Labdane-type diterpenoids and sesquiterpenes from Curcuma aromatica and their nitric oxide inhibitory activity in lipopolysaccharide-stimulated RAW264.7 macrophages.

One new labdane-type diterpenoid, 3ß,15-dihydroxylabda-8(17),12E-dien-16,15-olide (1) named curcumatin and twelve known compounds, coronarin D (2), isocoronarin D (3), (E)-labda-8(17),12-diene-15,16-dial (4), zerumin A (5), (E)-labda-8(17),12-dien-15,16-dioic acid (6), furanodiene (7), linderazulene (8), zedoarol (9), zedoarondiol (10), germacrone-1,10-epoxide (11), germacrone-4,5-epoxide (12), and zingiberenol (13) were isolated from the ethanol extract of the roots of Curcuma aromatica Salisb. Their structures were elucidated by 1D-, 2D-NMR spectroscopic analysis, HR-ESI-MS, and comparing with the NMR data reported in the literature. Compounds 2, 5, and 13 significantly inhibited the nitric oxide production effect in LPS-stimulated RAW 264.7 macrophages with IC50 values of 8.8 ± 1.7, 4.0 ± 0.9, and 6.2 ± 0.4 µM, respectively.

Molecular genotypic analysis of porcine circovirus type 2 reveals the predominance of PCV2d in Vietnam (2018-2020) and the association between PCV2h, the recombinant forms, and Vietnamese vaccines.

We conducted nucleotide and amino acid sequence alignment and phylogenetic analysis of porcine circovirus ORF2 (Cap protein) from 17 PCV2-positive clinical samples from nine different northern Vietnamese provinces (Mar 2018-Nov 2020), four local vaccines, and 77 reference strains. We identified one PCV2a (1/17 = 5.9%), five PCV2b (5/17 = 29.9%), and 11 PCV2d (11/17 = 64.7%) isolates, while only PCV2d was detected in 2020. Timeline analysis indicated an increasing predominance of PCV2d nationwide (2018-2020). With strong nodal support (98% for nucleotides and 74% for amino acids), the phylogenetic tree topology revealed a distinct PCV2h clade including recombinant/intermediate strains and local vaccines. The Cap protein sequences from 11 PCV2d field strains had the 2d-genotype-typical motif 86SNPLSV91 in loop CD, the motif TGID in loop GH-HI, and the motif 230PLNPK234 in loop CT. The PCV2h isolates (and vaccines) had the 86SNPLSV91, SAID, and 230L(N/H)PK234 motifs. Selection pressure analysis indicated positive selection at seven sites: A68N in immunoreactive region (IRR)-A; 119G and 130V in IRR-B; and 167L, T190(A/S), 194D and 202F in IRR-C. We identified PCV2h as the genotype of the recombinant strains, which resulted from intergenotype recombination of PCV2a, PCV2b, and PCV2d. The current data provide new information about the diversity, distribution, and dominance of the PCV2 genotype in Vietnam.

High Proportion of Genome-Wide Homology and Increased Pretreatment pvcrt Levels in Plasmodium vivax Late Recurrences: a Chloroquine Therapeutic Efficacy Study.

