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Five sesquiterpenoids including 2α-hydroxyoplopanone (1), oplopanone (2), 1β,4β,6α-trihydroxy-eudesmane (3), 1β,4β,7α-trihydroxy-eudesmane (4) and bullatantriol (5) were isolated from Homalomena pendula. The structure of the previously reported compound, 5,7-diepi-2α-hydroxyoplopanone (1a), has been revised to 1 by the spectroscopic evidences (1D-/2D-NMR, IR, UV and HRESIMS) and by comparison between experimental and theoretical NMR data using DP4+ protocol. Furthermore, the absolute configuration of 1 was unambiguously assigned by ECD experiments. Compounds 2 and 4 displayed a potent ability to stimulate osteogenic differentiation of MC3T3-E1 cells at 4 µg/mL (by 123.74% and 131.07%, respectively) and 20 µg/mL (by 112.45% and 126.41%, respectively) whilst 3 and 5 did not show any activities. At 20 µg/mL, 4 and 5 significantly promoted the mineralization of MC3T3-E1 cells with values of 112.95% and 116.37%, respectively, whereas 2 and 3 were inactive. The results indicated that 4 could be an excellent component for anti-osteoporosis studies from the rhizomes of H. pendula.

Wound healing is vital to maintain the physiological functions of the skin.

An efficient choline chloride-based DES method is used to extract curcumin in turmeric residue for the first time.

Lung cancer is one of the leading cancers and causes of cancer-related deaths worldwide. Due to its high prevalence and mortality rate, its clinical management remains a significant challenge. Previously, the in vitro anticancer activity of Aspiletrein A, a steroid and a saponin from Aspidistra letreae, against non-small cell lung cancer (NSCLC) cells was reported. However, the anticancer molecular mechanism of other Aspiletreins from A. letreae remains unknown. Using in silico network pharmacology approaches, the targets of Aspiletreins were predicted using the Swiss Target Prediction database. In addition, key mediators in NSCLC were obtained from the Genetic databases. The compound-target interacting networks were constructed using the STRING database and Cytoscape, uncovering potential targets, including STAT3, VEGFA, HSP90AA1, FGF2, and IL2. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis demonstrated that several pathways were highly relevant to cancer pathogenesis. Additionally, molecular docking and molecular dynamic analyses revealed the interaction between key identified targets and Aspiletreins, including hydrogen bonding and Van der Waals interaction. This study provides potential targets of Aspiletreins in NSCLC, and its approach of integrating network pharmacology, bioinformatics, and molecular docking is a powerful tool for investigating the mechanism of new drug targets on a specific disease.

Soil factors, especially metal elements in the soil, play a significant role in forming and accumulating secondary metabolites, which determine the medicinal properties of medicinal herbs. In this study, the concentrations of some metal elements (K, Mn, Fe, Cu, Zn, and Cr) in Cam Mountain and Tinh Bien Town, An Giang Province, Vietnam, were determined using the XRF method. We simultaneously determined the total phenolic and flavonoid content of some medicinal herbs collected from the collected soil sample areas, thereby assessing the influence of these elements on the formation of secondary metabolites in medicinal plants. The results showed that K, Mn, and Cr were mainly concentrated in the topsoil and transition layers; Fe and Cu elements tended to concentrate in the transition layer and the subsoil when surveying the soil profile. K, Mn, Cu, and Cr concentrations were more focused in Tinh Bien area, while Fe and Zn had higher concentrations at Cam Mountain. Additionally, results from evaluating the relationship between the content of the elements in the soil and the content of two active compounds also showed the corresponding relationship between Cr/Phenolic, Cu/Phenolic, and Zn/Flavonoid (R2 = 0.74; R2 = 0.75; R2 = 0.90, respectively) with the corresponding correlation equations at level six.

In the gastric mucosa, chronic inflammation due to

Three undescribed 9,10-seco-isopimarane diterpenoids, marginols I-K, and an unprecedent isopimara-8(9),15-diene diterpene, 14-epi-boesenberol F, together with a known 9,10-seco-isopimarane diterpenoid, kaemgalangol A, were isolated from the rhizomes of Vietnamese Kaempferia marginata. Marginols I and J contained a naturally very rare 6-oxabicyclo[3.2.1]octane-5-ol ring, while marginol K had a naturally rare oxepan-2-one ring in its structure. The unprecedented structures were elucidated by spectroscopic techniques, including HR-ESI-TOF-MS, UV, IR, and 1D and 2D NMR. The absolute configurations of marginols I-K and 14-epi-boesenberol F were determined by ECD calculations. The NO production inhibitory assay revealed that the isolated compounds, except marginol J, exhibited NO inhibitory activities with IC

