Spectral aliasing in 2D-NMR. A straightforward method to considerably increase the resolution of signal clusters and facilitate identification of two cubebin epimers in Drimys winteri

A new lupane type triterpene (1), together with betulinic acid (2), friedelin (3), aristolochic acid I (4), alpinumisoflavone (5) and 4’-O-methylepinumisoflavone (6) have been isolated from the leaves of Thecacoris annobonea. The structure of the new compound was elucidated on the basis of 1 and 2D NMR experiments. The isolated compounds were evaluated for their phytotoxicity and antimicrobial activity. 1 exhibited significant antimicrobial activity at 30 μg/ml and compounds 1, 2, 3, 4, 5 and 6 inhibited root growth lettuce at 100 μg/ml.

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Direct Plan View FIB Liftout for Near-Surface Defect Analysis in TEM

ISTFA 2013: Conference Proceedings from the 39th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2013p0560 ◽

2013 ◽

Author(s):

Max L. Lifson ◽

Carla M. Chapman ◽

D. Philip Pokrinchak ◽

Phyllis J. Campbell ◽

Greg S. Chrisman ◽

...

Keyword(s):

Failure Analysis ◽

Silicon Germanium ◽

Focused Ion Beam ◽

Surface Defects ◽

Ion Beam ◽

Misfit Dislocations ◽

Tem Analysis ◽

Plan View ◽

Near Surface ◽

Straightforward Method

Abstract Plan view TEM imaging is a powerful technique for failure analysis and semiconductor process characterization. Sample preparation for near-surface defects requires additional care, as the surface of the sample needs to be protected to avoid unintentionally induced damage. This paper demonstrates a straightforward method to create plan view samples in a dual beam focused ion beam (FIB) for TEM studies of near-surface defects, such as misfit dislocations in heteroepitaxial growths. Results show that misfit dislocations are easily imaged in bright-field TEM and STEM for silicon-germanium epitaxial growth. Since FIB tools are ubiquitous in semiconductor failure analysis labs today, the plan view method presented provides a quick to implement, fast, consistent, and straightforward method of generating samples for TEM analysis. While this technique has been optimized for near-surface defects, it can be used with any application requiring plan view TEM analysis.

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Isolation of New Glycosides from Anemarrhena Asphodeloides Rhizome and Screening of their Anticancer Activity

Letters in Organic Chemistry ◽

10.2174/1570178615666181102125553 ◽

2019 ◽

Vol 16 (6) ◽

pp. 474-477 ◽

Cited By ~ 1

Author(s):

Pham Van Khang ◽

Nguyen Thi Hien Lan ◽

Le Quang Truong ◽

Mai Thi Minh Chau ◽

Mai Xuan Truong ◽

...

Keyword(s):

Anticancer Activity ◽

Spectral Data ◽

Cell Lines ◽

Cancer Cell ◽

Spectroscopic Analysis ◽

2D Nmr ◽

Ic50 Values ◽

Nmr Techniques ◽

Inhibitory Activities ◽

Anemarrhena Asphodeloides

In this report, two new steroidal glycosides were isolated and determined from n-butanol fraction of A.asphodeloides. The structures were confirmed in comparison with the spectral data of known compounds by using different spectroscopic analysis approaches including 1D & 2D-NMR techniques and HRMS. The anti-proliferation screening against cancer cell lines A549 and HeLa indicated that compound 1 exhibited good inhibitory activities with IC50 values of 0.79 and 0.55 µg/mL, respectively.

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Nuclear Magnetic Resonance Spectroscopic Behaviour of Some Selective Natural Flavonoids: A Look Through

Mini-Reviews in Organic Chemistry ◽

10.2174/1570193x16666181224110603 ◽

2020 ◽

Vol 17 (2) ◽

pp. 185-196

Author(s):

Shyamal K. Jash ◽

Dilip Gorai ◽

Lalan C. Mandal ◽

Rajiv Roy

Keyword(s):

