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Publication

A density functional theory study on silver and bis-silver complexes with lighter tetrylene: are silver and bis-silver carbenes candidates for SARS-CoV-2 inhibition? Insight from molecular docking simulation

( 2020)

Thanh Q. Bui

;

Huynh Thi Phuong Loan

;

Tran Thi Ai My

;

Duong Tuan Quang

;

Bui Thi Phuong Thuy

;

Vo Duy Nhan

;

Phan Tu Quy

;

Pham Van Tat

;

Duy Quang Dao

;

Nguyen Tien Trung

;

Lam K. Huynh

;

Nguyen Thi Ai Nhung

Ribavirin and remdesivir have been preclinically reported as potential drugs for the treatment of SARS-CoV- 2 infection, while light silver tetrylene complexes (NHEPh–AgCl and (NHEPh–AgCl)2 with E ¼ C, Si, and Ge) have gained significant interest due to their promising applicability on the cytological scale. Firstly, the structures and bonding states of silver–tetrylene complexes (NHE–Ag) and bis-silver–tetrylene complexes (NHE–Ag-bis) were investigated using density functional theory (DFT) at the BP86 level with the def2-SVP and def2-TZVPP basis sets. Secondly, the inhibitory capabilities of the carbene complexes (NHC–Ag and NHC–Ag-bis) and the two potential drugs (ribavirin and remdesivir) on human-protein ACE2 and SARS-CoV-2 protease PDB6LU7 were evaluated using molecular docking simulation. The carbene ligand NHC bonds in a head-on configuration with AgCl and (AgCl)2, whereas, the other NHE (E ¼ Si and Ge) tetrylene ligands bond in a side-on mode to the metal fragments. The bond dissociation energy (BDE) of the NHE–Ag bond in the complex families follows the order of NHC–Ag > NHSi–Ag > NHGe–Ag and NHSi–Ag-bis > NHGe–Ag-bis > NHC–Ag-bis. The natural bond orbital analysis implies that the [NHEPh/AgCl] and [(NHEPh)2/(AgCl)2] donations are derived mainly from the s- and pcontributions of the ligands. The docking results indicate that both the ACE2 and PDB6LU7 proteins are strongly inhibited by silver–carbene NHC–Ag, bis-silver–carbene NHC–Ag-bis, ribavirin, and remdesivir with the docking score energy values varying from 17.5 to 16.5 kcal mol 1 and 16.9 to 16.6 kcal mol 1, respectively. The root-mean-square deviation values were recorded to be less than 2 A in all the calculated systems. Thus, the present study suggests that silver–carbene NHC–Ag and bissilver– carbene NHC–Ag-bis complexes are potential candidates to inhibit ACE2 and PDB6LU7, and thus potentially conducive to prevent infection caused by the SARS-CoV-2 virus.

Publication

A molecular docking simulation study on potent inhibitors against Rhizoctonia solani and Magnaporthe oryzae in rice: silver-tetrylene and bis-silver-tetrylene complexes vs. validamycin and tricyclazole pesticides

( 2020)

Bui Thi Phuong Thuy

;

Tran Thi Ai My

;

Nguyen Thi Thanh Hai

;

Huynh Thi Phuong Loan

;

Le Trung Hieu

;

Tran Thai Hoa

;

Thanh Q. Bui

;

Ho Nhat Tuong

;

Nguyen Thi Thu Thuy

;

Doan Kim Dung

;

Pham Van Tat

;

Phan Tu Quy

;