A new spirostanol steroid, aspidiata A (

Distichochlamys benenica is a native black ginger that grows in Vietnam. In point of fact, there is limitation of available information in the literature making mention of the chemical constituents and bioactive properties of this plant. This study is aimed at isolating trans-o-coumaric acid (1), trans-cinnamic acid (2), and borneol (3) from the rhizomes of D. benenica Q.B.Nguyen & Škorničk and evaluate the anti-inflammatory and antimicrobial activities of 1-3 using the carrageenan paw edema model and the dilution broth method, respectively. This revealed that 1 was as effective as diclofenac in reducing the intensity of the edema development. The in silico research showed that the activity of 1 might be derived from inhibiting COX-2 by generating h-bonds at the positions of Arg 120, Tyr 355, and Arg 513 residues. The antimicrobial activities against Gram-positive strains (Staphylococcus aureus and Bacillus subtilis) were comparable, with the minimum inhibitory concentrations ranging from 1.52 to 3.37 mM. This is the first study of the bioactivity of compounds isolated from D. benenica Q.B.Nguyen & Škorničk. Our results suggest that 1 may be a nature-derived compound which demonstrates the anti-inflammatory properties and inhibit the proliferation of several Gram-positive bacteria.

Novel ciprofloxacin composite imprinted materials are synthesized by using co-precipitation polymerization of dual functional monomers (methacrylic acid and 2-vinylpyridine) and polystyrene-co-divinylbenzene. The intermolecular interactions between monomers and template are evaluated by molecular modeling analysis. The physicochemical properties of the obtained polymers are characterized using FT-IR, TGA, and SEM. Batch adsorption experiments are used to investigate adsorption properties (kinetic, pH, and isotherm). These polymers are employed to prepare the solid phase extraction cartridges, and their extraction performances are analyzed by the HPLC-UV method. DFT calculations indicate that hydrogen bonding and π−π stacking are the driving forces for the formation of selective rebinding sites. The obtained polymers exhibit excellent adsorption properties, including fast kinetics and high adsorption capacity (up to 10.28 mg g−1) with an imprinted factor of 2.55. The Scatchard analysis indicates the presence of specific high-affinity adsorption sites on the imprinted polymer. These absorbents are employed to extract CIP in river water with recoveries in the range of 65.97–119.26% and the relative standard deviation of 3.59–14.01%. Furthermore, the used cartridges could be reused at least eight times without decreasing their initial adsorption capacity.

As a new Internet of Things (IoT) paradigm where smart devices work socially by exploiting social tie with adjacent devices, the Social IoT (SIoT) can effectively meet the real-time data sharing demands in Industrial IoT (IIoT) scenario, with the inter-device social relations as incentives. Besides, pre-caching on device level can potentially combat the backhaul capacity bottlenecks. Considering the limited cache memory, we may not use the whole capacity for caching, but leave a fraction for buffering data packets. In this paper, we investigate how to maximize the quality of experience (QoE) while minimizing the energy consumption. Firstly, we design a proactive cache placement scheme for cost minimization. Next, we conceive the content sharing prodecure with the framework of tripartite graph and propose a ternary stable matching algorithm to let devices self-organize the content sharing. Finally, we prove that inconspicuously manipulation with domino effect can further improve the system performance.

Due to the increase in video streaming traffic over the Internet, more innovative methods are in demand for improving both Quality of Experience (QoE) of users and Quality of Service (QoS) of providers. In recent years, HTTP Adaptive Streaming (HAS) has received significant attention from both industry and academia based on its impacts on the enhancement of media streaming services. However, HAS-alone cannot guarantee a seamless viewing experience, since this highly relies on the Network Operators’ infrastructure and evolving network conditions. Along with the development of future Internet infrastructure, Software-Defined Networking (SDN) has been researched and newly implemented as a promising solution in improving services of different Internet layers. In this paper, we present a novel architecture incorporating bitrate adaptation and dynamic route allocation. At the client side, adaptation logic of VBR videos streaming is built based on the MPEG-DASH standard. On the network side, an SDN controller is implemented with several routing strategies on top of the OpenFlow protocol. Our experimental results show that the proposed solution enhances at least 38% up to 185% in term of average bitrate in comparison with some existing solutions as well as achieves better viewing experience than the traditional Internet.

This paper proposes a new approach of digital predistortion (DPD) technique based on the adaptive indirect learning architecture (ILA) by using a recursive prediction error minimization (RPEM) algorithm for linearizing radio frequency (RF) power amplifiers (PAs) in emerging wideband communication systems. In the proposed RPEM-based linearization approach, the forgetting factor varies with time and is less sensitive to noise. Therefore, the predistorter (PD) parameter estimates become more consistent and accurate in steady state so that the mean square errors can be reduced. Both the error vector magnitude (EVM) and the adjacent channel power ratio (ACPR) are used to evaluate the DPD technique in RF PAs employing the proposed linearization. The efficiency validation of the proposed method is based on a simulated PA Wiener model. The simulation results have clarified the improvement of the proposed adaptive ILA-based DPD with RPEM algorithm in terms of both EVM and ACPR.

