Physicochemical study on some synthesized oxazolidine derivatives : differentiation of diastereomers

1975 ◽  
Vol 28 (1) ◽  
pp. 49 ◽  
Author(s):  
SA Soliman ◽  
H Abdine ◽  
S El-Nenaey
Keyword(s):  
Infrared Spectra ◽  
Opposite Effect ◽  
Molecular Rotation ◽  
Para Position ◽  
Physicochemical Study ◽  
Trans Isomers ◽  
Meta Position ◽  
Molecular Rotations ◽  
Derivatives Of

The synthesis of 15 diastereomeric oxazolidine derivatives of the type 2-(substituted phenyl)-3,4-dimethyl-5-phenyloxazolidine is reported. The specific as well as the molecular rotations of 31 diastereomeric oxazolidine derivatives of the same type of structure were determined. The cis com- pounds have higher specific and molecular rotation than the corresponding trans isomers. Substitution in the ortho or para position increased specific and molecular rotation while substitution in the meta position had an opposite effect. ��� The infrared spectra of 26 oxazolidine derivatives, having either a cis or a trans type of configuration, have been recorded in the range 2000-700 cm-1.

THE INFRARED AND THE NEAR-ULTRAVIOLET ABSORPTION SPECTRA OF POLYPHENYL DERIVATIVES OF THE ELEMENTS OF GROUPS IVb AND Vb

1961 ◽  
Vol 39 (1) ◽  
pp. 171-179 ◽  
Author(s):  
C. N. R. Rao ◽  
J. Ramachandran ◽  
A. Balasubramanian
Keyword(s):  
Absorption Spectra ◽  
Infrared Spectra ◽  
Ultraviolet Absorption ◽  
Para Position ◽  
Near Ultraviolet ◽  
Benzene Rings ◽  
Out Of Plane ◽  
Reactivity Constant ◽  
Derivatives Of ◽  
Absorption Frequencies

The near-ultraviolet absorption spectra of polyphenyl derivatives of the IVb and Vb elements have been studied in detail. In the case of the triphenyl derivatives of the Vb elements, the unshared p-electrons on the central atoms interact strongly with the π-orbitals of the benzene rings. When the central atoms do not possess unshared electrons as in the case of the derivatives of the IVb and the pentavalent Vb elements, there appears to be no such resonance interaction. The Hammett reactivity constants of the para- and meta-trityl, triphenylsilyl, and triphenylgermanyl groups are estimated to be close to zero. However, the reactivity constant of the triphenylsilyl group in the para position of phenol is estimated to be about 0.30. The infrared spectra of the phenyl derivatives of the IVb and Vb elements show smooth trends due to mass effects of the central atoms, in the C=C skeletal, C—H out-of-plane, and other vibrations. The absorption frequencies which are assigned to the phosphorus-phenyl and silicon–phenyl bonds in the literature do not appear to be unique for these linkages.

Para-position derivatives of fungal anthelmintic cyclodepsipeptides engineered with Streptomyces venezuelae antibiotic biosynthetic genes

2004 ◽  
Vol 22 (7) ◽  
pp. 848-855 ◽  
Author(s):  
Koji Yanai ◽  
Naomi Sumida ◽  
Kaoru Okakura ◽  
Tatsuki Moriya ◽  
Manabu Watanabe ◽  
...  
Keyword(s):  
Para Position ◽  
Streptomyces Venezuelae ◽  
Biosynthetic Genes ◽  
Derivatives Of

Infrared Spectra of Some Chloro Derivatives of s-Triazine

1966 ◽  
Vol 20 (3) ◽  
pp. 159-160 ◽  
Author(s):  
T. S. Herman
Keyword(s):  
Infrared Spectra ◽  
Triazine Ring ◽  
Chlorine Atoms ◽  
Vibrational Assignments ◽  
Fundamental Frequencies ◽  
Bending Mode ◽  
Chloro Derivatives ◽  
Derivatives Of

The effects of chlorine atoms on the fundamental frequencies of the s-triazine ring are discussed and the vibrational assignments in the region 1600–700 cm−1 are extended. The variation in the position of the C3N3-ring bending mode in the region near 810 cm−1 is discussed.