Nguyen Thi Ai Nhung

Rice, well known as the most important staple food source worldwide, is highly susceptible to many infectious diseases, especially rice sheath blight caused by fungus Rhizoctonia solani and rice blast caused by fungus Magnaporthe oryzae. The inhibitory ability of silver- and bis-silver-tetrylene complexes, including Ag-E and bis-Ag-E with E = C, Si, Ge, onto protein 4G9M in Rhizoctonia solani and protein 6JBR in Magnaporthe oryzae was theoretically investigated using molecular docking simulation methodology. Two commercial pesticides selected as inhibitory references are validamycin for 4G9M and tricyclazole for 6JBR. The results reveal that bis-silver-tetrylene complexes perform the strongest inhibitory effects towards both proteins. The structures of the complexes exhibit good site–site binding to both proteins given the observations on the hydrogen bond interactions, cation–π bonds, π–π bonds, and ionic interactions, interaction distance between amino acids and ligands, and van der Waals interactions. The inhibitory capacity onto protein 4G9M decreases in the following order: bis-Ag-C > bis-Ag-Si > bis-Ag-Ge > validamycin > Ag-C ≈ Ag-Si ≈ Ag-Ge. The corresponding order observed from the study for protein 6JBR is bis- Ag-C > bis-Ag-Si ≈ bis-Ag-Ge > tricyclazole ≈ Ag-C ≈ Ag-Si ≈ Ag-Ge. The study opens a promising approach to tackle rice blast and rice sheath blight based on a family of silver-tetrylene organometallic chemicals given the theoretical proof of environment-advanced properties and molecule-scaled effectiveness.

Publication

A new resorcinol derivative from the bark of Aegiceras floridum (Primulaceae)

( 2020)

Huynh-Van-Long Luu

;

Thi-Hoai-Thu Nguyen

;

Kim-Phi-Phung Nguyen

;

Huu-Hung Nguyen

;

Ngoc-Hong Nguyen

;

Thuc-Huy Duong

Chemical investigation of the Vietnamese plant Aegiceras floridum Roem. & Schult. (Primulaceae) led to the isolation of the new compound 3-methoxy-5-nonylphenol (1) along with five known ones 2,8,10-trihydroxy-6H-benzo[c]chromen-6-one (2), 2-hydroxy-5-methoxy-3-nonylbenzo-1,4-quinone (3), 5-(3-hydroxypropyl)-7-methoxy-3-(methylbenzofuran-2-yl)-3-methoxyphenol (4), 2,8-dihydroxy-7-methoxy-3,9-diundecyldibenzofuran-1,4-dione (5) and 10-hydroxy-4-methoxy-2,11-diundecylgomphilactone (6). The structures were elucidated by analysis of their HRESIMS and NMR data as well as the comparison of their NMR data with those reported in the literature. The cytotoxic activity of selected isolated compounds against some cancer cell lines such as human epithelial carcinoma (HeLa), human lung cancer (NCI-H460), liver hepatocellular carcinoma (HepG2), human breast cancer (MCF-7), and acute T cell leukemia (Jurkat) was evaluated. Among them, 3 showed moderate activities against MCF-7 with an IC50 of 17.77 µM and NCI-H460 with an IC50 of 25.02 µM. The result of DPPH radical scavenging activity assay indicated that compounds 2–4 and 6 revealed weak antioxidant activity.

Publication

A Review on: Extraction and Analysis of Phenolics in plants A Case Study in Basil Leaves

( 2020)

Ma Bich Nhu

;

Phan Phuoc Hien

Phenolic compounds are abundant in majority of food researches because of having numerous positive effects for health-protecting properties and enhancement. Similarly, it has been reported to possess antioxidant properties in basil leaves (Ocimum basilicum L.). Moreover, its phenolic compounds include simple phenol, hydrobenzonic acid and cinnamic acid derivatives, flavonoids, tannins, among others. The extraction of phenolics from raw materials is the first step for their analysis. Therefore, this paper provides a summary of background information and the extraction methods used for the analysis of phenolics in this plant material, especially in basil leaves, a case study.

Publication

Allelopathic Potential of Rice and Identification of Published Allelochemicals by Cloud Based Metabolomics Platform

( 2020)

Vũ Công Danh

The methanol extracts of nine popular cultivated Vietnamese rice cultivars (Oryza sativa L.cv. OM 2395, 5451, 6976, 380, 5930, 4498, 3536, N406, and 7347) were used to explore their allelopathic potential on barnyardgrass (Echinochola crus-galli L.). At 0.1 g mL􀀀1, OM 5930, OM 4498, and OM 6976 correlatively possessed greatest phytotoxicity on barnyardgrass shoot (98.77%, 90.75%, and 87.17%) and root (99.39%, 92.83%, and 86.56%) growth. The following study aimed to detect previously-known allelochemicals in those rice using XCMS online cloud-based metabolomics platform. Twenty allelochemicals were semi-quantified and seven of them were detected predominantly and five was putatively confirmed in OM 5930 (mg/ 100g fresh rice) as salicylic acid (5.0076), vanillic acid (0.1246), p-coumaric acid (0.1590), 2,4-dimethoxybenzoic acid (0.1045), and cinnamic acid (3.3230). These compounds were active at concentrations greater than 0.5mMand the average EC50 were 1.24 mM. The results indicated thatOM5930 may use as promising candidates in weed biological control for rice production.