Six new chiro-inositol derivatives (1–6) were isolated from the leaves of Chisocheton paniculatus collected in Vietnam. Their chemical structures were elucidated by 1D and 2D NMR and HRESIMS analys...

In this letter, we investigate how to leverage inter-human social ties to strike a trade-off between the physical layer security and throughput performance in device-to-device (D2D) communications with relay selection. Different from standard stable matching model assuming that all agents are trusted, we first relax this assumption by considering the fact that the blocking pair with social ties can facilitate the deviation. In the so-called socially stable matching model, we can find a stable matching over two independent graph models rather than over a reconstructed graph by reserving the intersection between edges in physical graph and social graph. Simulation results corroborate the superiority of our proposed scheme.

In this paper, we consider a social-aware unmanned aerial vehicle (UAV) assisted mobile crowd sensing (MCS) system for disaster relief networks, and investigate how to recruit suitable UAVs to perform sensing tasks in stochastic and dynamic environments (both UAVs and tasks arrive stochastically). We formulate the task assignment problem into a dynamic matching problem, and propose a multiple-waitlist based task assignment (MWTA) algorithm to find the stable matching in time-varying environment. We prove that MWTA can achieve the dynamic stability containing the strategy-proofness, efficiency, and envy-freeness. Simulation results demonstrate the performance improvement of our proposed scheme compared with the traditional matching algorithm applied to deterministic matching model in stochastic setting.

Aims: This study aimed to analyze the diagnostic values of the Adenosine Deaminase (ADA) test for detecting Tuberculosis (TB) ascites in Vietnam. Materials and Methods: A cross-sectional study was conducted on 43 patients with ascites. ADA, acid-fast bacilli (AFB) smear microscopy and culture as well as histological tests were performed. Diagnostic values including sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were estimated. Results : The area under the curve (AUC) of ascitic fluid ADA in diagnosis of TB ascites was 0.937 with p

Four compounds, luteolin (1), 6-γ,γ-dimethylallylquercetin 7-O-β-D-glucopyranoside (2), 6-γ,γ-dimethylallylkaempferol 7-O-β-D-glucopyranoside (3), and 6-γ,γ-dimethylallyldihydrokaempferol 7-O-β-D-glucoside (4), were isolated for the first time from AcOEt extract of the O. integerrima flower. We then evaluated the antioxidant effects of AcOEt, butanol, and MeOH extracts and their effects on H

Using waste materials to extract biologically active ingredients with green solvents is a new trend for sustainable development. Herein, different types of deep eutectic solvents (DESs) and surfactant solvents (SSs) were used to extract curcumin from turmeric residues (TRs), among which choline chloride-propylene glycol (ChCl-Pro) showed the highest yield. The optimized extraction conditions included a ChCl : Pro ratio of 1 : 2, water content in the DESs of 20%, solid : liquid ratio of 1 : 40 maintained for 60 min at 50 °C, and a TR particle size of 0.18 mm. The extraction yield was 54.2 mg g

A new spirostanol steroid, aspidiata A (1), and a new spirostanol steroidal saponin, aspidiata B (2), along with three known compounds, paris saponin VII (3), daucosterol (4), and (25R)-spirostane-1β,2β,3β,4β,5β,6β-hexol (5), were isolated from whole plants of Aspidistra triradiata collected in Vietnam. Their chemical structures were established by spectroscopic analysis and comparison with previously published data. Compound 3 showed strong cytotoxicity against LU-1, Hep-G2, MCF-7, and KB human cancer cell lines with half maximal inhibitory concentration (IC50) values ranging from 0.57 to 1.23 µM. Compound 5 exhibited weak cytotoxic activity against the LU-1 cell line, with an IC50 value of 95.81 µM.

