scholarly journals (±)-Perforison A, A Pair of New Chromone Enantiomers from Harrisonia perforata

2017 ◽  
Vol 12 (1) ◽  
pp. 1934578X1701200
Author(s):  
Wen-Juan Yuan ◽  
Wen-Fen Gao ◽  
Jia-Hui Zhang ◽  
Pei Cao ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Spectroscopic Data ◽  
Cytotoxic Activities ◽  
Significant Activity ◽  
Electronic Circular Dichroism ◽  
Extensive Analysis ◽  
Circular Dichroïsm

(+)-Perforison A and (-)-perforison A, a new pair of chromone enantiomers, along with four known compounds, were isolated from the leaves and stems of Harrisonia perforata. Their structures and absolute configurations were determined on the basis of extensive analysis of spectroscopic data and electronic circular dichroism (ECD) calculations. The cytotoxic activities in vitro of these compounds were evaluated, but none showed significant activity.

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 Electronic Circular Dichroism of the Cas9 Protein and gRNA:Cas9 Ribonucleoprotein Complex

2021 ◽  
Vol 22 (6) ◽  
pp. 2937
Author(s):  
Monika Halat ◽  
Magdalena Klimek-Chodacka ◽  
Jagoda Orleanska ◽  
Malgorzata Baranska ◽  
Rafal Baranski
Keyword(s):  
Circular Dichroism ◽  
Conformational Changes ◽  
Structural Changes ◽  
Electronic Circular Dichroism ◽  
Guide Rna ◽  
Cas9 Protein ◽  
Rnp Complex ◽  
Characteristic Features ◽  
Circular Dichroïsm

The Streptococcus pyogenes Cas9 protein (SpCas9), a component of CRISPR-based immune system in microbes, has become commonly utilized for genome editing. This nuclease forms a ribonucleoprotein (RNP) complex with guide RNA (gRNA) which induces Cas9 structural changes and triggers its cleavage activity. Here, electronic circular dichroism (ECD) spectroscopy was used to confirm the RNP formation and to determine its individual components. The ECD spectra had characteristic features differentiating Cas9 and gRNA, the former showed a negative/positive profile with maxima located at 221, 209 and 196 nm, while the latter revealed positive/negative/positive/negative pattern with bands observed at 266, 242, 222 and 209 nm, respectively. For the first time, the experimental ECD spectrum of the gRNA:Cas9 RNP complex is presented. It exhibits a bisignate positive/negative ECD couplet with maxima at 273 and 235 nm, and it differs significantly from individual spectrum of each RNP components. Additionally, the Cas9 protein and RNP complex retained biological activity after ECD measurements and they were able to bind and cleave DNA in vitro. Hence, we conclude that ECD spectroscopy can be considered as a quick and non-destructive method of monitoring conformational changes of the Cas9 protein as a result of Cas9 and gRNA interaction, and identification of the gRNA:Cas9 RNP complex.

Pseurotin A1 and A2, two new 1-oxa-7-azaspiro[4.4]non-2-ene-4,6-diones from the holothurian-derived fungus Aspergillus fumigatus WFZ-25

2011 ◽  
Vol 89 (1) ◽  
pp. 72-76 ◽  
Author(s):  
Fa-Zuo Wang ◽  
De-Hai Li ◽  
Tian-Jiao Zhu ◽  
Min Zhang ◽  
Qian-Qun Gu
Keyword(s):  
Circular Dichroism ◽  
Aspergillus Fumigatus ◽  
Spectroscopic Data ◽  
2D Nmr ◽  
Esi Ms ◽  
Extensive Analysis ◽  
Circular Dichroïsm ◽  
New Metabolites

Two new metabolites containing a 1-oxa-7-azaspiro[4.4]non-2-ene-4,6-dione core, pseurotin A1 (1) and A2 (2), as well as pseurotin A (3), were isolated from the holothurian-derived fungus Aspergillus fumigatus WFZ-25. These compounds were determined using extensive analysis of their spectroscopic data, including 1D and 2D NMR, HR-ESI-MS, and circular dichroism (CD) experiments.