Publication

An overview of phytochemicals and potential health-promoting properties of black walnut

( 2020)

Danh C. Vu

;

Trang H. D. Nguyen

;

Thi L. Ho

Black walnut (Juglans nigra L.) is one of the most widely consumed nuts in the United States. The nut has been recognized for its unique, bold flavor, and used as a versatile food ingredient. The objective of this review is to summarize available research data pertaining to phytochemicals present in black walnut and their previously reported health-promoting properties. Black walnut is rich in phenolics and contains higher levels of phytosterols, unsaturated fatty acids and tocopherols than many other commonly consumed nuts. Dietary intervention of these constituents has been associated with a great number of disease-preventive properties. Black walnut has a potential to inhibit the release of proinflammatory mediators in vitro. Similarities in contents of unsaturated fatty acids and tocopherols between black walnut and English walnut suggest that black walnut consumption may produce beneficial effects on cardiovascular disease risks. In addition, the high level of g-tocopherol in black walnut could make the nut a cancer-preventive option. Although evidence has shown black walnut kernel is a rich source of phytochemicals of potential importance to human health, there is a paucity of in vitro and in vivo studies on the bioactivities of these phytochemicals isolated from black walnut and the health-promoting properties of black walnut consumption. Clinical studies are needed to better understand the health benefits of black walnut.

Publication

Antioxidant activity of some natural essential oils in Vietnam: Comparison between QSAR simulation and experimental study

( 2020)

Tran Thi Ai My

;

Le Trung Hieu

;

Nguyen Thi Thanh Hai

;

Ton Nu My Phuong

;

Huynh Thi Phuong Loan

;

Bui Thi Phuong Thuy

;

Nguyen Thi Ai Nhung

Antioxidant activities of essential oils from leaves of Piper betle L. (T) and Cleistocalyx operculatus L. (V), and aerial parts of Ageratum conyzoides L. (H) natively grown in Thua Thien Hue province of Vietnam were investigated. Quantitative structure–activity relationship (QSAR) model was constructed from the 27 compounds including 4-hydroxy-chromene-2H-one and its derivatives. DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity was applied to estimate the antioxidant property of these essential oils through IC50 (μg/mL) values. QSAR model is used to predict the radical scavenging activity IC50 μg/mL of T, V, and H. The results indicate that there is a good agreement between the experimental data and the predicted values using the QSAR model. The three essential oils display the DPPH radical scavenging activities with the IC50 values being in the order of T > H > V of 3.71 μg/mL, 596.44 μg/mL and 637.03 μg/mL, respectively. The essential oil of T exhibits the strong DPPH radical scavenging activity that is close to the reference compound ascorbic acid (IC50 value of 3.03 μg /mL).

Publication

Chitin Hydrogels Prepared at Various Lithium Chloride/N,N-Dimethylacetamide Solutions by Water Vapor-Induced Phase Inversion

( 2020)

Khoa Dang Nguyen

;

Takaomi Kobayashi

;

Barbara Gawdzik

Chitin was chemically extracted from crab shells and then dissolved in N,N-dimethylacetamide (DMAc) solvent with lithium chloride (LiCl) at 3, 5, 7, and 10%. The concentrated chitin-DMAc/LiCl solutions were used for the preparation of chitin hydrogels by water vapor-induced phase inversion at 20°C. The coagulation process was investigated while altering the concentration of LiCl in the DMAc solution. The shear viscosity of the chitin solution increased with higher LiCl amounts and decreased when the concentration of LiCl was reduced by adding water to the chitin solution, implying high LiCl concentration delayed the coagulation of chitin solution in the presence of water. The viscoelasticity of the chitin solutions indicated the gel formation intensification was dependent on the dose of LiCl and chitin in the DMAc solution. After the chitin solution was coagulated, the resultant hydrogels had water contents of 387–461% and the tensile strength varied from 285 to 400 kPa when the concentration of LiCl in the hydrogel was adjusted to 3% and 7%, respectively. As for viscoelasticity, the complex modulus of the chitin hydrogels indicated that the increment of the LiCl concentration up to 7% formed the tight hydrogels. Atomic force microscopic (AFM) image revealed the formation of the entanglement network and larger domains of the aggregated chitin segments. However, the hydrogel prepared at 10% LiCl in DMAc solution exhibited weak mechanical properties due to the loose hydrogel networking caused by the strong aggregation of the chitin segments.

