scholarly journals IDENTIFIKASI SENYAWA AKTIF EKSTRAK DAUN CENGKEH (Syzygium aromaticum) SEBAGAI INHIBITOR Streptococcus mutans

2019 ◽  
Vol 12 (2) ◽  
pp. 229-239
Author(s):  
Usep Suhendar ◽  
Sogandi Sogandi
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Scanning Electron Microscopy ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Bioactive Compounds ◽  
Gas Chromatography Mass Spectrometry ◽  
Syzygium Aromaticum ◽  
Bacterial Cell Membrane ◽  
Scanning Electron

AbstrakKaries gigi adalah penyakit yang umum dialami oleh masyarakat yang terjadi karena buruknya kebersihan mulut. Kebiasaan masyarakat yang kurang menjaga kebersihan mulut mengakibatkan terbentuknya plak. Plak pada gigi terbentuk karena aktivitas dari berbagai macam mikroorganisme di mulut. Mikroorganisme yang diketahui terlibat dalam pembentukan karies gigi adalah Streptococcus mutans. Salah satu bahan alternatif sebagai antibakteri adalah daun cengkeh. Penelitian ini bertujuan untuk mengidentifikasi senyawa bioaktif daun cengkeh dan mengetahui mekanisme aksinya dalam menghambat pertumbuhan Streptococcus mutans. Daun cengkeh (Syzygium aromaticum) yang digunakan dalam penelitian ini dimaserasi menggunakan metanol 96%. Pengujian aktivitas antibakteri dilakukan dengan metode difusi agar, senyawa bioaktif diidentifikasi menggunakan gas chromatography mass spectrometry dan perubahan membran sel bakteri diamati dengan scanning electron microscopy. Hasil penelitian menunjukkan ekstrak metanol daun cengkeh memiliki aktivitas penghambatan terhadap pertumbuhan bakteri Streptococcus mutans dengan zona hambat sebesar ±32 mm serta nilai konsentrasi hambat minimum (KHM) 20% ekstrak. Mekanisme aksi penghambatan ekstrak daun cengkeh terhadap pertumbuhan bakteri diduga dengan membuat lubang pada membran sel bakteri. Hasil penelitian ini juga menunjukkan bahwa daun cengkeh memiliki kandungan senyawa bioaktif 3-allyl-6-methoxyphenol-eugenol, caryophyllene 1,4,7,-cycloundecatriene, 1,5,9,9-tetramethyl, phenol, 2-methoxy-4-(2-propenyl), dan eugenol acetate yang dapat menjadi kandidat penghasil senyawa aktif untuk mengatasi karies gigi.Abstract Dental caries is a common disease experienced by people who do not maintain oral hygiene. Habits of not maintain oral hygiene result in the formation of plaque. The microorganism known to be involved in the formation of dental caries is Streptococcus mutans. Plants that have antibacterial properties, such as clove (Syzygium aromaticum) leaf, can be an alternative for carrying this problem. This study aims to identify the bioactive compounds of clove leaves and to determine the mechanism of its action in inhibiting the growth of Streptococcus mutans. Clove leaves were macerated using 96% methanol for the extraction. Antibacterial activity was examined by agar diffusion method, bioactive compounds were identified using gas chromatography mass spectrometry, and bacterial cell membrane changes were observed by an image captured using scanning electron microscopy. The results showed that the methanol extract of clove leaf had inhibitory activity on Streptococcus mutans growth, with inhibitory zones of ±32 mm and the minimum inhibitory concentration (MIC) of 20% extract. It was suspected that the mechanism of inhibitory action is by making pores in the bacterial cell membrane. The results also showed that the clove leaves contain bioactive compounds of 3-allyl-6-methoxyphenol-eugenol, caryophyllene, 1,4,7, -cycloundecatriene, 1,5,9,9-tetramethyl, phenol, 2 -methoxy-4- (2-propenyl), and eugenol acetate which can be candidates for producing active compounds to overcome dental caries.