Chloroquine (CQ) is the first-line treatment for Plasmodium vivax malaria in most countries where malaria is endemic. Monitoring P. vivax CQ resistance (CQR) is critical but remains challenged by the difficulty to distinguish real treatment failure from reinfection or liver relapse. The therapeutic efficacy of CQ against uncomplicated P. vivax malaria was evaluated in Gia Lai Province, Vietnam. Sixty-seven patients were enrolled and followed for 42 days using microscopy and quantitative PCR. Adequate clinical and parasitological response (ACPR) was 100% (66/66) on day 28 but 75.4% (49/65) on day 42. Eighteen recurrences (27.7%) were detected, with a median time to recurrence of 42 days (interquartile range [IQR], 35 to 42) and blood CQ concentration of <100 ng/ml. Primary infections leading to recurrence occurred in younger individuals (median age for ACPR = 25 years [IQR, 20 to 28]; recurrences = 18 [16 to 21]; P = 0.002) had a longer parasite clearance time (PCT for ACPR = 47.5 h [IQR, 36.2 to 59.8 h]; recurrences = 54.2 [48.4 to 62.0]; P = 0.035) and higher pvcrt gene expression (median relative expression ratio for ACPR = 0.09 [IQR, 0.05 to 0.22]; recurrences = 0.20 [0.15 to 0.56]; P = 0.002), but showed no differences in ex vivo CQ sensitivity. Parasite genotyping by microsatellites, single nucleotide polymorphism (SNP) barcoding, and whole-genome sequencing (WGS) identified a majority of homologous recurrences, with 80% (8/10) showing >98% identity by descent to paired day 0 samples. This study shows that CQ remained largely efficacious to treat P. vivax in Gia Lai; i.e., recurrences occurred late (>day 28) and in the presence of low blood CQ concentrations. However, the combination of both WGS and gene expression analysis (pvcrt) data with clinical data (PCT) allowed us to identify potential emergence of low-grade CQR, which should be closely monitored. (This study has been registered at ClinicalTrials.gov under identifier NCT02610686.).

Efficacy of dihydroartemisinin/piperaquine and artesunate monotherapy for the treatment of uncomplicated Plasmodium falciparum malaria in Central Vietnam.

BACKGROUND: Artemisinin-based combination therapies (ACTs) have significantly contributed to reduce Plasmodium falciparum malaria burden in Vietnam, but their efficacy is challenged by treatment failure of dihydroartemisinin/piperaquine ACT in Southern provinces. OBJECTIVES: To assess the efficacy of dihydroartemisinin/piperaquine for uncomplicated P. falciparum malaria in Gia Lai, Central Vietnam, and determine parasite resistance to artemisinin (ClinicalTrials.gov identifier NCT02604966). METHODS: Sixty patients received either dihydroartemisinin/piperaquine (4 mg/kg/day, 3 days; n = 33) or artesunate monotherapy (4 mg/kg/day, 3 days; n = 27) followed by dihydroartemisinin/piperaquine (AS + DHA/PPQ). Clinical phenotypes were determined during a 42 day follow-up and analysed together with ex vivo susceptibility to antimalarials and molecular markers of drug resistance. RESULTS: Day 3 positivity rate was significantly higher in the AS + DHA/PPQ arm compared with dihydroartemisinin/piperaquine (70.4% versus 39.4%, P = 0.016). Parasite clearance time was 95.2 h (AS + DHA/PPQ) versus 71.9 h (dihydroartemisinin/piperaquine, P = 0.063) and parasite clearance half-life was 7.4 h (AS + DHA/PPQ) versus 7.0 h (dihydroartemisinin/piperaquine, P = 0.140). Adequate clinical and parasitological response at Day 42 was 100% in both arms. By RT-qPCR, 36% (19/53) patients remained positive until Day 7. No recurrences were detected. kelch13 artemisinin resistance mutations were found in 87% (39/45) of isolates and 50% (20/40) were KEL1/C580Y. The piperaquine resistance marker plasmepsin-2 was duplicated in 10.4% (5/48). Isolates from Day 3-positive patients (n = 18) had higher ex vivo survival rates to artemisinin compounds (P < 0.048) and prevalence of kelch13 mutations (P = 0.005) than Day 3-negative patients (n = 5). The WHO definition of artemisinin resistance was fulfilled in 60% (24/40) of cases. CONCLUSIONS: Although dihydroartemisinin/piperaquine remained effective to treat P. falciparum, the high Day 3 positivity rate and prevalence of KEL1 strains calls for continuous monitoring of dihydroartemisinin/piperaquine efficacy in Central Vietnam.

Integrated Analysis of the Wood Oil from Xanthocyparis vietnamensis Farjon & Hiep. by Chromatographic and Spectroscopic Techniques.