Publication

Coordination complexes of slight tetrylene with platinum(II)-8-hydroxyquinolines: Structure and bonding analysis

( 2020)

Huynh Thi Phuong Loan

;

Hoang Van Duc

;

Phan Tu Quy

;

Bui Thi Phuong Thuy

;

Pham Van Tat

;

Duong Tuan Quang

;

Nguyen Thi Ai Nhung

The structure and bonding situation in platinum complexes containing slight tetrylene ligands [{PtCl-C9H6NO}-NHE] (Pt-NHE) with E = C, Si, Ge were examined by DFT calculations with the levels are BP86/def2-SVP and BP86/def2-TZVPP. The predicted equilibrium structure of the ligands NHE in Pt-NHE are bonded in distorted end-on way to PtCl-8-hydroxyquinolines fragment with the bending angle, , exhibits the biggest value in carbenes systems then slightly decrease from Pt-NHC to Pt-NHGe. Bond dissociation energies (BDEs), De (kcal.mol-1), decrease from the carbene complex to the weaker bonded silylene and germylene manners. The BDE when considering dispersion correction at the BP86-D3(BJ)/def2-TZVPP level confirms that Pt-E bond in Pt-NHE belongs to the effect of the bulky group in slight tetrylene NHE and Pt(II)-group fragment which makes the intrinsic Pt-E bond strength decreases from carbene to germylene complexes. The hybridization of atoms E and Pt have large p characters while the hybridization of atom Pt has greater d character which lead to the Pt-E bond possesses not only NHE→{PtCl-C9H6NO} strong -donation but also a significant contribution π-donation NHE→{PtCl-C9H6NO} and weak π-backdonation metal-ligand NHE←{PtCl-C9H6NO} in complexes Pt-NHE.

Publication

Design and synthesis of new lupeol derivatives and their α-glucosidase inhibitory and cytotoxic activities

( 2020)

Hoang-Vinh-Truong Phan

;

Thuc-Huy Duong

;

Duc-Dung Pham

;

Hoang-Anh Pham

;

Van-Kieu Nguyen

;

Thi-Phuong Nguyen

;

Huu-Hung Nguyen

;

Ngoc-Hong Nguyen

;

Pornpat Sam-ang

;

Kiettipum Phontree

;

Jirapast Sichaem

were designed, synthesised and evaluated for their a-glucosidase inhibitory and cytotoxic activities. Among synthetic derivatives, lupeol analogues 2b and 2e containing a benzylidene chain exhibited the best activity against a-glucosidase and superior to the positive agent with the IC50 values of 29.4 ± 1.33 and 20.1 ± 0.91 lM, respectively. Lupeol analogues 2d and 3a showed weak cytotoxicity against K562 cell line with the IC50 values of 76.6 ± 2.40 and 94.4 ± 1.51 lM, respectively.

Publication

Design, modification of phyllanthone derivatives as anti-diabetic and cytotoxic agents

( 2020)

Ngoc-Hong Nguyen

;

Van-Giau Vo

;

Hoang-Vinh-Truong Phan

;

Thanh-The Ngo

;

Jirapast Sichaem

;

Thi-Phuong Nguyen

;

Huu-Hung Nguyen

;

Duc-Dung Pham

;

Tien-Cong Nguyen

;

Van-Kieu Nguyen

;

Thuc-Huy Duong

Twelve benzylidene derivatives, one Baeyer-Villiger oxidative, six imine derivatives were successfully designed and synthesized from phyllanthone. In the search for potential new anti-diabetic agents, phyllanthone along with its benzylidene and oxidation analogues were evaluated for enzyme inhibition against α-glucosidase. In the benzylidene series, most analogues displayed stronger activity than the mother compound. 1c revealed the strongest activity, outperforming the acarbose positive control with an IC50 value of 19.59 μM. Phyllanthone and its derivatives were then tested for cytotoxic activity against the K562 cell line. The imine analogues displayed the most powerful cytotoxic activity with 3c, 3d having IC50 values of 57.55 and 68.02 μM, respectively.

