1.Secondary Metabolites of Hemerocallis fulva var. kwanso Regel and Their PTP1B Inhibitory Potential
Thi Thanh LE ; Manh Tuan HA ; Trong Trieu TRAN ; Seung Eui MIN ; Kang-Hyun HAN ; Jungmoo HUH ; Jeong Ah KIM ; Byung Sun MIN
Natural Product Sciences 2026;32(1):76-83
A phytochemical study of the root extract of Hemerocallis fulva var. kwanso Regel resulted in the isolation and structural characterization of four lignans (1‒4), three flavanones (5, 6, and 8), one chalcone (9), and two monoterpenes (7 and 10). Enzyme inhibition assays revealed that two flavanone glucosides (5 and 6) showed significant inhibitory effect against protein tyrosine phosphatase 1B (PTP1B), with IC50 values of 31.38 µM and 51.46 µM, respectively. Further enzyme kinetic studies demonstrated that these two compounds acted as noncompetitive PTP1B inhibitors, with Ki values of 30.88 µM and 50.38 µM, respectively.
2.PTP1B Inhibitory Constituents from Dystaenia takeshimana: Mechanistic Insights via Kinetic and Molecular Docking Analyses
Manh Tuan HA ; Trong Trieu TRAN ; Thu Huong TRAN ; Jungmoo HUH ; Jeong Ah KIM ; Byung Sun MIN
Natural Product Sciences 2026;32(1):56-62
Dystaenia takeshimana (Nakai) Kitagawa belongs to the family Apiaceae (Umbelliferae) and is a perennial herb naturally endemic to Ulleung Island, Republic of Korea. Following its successful introduction and cultivation in mainland Korea, a phytochemical investigation of this plant was carried out. As a result, thirteen compounds were isolated and structurally characterized, including one flavonoid glycoside (1), two polyacetylenes (2 and3), one caffeoylquinic acid derivative (4), one aliphatic hydroxy acid (5), four phenolic acids and their derivatives(6, 8–10), one aromatic alcohol derivative (7), two carbohydrates (11 and 12), and one phytosterol (13). The structures of these compounds were elucidated based on spectroscopic analyses and comparison with previously reported literature data. To the best of our knowledge, this study represents the first report on the isolation of falcarinol (2), trans-4-hydroxy-2-nonenoic acid (5), and sucrose (11) from D. takeshimana and the evaluation of their protein tyrosine phosphatase 1B (PTP1B) inhibitory activity. Compounds 2, 3, and 5 exhibited potent PTP1B inhibitory effects with IC50 values of 10.74, 8.31, and 25.24 µM, respectively. Enzyme kinetic studies indicated noncompetitive inhibition by 2 and mixed-type inhibition by 5 against PTP1B. Furthermore, molecular docking analysis was performed to investigate the binding interactions between the active compounds and the enzyme active site.
3.A New Methoxyflavonoid Rutinoside and PTP1B-Inhibitory Phenolic Compounds from the Water Extract of Areca catechu L.
Manh Tuan HA ; Trong Trieu TRAN ; Thu Huong TRAN ; Seung Eui MIN ; Sang-Jin PARK ; Kang-Hyun HAN ; Jungmoo HUH ; Jeong Ah KIM ; Byung Sun MIN
Natural Product Sciences 2026;32(1):50-55
Phytochemical investigation of the water extract and alkaloid fraction of Areca catechu L. led to theisolation of one new methoxyflavonoid rutinoside (1), together with eleven known compounds (2−12), five of which (8−12) belong to the pyridine alkaloid class. The structure of the new compound was elucidated through extensive spectroscopic analyses, including 1D and 2D NMR experiments and high-resolution mass spectrometry.Notably, rhamnazin-3-O-rutinoside (2) is reported here for the first time from this species. The isolated compounds were evaluated for their inhibitory activity against protein tyrosine phosphatase 1B (PTP1B) using a p-nitrophenyl phosphate assay. Flavonoids (3 and 4) and stilbene (5) exhibited notable inhibitory activity, with IC50 values of 13.30 ± 0.71, 13.44 ± 0.84, and 8.68 ± 0.12 μM, respectively. In contrast, methoxyflavonoid rutinosides (1 and 2) and pyridine alkaloids (8−12) did not show significant inhibitory activity against PTP1B.These findings provide additional chemical insights into A. catechu and its constituents in relation to PTP1B inhibition.