In order to get better knowledge about the volatiles produced by Xanthocyparis vietnamensis, a species recently discovered in Vietnam, its wood oil has been analyzed by a combination of chromatographic (GC, CC) and spectroscopic (GC-MS, (13)C-NMR) techniques. Forty components that accounted for 87.9% of the oil composition have been identified. The composition is dominated by nootkatene (20.7%), 11,12,13-tri-nor-eremophil-1(10)-en-7-one (17.2%), γ-eudesmol (5.1%), nootkatone (4.7%), valencene (3.5%) and 13-nor-eremophil-1(10)-en-11-one (2.6%). The structure of two new compounds-10-epi-nor-γ-eudesmen-11-one and 12-hydroxy-isodihydroagarofuran-has been elucidated, while 11,12,13-tri-nor-eremophil-1(10)-en-7-ol is reported as a natural product for the first time. The composition of X. vietnamensis wood oil varied drastically from those of leaf oils, dominated by hedycaryol (34.4%), phyllocladene (37.8%) or by pimara-6(14)-15-diene (19.4%).

New ent-kauranes from the fruits of Annona glabra and their inhibitory nitric oxide production in LPS-stimulated RAW264.7 macrophages.

Three new ent-kaurane diterpenoids, 7ß,16α,17-trihydroxy-ent-kauran-19-oic acid (1), 7ß,17-dihydroxy-16α-ent-kauran-19-oic acid 19-O-ß-d-glucopyranoside ester (2), 7ß,17-dihydroxy-ent-kaur-15-en-19-oic acid 19-O-ß-d-glucopyranoside ester (3) along with five known compounds, paniculoside IV (4), 16α,17-dihydroxy-ent-kaurane (5), 16ß,17-dihydroxy-ent-kaurane (6), 16ß,17-dihydroxy-ent-kauran-19-al (7), and 16ß,17-dihydroxy-ent-kauran-19-oic acid (8) were isolated from the fruits of Annona glabra. Their chemical structures were elucidated by physical and chemical methods. All compounds were evaluated for inhibitory activity against nitric oxide (NO) production in LPS-stimulated RAW 264.7 macrophages. As the results, compound 3 showed potent inhibitory LPS-stimulated NO production in RAW 264.7 macrophages with the IC50 value of 0.01±0.01µM; compounds 1 and 7 showed significant inhibitory NO production with the IC50 values of 0.39±0.12µM and 0.32±0.04µM, respectively.

Chemical constituents of the Annona glabra fruit and their cytotoxic activity.

CONTEXT: Traditional Chinese medicines have attracted increasing interest as potential sources of novel drugs with a wide range of biological and pharmacological activities. Annona glabra Linn (Annonaceae) is used in traditional medicine as an anticancer drug. Phytochemical investigation of this plant led to the isolation of acetogenins, ent-kauranes, peptides, and alkaloids. In addition, compounds exhibited anticancer, anti-HIV-reserve, and antimalaria. OBJECTIVE: Isolation, structure determination, and cytotoxic activity evaluation of compounds from the methanol extract from A. glabra fruits. MATERIALS AND METHODS: Using chromatographic methods to isolate compounds from the A. glabra methanol extract. The cytotoxic activity of compounds was evaluated by a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, compounds which showed significant cytotoxic activity were chosen for further study apoptosis characteristics. RESULTS: One new, (2E,4E,1'R,3'S,5'R,6'S)-dihydrophaseic acid 1,3'-di-O-ß-d-glucopyranoside, and eight known compounds, (2E,4E,1'R,3'S,5'R,6'S)-dihydrophaseic acid 3'-O-ß-d-glucopyranoside (2), icariside D2 (3), icariside D2 6'-O-ß-d-xylopyranoside (4), 3,4-dimethoxyphenyl O-ß-d-glucopyranoside (5), 3,4-dihydroxybenzoic acid (6), blumenol A (7), cucumegastigmane I (8), and icariside B1 (9), were isolated from the fruits of A. glabra. Icariside D2 (3) was found to show significant cytotoxic activity on the HL-60 cell line with the IC50 value of 9.0 ± 1.0 µM and did not show cytotoxic activity on the Hel-299 normal cell line. The further test indicated that compound 3 induced apoptosis via alteration of expression of apoptosis-related proteins and decreased phosphorylation of AKT in HL-60 cells. DISCUSSION AND CONCLUSION: The results suggested that the constituents from A. glabra may contain effective compounds which can be used as anticancer agents.

