scholarly journals Identifikasi Komponen Kimia Damar Mata Kucing (Shorea Javanica) dengan Metode Pirolisis-GC/MS

2012 ◽  
Vol 14 (1) ◽  
pp. 155 ◽  
Author(s):  
Noryawati Mulyono ◽  
Christofora Hanny Wijaya ◽  
Dedi Fardiaz ◽  
Wuryaningsih Sri Rahayu
Keyword(s):  
Functional Groups ◽  
Infrared Spectra ◽  
Relative Concentration ◽  
Chemical Compounds ◽  
Cyclic Hydrocarbon ◽  
Crude Sample ◽  
Infrared Spectrophotometer ◽  
Natural Gum

The aim of this research was to identify chemical compounds in cat eye dammar. The method included functional groups characterizationby infrared spectrophotometer and identification using Pyrolisis-GC/MS. Infrared spectra of crude sample showed that there were somefunctional groups such as alkyl, carbonyl, vinyl, and hydroxyl. Identification by Pyrolisis-GC/MS showed that dammar consisted of at least67 compounds. This natural gum components could be categorized into 4 groups, i.e. tetra cyclic hydrocarbon (30 compounds, 49.57%),penta cyclic (3 compounds, 2.56%), C 15 compounds (11 compounds, 17.09%), and other group (23 compounds, 18.26%). According to thePy-GC/MS data, brassicasterol is the highest relative concentration in dammar, i.e. 20%.

scholarly journals Identifikasi Kandungan Senyawa Kimia Cuka Kayu dari Sekam Padi

2017 ◽  
Vol 19 (1) ◽  
pp. 30 ◽  
Author(s):  
Dian Laila Nugrahaini ◽  
Endang Kusdiyantini ◽  
Udi Tarwotjo ◽  
A. Heru Prianto
Keyword(s):  
Phenolic Compounds ◽  
Functional Groups ◽  
Rice Husk ◽  
Chemical Compound ◽  
Chemical Compounds ◽  
Pyrolysis Process ◽  
Wood Vinegar ◽  
Rotary Evaporator ◽  
Infrared Spectrophotometer

Wood vinegar rice husk contains a chemical compound that can be used as a biopesticides. Wood vinegar contained compounds which estimated potential as repellent, antifeedant, antimicrobials, antioxidants, disinfectants and as preservatives. The content of chemical compounds in the wood vinegar must be identified. Identification were done by calculating the concentration of acid, phenol and an infrared spectrophotometer. Production of wood vinegar made by the pyrolysis process used pirolisator. Most of the wood vinegar obtained is evaporated using a rotary evaporator and partly extracted using the method of separating funnel. Compound of acid and phenol in wood vinegar evaporation were higher than the extraction of wood vinegar. These results were confirmed by an infrared spectrophotometer spectrum showed the functional groups of acid and phenolic compounds. Keywords: wood vinegar rice husk, acid, phenol, pyrolysis, infrared spetrofotometer

scholarly journals Cinnamic Acid Derivatives as α-Glucosidase Inhibitor Agents

2017 ◽  
Vol 17 (1) ◽  
pp. 151 ◽  
Author(s):  
Teni Ernawati ◽  
Maksum Radji ◽  
Muhammad Hanafi ◽  
Abdul Mun’im ◽  
Arry Yanuar
Keyword(s):  
Functional Groups ◽  
Cinnamic Acid ◽  
Phenyl Group ◽  
Chemical Compounds ◽  
Cinnamic Acid Derivative ◽  
Cinnamic Acid Derivatives ◽  
Glucosidase Inhibitor ◽  
Glucosidase Inhibitors ◽  
Derivatives Of ◽  
Additive Reaction

This paper reviews biological activity of some cinnamic acid derivative compounds which are isolated from natural materials and synthesized from the chemical compounds as an agent of α-glucosidase inhibitors for the antidiabetic drug. Aegeline, anhydroaegeline and aeglinoside B are natural products isolated compounds that have potential as an α-glucosidase inhibitor. Meanwhile, α-glucosidase inhibitor class of derivatives of cinnamic acid synthesized compounds are p-methoxy cinnamic acid and p-methoxyethyl cinnamate. Chemically, cinnamic acid has three main functional groups: first is the substitution of the phenyl group, second is the additive reaction into the α-β unsaturated, and third is the chemical reaction with carboxylic acid functional groups. The synthesis and modification of the structure of cinnamic acid are very influential in inhibitory activity against α-glucosidase.

scholarly journals Computer elucidation of functional groups from infrared spectra.

