scholarly journals A Unique Naphthone Derivative and a Rare 4,5-seco-Lanostane Triterpenoid from Poria cocos

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2508 ◽  
Author(s):  
Ting Chen ◽  
La Hua ◽  
Guixin Chou ◽  
Xudong Mao ◽  
Xianliang Zou
Keyword(s):  
Mass Spectroscopy ◽  
Absolute Configuration ◽  
Cytotoxic Activities ◽  
Electronic Circular Dichroism ◽  
Poria Cocos ◽  
Etoh Extract ◽  
The Absolute ◽  
Lanostane Triterpenoid ◽  
New Compounds ◽  
Circular Dichroïsm

A previously undescribed naphthalenone derivative, sohiracillinone (1), and a novel 4,5-seco-lanostane triterpenoid, 11β-ethoxydaedaleanic acid A (2) were isolated with two new lanostane triterpenoids, ceanphytamic acids A (3) and B (4), from the EtOH extract of Poria cocos along with 17 known compounds 5–21. The absolute configuration of sohiracillinone (1) was unambiguously identified by NMR and electronic circular dichroism (ECD) data. The structures of other new compounds were elucidated on the basis of NMR and mass spectroscopy (MS), and the cytotoxic activities of all the isolated components were evaluated.

scholarly journals Absolute Configuration Sensing of Chiral Aryl- and Aryloxy-Propionic Acids by Biphenyl Chiroptical Probes

Chemosensors ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 154
Author(s):  
Stefania Vergura ◽  
Stefano Orlando ◽  
Patrizia Scafato ◽  
Sandra Belviso ◽  
Stefano Superchi
Keyword(s):  
Circular Dichroism ◽  
Absolute Configuration ◽  
Optical Rotation ◽  
Environmental Pollutants ◽  
Red Shift ◽  
Electronic Circular Dichroism ◽  
Configuration Assignment ◽  
Clear Sign ◽  
The Absolute ◽  
Circular Dichroïsm

The absolute configuration of chiral 2-aryl and 2-aryloxy propionic acids, which are among the most common chiral environmental pollutants, has been readily and reliably established by either electronic circular dichroism spectroscopy or optical rotation measurements employing suitably designed 4,4′-disubstituted biphenyl probes. In fact, the 4,4′-biphenyl substitution gives rise to a red shift of the diagnostic electronic circular dichroism signal of the biphenyl A band employed for the configuration assignment, removing its overlap with other interfering dichroic bands and allowing its clear sign identification. The largest A band red shift, and thus the most reliable results, are obtained by employing as a probe the 4,4′-dinitro substituted biphenylazepine 3c. The method was applied to the absolute configuration assignment of 2-arylpropionic acids ibuprofen (1a), naproxen (1b), ketoprofen (1c) and flurbiprofen (1d), as well as to the 2-aryloxypropionic acids 2-phenoxypropionic acid (2a) and 2-naphthoxypropionic acid (2b). This approach, allowing us to reveal the sample’s absolute configuration by simple optical rotation measurements, is potentially applicable to online analyses of both the enantiomeric composition and absolute configuration of these chiral pollutants.

scholarly journals Synthesis and Configurational Assignment of Vinyl Sulfoximines and Sulfonimidamides

2021 ◽  
Author(s):  
Gregory Craven ◽  
Edward L. Briggs ◽  
Charlotte Zammit ◽  
Alex McDermott ◽  
Stephanie Greed ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Late Stage ◽  
Chemical Biology ◽  
Chemical Space ◽  
Protein Inhibitors ◽  
Electronic Circular Dichroism ◽  
Configurational Assignment ◽  
The Absolute ◽  
Synthetic Methodologies ◽  
Circular Dichroïsm

Vinyl sulfones and sulfonamides are valued for their use as electrophilic warheads in covalent protein inhibitors. Conversely, the S(VI) aza-isosteres thereof, vinyl sulfoximines and sulfonimidamides, are far less studied and have yet to be applied to the field of protein bioconjugation. Herein, we report a range of different synthetic methodologies for constructing vinyl sulfoximine and vinyl sulfonimidamide architectures that allows access to new areas of electrophilic chemical space. We demonstrate how late stage functionalization can be applied to these motifs to incorporate alkyne tags, generating fully functionalized probes for future chemical biology applications. Finally, we establish a workflow for determining the absolute configuration of enantioenriched vinyl sulfoximines and sulfonimidamides by comparing experimentally and computationally determined electronic circular dichroism spectra, enabling access to configurationally assigned enantiomeric pairs by separation.