The effect of behavioral therapy on dysphagia of acute ischemic stroke patients feeding with a nasogastric tube.

This prospective observational study aimed to assess the impact of behavioral therapy on dysphagia in patients with acute ischemic stroke undergoing nasogastric tube feeding. The study was conducted between June 2020 and May 2022 at the Neurological Center of Bach Mai Hospital, Vietnam, with a sample size of 230 patients divided into two groups: a normal and a behavioral therapy group. The normal therapy group received routine care and treatment based on standard protocols, while the behavioral therapy group underwent daily swallowing exercises for approximately 60 minutes. The Gugging Swallowing Screen (GUSS) was utilized to screen individuals with dysphagia, and the difference-in-differences (DID) method was adopted to estimate the effect of behavioral therapy on dysphagia patients. The study concluded that behavioral therapy improved dysphagia in patients with acute ischemic stroke undergoing nasogastric tube feeding. This study highlights the potential of behavioral therapy as an effective intervention for dysphagia rehabilitation in stroke patients.

Therapeutic potential of natural products in schistosomiasis-associated liver fibrosis.

Schistosomiasis is a parasitic disease that endangers human health and social development. The granulomatous reaction of Schistosoma eggs in the liver is the main cause of hepatosplenomegaly and fibrotic lesions. Anti liver fibrosis therapy is crucial for patients with chronic schistosomiasis. Although Praziquantel is the only clinical drug used, it is limited in insecticide treatment and has a long-term large-scale use, which is forcing the search for cost-effective alternatives. Previous research has demonstrated that plant metabolites and extracts have effective therapeutic effects on liver fibrosis associated with schistosomiasis. This paper summarizes the mechanisms of action of metabolites and some plant extracts in alleviating schistosomiasis-associated liver fibrosis. The analysis was conducted using databases such as PubMed, Google Scholar, and China National Knowledge Infrastructure (CNKI) databases. Some plant metabolites and extracts ameliorate liver fibrosis by targeting multiple signaling pathways, including reducing inflammatory infiltration, oxidative stress, inhibiting alternate macrophage activation, suppressing hepatic stellate cell activation, and reducing worm egg load. Natural products improve liver fibrosis associated with schistosomiasis, but further research is needed to elucidate the effectiveness of natural products in treating liver fibrosis caused by schistosomiasis, as there is no reported data from clinical trials in the literature.

Corilagin alleviates atherosclerosis by inhibiting NLRP3 inflammasome activation via the Olfr2 signaling pathway in vitro and in vivo.

Introduction: Atherosclerosis, a leading cause of global cardiovascular mortality, is characterized by chronic inflammation. Central to this process is the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome, which significantly influences atherosclerotic progression. Recent research has identified that the olfactory receptor 2 (Olfr2) in vascular macrophages is instrumental in driving atherosclerosis through NLRP3- dependent IL-1 production. Methods: To investigate the effects of Corilagin, noted for its anti-inflammatory attributes, on atherosclerotic development and the Olfr2 signaling pathway, our study employed an atherosclerosis model in ApoE-/- mice, fed a high-fat, high-cholesterol diet, alongside cellular models in Ana-1 cells and mouse bone marrow-derived macrophages, stimulated with lipopolysaccharides and oxidized low-density lipoprotein. Results: The vivo and vitro experiments indicated that Corilagin could effectively reduce serum lipid levels, alleviate aortic pathological changes, and decrease intimal lipid deposition. Additionally, as results showed, Corilagin was able to cut down expressions of molecules associated with the Olfr2 signaling pathway. Discussion: Our findings indicated that Corilagin effectively inhibited NLRP3 inflammasome activation, consequently diminishing inflammation, macrophage polarization, and pyroptosis in the mouse aorta and cellular models via the Olfr2 pathway. This suggests a novel therapeutic mechanism of Corilagin in the treatment of atherosclerosis.

Circulation of human respiratory syncytial virus and new ON1 genotype in northern Viet Nam, 2017-2020.