Electrochemical oxidation of lignin for the production of value-added chemicals on Ni-Co bimetallic electrocatalysts

Holzforschung ◽  
2018 ◽  
Vol 72 (11) ◽  
pp. 951-960 ◽  
Author(s):  
Raziyeh Ghahremani ◽  
John A. Staser
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Scanning Electron Microscopy ◽  
Electrochemical Oxidation ◽  
Degradation Products ◽  
Value Added ◽  
Deposition Process ◽  
Gas Chromatography Mass Spectrometry ◽  
X Ray ◽  
Scanning Electron

AbstractLignin has been submitted to electrochemical oxidation in the presence of nickel (Ni), cobalt (Co) and Ni-Co bimetallic electrocatalysts, which were prepared by a simple electrochemical deposition process. The composition and morphology of the catalyst were studied by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA). The effects of the three electrocatalysts on the electrochemical oxidation of lignin were observed by cyclic voltammetry and chronoamperometry. The degradation products were quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS). The rate of electrochemical oxidation of lignin is higher with Ni-Co bimetallic electrocatalyst with higher Co contents and the main products obtained were vanillin, apocynin and 3-methylbenzaldehyde.

MDMA (3,4-methylenedioxymethamphetamine) nitrate – an atypical salt form or a new trend in the drug market?

2017 ◽  
Vol 296 ◽  
pp. 86-94
Author(s):  
Robert Bachliński ◽  
◽  
Małgorzata Galarda ◽  
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Scanning Electron Microscopy ◽  
Gas Chromatography ◽  
Infrared Spectroscopy ◽  
Illicit Drug ◽  
Drug Market ◽  
Gas Chromatography Mass Spectrometry ◽  
Salt Form ◽  
Scanning Electron

The article presents a case involving an appearance of an atypical 3,4-methylenedioxymethamphetamine (MDMA) in the form of nitrate on the illicit drug market. This compound can be identified only by using such analytical methods as capillary electrophoresis (CE) or scanning electron microscopy (SEM), which are not routinely applied to forensic analyses of this type of substances. Therefore, particular caution should be exercised whenever a gas chromatography-mass spectrometry (GC-MS) method unambiguously identifies a substance, yet infrared spectroscopy fails to confirm this result.

A Study of the Materials of Pontormo's “Portrait of Alessandro de' Medici”

2004 ◽  
Vol 852 ◽  
Author(s):  
Ken Sutherland ◽  
Beth A. Price ◽  
Irma Passeri ◽  
Mark Tucker
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Scanning Electron Microscopy ◽  
Gas Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Infrared Microspectroscopy ◽  
Fourier Transform Infrared Microspectroscopy ◽  
Materials Used ◽  
Scanning Electron

ABSTRACTIn studies of the materials of old master paintings, the characterization of thin and degraded layers often presents unusual challenges for routinely used methods of analysis. This paper discusses analyses performed as part of a study of the materials and techniques of Pontormo's “Portrait of Alessandro de’ Medici” (1534–5) carried out during a recent cleaning and restoration of the painting. Pontormo built up the portrait using a complex sequence of preparation, drawing and paint layers, the analysis of which was complicated further in some areas by the presence of degraded materials on the paint surface. The materials used for the various stages of preparation and painting were characterized by gas chromatography/mass spectrometry (GCMS), Fourier transform infrared microspectroscopy (FTIR) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). The focus of this paper will be the particular approaches taken to the characterization of the preparation layers and degraded surface materials.

scholarly journals Redox Mechanism of Azathioprine and Its Interaction with DNA

2021 ◽  
Vol 22 (13) ◽  
pp. 6805
Author(s):  
Mihaela-Cristina Bunea ◽  
Victor-Constantin Diculescu ◽  
Monica Enculescu ◽  
Horia Iovu ◽  
Teodor Adrian Enache
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Scanning Electron Microscopy ◽  
Structural Changes ◽  
Differential Pulse ◽  
Immunosuppressive Drug ◽  
Redox Mechanism ◽  
Before And After ◽  
Dna Film ◽  
Scanning Electron