4.Anti-inflammatory Constituents from Artemisia iwayomogi Kitamura: A Bioassay-guided Fractionation Study
Ngoc Khanh VU ; Thi Thanh LE ; Trong Trieu TRAN ; Manh Tuan HA ; Jeong Ah KIM ; Byung Sun MIN
Natural Product Sciences 2025;31(1):43-48
Bioassay-guided fractionation of the methanolic extract of Artemisia iwayomogi Kitamura led to the isolation of 12 known compounds (1‒12). Notably, this study marks the first report of 3-epimeridinol (1) being isolated and structurally characterized from a natural source. Additionally, compounds 3, 4, and 7 were isolated from the Asteraceae family for the first time. The structural elucidation of the isolated compound was achieved through analysis of 1D, 2D NMR, and MS data. Upon evaluation of their inhibitory effects against lipopolysaccharideinduced nitric oxide production, compound 12 demonstrated significant inhibitory activity with greater potency than the reference compound quercetin. These results established A. iwayomogi as a promising source of antiinflammatory agents.
5.Anti-inflammatory Constituents from Artemisia iwayomogi Kitamura: A Bioassay-guided Fractionation Study
Ngoc Khanh VU ; Thi Thanh LE ; Trong Trieu TRAN ; Manh Tuan HA ; Jeong Ah KIM ; Byung Sun MIN
Natural Product Sciences 2025;31(1):43-48
Bioassay-guided fractionation of the methanolic extract of Artemisia iwayomogi Kitamura led to the isolation of 12 known compounds (1‒12). Notably, this study marks the first report of 3-epimeridinol (1) being isolated and structurally characterized from a natural source. Additionally, compounds 3, 4, and 7 were isolated from the Asteraceae family for the first time. The structural elucidation of the isolated compound was achieved through analysis of 1D, 2D NMR, and MS data. Upon evaluation of their inhibitory effects against lipopolysaccharideinduced nitric oxide production, compound 12 demonstrated significant inhibitory activity with greater potency than the reference compound quercetin. These results established A. iwayomogi as a promising source of antiinflammatory agents.
6.Anti-inflammatory Constituents from Artemisia iwayomogi Kitamura: A Bioassay-guided Fractionation Study
Ngoc Khanh VU ; Thi Thanh LE ; Trong Trieu TRAN ; Manh Tuan HA ; Jeong Ah KIM ; Byung Sun MIN
Natural Product Sciences 2025;31(1):43-48
Bioassay-guided fractionation of the methanolic extract of Artemisia iwayomogi Kitamura led to the isolation of 12 known compounds (1‒12). Notably, this study marks the first report of 3-epimeridinol (1) being isolated and structurally characterized from a natural source. Additionally, compounds 3, 4, and 7 were isolated from the Asteraceae family for the first time. The structural elucidation of the isolated compound was achieved through analysis of 1D, 2D NMR, and MS data. Upon evaluation of their inhibitory effects against lipopolysaccharideinduced nitric oxide production, compound 12 demonstrated significant inhibitory activity with greater potency than the reference compound quercetin. These results established A. iwayomogi as a promising source of antiinflammatory agents.
