1,720,959 research outputs found
Isolasi dan Elusidasi Struktur Kimia Senyawa Flavonoid sebagai Inhibitor Enzim Α-Glukosidase dari Ekstrak Etanol Kulit Batang Raru (Vatica pauciflora Blume)
No full textRaru (Vatica pauciflora Blume) is a wild plant grows enormously in Central Tapanuli forest area.
Barks of this plant are utilized for antidiabetic medicine by boiling and consuming the decoction. The aim
of this study is to determine the chemical structure of bioactive compound from ethanolic extract of barks
of Raru (Vatica pauciflora Blume) that act as α-glucosidase enzyme inhibitor. Isolation was done by
extracting the barks using n-hexane, ethylacetate, ethanol, and water as solvents. The ethanolic extract
then were partitioned and run to column chromatography using SiO3 asd stationary phase. Compound
VpEt-9-4-4-1 isolated from ethanol extract showed α-glucosidase enzyme inhibition with IC50 93.46.
Based on spectral data of UV, FTIR. 1D NMR, 2D NMR (COSY, HMQC, HMBC) we got 2 methoxies,
1aromatic, and 1 carbonyl moieties. Compared to IUPAC data, compound VpEt-9-4-4-1 was determined
as as 3,4,9-trihydroxy-2-(hydroxymethyl)-8,10-dimethoxy-2,3,4-tetrahydropyrano-(3,2-c)-isochromen-6-
(10bH)-one with molecular formula C15H18O9. Mass measurement using HR-MS gave mass weight
341.087.Raru (Vatica pauciflora Blume) adalah tumbuhan yang banyak tumbuh liar di daerah hutan
Tapanuli Tengah. Kulit batang tanaman ini dimanfaatkan sebagai obat antidiabetes dengan cara merebus
dan meminumnya. Tujuan penelitian ini adalah untuk menentukan struktur kimia dari senyawa bioaktif
dari ekstrak etanol kulit batang Raru (Vatica pauciflora Blume) yang memiliki aktivitas sebagai
penghambat enzim α-glucosidase. Isolasi dilakukan dengan mengekstrak kulit batang menggunakan
pelarut n-heksan, etilasetat, etanol, dan air. Ekstrak etanol kemudian dipartisi dan dikromatografi kolom
menggunakan SiO3 sebagai fase diam. Senyawa VpEt-9-4-4-1yang diisolasi dari ekstrak etanol
memperlihatkan aktivitas penghambatan enzim α-glucosidase dengan IC50 93.46. Berdasarkan data
spektra UV, FTIR, NMR 1D, NMR 2D (COSY, HMQC, HMBC) diperoleh 2 metoksi, 1aromatik, dan 1
karbonil. Berdasarkan perbandingan data dengan IUPAC, senyawa VpEt-9-4-4-1 ditetapkan sebagai
3,4,9-trihidroksi-2-(hidroksmetil)-8,10-dimetoksi-2,3,4-tetrahidropirano-(3,2-c)-isokromen-6-(10bH)-
onedengan rumus molekul C15H18O9. Pengukuran massa menggunakan HR-MS memberikan bobot massa
341.087.104 HalamanDisertasi Dokto
Isolasi dan Elusidasi Struktur Kimia Senyawa Flavonoid sebagai Inhibitor Enzim Α-Glukosidase dari Ekstrak Etanol Kulit Batang Raru (Vatica pauciflora Blume)
No full textRaru (Vatica pauciflora Blume) is a wild plant grows enormously in Central Tapanuli forest area.
Barks of this plant are utilized for antidiabetic medicine by boiling and consuming the decoction. The aim
of this study is to determine the chemical structure of bioactive compound from ethanolic extract of barks
of Raru (Vatica pauciflora Blume) that act as α-glucosidase enzyme inhibitor. Isolation was done by
extracting the barks using n-hexane, ethylacetate, ethanol, and water as solvents. The ethanolic extract
then were partitioned and run to column chromatography using SiO3 asd stationary phase. Compound
VpEt-9-4-4-1 isolated from ethanol extract showed α-glucosidase enzyme inhibition with IC50 93.46.
Based on spectral data of UV, FTIR. 1D NMR, 2D NMR (COSY, HMQC, HMBC) we got 2 methoxies,
1aromatic, and 1 carbonyl moieties. Compared to IUPAC data, compound VpEt-9-4-4-1 was determined
as as 3,4,9-trihydroxy-2-(hydroxymethyl)-8,10-dimethoxy-2,3,4-tetrahydropyrano-(3,2-c)-isochromen-6-
(10bH)-one with molecular formula C15H18O9. Mass measurement using HR-MS gave mass weight
341.087.Raru (Vatica pauciflora Blume) adalah tumbuhan yang banyak tumbuh liar di daerah hutan
Tapanuli Tengah. Kulit batang tanaman ini dimanfaatkan sebagai obat antidiabetes dengan cara merebus
dan meminumnya. Tujuan penelitian ini adalah untuk menentukan struktur kimia dari senyawa bioaktif
dari ekstrak etanol kulit batang Raru (Vatica pauciflora Blume) yang memiliki aktivitas sebagai
penghambat enzim α-glucosidase. Isolasi dilakukan dengan mengekstrak kulit batang menggunakan
pelarut n-heksan, etilasetat, etanol, dan air. Ekstrak etanol kemudian dipartisi dan dikromatografi kolom
menggunakan SiO3 sebagai fase diam. Senyawa VpEt-9-4-4-1yang diisolasi dari ekstrak etanol
memperlihatkan aktivitas penghambatan enzim α-glucosidase dengan IC50 93.46. Berdasarkan data
spektra UV, FTIR, NMR 1D, NMR 2D (COSY, HMQC, HMBC) diperoleh 2 metoksi, 1aromatik, dan 1
karbonil. Berdasarkan perbandingan data dengan IUPAC, senyawa VpEt-9-4-4-1 ditetapkan sebagai
3,4,9-trihidroksi-2-(hidroksmetil)-8,10-dimetoksi-2,3,4-tetrahidropirano-(3,2-c)-isokromen-6-(10bH)-
onedengan rumus molekul C15H18O9. Pengukuran massa menggunakan HR-MS memberikan bobot massa
341.087.104 HalamanDisertasi Dokto
ASSESSMENT OF THE QUALITY OF CRUDE PALM OIL FROM ELAEIS GUINEENSIS GROWING AREAS OF THE PT. LANGKAT NUSANTARA KEPONG-PTPN II NORTH SUMATERA
Full text linkPalm oil is one of the major fats and oils produced in Indonesia, which is of great value in the diet of many people. The quality of palm oil could be affected by various factors ranging from improper postharvest handling, processing and storage. Recently, there has been wide spread speculation that palm oil is adulterated in order to maximize profit (Madubuike et al., 2015). The quality parameters of palm oil are generally determined by the moisture content, impurity, specific gravity, percentage of free fatty acid (FFA), iodine value, peroxide value and saponification values. The objective of this research therefore was to evaluate the quality of palm oil samples obtained from elaeis guineensis growing areas of the PT. Langkat Nusantara Kepong-PTPN II North Sumatera. The results showed that mean value of the quality parameters are 0.15% moisture content; 5.71% impurity level; 0.935 specific gravity;8.43% FFA; 52.13 iodine value; 13.71meq/kg peroxide value; and 181,89 mg KOH/g saponification value. The quality parameters are associated with the method of processing.Keywords: Moisture Content, Impurity, Specific Gravity, Percentage Of Free Fatty Acid, Iodine Value, Peroxide Value And Saponification Values
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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