Publication

Dilatatone, a new chlorinated compound from Parmotrema dilatatum

( 2020)

Hoang-Vinh-Truong Phan

;

Asshaima Paramita Devi

;

Hoang-Duy Le

;

Thanh-Trung Nguyen

;

Huu-Hung Nguyen

;

Tran-Thai-Duong Le

;

Tai Hoang Nguyen

;

Jirapast Sichaem

;

Thuc-Huy Duong

Chemical investigation of the lichen Parmotrema dilatatum led to the isolation of a new chlorinated compound, named dilatatone (1), along with a known compound, sernanderin (2). Their chemical structures were determined by analysis of their 1D and 2D NMR spectra, HRESIMS, and ECD data. Both compounds showed weak a-glucosidase inhibitor activity.

Publication

Engineering a homogeneous alloy-oxide interface derived from metal-organic frameworks for selective oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid

( 2020)

Yu-Te Liao

;

Van Chi Nguyen

;

Nozomu Ishiguro

;

Allison P. Young

;

Chia-Kuang Tsung

;

Kevin C.-W. Wu

The selective oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is an important biomass conversion reaction. However, the multiple intermediates of the reaction make the catalyst design challenging. We engineered an active and selective catalyst with an active interface between Au-Pd alloy nanoparticles (NPs) and cobalt oxide supports via calcination of a composite of NPs encapsulated in metal-organic frameworks (MOFs). The catalyst shows an effective HMF-to-FDCA oxidation with total conversion and 95 % yield by 10 % hydrogen peroxide solution at 90 °C in one hour under atmospheric pressure. The mechanistic study shows that the engineered interface promotes the formation of hydroperoxyl radicals and dioxygen molecules, which accelerate the oxidation of reactive intermediates to FDCA. This work demonstrates the advantage of using MOF composites as a precursor to generate complex but active interfaces with a strong interaction between the metal and metal oxides.

Publication

Evaluation of the Anti Inflammatory and Anticancer Activities of Catechins Extracted from Green Tea (Camellia Sinensis) in Some Cancer Cell Lines

( 2020)

Ho Thi Ngoc Tram

Catechins from Green tea (Camellia sinensis) is widely known for many biological activities, special anti-cancer and anti-inflammatory properties. Catechins were extracted by mechanical blending, and using citric acid, with 2.31% in extraction efficiency. The result of determining by HPLC-UV showed that Catechin< EC < EGC < ECG < EGCG in concentration compared to dry powder, reaching a total content of 634.51 mg/g, higher than tea powder (537.65 mg/g). Then, anti-inflammatory and anticancer activities of these extracts were investigated. Cell viability assay (MTT) showed that catechin extracts were not toxic to Normal Human Dermal Fibroblasts Cells. They even exhibited anti-inflammatory activities by suppressing the production of NO and proinflammatory cytokines. The results also showed that the extracted catechin powder also showed good anti-inflammatory activity, at a concentration of 45 ?g/mL, NO proliferation reached 44.4%. Anticancer activities of these extracts were displayed through their ability to inhibit the growth of cancer cell lines: liver cancer cell line (HepG2), lung cancer cell line (A549), leukemia cancer cell line (K562), with IC50 values of 181.1 μg/mL, 186 μg/mL, 137.8 μg/mL, respectively. So catechin extracts from green tea may have the potential to be applied in pharmaceutical.