Objective: Human respiratory syncytial virus (RSV) is a primary cause of paediatric severe acute respiratory infection (SARI) worldwide, especially in developing countries. We investigated the genetic characteristics of RSV in northern Viet Nam to determine the prevalence and distribution of subtypes as well as the diversity and transmission patterns of genotypes. Methods: In two facilities, from January 2017 to December 2020, 1563 clinical specimens were collected from paediatric patients hospitalized with SARI and tested for RSV. Selected positive samples underwent sequencing analysis targeting the second hypervariable region of the G gene using next-generation sequencing. Results: The RSV positivity rate was 28.02% (438/1563 samples), and prevalence was highest in children aged < 1 year (43.84%; 192/438). Subtype RSV-A accounted for 53.42% (234/438) of cases, RSV-B for 45.89% (201/438), and there was coinfection in 0.68% (3/438). Both subtypes cocirculated and peaked during August-September in each year of the study. Phylogenetic analysis showed that RSV-A samples belonged to the ON1 genotype, which has three subgenotypes: ON1.1, ON1.2 and ON1.3. However, we did not find the 72-nucleotide duplication in the second hypervariable region of the G gene, a characteristic of genotype ON1, in any RSV-A samples. RSV-B samples belonged to genotype BA9. Discussion: Our results provide additional molecular characterization of RSV infections in Viet Nam. Specially, our study is the first to report the absence of the 72-nucleotide duplication in the G gene of RSV-A genotype ON1 in Viet Nam, which may help in understanding the genetic evolution of RSV and be useful for vaccine development in the future.

Alpha-Glucosidase Inhibitory Activity of Saponins Isolated from Vernonia gratiosa Hance.

Species belonging to the Vernonia (Asteraceae), the largest genus in the tribe Vernonieae (consisting of about 1,000 species), are widely used in food and medicine. These plants are rich sources of bioactive sesquiterpene lactones and steroid saponins, likely including many as yet undiscovered chemical components. A phytochemical investigation resulted in the separation of three new stigmastane-type steroidal saponins (1 - 3), designated as vernogratiosides A-C, from whole plants of V. gratiosa. Their structures were elucidated based on infrared spectroscopy (IR), one-dimensional (1D) and two-dimensional nuclear magnetic resonance (2D NMR), high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), and electronic circular dichroism analyses (ECD), as well as chemical reactivity. Molecular docking analysis of representative saponins with α-glucosidase inhibitory activity was performed. Additionally, the intended substances were tested for their ability to inhibit α-glucosidase activity in a laboratory setting. The results suggested that stigmastane-type steroidal saponins from V. gratiosa are promising candidate antidiabetic agents.

Synthesis of cuprous oxide/silver (Cu2O/Ag) hybrid as surface-enhanced Raman scattering probe for trace determination of methyl orange.

Recently, there have been publications on preparing hybrid materials between noble metal and semiconductor for applications in surface-enhanced Raman scattering (SERS) substrates to detect some toxic organic dyes. However, the use of cuprous oxide/silver (Cu2O/Ag) to measure the trace amounts of methyl orange (MO) has not been reported. Therefore, in this study, the trace level of MO in water solvent was determined using a SERS substrate based on Cu2O microcubes combined with silver nanoparticles (Ag NPs). Herein, a series of Cu2O/Agx (x= 1-5) hybrids with various Ag amounts was synthesized via a solvothermal method followed by a reduction process, and their SERS performance was studied in detail. X-ray diffraction (XRD) and scanning electron microscopy results confirmed that 10 nm Ag NPs were well dispersed on 200-500 nm Cu2O microcubes to form Cu2O/Ag heterojunctions. Using the as-prepared Cu2O and Cu2O/Agx as MO probe, the Cu2O/Ag5 nanocomposite showed the highest SERS activity of all samples with the limit of detection as low to 1 nM and the enhancement factor as high as 4 × 108. The logarithm of the SERS peak intensity at 1389 cm-1 increased linearly with the logarithm of the concentration of MO in the range from 1 nM to 0.1 mM.

Four new lignans obtained from the leaves of Schisandra cauliflora and their effect on skeletal muscle cell proliferation.

