identified as E. explanatum based on the internal transcribed spacer 2 (ITS2) region of nuclear ribosomal DNA. Analysis of the mitochondrial NADH dehydrogenase subunit 1 (nad1) gene from DNA samples detected 18 haplotypes, and five of them were identical to those from the Indian E. explanatum. The pairwise fixation index value indicated that the Sri Lankan population had a comparatively closer relationship with the Indian population than with the Bangladeshi or Nepalese populations. The Sri Lankan population showed significantly lower genetic variability than the Indian population, suggesting that the Indian population was the ancestor of the Sri Lankan population. The movement of host ruminants, including water buffaloes, was probably involved in the introduction of the fluke into Sri Lanka. The results of our study provide useful information for elucidating the geographic origin of E. explanatum distributed in the Indian subcontinent.

Parasitology International, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Journal of Intelligent & Fuzzy Systems, 2020

In this article, we use the monotonic optimization approach to propose an outcome-space outer app... more In this article, we use the monotonic optimization approach to propose an outcome-space outer approximation by copolyblocks for solving strictly quasiconvex multiobjective programming problems and especially in the case that the objective functions are nonlinear fractional. After the algorithm is terminated, with any given tolerance, we obtain an approximation of the weakly efficient solution set, that contains the whole weakly efficient solution set of the problem. The algorithm is proved to be convergent and it is suitable to be implemented in parallel using standard convex programming tools. Some computational experiments are reported to show the accuracy and efficiency of the proposed algorithm.

Parasitology International, 2019

Recently, phosphoenol pyruvate carboxykinase (pepck) and DNA polymerase delta (pold) were establi... more Recently, phosphoenol pyruvate carboxykinase (pepck) and DNA polymerase delta (pold) were established as reliable nuclear markers for species identification of Fasciola spp. in multiplex polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism-based assays, respectively. Currently, little is known about Fasciola species distribution in Central Asia. Therefore, the objective of the present study was to perform precise molecular species identification of liver flukes from Afghanistan and to reveal their dispersal route(s) via phylogenetic analysis based on mitochondrial nad1 haplotypes. Ninety-two Fasciolaflukes collected from sheep in Kabul, Afghanistan, were identified as F. hepatica based on pepck and pold screening. Although the pepck fragment pattern obtained via multiplex PCR analysis could not distinguish the species of the seven Fasciola flukes, the pepck nucleotide sequence data confirmed that they were F. hepatica.The 20 nad1 haplotypes detected among the Afghani liver flukes were closely related to those from China and Egypt, with the F ST value (−0.003, P = .41) between the F. hepatica populations from Afghanistan and China confirming a very close relationship. Nucleotide diversity was greater in the population from Afghanistan compared with that from China, indicating that the Afghani population was older, and that the dispersal direction of F. hepatica was from Afghanistan to China. The results of the present study contribute to our understanding of the dispersal of F. hepatica from its predicted origin, the Fertile Crescent.

2013 Asia-Pacific Symposium on Electromagnetic Compatibility (APEMC), 2013

ABSTRACT

Electric Power Systems Research, 2015

ABSTRACT In this paper, a simplified model of corona discharge for the finite-difference time-dom... more ABSTRACT In this paper, a simplified model of corona discharge for the finite-difference time-domain (FDTD) computations has been applied to analysis of transient voltages at the tower of a transmission line caused by direct lightning strikes to an upper phase conductor. In the simulations, three 40-m towers, separated by 300 m, with one overhead ground wire and three phase conductors are employed. Corona is assumed to occur only on the upper phase conductor struck by lightning. The progression of corona streamers from the conductor is represented as the radial expansion of cylindrical conducting region around the conductor. The reduction of transient-voltage peak due to corona is not very significant, so that the voltage at the nearest tower exceeds the insulation level of 66/77 kV power line considered in this paper. For a 10-kA peak current, the upper-phase-conductor voltage peaks are reduced by 26% and 21% for a positive stroke with 1-us and 3-us-risetime currents, respectively, and those for negative-stroke case are reduced by 18% and 13%, respectively. For a 20-kA peak current, the corresponding upper-phase-voltage peaks are reduced by 32% and 25% for the positive-stroke case, and those for the negative-stroke case are reduced by 22% and 15%.

