Vibrational optical activity for structural characterization of natural products

2020 ◽  
Vol 37 (12) ◽  
pp. 1661-1699 ◽  
Author(s):  
Prasad L. Polavarapu ◽  
Ernesto Santoro
Keyword(s):  
Natural Products ◽  
Optical Activity ◽  
Structural Characterization ◽  
Recent Progress

This review presents the recent progress towards elucidating the structures of chiral natural products and applications using vibrational optical activity (VOA) spectroscopy.

Improvements in the practical utility of the “crystalline sponge” method for structural characterization of natural products

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
GW Walhart ◽  
BD Santarsiero ◽  
J Orjala ◽  
NP Mankad
Keyword(s):  
Natural Products ◽  
Structural Characterization ◽  
Practical Utility

Structural characterization of proteins and viruses using Raman optical activity

2004 ◽  
Vol 35 (1-2) ◽  
pp. 87-92 ◽  
Author(s):  
Ewan W Blanch ◽  
Iain H McColl ◽  
Lutz Hecht ◽  
Kurt Nielsen ◽  
Laurence D Barron
Keyword(s):  
Optical Activity ◽  
Structural Characterization ◽  
Raman Optical Activity

Structural Characterization of Natural Products By Means of Quantum Chemical Calculations of NMR Parameters: New insights

2021 ◽  
Author(s):  
Fabio Luiz Paranhos Costa ◽  
Ana Carolina Ferreira de Albuquerque ◽  
Rodolfo Goetze Fiorot ◽  
Luciano Morais Lião ◽  
Lucas Haidar Martorano ◽  
...  
Keyword(s):  
Natural Products ◽  
Structural Characterization ◽  
Quantum Chemical ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Nmr Parameters ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling

The calculation of NMR parameters for natural products was pioneered by Bifulco and coworkers in 2002. Since then, modelling 1H and 13C chemical shifts and spin-spin coupling constants for this...

scholarly journals Estudo do tautomerismo ceto-enólico da 7-epi-clusianona através de cálculos teóricos de deslocamentos químicos de RMN

2020 ◽  
Author(s):  
Ana Carolina Ferreira de Albuquerque ◽  
José Walkimar de Mesquita Carneiro ◽  
Fernando Martins dos Santos Junior
Keyword(s):  
Natural Products ◽  
Structural Characterization ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Spectroscopic Techniques ◽  
Chemical Structures ◽  
Nmr Parameters

The properties of natural products, including their biological and pharmacological activities, are directly correlated with their chemical structures. Thus, a correct structural characterization of these compounds is a crucial step to the understanding of their biological activities. However, despite the recent advances in spectroscopic techniques, structural studies of natural products can be challenging. This way, theoretical calculations of Nuclear Magnetic Resonance (NMR) parameters (such as chemical shifts and coupling constants) have proven to be a powerful and low-cost tool for the aid to experimental techniques traditionally used for the structural characterization of natural products. One of the several applications of quantum-mechanical calculations of NMR parameters is the study of tautomerism. Since chemical shifts are sensitive to the tautomeric equilibrium, this technique can provide crucial informations. In this work, it was applied a protocol for theoretical calculations of ¹³C chemical shifts in order to study the tautomerism of the natural product 7-epi-clusianone, isolated from Rheedia gardneriana. This protocol consists in a Monte Carlo conformational search, followed by geometry optimization and shielding tensors calculations, both using a density functional level of theory. After comparison of theoretical and experimental data, it was possible to confirm the two tautomers present in equilibrium in the experimental solution. Furthermore, this study highlights how this theoretical protocol can be an effective method in identifying the preferred tautomeric form in solution.

Use of Raman and Raman optical activity for the structural characterization of a therapeutic monoclonal antibody formulation subjected to heat stress

2015 ◽  
Vol 46 (6) ◽  
pp. 531-536 ◽  
Author(s):  
Geetha Thiagarajan ◽  
Effendi Widjaja ◽  
Jun Hyuk Heo ◽  
Jason K. Cheung ◽  
Busolo Wabuyele ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Heat Stress ◽  
Optical Activity ◽  
Structural Characterization ◽  
Therapeutic Monoclonal Antibody ◽  
Raman Optical Activity

scholarly journals Recent Progress in Structural and Electrochemical Properties in Composite Based LiFePO4 Batteries