1986 ◽  
Vol 35 (6) ◽  
pp. 518-523
Author(s):  
Kazutoshi TANABE ◽  
Tadao TAMURA ◽  
Seiji TSUZUKI
Keyword(s):  
Functional Groups ◽  
Infrared Spectra

Identification of Chemical Structures from Infrared Spectra by Using Neural Networks

2001 ◽  
Vol 55 (10) ◽  
pp. 1394-1403 ◽  
Author(s):  
Kazutoshi Tanabe ◽  
Takatoshi Matsumoto ◽  
Tadao Tamura ◽  
Jiro Hiraishi ◽  
Shinnosuke Saeki ◽  
...  
Keyword(s):  
Neural Networks ◽  
Functional Groups ◽  
Infrared Spectra ◽  
Identification Accuracy ◽  
Inductive Method ◽  
Structure Identification ◽  
Chemical Substances ◽  
Chemical Structures ◽  
Quantum Chemistry Calculations ◽  
Wide Range

Structure identification of chemical substances from infrared spectra can be done with various approaches: a theoretical method using quantum chemistry calculations, an inductive method using standard spectral databases of known chemical substances, and an empirical method using rules between spectra and structures. For various reasons, it is difficult to definitively identify structures with these methods. The relationship between structures and infrared spectra is complicated and nonlinear, and for problems with such nonlinear relationships, neural networks are the most powerful tools. In this study, we have evaluated the performance of a neural network system that mimics the methods used by specialists to identify chemical structures from infrared spectra. Neural networks for identifying over 100 functional groups have been trained by using over 10 000 infrared spectral data compiled in the integrated spectral database system (SDBS) constructed in our laboratory. Network structures and training methods have been optimized for a wide range of conditions. It has been demonstrated that with neural networks, various types of functional groups can be identified, but only with an average accuracy of about 80%. The reason that 100% identification accuracy has not been achieved is discussed.

Effect of functional group conformation on the infrared spectra of some gem difunctional phenylethylene derivatives

1969 ◽  
Vol 47 (17) ◽  
pp. 3147-3152 ◽  
Author(s):  
D. J. Currie ◽  
C. E. Lough ◽  
F. K. McClusky ◽  
H. L. Holmes
Keyword(s):  
Absorption Band ◽  
Functional Groups ◽  
Infrared Spectra ◽  
Functional Group ◽  
Plane Deformation ◽  
Carbonyl Groups ◽  
Deformation Bands ◽  
Or Groups ◽  
Out Of Plane ◽  
Stretching Vibrations

Except for the benzalmalononitriles, two functional group stretching vibrations occur in the infrared (i.r.) spectra of the β,β-difunctional-styrenes with similar functional groups. For geometrically homogeneous compounds with dissimilar functional groups only one absorption band occurs for each functional group. The two bands for similar functional groups have been ascribed to S-cis- and S-trans-conformations of the carbonyl groups with respect to the ethylene and variation in the frequencies of each of these oriented carbonyls to rotation of the functional group or groups out of the plane of the ethylene by steric factors.Frequencies for ethylenic C—H out of plane deformation bands for β-monofunctional styrenes accorded with those already assigned to this vibration. A similar assignment could not be made for the difunctional analogues.

