scholarly journals Simalikalactone D, a Potential Anticancer Compound from Simarouba tulae, an Endemic Plant of Puerto Rico

Plants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 93
Author(s):  
Belmari Mendez ◽  
Jeyshka Reyes ◽  
Isabel Conde ◽  
Zulma Ramos ◽  
Eunice Lozada ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Chloroform Extract ◽  
X Ray Diffraction ◽  
Endemic Plant ◽  
X Ray ◽  
Cytotoxicity Activity ◽  
Breast Cell Lines ◽  
Therapeutic Properties ◽  
High Cytotoxicity ◽  
Anticancer Compound

Species of the genus Simarouba have been studied because of their antimalarial and antileukemic activities. A group of oxygenated terpenes called quassinoids have been isolated from species of the Simarouba genus, and are responsible for its therapeutic properties. We hypothesized that Simarouba tulae, an endemic plant from Puerto Rico, is a natural source rich in quassinoid compounds with anticancer activity. The leaves were processed and extracted with solvents of different polarities. The extracts were screened for their antiproliferative activity, and it was shown that the chloroform extract was the most active extract. This extract was purified using different chromatographic techniques to afford the quassinoid simalikalactone D (SKD). This compound was further characterized using NMR and X-ray diffraction analysis. A reassessment of original structural assignments for SKD is proposed. SKD showed high cytotoxicity activity, with an IC50 of 55, 58, and 65 nM in A2780CP20 (ovarian), MDA-MB-435 (breast), and MDA-MB-231 (breast) cell lines, respectively. Exposure to SKD led to 15% inhibition of the migration of MDA-MB-231 cells.

scholarly journals Withanolides from Physalis angulata L.

2021 ◽  
Vol 77 (8) ◽  
pp. 804-808
Author(s):  
R. Ya. Okmanov ◽  
M. M. Makhmudova ◽  
I. D. Bobaev ◽  
B. Tashkhodjaev
Keyword(s):  
Hydrogen Bonds ◽  
Absolute Configuration ◽  
Chloroform Extract ◽  
Molecular Structures ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aerial Parts ◽  
Dimensional Network ◽  
Physalis Angulata

The compounds (17S,20R,22R,24R,25S)-5β,6β:20,24-diepoxy-4β,25-dihydroxy-1-oxowith-2-en-26,22-olide and (20R,22R)-5α,14α,20-Trihydroxy-1-oxo-6α,7α-epoxywitha-2-enolide were isolated from a chloroform extract of the aerial parts of Physalis angulata L. (Solanaceae). Two products were isolated from the chromatographic separation extract. Compound I corresponds to physangulide B chloroform monosolvate, C28H38O7·CHCl3, while compound II is 14α-hydroxyixocarpanolide, C28H40O7. In the two molecular structures, the conformation of the steroid part (rings A, B, C, D) does not differ. In both crystals, molecules are linked by intermolecular O—H...O hydrogen bonds along the c-axis direction and form a two-dimensional network parallel to the ac plane. The absolute configuration was determined from X-ray diffraction data.

Crystal Structures and Cytotoxicity of Four Silver(I)carboxylate Complexes with 1,2-Ethylenediamine Analogues

2019 ◽  
Vol 4 (1-2) ◽  
pp. 18-23
Author(s):  
Suo-Ping Xu ◽  
Qian Dong
Keyword(s):  
Crystal Structures ◽  
Coordination Geometry ◽  
X Ray Diffraction ◽  
Carboxylate Complexes ◽  
X Ray ◽  
High Cytotoxicity ◽  
Linear Coordination

Four silver(I) compounds, [Ag(dapn)(dnbc)]n·1.5nH2O (1), [Ag(en)]n[Ag(dnbc)2]n·2nH2O (2), [Ag(en)]n[Ag(nbc)2]n·2nH2O (3) and [Ag(dapn)]n -(nbc)n·2nH2O (4), where dapn = 1,2-diaminopropane, dnbc = 3,5-dinitrobenzoate, en = 1,2-diaminoethane and nbc = 4-nitrobenzoate, have been synthesized and characterized by X-ray diffraction. The Ag(I) ions show T-shaped coordination geometry in compound 1 but linear coordination geometry in compounds 2, 3 and 4. There are ligand-unsupported Ag…Ag interaction in compounds 2 and 3 with Ag…Ag distance of 3.177 ~3.267 Å. All the four complexes showed high cytotoxicity properties.