2015 ◽  
Vol 18 (4) ◽  
pp. 193-205
Author(s):  
Lubna Tabassam ◽  
Uzma Tabassam ◽  
Umair Manzoor
Keyword(s):  
Cathode Material ◽  
Electrochemical Properties ◽  
Structural Characterization ◽  
Cathode Materials ◽  
Recent Progress ◽  
Environmental Friendliness ◽  
Recent Developments ◽  
High Theoretical Capacity ◽  
Li Ion

This review describes some recent developments in the composite doped cathode materials such as LiCoO2, LiNiO2, LiMn2O4, and LiMnO2 with focus on LiFePO4. Olivine LiFePO4 have attracted considerable attention since last decade because of its promising properties as a cathode material in Li ion based batteries (LIBs), that is, it offers high theoretical capacity, environmental friendliness, and less toxicity. The electrochemical and structural characterization of this system will be discussed in more detail as compared with its other counterpart.

Recent advances in the use of vibrational chiroptical spectroscopic methods for stereochemical characterization of natural products

2015 ◽  
Vol 32 (9) ◽  
pp. 1280-1302 ◽  
Author(s):  
João M. Batista Jr. ◽  
Ewan W. Blanch ◽  
Vanderlan da Silva Bolzani
Keyword(s):  
Natural Products ◽  
Natural Product ◽  
Optical Activity ◽  
Spectroscopic Methods ◽  
Recent Advances

A comprehensive look into application of vibrational optical activity methods for conformational and configurational assignments in natural product molecules over the last 15 years is provided.

scholarly journals Structural characterization of three noncanonical NTF2-like superfamily proteins: implications for polyketide biosynthesis

2020 ◽  
Vol 76 (8) ◽  
pp. 372-383
Author(s):  
Nemanja Vuksanovic ◽  
Xuechen Zhu ◽  
Dante A. Serrano ◽  
Vilja Siitonen ◽  
Mikko Metsä-Ketelä ◽  
...  
Keyword(s):  
Natural Products ◽  
Structural Characterization ◽  
Unknown Function ◽  
Biosynthetic Pathway ◽  
Streptomyces Coelicolor ◽  
Biosynthetic Pathways ◽  
Polyketide Biosynthesis ◽  
X Ray ◽  
Bona Fide

Proteins belonging to the NTF2-like superfamily are present in the biosynthetic pathways of numerous polyketide natural products, such as anthracyclins and benzoisochromanequinones. Some have been found to be bona fide polyketide cyclases, but many of them have roles that are currently unknown. Here, the X-ray crystal structures of three NTF2-like proteins of unknown function are reported: those of ActVI-ORFA from Streptomyces coelicolor A3(2) and its homologs Caci_6494, a protein from an uncharacterized biosynthetic cluster in Catenulispora acidiphila, and Aln2 from Streptomyces sp. CM020, a protein in the biosynthetic pathway of alnumycin. The presence of a solvent-accessible cavity and the conservation of the His/Asp dyad that is characteristic of many polyketide cyclases suggest a potential enzymatic role for these enzymes in polyketide biosynthesis.

New ultrastructural findings about Borrelia burgdorferi by cryofixation, negative staining, thin sectioning and scanning techniques

1990 ◽  
Vol 48 (3) ◽  
pp. 582-583
Author(s):  
S. F. Hayes ◽  
M. D. Corwin ◽  
T. G. Schwan ◽  
D. W. Dorward ◽  
W. Burgdorfer
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Structural Characterization ◽  
Negative Staining ◽  
Low Speed ◽  
Thin Sectioning ◽  
Ultrastructural Findings

Characterization of Borrelia burgdorferi strains by means of negative staining EM has become an integral part of many studies related to the biology of the Lyme disease organism. However, relying solely upon negative staining to compare new isolates with prototype B31 or other borreliae is often unsatisfactory. To obtain more satisfactory results, we have relied upon a correlative approach encompassing a variety EM techniques, i.e., scanning for topographical features and cryotomy, negative staining and thin sectioning to provide a more complete structural characterization of B. burgdorferi.For characterization, isolates of B. burgdorferi were cultured in BSK II media from which they were removed by low speed centrifugation. The sedimented borrelia were carefully resuspended in stabilizing buffer so as to preserve their features for scanning and negative staining. Alternatively, others were prepared for conventional thin sectioning and for cryotomy using modified procedures. For thin sectioning, the fixative described by Ito, et al.

Sign in / Sign up

Export Citation Format

Share Document