Plants of the Schisandra genus are commonly used in folk medicinal remedies. Some Schisandra species and their lignans have been reported to improve muscle strength. In the present study, four new lignans, named schisacaulins A-D, together with three previously described compounds ananonin B, alismoxide, and pregomisin were isolated from the leaves of S. cauliflora. Their chemical structures were determined by extensive analyses of HR-ESI-MS, NMR, and ECD spectra. Schisacaulin D and alismoxide significantly stimulated skeletal muscle cell proliferation by increasing the number of fused myotubes and expression of myosin heavy chain (MyHC) which may be good candidates for the treatment of sarcopenia.

Unveiling the future of COVID-19 patient care: groundbreaking prediction models for severe outcomes or mortality in hospitalized cases.

Background: Previous studies have identified COVID-19 risk factors, such as age and chronic health conditions, linked to severe outcomes and mortality. However, accurately predicting severe illness in COVID-19 patients remains challenging, lacking precise methods. Objective: This study aimed to leverage clinical real-world data and multiple machine-learning algorithms to formulate innovative predictive models for assessing the risk of severe outcomes or mortality in hospitalized patients with COVID-19. Methods: Data were obtained from the Taipei Medical University Clinical Research Database (TMUCRD) including electronic health records from three Taiwanese hospitals in Taiwan. This study included patients admitted to the hospitals who received an initial diagnosis of COVID-19 between January 1, 2021, and May 31, 2022. The primary outcome was defined as the composite of severe infection, including ventilator use, intubation, ICU admission, and mortality. Secondary outcomes consisted of individual indicators. The dataset encompassed demographic data, health status, COVID-19 specifics, comorbidities, medications, and laboratory results. Two modes (full mode and simplified mode) are used; the former includes all features, and the latter only includes the 30 most important features selected based on the algorithm used by the best model in full mode. Seven machine learning was employed algorithms the performance of the models was evaluated using metrics such as the area under the receiver operating characteristic curve (AUROC), accuracy, sensitivity, and specificity. Results: The study encompassed 22,192 eligible in-patients diagnosed with COVID-19. In the full mode, the model using the light gradient boosting machine algorithm achieved the highest AUROC value (0.939), with an accuracy of 85.5%, a sensitivity of 0.897, and a specificity of 0.853. Age, vaccination status, neutrophil count, sodium levels, and platelet count were significant features. In the simplified mode, the extreme gradient boosting algorithm yielded an AUROC of 0.935, an accuracy of 89.9%, a sensitivity of 0.843, and a specificity of 0.902. Conclusion: This study illustrates the feasibility of constructing precise predictive models for severe outcomes or mortality in COVID-19 patients by leveraging significant predictors and advanced machine learning. These findings can aid healthcare practitioners in proactively predicting and monitoring severe outcomes or mortality among hospitalized COVID-19 patients, improving treatment and resource allocation.

Detection of Quorum Sensing Signal Molecules in Edwardsiella ictaluri Ei-151.

Edwardsiella ictaluri is a Gram-negative pathogenic bacterium in the family Enterobacteriaceae that causes enteric septicemia of catfish, which has become a significant problem in the aquaculture of striped catfish (Pangasianodon hypophthalmus) in Vietnam. In this study, a bacterium designated as Ei-151 was isolated from diseased striped catfish and proved to be virulent. Based on 16S rDNA sequencing and phenotypic tests, the pathogenic bacterium was identified as Edw. ictaluri. The presence of quorum sensing signal molecules in Edw. ictaluri Ei-151 was detected with different biosensor strains. The results showed that Ei-151 produced at least three kinds of acylated homoserine lactone (AHL) signal molecules as detected with the biosensor Agrobacterium tumefaciens KYC55, and the AHLs fingerprint was similar to that of Edw. tarda. During its entire growth, the levels of AHLs and autoinducer-2 produced by Ei-151 peaked at the stationary phase (OD600 1.8), which suggested that both of them may function at the stationary phase. No Cholerae autoinducer-1-like activity (including Edw. ictaluri LMG7860(T)) was detected.

Iridoid glycosides link with phenylpropanoids from Rehmannia glutinosa.