In the gastric mucosa, chronic inflammation due to Helicobacter pylori infection promotes gastrocarcinogenesis. Polysaccharides of Caulerpa lentillifera are well-characterized by broad antimicrobial activity and anti-inflammatory potentials. The present study was undertaken to investigate whether the low molecular sulfate polysaccharides of C. lentillifera (CLCP) exhibit any anti-adhesive activity against H. pylori. After a hot water extraction and purification process, two purified polysaccharide fractions (CLCP-1 and CLCP2) were studied based on structural characterization and bioactivity determination. The results implied that except for the molar ratio, CLCP-1 and CLCP-2 contain high sulfate, mannose, galactose, xylose, glucose levels, and low protein levels. The molecular weight and Fourier transform infrared spectroscopy (FT-IR) assays confirmed that CLCP-1 and CLCP-2 are sulfate polysaccharides with an average molecular weight (Mw) of 963.15 and 648.42 kDa, respectively. In addition, CLCP-1 and CLCP-2 exhibited stronger antibacterial activity against H. pylori. CLCP-1 and CLCP-2 could significantly promote macrophage proliferation and decrease the production of nitric oxide (NO) through downregulated expression of inducible nitric oxide synthase (iNOS). Meanwhile, CLCP-1 and CLCP-2 in this study showed efficiently protected gastric adenocarcinoma (AGS) cells against H. pylori with the inhibition of the IL-8/NF-κB axis. These findings suggested the effect of Caulerpa lentillifera polysaccharides on H. pylori adhesion, a potential supply of nutrients for eradication therapy through the reduction of cell count and inflammation.

Three new flavanols, (2R,3S)-7-methoxy-flavan-3-ol (1), (2R,3S)-7-hydroxy-flavan-3-ol (2), and (2R,3S)-2′-hydroxy-7-methoxy-flavan-3-ol (3), together with two known flavans (4 and 5), were isolated from the chloroform extract of Crinum asiaticum. Their structures were elucidated by various spectroscopic methods, including 1D and 2D NMR, HR-ESI-MS, and CD data. The isolated compounds 1 and 3−5 showed inhibitory activity toward LPS-induced nitric oxide (NO) production. Further investigation of the NF-κB pathway mechanisms indicated that 1 and 3−5 inhibited the LPS-induced IL-6 production and p65 subunit phosphorylation of NF-κB in RAW264.7 cells, with an effective dose of 10 µM.

Panax vietnamensis, or Vietnamese ginseng (VG), an endemic Panax species in Vietnam, possesses a unique saponin profile and interesting biological activities. This plant is presently in danger of extinction due to over-exploitation, resulting in many preservation efforts towards the geographical acclimatization of VG. Yet, no information on the saponin content of the acclimatized VG, an important quality indicator, is available. Here, we analyzed the saponin content in the underground parts of two- to five-year-old VG plants acclimatized to Lam Dong province. Nine characteristic saponins, including notoginsenoside-R1, ginsenoside-Rg1, -Rb1, -Rd, majonoside-R1, -R2 vina-ginsenoside-R2, -R11, and pseudoginsenoside-RT4, were simultaneously determined by HPLC coupled with UV and with a charged aerosol detector (CAD). Analyzing the results illustrated that the detection of characteristic ocotillol-type saponins in VG by CAD presented a superior capacity compared with that of UV, thus implying a preferential choice of CAD for the analysis of VG. The quantitative results indicating the saponin content in the underground parts of VG showed an increasing tendency from two to five years old, with the root and the rhizome exhibiting different saponin accumulation patterns. This is the first study that reveals the preliminary success of VG acclimatization and thereby encourages the continuing efforts to develop this valuable saponin-rich plant.

Novel ciprofloxacin composite imprinted materials are synthesized by using co-precipitation polymerization of dual functional monomers (methacrylic acid and 2-vinylpyridine) and polystyrene

In flying Internet of Things (Flying IoT) scenario, the relay technology can effectively solve the problem of timely communication with distant unmanned aerial vehicles (UAVs). It is practical to design a distributed approach to let UAVs self-organize their relay selection strategy while considering the impact of social networks of objects. In this letter, we first propose a social-aware relay selection scheme using matching theory, which takes both physical condition and inter-device social tie into account. Besides, we study how to find the unilaterally Pareto-optimal stable matching through inconspicuous manipulating the preference list. Simulation results demonstrate that the proposed scheme can strike a better trade-off among throughput, reliability, and computational complexity performance than other benchmarks.

Sensing network of the Internet of Things (IoT) has become the infrastructure to facilitate the near real-time monitoring of potential events, where the accuracy and energy-efficiency are essential factors to be considered when determining the boundary of continuous objects. This paper proposes an energy-efficient boundary detection mechanism in IoT sensing networks. Specifically, a sleeping mechanism is adapted to detect the relatively coarse boundary through applying the convex hull algorithm, where only the relay nodes are activated. Leveraging the analysis of the relation for corresponding boundary nodes, the boundary area around a boundary node is categorized as three types of sub-areas with the descending possibility of event occurrence, i.e., the most possible, possible, and impossible areas. An optimized greedy algorithm is adapted to selectively activate certain numbers of one-hop neighboring IoT nodes in respective sub-areas, to avoid the activation of all one-hop neighboring nodes in a flooding manner. Consequently, the boundary is refined and optimized according to sensory data of these activated IoT nodes. The experimental results demonstrate that this technique can achieve a better detection accuracy, while reducing energy consumption to a large extent, than the state of art’s techniques.

