Research List

No.	Researcher	Title	Abstract	Year
1531	San San Aye	BIOLOGICAL PROPERTIES AND CHEMICAL INVESTIGATION OF MYANMAR FERMENTED TEA LEAF (CAMELLIA SINENSIS L.)	Tea leaves possess many useful biological activities and are consumed in the daily life of the Myanmar people which have been the reason for the selection of this plant for the present paper. Bioassay offers special advantages to know about the biological activity of plant extracts and provide information to isolate active compounds which is a preliminary key step for drug discovery system. Bioassays such as antimicrobial activity, antiproliferative and anti-inflammatory activities were determined. The main aim of the present research was to evaluate the biological properties of Camellia sinensis L. leaves. The antimicrobial activity of polar and non-polar extracts of the fermented tea leaves was screened by using agar well diffusion method. Among the tested extracts, flavonoid extract of fermented tea leaves possessed higher antimicrobial activity (30 mm- 35 mm) than the other extracts. In vitro antiproliferative activity of ethanol and watery extracts of the fermented tea leaves was investigated against human lung cancer and human cervix cancer by MTT assay. The IC50 values of ethanol and watery extracts for human lung cancer were observed 95.34 �g/mL and 123.44 �g/mL, respectively. In the case of human cervix cancer, the IC50 values for ethanol and watery extracts were found to be 116.26 �g/mL and 124.39 �g/mL, respectively. No antiinflammatory activity was found in both water and 70 % EtOH extracts by % NO inhibition assay and there was also no toxicity effect up to >100 �g/mL concentration. The fermented tea leaves were extracted with 70 % ethanol and followed by column chromatographic separation technique. Five compounds were isolated from the ethanol extract. The structures of isolated pure compounds were elucidated by 1H NMR, 13C NMR and ESI-MS spectroscopic methods. In conclusion, 70 % ethanol extracts of the fermented tea leaves possess significantly anticancer activity and antimicrobial activity. Therefore, fermented tea leaves (C. sinensis L.) may be used for preventing cancer and used as antimicrobial agent.	2021
1532	Khin Hnin Htay	ANTIMICROBIAL, ANTIOXIDANT PROPERTIES OF DIOSCOREA BULBIFERA (AIR POTATO) TUBER EXTRACT AND STRUCTURE ELUCIDATION OF ISOLATED BIBENZYL DERIVATIVE	Chemical investigation of tuber of Dioscorea bulbifera Linn. (Local name Put-sar-u) led to the isolation of bibenzyl derivative namely, 3-methoxy-4, 3', 5' -trihydroxybibenzyl (1). The structure of isolated metabolite was elucidated by spectroscopic techniques, particularly by 1D and 2D NMR spectroscopy and mass spectrometry. Antioxidant and antimicrobial properties of various solvent extracts was studied by using DPPH radical scavenging assay and agar-well diffusion method respectively.	2021
1533	Han Su Lwin	ISOLATION AND STRUCTURE ELUCIDATION OF PHENYLNAPHTHALENE DERIVATIVE FROM TUBEROUS ROOTS OF ORTHOSIPHON RUBICUNDUS (D.DON) BENTH. AND STUDY ON ITS ANTIOXIDANT PROPERTY	The present study was conducted to investigate bioactive chemical constituent from Myanmar medicinal plant, Orthosiphon rubicundus (D.Don) Benth. Firstly, phytochemical screening of the selected medicinal plant was performed according to standard procedure. Then, the antimicrobial assay of various extracts was performed on six test microorganisms. Phenylnaphthalene derivative namely, 1-(4-hydroxy-3,5-dimethoxyphenyl)-2,3-dimethyl-5,6,7-trimethoxynaphthalene (1) was isolated from ethyl acetate extract by using separation techniques such as thin layer and column chromatographic methods. Moreover, the antioxidant activities of crude extract and isolated compound were evaluated using DPPH radical scavenging assay. Furthermore, structure elucidation of isolated compound was performed by spectroscopic techniques, particularly by 1D and 2D NMR spectroscopy.	2021
1534	Hnin Thanda Aung	ANTIOXIDANT AND ANTICANCER ACTIVITIES OF CHEMICAL CONSTITUENTS FROM THE RHIZOMES OF Geodrum recurvum (Roxb.)	Plants have been used for medicinally since prehistoric period. The rhizomes of Geodrum recurvum Roxb. (Orchidaceae) (Myanmar name � Thudar) are used by local people in Lashio Township for cancer treatment, however, it lacks scientific investigation. The purpose of this study is the isolation of bioactive compounds from the rhizomes of Geodrum recurvum Roxb. and evaluation of their anticancer and antioxidant activities. The three monophenanthrenes (1-3) were isolated, during the first investigation of the rhizomes of Geodrum recurvum collected in Myanmar by advanced separation techniques. Their structures were determined by 1D and 2D NMR, and FAB-MS spectral data. The anticancer activity of isolated compounds (1-3) was evaluated in vitro against Hela cells using cell counting kit 8. Compounds (1-3) showed the potent activity against Hela cancer cells. In addition, compounds (1-3) exhibited potent antioxidant activity according to DPPH radicalscavenging assay. The present study provides scientific evidence for the use of Geodrum recurvum in cancer treatment and as a source of antioxidants for pharmacological preparations by traditional healer.	2021