Two new iridoid glycosides link with phenylpropanoids, rehmanniosides G (1) and H (2) along with 11 known compounds, 6-O-(E)-caffeoylajugol (3), 6-O-(E)-feruloylajugol (4), verbasoside (5), jionoside C (6), acteoside (7), leucosceptoside A (8), brachynoside (9), jionoside B1 (10), jionoside A1 (11), isoacteoside (12) and isomartynoside (13) were isolated from the roots of Rehmannia glutinosa (Gaertn.) DC. Their chemical structures were elucidated on the basis of extensive spectroscopic methods, including 1D, 2D NMR and mass spectra. Compounds 7 - 11 showed significant inhibitory α-glucosidase with IC50 values ranging from 261.4 to 408.7 µM (acarbose, IC50 of 204.2 ± 19.9 µM).[Formula: see text].

Fundamental Properties of Hydrogen-Functionalized GaSe Monolayer.

Functionalization reveals potential opportunities for modifying essential properties and designing materials due to the strong interaction between functionalized atoms and the surface. Among them, hydrogenation possesses such a way to control electronic and optical characteristics. In this paper, the stability and transformed electronic, optical properties of H-functionalized GaSe in two cases (single and double sites) were reported that exhibit the effects of hydrogen functionalization via first-principles calculations. Formation energies suggest that H-functionalized GaSe systems are stable for construction. H-GaSe and 2H-GaSe display distinct properties based on the functionalized way (single- or double-site functionalization). Accordingly, H-GaSe is metallic, while 2H-GaSe belongs to a semiconductor. The magnetic configuration with ferro- and anti-ferromagnetic could be found in H- and 2H-functionalized cases through spin distribution, respectively. Especially, the chemical hybridized bonds of Se-H, Ga-Se, and Ga-Ga corresponding to s-sp3 and sp3-sp3 bondings, respectively, are clearly verified in the orbital-projected density of states and charge density. The optical properties of 2H-GaSe could provide the main characteristics of a semiconductor, which is the limited range of transparency by electronic absorption at short and long wavelengths. Moreover, increasing the number of GaSe segments (L) could change the band gap leading to application in the band gap engineering of the 2H-GaSe systems. Thus, hydrogen functionalization could provide the possible manner for adjusting and controlling features of GaSe, promising for the development of electronic devices and applications.

Chemical constituents from the branches and leaves of Alchornea annamica.

Phytochemical investigation of the branches and leaves of Alchornea annamica led to isolation of ten secondary metabolites, including two new megastigmane glucosides alnamicosides A (1) and B (2). The structure elucidation was confirmed by 1 D and 2 D NMR, ECD as well as HR-QTOF-MS experiments. The megastigmane derivatives 1 - 3 exhibited inhibitory effects on LPS-induced NO production in RAW264.7 cells with IC50 values of 78.72 ± 1.90, 77.40 ± 9.40 and 82.16 ± 4.56 µM, respectively. This is the first report on chemical constituents and biological activity of the plant A. annamica.

Polyacetylene and phenolic constituents from the roots of Codonopsis javanica.

Chemical investigation of the roots of Codonopsis javanica resulted in isolation of 12 compounds, including one new polyacetylene, codojavanyol (1), one new phenolic glycoside, codobenzyloside (7), and 10 known compounds, (2E,8E)-9-(tetrahydro-2H-pyran-2-yl)nona-2,8-diene-4,6-diyl-1-ol (2), lobetyol (3), lobetyolin (4), lobetyolinin (5), cordifolioidyne B (6), benzyl-α-L-arabinopyranosyl (1-6)-ß-D-glucopyranoside (8), (Z)-8-ß-D-glucopyranosyloxycinnamic acid (9), syringin (10), syringaresinol (11), and tryptophan (12). Their structures were elucidated by 1 D and 2 D NMR and MS spectroscopic analyses in comparison with the data reported in the literature. The stereochemistry of the C-2' position of 1 was identified based on time-dependent density functional theory (TDDFT) electronic circular dichroism (ECD) calculation. Among the isolates, compounds 3-5 were shown to have weak cytotoxicity toward three human carcinoma cell lines, including lung (A549), liver (HepG2), and breast (MCF7), with the induction of 41.4 to 55.6% cell death at the concentration of 100 µM.