Device-to-device (D2D) communications is the integral part of public safety (PS) communications. However, the most important requirement is the users’ rapid discovery to timely communicate the emergency information. The existing half-duplex (HD) results in large time delays because it cannot transceive during same time slot. In-band full duplex (IB-FD) communications is an enabler to quickly discover the user because of simultaneous transmission and reception during same time-frequency block. In this paper, we proposed the frame structure for IB-FD system with prioritized PS users in resource allocation. Moreover, to improve spectral efficiency, time-efficient device discovery resource allocation (TE-DDRA) scheme has been proposed as well, where a user can switch the transmission mode from HD to IB-FD when the demand exceeds the available resources in HD mode. The proposal is validated by system-level simulations in terms of discovery time with conventional random access mode. The simulation results shows that with PS priority mode around 37% discovery time as compared with random access mode.

We report a hydrothermal synthesis of a hybrid structure between gold nanoparticles and a metal organic framework, ZIF-8 (abbreviated as Au@ZIF-8). Au nanoparticles encapsulated in polyvinylpyrrolidone (PVP) was employed as seeds to grow the framework of ZIF-8. We controlled the position and concentrations of Au nanoparticles on ZIF-8 crystal by adjusting the volume of Au nanoparticles dissolved in DI water during the growth of ZIF-8. Morphology, structure, distribution of the hybrid structure were investigated by transmission microscope, powder xray diffraction, and diffuse reflectance UV-Vis spectroscopy. We tested out catalytic properties of Au@ZIF-8 through the reaction of 2-nitrophenol and NaBH4.

Objective: This study aimed to perform the reverse-transcription polymerase chain reaction (RT-PCR) to express the survivin mRNA among patients with breast cancer in Vietnam and identify some potential associated clinical and pathological factors. Methods: Peripheral blood (PB) samples and tissues on 43 patients with breast cancer and 21 patients with fibroids were obtained. The Real-time RT-PCR and gene sequencing techniques were employed to detect survivin gene in breast cancer cell lines and cancer tissues. Results: Survivin mRNA transcription was detected in 32/43 (74,4%) of breast cancer tissues and 19/43 (44,2%) of PB samples of breast cancer patients, while it was detected in only 14,3 % fibrosis tissues and 0% in the blood of fibrosis patients. Survivin mRNA on the peripheral blood of breast cancer patients increased with tumor size, and stage of cancer (p < 0.05). In terms of breast cancer tissue, no difference was found in the rate of survivin mRNA expression in according to age, distant metastasis, lymph node, stages of cancer, and histopathology (p > 0.05). Conclusions: Results provide the initial evidence of the expression of survivin mRNA in breast cancer patients in Vietnam, suggesting the role of survivin mRNA in breast cancer molecular pathology.

Background Detecting circulating tumor cells (CTCs) is a promising approach for evaluating the progression of occult metastases as well as the efficacy of treatment therapies among patients with breast cancer. A real-time reverse transcriptase polymerase chain reaction (RT-PCR) technique has been proposed for detecting CTCs due to its high sensitivity. In this study, we aimed to validate the RT-PCR technique for human mammaglobin (hMAM) mRNA detection among Vietnamese women with breast cancer. Patients and methods Peripheral blood samples and breast cancer tissues from 43 patients suffering from breast cancer and 21 patients with fibroids were obtained. Real-time RT-PCR and gene sequencing techniques were employed to detect hMAM gene in CTCs of breast cancer cell lines and cancer tissues. Results hMAM mRNA transcription was detected in 36 out of 43 (83.7%) breast cancer tissues and in blood of 23 out of 43 (53.5%) breast cancer patients, while it was detected in only 9.5% out of tissues and 0% of the blood of fibrosis patients. hMAM mRNA in the peripheral blood of breast cancer patients increased with tumor size, stage of cancer and distant metastasis (P 0.05). Conclusion The study highlighted the expression of hMAM mRNA in breast cancer cells and tissues. This reveals the overall picture of the replication of hMAM mRNA in breast cancer, suggesting the role of hMAM mRNA in breast cancer molecular pathology.

A new xanthone derivative, aspidxanthone A (1), and three known compounds ((2S)-1-(β-D-galactopyranosyloxy)-3-(hexadecanoyloxy)propan-2-yl (9Z,12Z)-octadeca-9,12-dienoate (2), (25S)-spirostane-1β,3α,5β-triol (3), and asparenyldiol (4)) were isolated from the whole of the endemic species Aspidistra letreae in Vietnam. Their structures were elucidated by means of extensive spectroscopic analyses and comparison with published data. In this study, we report the isolation and structure elucidation of a new compound aspidxanthone A, antioxidant activities of the extract and isolates 1-4, and in silico molecular docking of aspidxanthone A. The ethyl acetate extract had good antioxidant activity with an IC50 value of 26.3 μg mL-1 . Among the isolates, aspidxanthone A exhibited DPPH reduction activity with an IC50 value of 11.2 μM, which is in the same range as that of the positive control, ascorbic acid. The mechanism of action of aspidxanthone A on the tyrosinase and xanthine oxidase proteins have been clarified by in silico studies.