scholarly journals Aspidoptoids A–D: Four New Diterpenoids from Aspidopterys obcordata Vine

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 529
Author(s):  
Sun ◽  
Cao ◽  
Xiao ◽  
Zhang ◽  
Wang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Circular Dichroism ◽  
Absolute Configuration ◽  
2D Nmr ◽  
Cytotoxic Activities ◽  
No Production ◽  
Inhibitory Effects ◽  
Electronic Circular Dichroism ◽  
Spectroscopic Analyses ◽  
Circular Dichroïsm

Four new diterpenoids, named aspidoptoids A–D (1–4), together with two known analogues (5–6) were isolated from Aspidopterys obcordata vine. Aspidoptoids A–B (1–2) are the first examples of phenylethylene-bearing 20-nor-diterpenoids of which aspidoptoid B (2) possesses a rare 3,10-oxybridge. Their structures and absolute configuration were determined by extensive spectroscopic analyses (IR, HRESIMS, 1D and 2D NMR) and electronic circular dichroism (ECD) calculation. In addition, all the isolates were evaluated for their cytotoxic activities and inhibitory effects on the nitric oxide (NO) production.

scholarly journals Mass-resolved electronic circular dichroism ion spectroscopy

Science ◽  
2020 ◽  
Vol 368 (6498) ◽  
pp. 1465-1468 ◽  
Author(s):  
Steven Daly ◽  
Frédéric Rosu ◽  
Valérie Gabelica
Keyword(s):  
Circular Dichroism ◽  
Three Dimensional ◽  
Polarized Light ◽  
Negative Ions ◽  
Data Interpretation ◽  
Electronic Circular Dichroism ◽  
Circularly Polarized Light ◽  
Chiral Compounds ◽  
Electron Photodetachment ◽  
Circular Dichroïsm

DNA and proteins are chiral: Their three-dimensional structures cannot be superimposed with their mirror images. Circular dichroism spectroscopy is widely used to characterize chiral compounds, but data interpretation is difficult in the case of mixtures. We recorded the electronic circular dichroism spectra of DNA helices separated in a mass spectrometer. We studied guanine-rich strands having various secondary structures, electrosprayed them as negative ions, irradiated them with an ultraviolet nanosecond optical parametric oscillator laser, and measured the difference in electron photodetachment efficiency between left and right circularly polarized light. The reconstructed circular dichroism ion spectra resembled those of their solution-phase counterparts, thereby allowing us to assign the DNA helical topology. The ability to measure circular dichroism directly on biomolecular ions expands the capabilities of mass spectrometry for structural analysis.

Chemical Constituents from Chloranthus elatior and Their Inhibitory Effect on Human Dihydroorotate Dehydrogenase

Planta Medica ◽  
2021 ◽  
Author(s):  
Qian Yang ◽  
An Jia ◽  
Xizi Liu ◽  
Shiyi Han ◽  
Siyang Fan
Keyword(s):  
Circular Dichroism ◽  
Chemical Constituents ◽  
Inhibitory Effect ◽  
Mass Spectrometric ◽  
Dihydroorotate Dehydrogenase ◽  
Active Compounds ◽  
Electronic Circular Dichroism ◽  
Aerial Parts ◽  
Ic50 Values ◽  
Circular Dichroïsm

AbstractA new sesquiterpene, chlorantholide G (1), a new sesquiterpene dimer, elatiolactone (2), and 2 new diterpenes, elatiorlabdane B (3) and elatiorlabdane C (4), together with 51 known compounds, were isolated from the aerial parts of Chloranthus elatior. The new structures including their absolute configurations were mainly established by mass spectrometric, NMR, and electronic circular dichroism experiments. All isolated compounds were tested for their anti-hDHODH activity. (4S,6R)-4-hydroxy-6-isopropyl-3-methylcyclohex-2-enone (5) and (4S,5R,9S,10R)-8(17),12,14-labdatrien-18-oic acid (29) were the most active compounds with IC50 values of 18.7 and 30.7 µM, respectively.

Sign in / Sign up

Export Citation Format

Share Document