Publication

Green synthesis of cobalt-oxide nanoparticle using jumbo Muscadine (Vitis rotundifolia): Characterization and photo-catalytic activity of acid Blue-74

( 2020)

Melvin S. Samuel

;

E. Selvarajan

;

Thangavel Mathimani

;

Needhidasan Santhanam

;

Tran Nhat Phuong

;

Kathirvel Brindhadevi

;

Arivalagan Pugazhendhi

In the recent years, plant and microbial extract based nanoparticles (NPs) have become a sophisticated technology serving as an alternative strategy for the purpose of developing materials functionalized by structural diversity and enhanced energy efficiencies. Cobalt oxide nanoparticles (GCoO-NPs) have wide applications in several sectors due to their high resistance to corrosion as well as oxidation, ecofriendly nature, cost effectiveness and nontoxic potential. Plant based particles are credible alternatives as they reduce the burden of complicated and laborious protocols of physiochemical reliance. In this study, GCoO-NPs were synthesized using the grape Jumbo Muscadine (Vitis rotundifolia) using co-precipitation. The synthesized GCoO-NPs were characterized by UV–Vis spectrophotometer, Fourier transform infrared spectroscopy (FTIR), Powder X-ray diffraction (PXRD) and Scanning electron microscopy (SEM). The photocatalytic activity of the GCoO-NPs was estimated by the degradation of Acid Blue-74 (AB-74) dye and the complete degradation of 98% was accomplished at the reaction time of 150 min at pH 10 and 60 mg/100 mL concentration. The outcomes of this study indicated the excellent performance of the GCoO-NPs on par with some of the earlier findings and this can be an appealing aspirant of extreme potential to be employed as a catalyst alternative to the conventional wastewater treatment methods.

Publication

Investigation into SARS-CoV-2 Resistance of Compounds in Garlic Essential Oil

( 2020)

Bui Thi Phuong Thuy

;

Tran Thi Ai My

;

Nguyen Thi Thanh Hai

;

Le Trung Hieu

;

Tran Thai Hoa

;

Huynh Thi Phuong Loan

;

Nguyen Thanh Triet

;

Tran Thi Van Anh

;

Phan Tu Quy

;

Pham Van Tat

;

Nguyen Van Hue

;

Duong Tuan Quang

;

Nguyen Tien Trung

;

Vo Thanh Tung

;

Lam K. Huynh

;

Nguyen Thi Ai Nhung

Eighteen active substances, including 17 organosulfur compounds found in garlic essential oil (T), were identified by GC−MS analysis. For the first time, using the molecular docking technique, we report the inhibitory effect of the considered compounds on the host receptor angiotensin-converting enzyme 2 (ACE2) protein in the human body that leads to a crucial foundation about coronavirus resistance of individual compounds on the main protease (PDB6LU7) protein of SARS-CoV-2. The results show that the 17 organosulfur compounds, accounting for 99.4% contents of the garlic essential oil, have strong interactions with the amino acids of the ACE2 protein and the main protease PDB6LU7 of SARS-CoV- 2. The strongest anticoronavirus activity is expressed in allyl disulfide and allyl trisulfide, which account for the highest content in the garlic essential oil (51.3%). Interestingly, docking results indicate the synergistic interactions of the 17 substances, which exhibit good inhibition of the ACE2 and PDB6LU7 proteins. The results suggest that the garlic essential oil is a valuable natural antivirus source, which contributes to preventing the invasion of coronavirus into the human body

Publication

Luminescence and Thermal-Quenching Properties of Red-Emitting Ca2Al2SiO7:Sm3+ Phosphors

( 2020)

Nguyen Manh Son

;

Do Thanh Tien

;

Nguyen Thi Quynh Lien

;

Vu Xuan Quang

;

Nguyen Ngoc Trac

;

Tran Thi Hong

;

Ho Van Tuyen

Ca2Al2SiO7:x.Sm3+ (x = 0.5, 1.0, 1.5, 2.0, 2.5, and 3.5 mol.%) (CAS:x.Sm3+) phosphors were synthesized by a solid-state reaction technique. The structure, photoluminescence properties and thermal stability of phosphors were investigated in detail. Results of X-ray diffraction show that CAS:x.Sm3+ materials have a single-phased tetragonal structure, and an expansion of the unit cell relates to the increasing of Sm3+ concentration. Photoluminescence study displayed that the CAS:x.Sm3+ phosphors reach the highest emission intensity at 1.5 mol.% Sm3+ and achieved the luminescence quenching phenomenon a higher concentration. The dominant interaction mechanism of the concentration quenching process is determined due to the dipole–dipole interaction, and the critical transfer distance (Rc) is 26.7 A ° . The temperature dependence of photoluminescence spectra indicates that the Ca2Al2SiO7:Sm3+ (1.5 mol.%) phosphor possess good thermal stability, and that the activation energy is around 0.12 eV (968 cm 1). Several characteristic vibrations in the 200–1000-cm 1 region were observed by Raman spectra, and the color chromaticity coordinates of the samples were also calculated and discussed.