Kaempferia marginata rhizomes are used as an herb in food and as traditional medicine for the treatment of inflammatory-related diseases in Asian countries. In contrast to the previously reported phytochemical investigation of Thai and Chinese K. marginata rhizomes, which demonstrated the presence of sandaracopimaradiene and ent-sandaracopimaradiene, our first investigation of Vietnamese K. marginata rhizomes led to the isolation of eight undescribed pimarane diterpenoids, marginols A‒H, along with 18 known pimarane diterpenoids. The structures of these compounds were elucidated by spectroscopic techniques, including 1D and 2D NMR, HRESIMS, and CD spectroscopy and/or by comparisons of their NMR data with previously reported data. Furthermore, evaluations of the NO production inhibitory activity against LPS-stimulated RAW264.7 cells revealed that the undescribed compounds, marginols B and D‒G, and the known compounds, sandaracopimaradien-6β,9α-diol-1-one and 6-acetoxysandaracopimardien-9-ol-1-one, showed potent activities. These results provide insights into the chemodiversity of Vietnamese K. marginata rhizomes as well as their traditional usage from the viewpoint of their chemical constituents.

Distichochlamys benenica is a native black ginger that grows in Vietnam. In point of fact, there is limitation of available information in the literature making mention of the chemical constituents and bioactive properties of this plant. This study is aimed at isolating trans-o-coumaric acid (1), trans-cinnamic acid (2), and borneol (3) from the rhizomes of D. benenica Q.B.Nguyen & Škorničk and evaluate the anti-inflammatory and antimicrobial activities of 1-3 using the carrageenan paw edema model and the dilution broth method, respectively. This revealed that 1 was as effective as diclofenac in reducing the intensity of the edema development. The in silico research showed that the activity of 1 might be derived from inhibiting COX-2 by generating h-bonds at the positions of Arg 120, Tyr 355, and Arg 513 residues. The antimicrobial activities against Gram-positive strains (Staphylococcus aureus and Bacillus subtilis) were comparable, with the minimum inhibitory concentrations ranging from 1.52 to 3.37 mM. This is the first study of the bioactivity of compounds isolated from D. benenica Q.B.Nguyen & Škorničk. Our results suggest that 1 may be a nature-derived compound which demonstrates the anti-inflammatory properties and inhibit the proliferation of several Gram-positive bacteria.

A new decenoic acid derivative, gelliodesinic acid, and a naturally new alkaloid, together with three known furanoterpenoids and two known indole alkaloids, were isolated from the MeOH extract of the marine sponge Gelliodes sp. collected in Vietnam. The chemical structures of the isolated compounds were determined by analyses of 1D- and 2D-NMR and MS data and by comparisons of the data with those reported in the literature. The cytotoxicity assay against HeLa, MCF-7, and A549 cancer cell lines revealed that the three known furanoterpenes exhibited cytotoxic activities with IC50 values ranging from 23.6 to 75.5 μM against the three cell lines, and that 1H-indole-3-carboxylic acid showed cytotoxicity with an IC50 value of 89.2 μM against A549 cancer cell lines.

The ocotillol (OCT)-type saponins have been known as a tetracyclic triterpenoid, possessing five- or six-membered epoxy ring in the side chain. Interestingly, this type saponin was mostly found in Panax vietnamensis Ha et Grushv., Araliaceae (VG), hence making VG unique from the other Panax spp. Five OCT-type saponins, majonoside R2, vina-ginsenoside R2, majonoside R1, pseudoginsenoside RT4, vina-ginsenoside R11, together with three protopanaxadiol (PPD)-type saponins and four protopanaxatriol (PPT)-type saponins from VG were evaluated for their antimelanogenic activity. All of isolates were found to be active. More importantly, the five OCT-type saponins inhibited melanin production in B16-F10 mouse melanoma cells, without showing any cytotoxicity. Besides ginsenoside Rd and ginsenoside Rg3 in PPD and notoginsenoside R1 in PPT-type saponins, majonoside R2 was the most potent melanogenesis inhibitory activity in OCT-type saponins. In this article, we highlighted antimelanogenic activity of OCT-type saponins and potential structure-activity relationship (SAR) of ginsenosides. Our results suggested that OCT-type saponins could be used as a depigmentation agent.