Journal of Essential Oil Bearing Plants, 2014

ABSTRACT Essential oil obtained by hydrodistillation from the leaf of Amomum aculeatum Roxb. grow... more ABSTRACT Essential oil obtained by hydrodistillation from the leaf of Amomum aculeatum Roxb. grown in Vietnam were analysed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS). Monoterpene hydrocarbons (57.4 %) and sesquiterpene hydrocarbons (30.1 %) were the main class of compounds present in the oil. The main compounds were identified to be limonene (20.8 %), valencene (18.0 %), α-phellandrene (8.7 %), α-pinene (6.9 %) and bsequiphellandrene (6.1 %). The volatile oil contents were being reported for the first time.

Advances in Intelligent Systems and Computing, 2015

The problem of optimizing a real function over the efficient set of a multiple objective programm... more The problem of optimizing a real function over the efficient set of a multiple objective programming problem arises in a variety of applications. Because of its interesting mathematical aspects as well as its wide range of applications, this problem has attracted the attention of many authors. In this article, we propose a branch and bound algorithm in outcome space for minimizing a function \(h(x)=\varphi (f(x))\) over the efficient set \(X_{E}\) of the bi-criteria convex programming problem \(\mathrm{{Vmin}}\{f(x)=(f_{1}(x),f_{2}(x))^{T}|x\in X\}\), where the function \(\varphi \) is a quasi-concave function defined on \(f(X)\). The convergence of the algorithm is established. Preliminary computational results are reported.

2010 Asia-Pacific International Symposium on Electromagnetic Compatibility, 2010

We have modeled corona discharge from an overhead wire struck by lightning for surge and electrom... more We have modeled corona discharge from an overhead wire struck by lightning for surge and electromagnetic-pulse calculations using the finite-difference time-domain (FDTD) method. The radial progression of corona discharge from the wire is represented as the radial expansion of conducting region whose conductivity is several tens of micro Siemens per meter. The critical electric field on the surface of a

Journal of Essential Oil Bearing Plants, 2004

ABSTRACT The volatile oil from the fresh leaves of Canarium bengalense Roxb. was obtained by stea... more ABSTRACT The volatile oil from the fresh leaves of Canarium bengalense Roxb. was obtained by steam distillation. The essential oil was analyzed by the use of Capillary GC and GC/MS. 37 components were identified of which the major components were sabinene (15.9%), caryophyllene (17.5%) and epi-bicyclosesquiterpene (10.4% ). Predominant minor constituents included Δ3-carene (3.6%), p-cymene (3.7%), y-terpinene (6.2%), terpinen -4 -ol (3.7%), a - humulene (3.1%), germacrene B (2.6%), y-elemene (7.3%), and caryophyllene oxide (2.0%). All the other constituents including the unknown were in concentrations of less than 1%.

Journal of Essential Oil Bearing Plants, 2005

ABSTRACT The genus Michelia comprises over 50 species and is distributed in tropical areas and bo... more ABSTRACT The genus Michelia comprises over 50 species and is distributed in tropical areas and both hemisphere. The volatile components of the leaf oil of Michelia balansae (A.DC.) Dandy from the Nghean province, Vietnam were analyzed by Capillary GC, GC/MS as well as by background substraction of coeluting compounds. The major components in the leaf oil were α-pinene (18.41%), (α and β-phellandrene (17.36% and 7.42%), germacrene D (17.98%) and bicyclogermacrene (7.55%). The lesser amounts were β-myrcene (3.88%),δ-elemene (5.11%) and β-caryophyllene (3.47%).

Journal of Essential Oil Bearing Plants, 2013

Abstract The chemical composition of the leaf oil of Lindera rufa Hook. f. grown in Vietnam were ... more Abstract The chemical composition of the leaf oil of Lindera rufa Hook. f. grown in Vietnam were study by GC and GC-MS. The oil yield was 0.9 % on fresh leaves. Thirty-two compounds were identified (97.6% of the total composition), of which the most prominent was camphor (67.5 %).