Functional groups prediction from infrared spectra based on computer-assist approaches

2020 ◽  
Vol 159 ◽  
pp. 105395
Author(s):  
Zhimeng Wang ◽  
Xiaoyu Feng ◽  
Junhong Liu ◽  
Minchun Lu ◽  
Menglong Li
Keyword(s):  
Functional Groups ◽  
Infrared Spectra ◽  
Computer Assist

scholarly journals Ligand-Based and Structured-Based In Silico Repurposing Approaches to Predict Inhibitors of SARS-CoV-2 Mpro Protein

2020 ◽  
Vol 88 (4) ◽  
pp. 54
Author(s):  
Alfredo Juárez-Saldívar ◽  
Edgar E. Lara-Ramírez ◽  
Francisco Reyes-Espinosa ◽  
Alma D. Paz-González ◽  
Juan Carlos Villalobos-Rocha ◽  
...  
Keyword(s):  
Virtual Screening ◽  
Severe Acute Respiratory Syndrome ◽  
Functional Groups ◽  
In Silico ◽  
Chemical Structure ◽  
Specific Treatment ◽  
Chemical Compounds ◽  
Screening Strategy ◽  
High Potential

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a coronavirus that causes the pandemic Coronavirus Disease 2019 (COVID-19). There is no current specific treatment for this new coronavirus. In this study, we employed a virtual screening repurposing strategy to search for potential SARS-CoV-2 Mpro inhibitors. The databases PDB, ChEMBL, BindingDB and DrugBank were queried with several filtering steps based on ligand-based and structure-based approaches. As a result, we obtained 58 molecules (37 from ChEMBL and 21 from DrugBank) that potentially inhibit SARS-CoV-2 Mpro. These molecules have on their chemical structure functional groups that favor stronger docking scores than the inhibitor N3. Several of these molecules are reported experimentally as SARS-CoV Mpro inhibitors. Hence, a combined virtual screening strategy allowed finding chemical compounds with a high potential for the inhibition of SARS-CoV-2 Mpro.

scholarly journals Low Kinetic Energy Oxygen Ion Irradiation of Vertically Aligned Carbon Nanotubes

2019 ◽  
Vol 9 (24) ◽  
pp. 5342 ◽  
Author(s):  
Selene Acosta ◽  
Juan Casanova Chafer ◽  
Ayrton Sierra Castillo ◽  
Eduard Llobet ◽  
Rony Snyders ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Kinetic Energy ◽  
Functional Groups ◽  
Ion Irradiation ◽  
Relative Concentration ◽  
Oxygen Plasma Treatment ◽  
Oxygen Ion ◽  
Cnts Surface ◽  
Vertically Aligned

Vertically aligned multiwalled carbon nanotubes (v-CNTs) were functionalized with oxygen groups using low kinetic energy oxygen ion irradiation. X-ray photoelectron spectroscopy (XPS) analysis indicates that oxygen ion irradiation produces three different types of oxygen functional groups at the CNTs surface: epoxide, carbonyl and carboxyl groups. The relative concentration of these groups depends on the parameters used for oxygen ion irradiation. Scanning electron microscopy (SEM) shows that the macroscopic structure and alignment of v-CNTS are not affected by the ion irradiation and transmission electron microscopy (TEM) proves tip functionalization of v-CNTs. We observed that in comparison to oxygen plasma treatment, oxygen ion irradiation shows higher functionalization efficiency and versatility. Ion irradiation leads to higher amount of oxygen grafting at the v-CNTs surface, besides different functional groups and their relative concentration can be tuned varying the irradiation parameters.

On Line Infrared Identification of Gas Chromatography Effluents

1975 ◽  
Vol 29 (1) ◽  
pp. 24-28 ◽  
Author(s):  
B. Katlafsky ◽  
M. W. Dietrich
Keyword(s):  
Gas Chromatography ◽  
Functional Groups ◽  
Infrared Spectra ◽  
Functional Group ◽  
Fold Increase ◽  
Polar Compounds ◽  
Signal Averaging ◽  
On Line ◽  
Averaging Techniques

On-line infrared spectra obtained with the Norcon RS-1 gas chromatographic identifier are of sufficient quality for qualitative identification of functional groups, chemical classes, or chemical entities. Identification limits for chemical entities vary between 20 and 200 µg, polar compounds having higher sensitivities. Functional group identifications can be made with correspondingly smaller samples. A 5-fold increase in sensitivity was demonstrated using signal-averaging techniques.

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