1535	Khaing Yin Mon	ISOLATION AND STRUCTURE ELUCIDATION OF ISOFLAVAN DERIVATIVE FROM THE BARK OF ERYTHRINA CRISTA-GALLI LINN.	Purification of ethyl acetate extract of Erythrina crista-galli Linn. led to the isolation of isolflavan derivative, namely, 4', 6', 7-trihydroxy-5'-prenyl isoflavan-4-ol. The structure of isolated compound was elucidated on the basis of 1D and 2D NMR spectral data and mass spectrometry. Moreover, antimicrobial and antioxidant properties of Erythrina crista-galli extract were also evaluated by agar-well diffusion method and DPPH radical scavenging assay respectively.	2021
1536	Kyaw Aung	chromatography, flavonoid, DPPH	In the present research, the bark of Albizia procera (Roxb.) Benth. (Local name = Thit-phyu) was selected for chemical investigation. Preliminary phytochemical investigation was carried out according to the standard procedures. Antimicrobial properties was evaluated by using agar-well diffusion method on six test microorganisms such as Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus pumilus, Candida albican and Mycobacterium species. Moreover, a pure compound, pale yellow needled shape crystals, was isolated by using separation techniques such as thin layer and column chromatography. The isolated compound was assigned as flavonoid derivative, namely, 2(R), 3(S)-2-(2, 4-dihydroxy phenyl) chroman-3,5,7-triol by using spectroscopic methods, such as FT-IR, 1H NMR, 13C NMR (125 MHz), DEPT, DQF-COSY, HMQC, HMBC, NOESY, and EI mass spectral data. The isolated compound was further confirmed by phytochemical test which gave rise to positive for flavonoid test. The yield percent was calculated as (33.87 mg), (1.07%) based upon the ethyl acetate crude extract and the melting point was 191�C� 192�C. Moreover, the antioxidant activity of isolated flavonoid compound was measured by DPPH (1,1�Diphenyl-2-picryl-hydrazyl) assay. The isolated compound showed the high antioxidant activity.	2021
1537	Ei Ei Khaing	STUDY ON ESSENTIAL OIL AND SOME BIOACTIVITIES OF Citrus hystrix DC. LEAF	Citrus hystrix DC. (Shout-nu) used in household remedy for medicinal purposes was chosen for present study. Gastrointestinal tract problems and some diseases caused by mosquito become challenges in Myanmar people that many researchers have revealed the finding results of therapeutic properties from natural sources. The aim of this study is to analyze essential oil extracted from Citrus hystrix leaf Essential oil (0.02 g, 0.04 %) was extracted from leaf sample by hydro distillation method and was analysed by Fourier transform infrared (FT IR) spectroscopy. The chemical composition with molecular mass in essential oil was then determined by gas chromatography-mass spectrometry (GC-MS). Eight compounds of terpenes: alpha-pinene, D-limonene, beta-ocimene, gamma-terpinene, isopulegol, citronellol, caryophyllene and beta-bisabolene were detected. By solvent extraction method, four crude extracts of Citrus hystrix leaf were prepared with various solvents: petroleum ether, ethyl acetate, 96 % ethanol and water. Antimicrobial activity of four crude extracts was investigated against ten microorganisms by paper disc diffusion method. It was found that all tested leaf extracts exhibited ten tested microorganisms with the inhibition zone diameters range between 9~27 mm. Nevertheless, acute toxicity of 96 % EtOH and water extracts from Citrus hystrix leaf was evaluated by the method of (OECD) guidelines 423 that all tested Citrus hystrix leaf sample showed no toxicity. In addition, larvicidal activity of PE, EtOAc, water extracts and essential oil was studied by WHO standard method. According to larvicidal activity test, PE extract and essential oil have the highest larvicidal activity in vivo test larvae model, 3rd and 4th instar Aedes larvae. This research can support to the formulation of antimicrobial drugs and can provide on alternative source of mosquito control agents.	2021