Promising antiviral, antimicrobial and therapeutic properties of green nanoceria

Nanomedicine ◽  
2020 ◽  
Vol 15 (5) ◽  
pp. 467-488 ◽  
Author(s):  
Hamza E Ahmed Mohamed ◽  
Shakeeb Afridi ◽  
Ali T Khalil ◽  
Muhammad Ali ◽  
Tanzeel Zohra ◽  
...  
Keyword(s):  
Luminescent Properties ◽  
In Vitro Assays ◽  
X Ray Diffraction ◽  
Green Method ◽  
X Ray ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Selected Area Electron Diffraction ◽  
Therapeutic Properties ◽  
Ultraviolet Absorption Spectroscopy

Aim: To demonstrate synthesis of cerium oxide nanoparticles (CeO2 NPs) by a green method using Hyphaene thebaica, and investigate their therapeutic applications. Materials & methods: Structural, vibrational and luminescent properties were established using x-ray diffraction, Fourier transformed infrared spectroscopy, Raman spectroscopy, ultraviolet absorption spectroscopy, selected area electron diffraction, electron microscopy and photolumincence spectroscopy. Therapeutic properties were established using different in vitro assays. Results: CeO2 NPs were determined to be crystalline in nature with a grain size of approximately 14 nm. They had characteristic Ce–O vibration at 481 cm-1. Photoluminescence spectra revealed broad bands at 463 and 600 nm. ζ potential was recorded as -17.2 mV. Potent antimicrobial and antiviral properties with hemocompatibility were reported. Conclusion: Biosynthesized CeO2 NPs revealed multifunctional therapeutic properties.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Ribosome Structural Organization

1974 ◽  
Vol 32 ◽  
pp. 332-333
Author(s):  
James A. Lake
Keyword(s):  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Small Subunit ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Specific Antibodies ◽  
X Ray ◽  
E Coli ◽  
Complete Sequences

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.

Electron Microscopy of Human Gallstones

1971 ◽  
Vol 29 ◽  
pp. 296-297
Author(s):  
C. Wolpers ◽  
R. Blaschke
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bile Pigment ◽  
X Ray Diffraction ◽  
Triclinic Crystal System ◽  
X Ray ◽  
Follow Up Study ◽  
Infra Red ◽  
Main Components

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Electron Microscopy of Shock Loaded Polycrystalline Beryllium

1974 ◽  
Vol 32 ◽  
pp. 506-507 ◽  
Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens
Keyword(s):  
Electron Microscopy ◽  
Wave Propagation ◽  
Structural Change ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Shock Loading ◽  
Slip Systems ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.

Chemical modification of the bacterial wall to determine sites of metal deposition

1978 ◽  
Vol 36 (2) ◽  
pp. 350-351
Author(s):  
T. J. Beveridge
Keyword(s):  
Electron Scattering ◽  
Metal Salt ◽  
Metal Deposition ◽  
Suitable Model ◽  
X Ray Diffraction ◽  
Subtilis Cell ◽  
Thin Sections ◽  
X Ray ◽  
Section Data ◽  
Metal Impregnation

The Bacillus subtilis cell wall provides a protective sacculus about the vital constituents of the bacterium and consists of a collection of anionic hetero- and homopolymers which are mainly polysaccharidic. We recently demonstrated that unfixed walls were able to trap and retain substantial amounts of metal when suspended in aqueous metal salt solutions. These walls were briefly mixed with low concentration metal solutions (5mM for 10 min at 22°C), were well washed with deionized distilled water, and the quantity of metal uptake (atomic absorption and X-ray fluorescence), the type of staining response (electron scattering profile of thin-sections), and the crystallinity of the deposition product (X-ray diffraction of embedded specimens) determined.Since most biological material possesses little electron scattering ability electron microscopists have been forced to depend on heavy metal impregnation of the specimen before obtaining thin-section data. Our experience with these walls suggested that they may provide a suitable model system with which to study the sites of reaction for this metal deposition.

Polygonal profiles of ferritin molecules

1983 ◽  
Vol 41 ◽  
pp. 600-601
Author(s):  
William H. Massover
Keyword(s):  
Axial Ratio ◽  
X Ray Diffraction ◽  
Rhombic Dodecahedron ◽  
Apparent Contradiction ◽  
Iron Storage ◽  
X Ray ◽  
Hexagonal Shape ◽  
Axes Of Symmetry ◽  
Apparent Conflict ◽  
Iron Storage Protein

The molecular structure of the iron-storage protein, ferritin, is becoming known in ever finer detail. The 24 apoferritin subunits (MW ca. 20,000) have a 2:1 axial ratio and are polymerized with 4:3:2 symmetry to form an outer shell surrounding a variable amount of microcrystalline iron, Recent x-ray diffraction results indicate that the projected outline of the native molecule has a quasi-hexagonal shape when viewed down the 3-fold axes of symmetry, and a quasi-square shape when looking down the 4-fold axes. To date, no electron microscope study has reported observing anything other than circular profiles, which would indicate that ferritin is strictly spherical. The apparent conflict between the "hollow sphere" of electron microscopy (E.M.) and the "truncated rhombic dodecahedron" of x-ray diffraction could reflect the poorer effective resolution of E.M. coming from radiation damage, staining, drying, etc. The present study investigates the detailed shape of individual ferritin molecules in order to search for the predicted aspherical profiles and to interpret the nature of this apparent contradiction.

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