The electrochemical behavior and the interaction of the immunosuppressive drug azathioprine (AZA) with deoxyribonucleic acid (DNA) were investigated using voltammetric techniques, mass spectrometry (MS), and scanning electron microscopy (SEM). The redox mechanism of AZA on glassy carbon (GC) was investigated using cyclic and differential pulse (DP) voltammetry. It was proven that the electroactive center of AZA is the nitro group and its reduction mechanism is a diffusion-controlled process, which occurs in consecutive steps with formation of electroactive products and involves the transfer of electrons and protons. A redox mechanism was proposed and the interaction of AZA with DNA was also investigated. Morphological characterization of the DNA film on the electrode surface before and after interaction with AZA was performed using scanning electron microscopy. An electrochemical DNA biosensor was employed to study the interactions between AZA and DNA with different concentrations, incubation times, and applied potential values. It was shown that the reduction of AZA molecules bound to the DNA layer induces structural changes of the DNA double strands and oxidative damage, which were recognized through the occurrence of the 8-oxo-deoxyguanosine oxidation peak. Mass spectrometry investigation of the DNA film before and after interaction with AZA also demonstrated the formation of AZA adducts with purine bases.

scholarly journals Suppressive Effects of Hainosan (Painongsan) against Biofilm Production by Streptococcus mutans

2020 ◽  
Vol 8 (3) ◽  
pp. 71
Author(s):  
Masaaki Minami ◽  
Hiroshi Takase ◽  
Masayo Taira ◽  
Toshiaki Makino
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Confocal Laser Microscopy ◽  
Confocal Laser ◽  
Transmission Electron Microscopy Analysis ◽  
Laser Microscopy ◽  
Dental Plaques ◽  
Scanning Electron

Streptococcus mutans, a bacterium that causes dental plaques, forms a biofilm on tooth surfaces. This biofilm can cause gingivitis by stimulating the gingival margin. However, there is no established treatment for biofilm removal. Hainosan (Painongsan), a traditional Japanese Kampo formula, has been used to treat gingivitis. Therefore, we investigated the biofilm suppressive effects of the hainosan extract (HNS) and its components on S. mutans. We conducted scanning electron microscopy and confocal laser microscopy analyses to clarify the anti-biofilm activities of HNS and its crude drugs. We also performed a quantitative RT-PCR assay to assess the biofilm-related gene expression. HNS showed a significant dose-dependent suppressive effect on biofilm formation. Both the scanning electron microscopy and confocal laser microscopy analyses also revealed the significant inhibitory effects of the extract on biofilm formation. Transmission electron microscopy analysis showed that HNS disrupted the surface of the bacterial wall. Furthermore, HNS reduced the hydrophobicity of the bacteria, and suppressed the mRNA expression of β-glucosyltransferase (gtfB), glucosyltransferase-SI (gtfC), and fructosyltransferase (ftf). Among the constituents of hainosan, the extract of the root of Platycodon grandiflorum (PG) showed the strongest biofilm suppression effect. Platycodin D, one of the constituent natural compounds of PG, inhibited S. mutans-associated biofilm. These findings indicate that hainosan eliminates dental plaques by suppressing biofilm formation by S. mutans.

Growth of Frankia in the rhizosphere of Betula pendula, a nonhost tree species

1990 ◽  
Vol 36 (9) ◽  
pp. 649-656 ◽  
Author(s):  
A. Smolander ◽  
R. Rönkkö ◽  
E.-L. Nurmiaho-Lassila ◽  
K. Haahtela
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Energy Source ◽  
Betula Pendula ◽  
Defined Medium ◽  
Gas Chromatography Mass Spectrometry ◽  
Favourable Effect ◽  
Culture Solution ◽  
Alnus Incana ◽  
Scanning Electron

The growth of Frankia in the rhizosphere of Betula pendula was studied to understand the favourable effect of this nonhost species on Alnus-nodulating Frankia in soil. Axenic Betula pendula and Alnus incana seedlings were inoculated with Frankia strains. The development of Frankia in the rhizosphere was examined by light and scanning electron microscopy. Some Frankia strains grew in the rhizosphere of Betula pendula seedlings without addition of a carbon and energy source. In addition to hyphae and sporangia, vesicles were also formed. Growth (if any) was more local and less abundant in the rhizosphere of Alnus incana seedlings. Frankia strains were grown in defined medium supplemented with tryptophan. Indole-3-ethanol was detected in the culture solution by gas chromatography – mass spectrometry. Key words: Alnus incana, Betula pendula, Frankia, indole-3-ethanol.

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