7.Anti-inflammatory Constituents from Artemisia iwayomogi Kitamura: A Bioassay-guided Fractionation Study
Ngoc Khanh VU ; Thi Thanh LE ; Trong Trieu TRAN ; Manh Tuan HA ; Jeong Ah KIM ; Byung Sun MIN
Natural Product Sciences 2025;31(1):43-48
Bioassay-guided fractionation of the methanolic extract of Artemisia iwayomogi Kitamura led to the isolation of 12 known compounds (1‒12). Notably, this study marks the first report of 3-epimeridinol (1) being isolated and structurally characterized from a natural source. Additionally, compounds 3, 4, and 7 were isolated from the Asteraceae family for the first time. The structural elucidation of the isolated compound was achieved through analysis of 1D, 2D NMR, and MS data. Upon evaluation of their inhibitory effects against lipopolysaccharideinduced nitric oxide production, compound 12 demonstrated significant inhibitory activity with greater potency than the reference compound quercetin. These results established A. iwayomogi as a promising source of antiinflammatory agents.
8.Anti-inflammatory Constituents from Artemisia iwayomogi Kitamura: A Bioassay-guided Fractionation Study
Ngoc Khanh VU ; Thi Thanh LE ; Trong Trieu TRAN ; Manh Tuan HA ; Jeong Ah KIM ; Byung Sun MIN
Natural Product Sciences 2025;31(1):43-48
Bioassay-guided fractionation of the methanolic extract of Artemisia iwayomogi Kitamura led to the isolation of 12 known compounds (1‒12). Notably, this study marks the first report of 3-epimeridinol (1) being isolated and structurally characterized from a natural source. Additionally, compounds 3, 4, and 7 were isolated from the Asteraceae family for the first time. The structural elucidation of the isolated compound was achieved through analysis of 1D, 2D NMR, and MS data. Upon evaluation of their inhibitory effects against lipopolysaccharideinduced nitric oxide production, compound 12 demonstrated significant inhibitory activity with greater potency than the reference compound quercetin. These results established A. iwayomogi as a promising source of antiinflammatory agents.
9.Respiratory virus laboratory pandemic planning and surveillance in central Viet Nam, 2008–2010
Tran Thomas ; Chien Bui Trong ; Papadakis Georgina ; Druce Julian ; Birch Chris ; Chibo Doris ; An Truong Phuoc ; Trang Le Thi Kim ; Trieu Nguyen Bao ; Thuy Doan Thi Thanh ; Catton Mike ; Mai Trinh Xuan
Western Pacific Surveillance and Response 2012;3(3):49-56
Introduction: Laboratory capacity is needed in central Viet Nam to provide early warning to public health authorities of respiratory outbreaks of importance to human health, for example the outbreak of influenza A(H1N1) pandemic in 2009. Polymerase chain reaction (PCR) procedures established as part of a capacity-building process were used to conduct prospective respiratory surveillance in a region where few previous studies have been undertaken. Methods: Between October 2008 and September 2010, nose and throat swabs from adults and children (approximately 20 per week) presenting with an acute respiratory illness to the Ninh Hoa General Hospital were collected. Same-day PCR testing and result reporting for 13 respiratory viruses were carried out by locally trained scientists. Results: Of 2144 surveillance samples tested, 1235 (57.6%) were positive for at least one virus. The most common were influenza A strains (17.9%), with pandemic influenza A(H1N1) 2009 and seasonal H3N2 strain accounting for 52% and 43% of these, respectively. Other virus detections included: rhinovirus (12.4%), enterovirus (8.9%), influenza B (8.3%), adenovirus (5.3%), parainfluenza (4.7%), respiratory syncytial virus (RSV) (3.9%), human coronavirus (3.0%) and human metapneumovirus (0.3%). The detection rate was greatest in the 0–5 year age group. Viral co-infections were identified in 148 (6.9%) cases. Discussion: The outbreak in 2009 of the influenza A(H1N1) pandemic strain provided a practical test of the laboratory’s pandemic plan. This study shows that the availability of appropriate equipment and molecular-based testing can contribute to important individual and public health outcomes in geographical locations susceptible to emerging infections.


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