Infrared spectra of some derivatives of unsaturated phosphinic acids

1961 ◽  
Vol 10 (1) ◽  
pp. 62-66 ◽  
Author(s):  
N. A. Slovokhotova ◽  
K. N. Anisimov ◽  
G. M. Kunitskaya ◽  
N. E. Kolobova
Keyword(s):  
Infrared Spectra ◽  
Phosphinic Acids ◽  
Derivatives Of

Infrared Spectra in Identification of Derivatives of Cyclopropane

1952 ◽  
Vol 24 (4) ◽  
pp. 623-625 ◽  
Author(s):  
S. E. Wiberley ◽  
S. C. Bunce
Keyword(s):  
Infrared Spectra ◽  
Derivatives Of

scholarly journals Reducing Glucokinase Activity Restores Endogenous Pulsatility and Enhances Insulin Secretion in Islets From db/db Mice

Endocrinology ◽  
2018 ◽  
Vol 159 (11) ◽  
pp. 3747-3760 ◽  
Author(s):  
Ishrat Jahan ◽  
Kathryn L Corbin ◽  
Avery M Bogart ◽  
Nicholas B Whitticar ◽  
Christopher D Waters ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Insulin Release ◽  
Opposite Effect ◽  
Glucose Sensing ◽  
Β Cell ◽  
Left Shift ◽  
Low Glucose ◽  
Mouse Islets ◽  
Secretion Rates

Abstract An early sign of islet failure in type 2 diabetes (T2D) is the loss of normal patterns of pulsatile insulin release. Disruptions in pulsatility are associated with a left shift in glucose sensing that can cause excessive insulin release in low glucose (relative hyperinsulinemia, a hallmark of early T2D) and β-cell exhaustion, leading to inadequate insulin release during hyperglycemia. Our hypothesis was that reducing excessive glucokinase activity in diabetic islets would improve their function. Isolated mouse islets were exposed to glucose and varying concentrations of the glucokinase inhibitor d-mannoheptulose (MH) to examine changes in intracellular calcium ([Ca2+]i) and insulin secretion. Acutely exposing islets from control CD-1 mice to MH in high glucose (20 mM) dose dependently reduced the size of [Ca2+]i oscillations detected by fura-2 acetoxymethyl. Glucokinase activation in low glucose (3 mM) had the opposite effect. We then treated islets from male and female db/db mice (age, 4 to 8 weeks) and heterozygous controls overnight with 0 to 10 mM MH to determine that 1 mM MH produced optimal oscillations. We then used 1 mM MH overnight to measure [Ca2+]i and insulin simultaneously in db/db islets. MH restored oscillations and increased insulin secretion. Insulin secretion rates correlated with MH-induced increases in amplitude of [Ca2+]i oscillations (R2 = 0.57, P < 0.01, n = 10) but not with mean [Ca2+]i levels in islets (R2 = 0.05, not significant). Our findings show that correcting glucose sensing can restore proper pulsatility to diabetic islets and improved pulsatility correlates with enhanced insulin secretion.

DFT STUDY ON SECOND-ORDER NONLINEAR OPTICAL PROPERTIES OF THE DERIVATIVES OF DISUBSTITUTED SEVEN-VERTEX COBALTACARBORANE METALLOCENYL

2010 ◽  
Vol 09 (01) ◽  
pp. 219-231 ◽  
Author(s):  
XIAODONG LIU ◽  
YONGQING QIU ◽  
SHILING SUN ◽  
CHUNGUANG LIU ◽  
ZHONGMIN SU
Keyword(s):  
Nonlinear Optical ◽  
Membered Ring ◽  
Second Order ◽  
Meta Position ◽  
Nlo Response ◽  
B3lyp Method ◽  
Acceptor Group ◽  
Calculation Results ◽  
Optimum Model ◽  
Derivatives Of

DFT B3LYP method was employed to calculate the second-order nonlinear optical (NLO) responses of the derivatives of disubstituted seven-vertex cobaltacarborane metallocenyl. The results show that cobaltacarborane metallocenyl plays a pushing/pulling role and a bridge role to transfer electron in these molecules. The five-membered ring of cyclopentadiene is more beneficial to increase second-order NLO response than the five-membered ring composed of two C atoms and three B atoms in cobaltacarborane. Moreover, the second-order NLO response is more powerful when one substituent containing electron donor group and one substituent containing electron acceptor group are located at meta position. Accordingly, among the nine models, model c2 is the optimum model with largest value of βtot. The calculation results also show that cobaltacarborane metallocenyl and ferrocene parts play the same roles to increase second-order NLO response. Thus, cobaltacarborane metallocenyl can be a promising second-order NLO material.

scholarly journals State of the art paper The role of nateglinide and repaglinide, derivatives of meglitinide, in the treatment of type 2 diabetes mellitus

2013 ◽  
Vol 5 ◽  
pp. 936-943 ◽  
Author(s):  
Rodolfo Guardado-Mendoza ◽  
Annamaria Prioletta ◽  
Lilia M. Jiménez-Ceja ◽  
Aravind Sosale ◽  
Franco Folli
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
State Of The Art ◽  
Derivatives Of
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