Journal of Forest and Livelihood, 2013

DOI: http://dx.doi.org/10.3126/jfl.v11i1.8614 Journal of Forestry and Livelihood Vol.11(1) 2013 8... more DOI: http://dx.doi.org/10.3126/jfl.v11i1.8614 Journal of Forestry and Livelihood Vol.11(1) 2013 82-93

Journal of Essential Oil Bearing Plants, 2004

ABSTRACT The composition of the essential oil of Canarium album (Lour.) Raeusch. leaves Vietnam i... more ABSTRACT The composition of the essential oil of Canarium album (Lour.) Raeusch. leaves Vietnam is reported. The essential oil content was 0.1%. More than 50 compounds could be detected of which nearly the same constituents were identified. The main components of the oil obtained from fresh leaves were β-myrcene (23.7%) and β-caryophyllene (15.0%). The olfactorially valuable compounds that were found with concentration higher than 0.1% were: (Z)-3-hexenyl acetate, 1-hexyl acetate, terpinen-4-ol, salicyl methylate, β-ionone, nerolidol, (Z)-3-hexenyl benzoate, linalyl acetate, τ-muurulol, 6,10,14-trimethyl-2-pentadecanone, and phytol.

Phytochemistry, 2012

Glycosides, clausenosides A and B, and carbazole alkaloids, clausenaline A, claulamine A, and cla... more Glycosides, clausenosides A and B, and carbazole alkaloids, clausenaline A, claulamine A, and claulamine B, together with 50 known compounds, were isolated from the stems of Clausena lansium. Their structures were determined by means of spectroscopic methods, including that of CD and 1D/2D NMR analysis. Claulamine A has a 1-oxygenated carbazole skeleton with a rare 2,3-lactone ring, and claulamine B represents an hitherto unknown acetal carbazole alkaloid. Thirty-one of the isolated known compounds were evaluated in various assays for anti-inflammatory activity. Among them, imperatorin, isoheraclenin, and osthol exhibited selective and potent inhibition of formyl-L-methionyl-L-leucyl-L-phenylalanine/cytochalasin B (fMLP/CB)-induced superoxide anion generation, and lansiumarin C also decreased nitric oxide (NO) and tumor necrosis factor-a (TNF-a) production in lipopolysaccharide (LPS)-induced macrophages. In addition, a modified HPLC method of pre-column derivatization was developed that is more practical for simultaneous analysis of aldose enantiomers as compared to the literature method. The absolute configurations of the sugar moieties in clausenosides A and B were determined with this modified method.

Natural Product Research, 2013

Essential oils isolated from the air-dried leaves of Alphonsea philastreana and Alphonsea gaudich... more Essential oils isolated from the air-dried leaves of Alphonsea philastreana and Alphonsea gaudichaudiana growing in Vietnam have been studied for their constituents by means of gas chromatography with flame ionization detector and gas chromatography coupled with mass spectrometry. Sesquiterpenes were the most prominent class of compound identified in the oils. The quantitatively significant constituents of the oils were (E)-β-ocimene (6.9% and 8.5%), bicycloelemene (8.9% and 6.3%), β-caryophyllene (5.1% and 5.9%), α-humulene (5.8% and 4.6%), bicyclogermacrene (9.3% and 6.3%), guaiol (9.0% and 5.2%) and α-eudesmol (8.3% and 5.5%), respectively, for A. philastreana and A. gaudichaudiana. This is the first comprehensive report on the volatile oil constituents of the studied species.

Molecules, 2013

In the present study, the chemical investigation of the leaves of Annona reticulata has resulted ... more In the present study, the chemical investigation of the leaves of Annona reticulata has resulted in the identification of nine compounds, including annonaretin A, (1), a new triterpenoid. The purified compounds were subjected to the examination of their effects on NO inhibition in LPS-activated mouse peritoneal macrophages and most of them exhibited significant NO inhibition, with IC 50 values in the range of 48.6 ± 1.2 and 99.8 ± 0.4 μM.