Three new steroidal saponins, aspiletreins A–C (1–3), together with 2H-chromen-2-one (4), and α-tocopherol (5), were isolated from whole Aspidistra letreae plants collected in Vietnam. Their structures were elucidated by a combination of spectroscopic analyses, including 1D- and 2D-NMR, IR, and HRESIMS, and by comparison with the reported data in the literature. Compounds 1–3 exhibited moderate cytotoxicities against the LU-1, HeLa, MDA-MB-231, HepG2, and MKN-7 human cancer cell lines, with IC50 values ranging from 7.69 ± 0.40 to 20.46 ± 3.11 µM.

Sesquiterpenoid quinones with remarkable properties, such as anti-inflammatory, antibacterial, antiviral, antitumor, antiangiogenic, and differentiation-inducing activities, have reportedly been isolated from the marine sponge genera Dysidea, Spongia, and Dactylospongia. In our continuing search for bioactive compounds from marine sponges, three new sesquiterpenoid quinones, langcoquinones D-F (1-3), were isolated from the ethyl acetate extract of Spongia sp. collected from Vietnam. Their chemical structures were elucidated on the basis of extensive spectroscopic analyses. The newly isolated compounds 1-3 were assessed for their antibacterial activities against Gram-positive bacteria, Bacillus subtilis and Staphylococcus aureus, and Gram-negative bacteria, Klebsiella pneumoniae and Escherichia coli, as well as their cytotoxic activities against three human cancer cell lines (A549, lung cancer; MCF7, breast cancer; HeLa, cervical cancer) and a human normal cell line (WI-38 fibroblast). All compounds were inactive against the Gram-negative bacteria. Furthermore, langcoquinones E (2) and F (3) lacked antibacterial activities against the Gram-positive bacteria and cytotoxic activities against the tested cell lines. However, langcoquinone D (1) exhibited good antibacterial activities against Bacillus subtilis and Staphylococcus aureus, with MIC values of 12.5 and 25.0 µM, respectively. Furthermore, 1 exhibited significant cytotoxic activities against three human cancer cell lines (A549, lung cancer; MCF7, breast cancer; HeLa, cervical cancer) and a human normal cell line (WI-38 fibroblast).

The aim of the research was to study the active constituents of Anodendron paniculatum Roxb. (Apocynaceae). A new triterpene ester, named anopaniester (1), and cycloartenol (2), ursolic acid (3), esculenic acid (4), bis-(2-ethylhexyl) phthalate (5), desmosterol (6), stigmasterol (7), vaniline (8), and (E)-phytol (9), were isolated from the aerial parts of A. paniculatum. Compounds 3 and 6 showed the significant inhibitory effect (IC50 values ranging from 30.89 ± 3.60 to 44.37 ± 5.40 μg/ml) against tested human cancer cell lines LU-1 and MKN-7. The compounds 1–4, and 6 were isolated from this genus Anodendron for the first time.

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In this paper, we investigate a three-phase two-way (TW) amplify-and-forward (AF) relaying for cognitive radio networks. By utilizing the direct communications, the end user can employ maximal ratio combining to achieve the full diversity. We derive the closed-form and asymptotic expressions for user and system outage probabilities which allow us to highlight the advantage of cooperative cognitive communications. The numerical results, obtained through compact forms of these outage probabilities, yield that the cognitive TW AF relaying scheme can significantly enhance the reliability of unlicensed networks in which the transmit power at each secondary user is strictly governed.

This paper introduces for the first time a relay-assisted heterogeneous vehicular model including numerous stationary small cells, a mobile relay and a mobile receiver with unreliable backhaul. In this proposed system model, a macro-base station connected to the cloud communicates to numerous small cells through wireless backhaul links. A Bernoulli process is utilized to model the backhaul reliability. A relay using decode-and-forward protocol is considered to help the transmission from the stationary small cells to the mobile receiver. Moreover, at the mobile relay side, a selection combining protocol is applied to maximize the received signal-to-noise ratio. The links between stationary small cells and mobile relay are Rayleigh fading channels, and the link between mobile relay and mobile receiver is double-Rayleigh fading channel. A closed-form expression for outage probability is provided to evaluate the influence of the number of small cells and the backhaul reliability on the proposed system performance.

A cognitive heterogeneous network with unreliable backhaul connections is studied in this paper. In this system, a macro-base station connected to cloud transmits information to multiple small cells via backhaul links. In addition, multiple small cells acting as secondary transmitters send information to a receiver by sharing the same spectrum with multiple primary users. Bernoulli process is adopted to model the backhaul reliability. Selection combining protocol is used at the receiver side to maximize the received signal-to-noise ratio. We investigate the impacts of the number of small-cells, the number of primary users as well as the backhaul reliability on the system performance, i.e., outage probability in Rayleigh fading channels. Closed-form expressions are derived and asymptotic analysis is also provided.

