Near Infrared Spectra of Compounds with Two Peptide Bonds and the Configuration of a Polypeptide Chain. VI. Further Evidence of the Internal Hydrogen Bonding and an Estimation of its Energy

1957 ◽  
Vol 79 (20) ◽  
pp. 5357-5361 ◽  
Author(s):  
San-Ichiro Mizushima ◽  
Takehiko Shimanouchi ◽  
Masamichi Tsuboi ◽  
Tetsutaro Arakawa
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Polypeptide Chain ◽  
Peptide Bonds ◽  
Internal Hydrogen ◽  
Near Infrared Spectra

Near Infrared Spectra of Compounds with Two Peptide Bonds and the Configuration of a Polypeptide Chain V

1954 ◽  
Vol 76 (23) ◽  
pp. 6003-6006 ◽  
Author(s):  
San-Ichiro Mizushima ◽  
Masamichi Tsuboi ◽  
Takehiko Shimanouchi ◽  
Masatomo Asai
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Polypeptide Chain ◽  
Peptide Bonds ◽  
Near Infrared Spectra

Near Infrared Spectra of Compounds with Two Peptide Bonds and the Configuration of a Polypeptide Chain. II

1952 ◽  
Vol 74 (18) ◽  
pp. 4639-4641 ◽  
Author(s):  
San-ichiro Mizushima ◽  
Takehiko Shimanouchi ◽  
Masamichi Tsuboi ◽  
Tadao Sugita ◽  
Kazuo Kurosaki ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Polypeptide Chain ◽  
Peptide Bonds ◽  
Near Infrared Spectra

Near Infrared Spectra of Compounds with Two Peptide Bonds and the Configuration of a Polypeptide Chain. IV.

1954 ◽  
Vol 76 (9) ◽  
pp. 2479-2482 ◽  
Author(s):  
San-ichiro Mizushima ◽  
Masamichi Tsuboi ◽  
Takehiko Shimanouchi ◽  
Tadao Sugita ◽  
Toshio Yoshimoto
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Polypeptide Chain ◽  
Peptide Bonds ◽  
Near Infrared Spectra

Near Infrared Spectra of Compounds with Two Peptide Bonds and the Configuration of a Polypeptide Chain. III

1953 ◽  
Vol 75 (8) ◽  
pp. 1863-1865 ◽  
Author(s):  
San-ichiro Mizushima ◽  
Takehiko Shimanouchi ◽  
Masamichi Tsuboi ◽  
Kenji Kuratani ◽  
Tadao Sugita ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Polypeptide Chain ◽  
Peptide Bonds ◽  
Near Infrared Spectra

Near Infrared Spectra of Compounds with Two Peptide Bonds and the Configuration of a Polypeptide Chain

1951 ◽  
Vol 73 (3) ◽  
pp. 1330-1333 ◽  
Author(s):  
San-ichiro Mizushima ◽  
Takehiko Shimanouchi ◽  
Masamichi Tsuboi ◽  
Tadao Sugita ◽  
Eizo Kato ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Polypeptide Chain ◽  
Peptide Bonds ◽  
Near Infrared Spectra

HYDROGEN BONDING IN THE AMINE HYDROHALIDES: III. NEAR-INFRARED SPECTRA OF ALIPHATIC AMINE HYDROHALIDES

1960 ◽  
Vol 38 (10) ◽  
pp. 1901-1910 ◽  
Author(s):  
P. Sauvageau ◽  
C. Sandorfy
Keyword(s):  
Hydrogen Bonding ◽  
Secondary Amine ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Potential Surface ◽  
Aliphatic Amine ◽  
Bending Vibrations ◽  
Near Infrared Spectra ◽  
Combination Bands

The first overtones of the [Formula: see text] stretching fundamentals are very weak and difficult to locate. Binary combinations between [Formula: see text] stretching and [Formula: see text] bending vibrations and also [Formula: see text] stretching–bending combinations fall into the 4600–4400 cm−1 area for primary and secondary amine hydrohalides and are much stronger. The intensity of these combination bands is not due to the anharnionicity of the potential surface but to the electrical anharmonicity of bending vibrations.

Discrimination of Organic Solvents Using an Infrared-Emitting Diode-Based Analyzer. Part I: Feasibility

1995 ◽  
Vol 49 (11) ◽  
pp. 1590-1597 ◽  
Author(s):  
Anthony S. Bonanno ◽  
Peter R. Griffiths
Keyword(s):  
Hydrogen Bonding ◽  
Temperature Variation ◽  
Organic Solvents ◽  
Infrared Spectra ◽  
Mahalanobis Distance ◽  
Near Infrared ◽  
Short Wave ◽  
Multivariate Statistical Methods ◽  
Multivariate Statistical ◽  
Near Infrared Spectra

This report demonstrates the feasibility of discriminating organic solvents on the basis of short-wave near-infrared spectra (from 0.7 to 1.1 μm). Both library searching and multivariate statistical methods were applied to 8-cm−1 spectra and to spectra de-resolved to the point achievable with an analyzer using discrete infrared-emitting diode sources. Library searching performed satisfactorily if the unknown and library spectra were collected under reasonably similar conditions, but performed poorly if the temperature of hydrogen-bonding solvents was varied. A multivariate discrimination technique based on Mahalanobis distance computation was capable of discriminating between several alcohols while allowing for a temperature variation of 20°C. These results indicate that a very low resolution (on the order of 100 cm−1) short-wave near-infrared analyzer can achieve successful discrimination between similar solvents under variable conditions.

Rapid Determining Contents of the Rhubarb Anthraquinones Compounds by Support Vector Machines Modeling based on Near Infrared Spectra

2020 ◽  
Vol 16 ◽  
Author(s):  
Linqi Liu ◽  
JInhua Luo ◽  
Chenxi Zhao ◽  
Bingxue Zhang ◽  
Wei Fan ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Mean Squared Error ◽  
Rapid Determination ◽  
Partial Least Square ◽  
Least Square ◽  
Support Vector ◽  
Near Infrared Spectra ◽  
Aloe Emodin ◽  
Relative Differences

BACKGROUND: Measuring medicinal compounds to evaluate their quality and efficacy has been recognized as a useful approach in treatment. Rhubarb anthraquinones compounds (mainly including aloe-emodin, rhein, emodin, chrysophanol and physcion) are its main effective components as purgating drug. In the current Chinese Pharmacopoeia, the total anthraquinones content is designated as its quantitative quality and control index while the content of each compound has not been specified. METHODS: On the basis of forty rhubarb samples, the correlation models between the near infrared spectra and UPLC analysis data were constructed using support vector machine (SVM) and partial least square (PLS) methods according to Kennard and Stone algorithm for dividing the calibration/prediction datasets. Good models mean they have high correlation coefficients (R2) and low root mean squared error of prediction (RMSEP) values. RESULTS: The models constructed by SVM have much better performance than those by PLS methods. The SVM models have high R2 of 0.8951, 0.9738, 0.9849, 0.9779, 0.9411 and 0.9862 that correspond to aloe-emodin, rhein, emodin, chrysophanol, physcion and total anthraquinones contents, respectively. The corresponding RMSEPs are 0.3592, 0.4182, 0.4508, 0.7121, 0.8365 and 1.7910, respectively. 75% of the predicted results have relative differences being lower than 10%. As for rhein and total anthraquinones, all of the predicted results have relative differences being lower than 10%. CONCLUSION: The nonlinear models constructed by SVM showed good performances with predicted values close to the experimental values. This can perform the rapid determination of the main medicinal ingredients in rhubarb medicinal materials.

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