Two Rare Hydroazulene-type Sesquiterpenes from the Roots of Aristolochia yunnanensis

2014 ◽  
Vol 69 (6) ◽  
pp. 742-746 ◽  
Author(s):  
Zhuo Du ◽  
Feng-Ni Wen ◽  
Ji-Ping Zhang ◽  
Jian-Feng Wua ◽  
Fang Liu ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Cell Lines ◽  
Spectroscopic Data ◽  
Cytotoxic Activities ◽  
Moderate Activity ◽  
Electronic Circular Dichroism ◽  
The Third ◽  
The Absolute ◽  
First Time ◽  
Circular Dichroïsm

Two new sesquiterpenes, named aristoyunnolin I (1) and J (2), together with eight known compounds (3 - 10) were isolated from the roots of Aristolochia yunnanensis. Compounds 1 and 2 feature a rare hydroazulene-type sesquiterpene skeleton and represent the third and fourth examples of this kind found in nature. The structures were determined from spectroscopic data, and the absolute configurations of 1 - 3 were assigned by comparing experimental with simulated electronic circular dichroism (ECD) spectra. Compounds 1, 2, 6 - 10 were isolated from this plant for the first time. The cytotoxic activities of 1 - 10 were evaluated against P-388 and A-549 cell lines. Only compounds 4 and 5 showed moderate activity with IC50 values ranging from 12.0 to 18.2 μM.

scholarly journals Use of Circular Dichroism to Determine the Absolute Configuration of a Pimarane Diterpenoid from the Southern African Sclerocroton integerrimus (Euphorbiaceae)

2014 ◽  
Vol 9 (8) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Vuyelwa J. Tembu ◽  
Moses K. Langat ◽  
Neil R. Crouch ◽  
Dulcie A. Mulholland
Keyword(s):  
Circular Dichroism ◽  
Absolute Configuration ◽  
Spectroscopic Analysis ◽  
Stem Bark ◽  
Electronic Circular Dichroism ◽  
The Absolute ◽  
Circular Dichroïsm

From the stem bark and leaves of Sclerocroton integerrimus, eight compounds, including 17-hydroxy- ent-pimara-8(14),15-dien-3-one (1), were isolated. The structures of the compounds were determined on the basis of spectroscopic analysis. The absolute configuration of 17-hydroxy- ent-pimara-8(14),15-dien-3-one was confirmed from electronic circular dichroism studies.

New Phenolic Glycosides and Lignans from the Roots of Lilium dauricum

Planta Medica ◽  
2021 ◽  
Author(s):  
Xiao Xia ◽  
Jiao Zhang ◽  
Xiao-Jiang Wang ◽  
Yan Lu ◽  
Dao-Feng Chen
Keyword(s):  
Inhibitory Activity ◽  
Phenolic Glycosides ◽  
Anticomplementary Activity ◽  
Chemical Methods ◽  
Electronic Circular Dichroism ◽  
Circular Dichroism Analysis ◽  
Ic50 Values ◽  
The Absolute ◽  
New Compounds ◽  
Circular Dichroïsm

AbstractThree new phenolic glycosides, carvacrol-2-O-β-D-apiofuranosyl-(1 → 6)-β-D-glucopyranoside (1), 1-methyl-3-isopropylphenol-4-O-β-D-apiofuranosyl-(1 → 6)-β-D-glucopyranoside (2), p-methoxythymol-5-O-β-D-apiofuranosyl-(1 → 6)-β-D-glucopyranoside (3), and a pair of new 8-O-4′ neolignan enantiomers (5a/5b), together with 26 known compounds (4, 6 – 30) were isolated from the roots of Lilium dauricum. The structures of the new compounds were elucidated based on extensive spectroscopic and chemical methods, and the absolute configurations of 5a and 5b were established by electronic circular dichroism analysis. Nine compounds (1, 3, 4, 8, 9, 17, 25, 29, and 30) exhibited potent α-glucosidase inhibitory activity with IC50 values ranging from 73.4 µM to 988.2 µM. Besides, compound 19 displayed strong anticomplementary activity (CH50: 71.6 µM).

scholarly journals Synthesis and Configurational Assignment of Vinyl Sulfoximines and Sulfonimidamides

2021 ◽  
Author(s):  
Gregory Craven ◽  
Edward L. Briggs ◽  
Charlotte Zammit ◽  
Alex McDermott ◽  
Stephanie Greed ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Late Stage ◽  
Chemical Biology ◽  
Chemical Space ◽  
Protein Inhibitors ◽  
Electronic Circular Dichroism ◽  
Configurational Assignment ◽  
The Absolute ◽  
Synthetic Methodologies ◽  
Circular Dichroïsm

Vinyl sulfones and sulfonamides are valued for their use as electrophilic warheads in covalent protein inhibitors. Conversely, the S(VI) aza-isosteres thereof, vinyl sulfoximines and sulfonimidamides, are far less studied and have yet to be applied to the field of protein bioconjugation. Herein, we report a range of different synthetic methodologies for constructing vinyl sulfoximine and vinyl sulfonimidamide architectures that allows access to new areas of electrophilic chemical space. We demonstrate how late stage functionalization can be applied to these motifs to incorporate alkyne tags, generating fully functionalized probes for future chemical biology applications. Finally, we establish a workflow for determining the absolute configuration of enantioenriched vinyl sulfoximines and sulfonimidamides by comparing experimentally and computationally determined electronic circular dichroism spectra, enabling access to configurationally assigned enantiomeric pairs by separation.

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