This paper proposes the adaptive indirect learning architecture (ILA) based digital predistortion (DPD) technique using a recursive prediction error minimization (RPEM) algorithm for linearizing radio frequency (RF) power amplifiers (PAs). The RPEM algorithm allows the forgetting factor to vary with time, which makes the predistorter (PD) parameter estimates more consistent and accurate in steady state, and hence reduces mean square errors. The proposed DPD technique is evaluated with respect to the error vector magnitude (EVM) and the adjacent channel power ratio (ACPR). The simulated PA Wiener model is used to validate the efficiency of the proposed algorithms. The simulation results have confirmed the improvement of the proposed adaptive RPEM ILA based DPD in terms of EVM and ACPR.

Several metals in soil affect the production of secondary metabolites in medicinal plants. In this study, we have determined concentrations of K, Mn, Fe, Zn, Cu in soils collected at Tinh Bien, Tri Ton, Thoai Son, and Cam Mountain areas in An Giang province by X-Ray Fluorescence Spectroscopy (XRF). We simultaneously evaluated the total phenolic and flavonoid content of methanol extracts from Solanum torvum (Sw.) leaves and Zingiber zerumbet (L.) rhizomes harvested in Tinh Bien and Cam Mountain. The results showed that the concentrations of metals reached the highest values at the soil particle size 0.25 mm among three sizes: 0.25 mm, 1 mm, and 2 mm. Whereas, the metal contents at two sampling depths 0-15 cm and 15-30 cm were similar. The concentrations of K and Cu in the soil in Tinh Bien are higher than Cam Mountain at 1.18 times and 1.70 times; however, the Fe, Zn, Mn content in Tinh Bien is lower at 2.16 times, 1.64 times, and 1.43 times. Thereby, it can be seen that the higher concentration of K and Cu may contribute to increasing the total phenolic content about 1.8 times with the Zingiber zerumbet (L.) rhizomes sample, and the flavonoid content by 2.5 times for the Solanum torvum (Sw.) leaves sample in Tinh Bien compared to Cam Mountain. Meanwhile, the concentrations of Fe, Zn, and Mn did not affect the flavonoid and phenolic content in these two plants

Two new sesquiterpene aminoquinones, langcoquinones A ( 1 ) and B ( 2 ), together with seven known meroterpenoids ( 3 ⿿ 9 ), were isolated from the marine sponge Spongia sp. collected in Vietnam. Their structures were determined on the basis of spectroscopic analyses and comparisons with published data. The antibacterial activities of the isolated compounds ( 1 ⿿ 9 ) were investigated against four bacterial strains. Among these, the new sesquiterpene aminoquinones ( 1 and 2 ) and the known related compounds ( 3 , 5 , 6 , 8 , and 9 ) exhibited significant antibacterial activities against Staphylococcus aureus and Bacillus subtilis , with MICs ranging from 6.25 to 12.5 μM.

Cassaine diterpenoids amides from the stem bark of Vietnamese Erythrophleum fordii Oliver were screened for their cytotoxic activity against human cancer cells. The cell proliferation assay results showed that, among the active compounds, 3&beta, acetyl-nor-erythrophlamide (3AEP) exhibited the most potential cytotoxicity against human leukemia HL-60 and KG cells with IC50 values of 12.0 &plusmn, 1.2 and 18.1 &plusmn, 2.7 &micro, M, respectively. Treatment of 3AEP resulted in the apoptosis of HL-60 cells via the activation of caspase 3, and poly (ADP-ribose) polymerase (PARP). Molecular docking in silico results showed that the 3AEP can bind to both the procaspase-3 allosteric site and the PARP-1 active site, with binding energies of &minus, 7.51 and &minus, 9.63 kcal/mol respectively. These results indicated that the stem bark of Vietnamese E. fordii and its cassaine diterpenoid amides may be useful in the apoptosis induction of human leukemia cancer cells.

This chapter describes the folding of synthetic homogeneous glycosylpolypeptides into glycoproteins depending on the position and number of glycosylation sites and oligosaccharide structures. To evaluate the role of oligosaccharides in protein folding, we synthesized small glycoprotein models, homogeneous misfolded glycoproteins, and erythropoietins. In addition to these chemical syntheses, this chapter introduces a unique method for

A new sterol, langcosterol A (1), together with two known sterols 2 and 3, were isolated from the marine sponge Xestospongia testudinaria collected in Vietnam. Their chemical structures were elucidated on the basis of extensive spectroscopic analyses and comparisons with published data. The new compound 1 and the known compound 3 exhibited moderate cytotoxic activities against three human cancer cell lines (A549, lung cancer; MCF7, breast cancer; HeLa, cervical cancer) and a human normal cell line (WI-38 fibroblast), with IC50 values ranging from 29.0 to 68.0 μM.