Nuclear Magnetic Resonance ◽

Natural Products ◽

Magnetic Resonance ◽

Hard Core ◽

2D Nmr ◽

Vital Role ◽

Spectral Technique ◽

Nmr Techniques ◽

Significant Class ◽

Nuclear Magnetic

Flavonoids are considered as a significant class of compounds among the natural products, exhibiting a variety of structural skeletons as well as multidirectional biological potentials. In structural elucidations of natural products, Nuclear Magnetic Resonance (NMR) spectroscopy has been playing a vital role; the technique is one of the sharpest tools in the hands of natural products chemists. The present resume deals with hard-core applications of such spectral technique, particularly in structural elucidation of flavonoids; different NMR techniques including 1H-NMR, 13C-NMR, and 2D-NMR [viz. 1H-1H COSY, COLOC, HMBC, HMQC] are described in detail.

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A Cytotoxic Natural Product from Patrinia villosa Juss

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520619666190416101014 ◽

2019 ◽

Vol 19 (11) ◽

pp. 1399-1404 ◽

Cited By ~ 1

Author(s):

Yangcheng Liu ◽

Wei Liu ◽

Changlan Chen ◽

Zheng Xiang ◽

Hongwei Liu

Keyword(s):

Cell Cycle ◽

Cell Lines ◽

Silica Gel ◽

Column Chromatography ◽

Bioactive Compound ◽

Antitumor Agent ◽

2D Nmr ◽

Preparative Hplc ◽

Dependent Manner ◽

2D Nmr Spectra

Background and Purpose:: Patrinia villosa Juss is an important Chinese herbal medicine widely used for thousands of years, but few reports on the ingredients of the herb have been presented. In this study, we aim to isolate the bioactive compound from the plant. Material and Methods:: The air-dried leaves of P. villosa (15kg) were extracted three times with 70% EtOH under reflux. The condensed extract was suspended in H2O and partitioned with light petroleum, dichloromethane and n-BuOH. The dichloromethane portion was then subjected to normal-phase silica gel column chromatography, ODS silica gel column chromatography and semi-preparative HPLC to yield compound 1. Cytotoxicities of 1 were assayed on HepG2, A549 and A2780 cell lines. The mechanism of apoptosis and cell cycle on A549 was confirmed subsequently. Results: A new impecylone (Impecylone A) was isolated from the leaves of Patrinia villosa Juss, and its structures were established using 1D, 2D-NMR spectra and HR-ESI-MS. Impecylone A could selectivity inhibit HepG2 and A549 cell lines. The compound could induce apoptosis of A549 and arrest the cell cycle at G2/M phase in a dose-dependent manner. Conclusion: Impecylone A is a novel compound from Patrinia villosa Juss and could be a potential antitumor agent especially in the cell lines of A549.

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Co-Translational Insertion of Aquaporins into Liposome for Functional Analysis via an E. coli Based Cell-Free Protein Synthesis System

Cells ◽

10.3390/cells8111325 ◽

2019 ◽

Vol 8 (11) ◽

pp. 1325 ◽

Cited By ~ 1

Author(s):

Ke Yue ◽

Tran Nam Trung ◽

Yiyong Zhu ◽

Ralf Kaldenhoff ◽

Lei Kai

Keyword(s):

Functional Analysis ◽

Membrane Proteins ◽

Fluorescent Protein ◽

Water Channel ◽

New Approach ◽

E Coli ◽

Straightforward Method ◽

Lipid Environment ◽

Green Fluorescent ◽

Eukaryotic Organisms

Aquaporins are important and well-studied water channel membrane proteins. However, being membrane proteins, sample preparation for functional analysis is tedious and time-consuming. In this paper, we report a new approach for the co-translational insertion of two aquaporins from Escherichia coli and Nicotiana tabacum using the CFPS system. This was done in the presence of liposomes with a modified procedure to form homogenous proteo-liposomes suitable for functional analysis of water permeability using stopped-flow spectrophotometry. Two model aquaporins, AqpZ and NtPIP2;1, were successfully incorporated into the liposome in their active forms. Shifted green fluorescent protein was fused to the C-terminal part of AqpZ to monitor its insertion and status in the lipid environment. This new fast approach offers a fast and straightforward method for the functional analysis of aquaporins in both prokaryotic and eukaryotic organisms.

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