Publication

Manilkzapotane, a novel dimeric alkylresorcinol derivative from the stem bark of Manilkara zapota

( 2020)

Thuc-Huy Duong

;

Nguyen Tien Trung

;

Cam-Tu D. Phan

;

Van-Kieu Nguyen

;

Vassana Musa

;

Thanatip Ruksilp

;

Ngoc-Hong Nguyen

;

Huu-Hung Nguyen

;

Jirapast Sichaem

A novel dimeric alkylresorcinol derivative, manilkzapotane (1), along with seven known compounds, lupeol acetate (2), lupeol (3), arjunolic acid (4), ergosterol peroxide (5), taraxerol (6), hederagonic acid (7), and glochidiol (8) were isolated from the stem bark of Manilkara zapota. Their structures were determined on the basis of spectroscopic data. DFT-NMR chemical shift calculations and a modified probability (DP4þ) method were applied to define the relative configuration of 1. To the best of our knowledge, this represents the first isolation of a dimeric alkylresorcinol derivative from the Sapotaceae family.

Publication

Metal organic Framework 118 (MOF 118): A Heterogeneous Catalyst for Effective Synthesis of Pyrroles from Aryl Amines and 2,5 hexanedione

( 2020)

Nguyen Van Chi

;

Nguyen Thi Hong Huong

Metal-organic frameworks (MOFs) have been widely used in many applications, particularly catalysis. Here, we reported the synthesis and characteristics of metal–organic framework-118 (MOF-118), which was used for pyrroles synthesis via Paal-Knorr reaction between diketone and aryl amines. It was found that MOF-118 exhibited excellent activity in the reaction between p-anisidine and 2,5-hexanedione. The reaction parameters including catalyst concentrations, reaction temperatures, molar ratio of p-anisidine/2,5-hexadione, and solvents, were systematically investigated. Almost 100% conversion was achieved under the optimized reaction conditions. The reusability of MOF-118 catalyst was studied. Furthermore, we demonstrated that the functional groups on aryl amines have strongly effect on the reaction rate.

Publication

Molecular Docking Studies of Glycyrrhetinic Acid Derivatives as Anti-Colorectal Cancer Agents

( 2021)

Nam Q.H. Doan

;

Tuyen N. Truong

;

Phuong T.V. Nguyen

In this study, the anti-CRC activities of 40 glycyrrhetinic acid derivatives were proposed and evaluated by the molecular docking method, which allowed the flexibility of both ligand-receptor, with twelve CRC-related targets. The proposed derivatives, which clearly distinguish isomers at position 18 as well as the different tautomers, were divided into five groups including (1) glycyrrhetinic acid and its oxidation derivatives, (2) glycoside derivatives, (3) 3β-amine derivatives, (4) five-membered heterocyclic ring-combined derivatives, and (5) six-membered heterocyclic ringcombined derivatives. Finally, we selected four out of twelve proposed targets related to CRC with good binding affinities to the proposed glycyrrhetinic acid derivatives including Epidermal Growth Factor Receptor (EGFR), Focal Adhesion Kinase (FAK), Lactate Dehydrogenase A (LDHA), and Thymidylate Synthase (TS). From there, we also gained 9/40 derivatives for EGFR (pKd ≥ 9); 10/40 derivatives for FAK (pKd ≥ 10); 9/40 derivatives for LDHA (pKd ≥ 10), and 6/40 derivatives for TS (pKd ≥ 9). The glycoside derivatives showed the best binding affinity (especially the glucuronide derivative 5b), followed by the 3β-amino derivatives (especially the 3β-(phenylamino) derivative 8b) and the five-membered heterocyclic ring-combined derivatives (especially the pyrrole derivative 10a or pyrazole derivative 11.2a), while the six-membered heterocyclic ring-combined derivatives had less potential to inhibit selected targets.

Journal Articles - Natural Science - 2020

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