1538	Nwe Thin Ni	ECO-FRIENDLY STARCH SILVER NANOCOMPOSITES FILM FROM TRITICUM AESTIVUM L. AND MANIHOT ESCULENTA C. AND THEIR ANTIMICROBIAL ACTIVITIES	In this research work, the eco-friendly starch silver nanocomposite films from Triticum aestivum L. (Wheat) and Manihot esculenta C. (Cassava Roots) were studied. Biosynthesis of starch silver nanoparticles was conducted by using silver nitrate as metal precursor and the starch solution of two plants: T. aestivum and M. esculenta as reducing and capping agents. The characterization of prepared starch capped silver nanoparticles and nanocomposite films from Wheat Flour and Cassava Roots were confirmed by XRD, FESEM and FT IR. The average crystallite sizes of prepared silver nanoparticles from T. aestivum (Wheat Flour) and M. esculenta (Cassava Root) were obtained in the range of 25-30 nm from XRD data. Different ratios of starch silver nanocomposite film were performed by the various concentrations of starch Wheat Flour solution, starch Cassava Root solution, silver nitrate solution, different stirring times and different temperatures. In addition, mechanical properties of prepared nanocomposite films were determined by thickness, tear strength, tensile strength and elongation at break. The swelling [S%] of the prepared nanocomposite films in distilled water was calculated. The antimicrobial activity of prepared nanocomposite film of Cassava Root was higher than those of pure starch extract of wheat flour and Cassava Root against S. aureus and B. subtilis by agar well diffusion method.	2021
1539	Naw Mon Thae Oo	LiNi1-xCoxO2 crystalline nanopowders, cold pressing method, ac conductivity, optical band gap	The main aim of the research is to study structural, electrical and optical properties of LiNi1-xCoxO2 (0.3 ? x ? 0.5) nanocrystalline powder. LiNi1-xCoxO2 (0.3 ? x ? 0.5) nanocrystalline powders were prepared by a modified sol�gel method using lithium nitrate (LiNO3), cobalt(II) nitrate (Co(NO3)2.6H2O) and nickel(II) nitrate (Ni(NO3)2.6H2O) as starting materials, de-ionized water as solvent, citric acid (C6H8O7.H2O) as chelating agents and carboxy methyl cellulose as dispersant agent. The prepared samples were calcined at 800 �C. The calcined powder was made as pellet form by using cold pressing method. The pellets were sintered at 900 �C. The pellets of LiNi1-xCoxO2 were characterized by XRD, FT IR and SEM. Electrical properties were examined by LCR meter in the frequency range 100 kHz � 2 MHz and frequency depended on prepared sample. The optical properties were investigated by UV-Vis spectrophotometer. From XRD data, the observed values of the average crystallite sizes of LiNi0.7Co0.3O2, LiNi0.6Co0.4O2 and LiNi0.5Co0.5O2 sintered at 900 �C were 13.58 nm, 44.31 nm and 48.03 nm, respectively. By increasing Co doping level, the average crystallite size also increased. FT IR spectra indicated the presence of the stretching vibrations of metal-oxygen (Ni-O and Co-O) chemical bonds. The spherical-shaped nanocrystalline powders were observed in SEM images. Electrical measurement revealed that the ac conductivity increased with increase in frequency. The ac conductivity of LiNi0.5Co0.5O2 was lower than those of other two prepared nanopowder samples (LiNi0.7Co0.3O2 and LiNi0.6Co0.4O2). The value of ac conductivity was between 10-2 and 10-4 S cm-1 . Dielectric constants and dielectric loss were found to decrease with increase in frequency. The experimental results indicated that the ac conductivity, dielectric constant and dielectric loss of prepared samples depend on the frequencies. From UVVis data, the optical band gap values of LiNi0.7Co0.3O2, LiNi0.6Co0.4O2 and LiNi0.5Co0.5O2 nanopowder samples were found to be 3.2, 3.4 and 3.6 eV, respectively. These band gap values (Eg) are also reliable within semiconductor band gap range.	2021
1540	Mya Theingi	STRUCTURAL AND OPTICAL PROPERTIES OF LaFeO3 AND La0.8Sr0.2FeO3 POWDERS	LaFeO3 is one of the perovskite structure materials and its optical, electrical and magnetic properties had been frequently investigated. In the present work, nanoparticles of pure LaFeO3 was prepared using the citrate sol-gel method. Sr2+ ion doped LaFeO3 or La0.8Sr0.2FeO3 was also synthesized by the same method to study the enhancement of the structural and optical properties. The synthesis involved the sol-gel method, followed by gradual heat treatment for the combustion of organic substances. The resulting powders were characterized by several techniques such as X-Ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectroscopy to study structure, morphology and the average particle size, phase, and composition. Optical properties were investigated by using the Tauc plot methodology. The optical band gap values were evaluated by diffuse reflectance spectroscopy measurements. The calculated optical band gap were found to be 2.20 eV, 2.37 eV for x = 0.00 and 0.2, respectively. The obtained results show that the structural, morphological and optical properties have affected by the substitution of Sr2+ on La3+ ion in the crystal lattice of LaFeO3.	2021

Research Publications

Myanmar Academy of Art & Science List of Research