A COMPARISON OF X-RAY INDUCED AND NATURALLY OCCURRING CHROMOSOMAL VARIATIONS IN DROSOPHILA PSEUDOOBSCURA

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.

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Hydrochloric Acid Modification and Lead Removal Studies on Naturally Occurring Zeolites from Nevada, New Mexico, and Arizona

Processes ◽

10.3390/pr9071238 ◽

2021 ◽

Vol 9 (7) ◽

pp. 1238

Author(s):

Garven M. Huntley ◽

Rudy L. Luck ◽

Michael E. Mullins ◽

Nick K. Newberry

Keyword(s):

New Mexico ◽

Surface Area ◽

Bet Surface Area ◽

Lead Removal ◽

X Ray Diffraction ◽

Sem Images ◽

X Ray ◽

Naturally Occurring ◽

27Al Mas Nmr ◽

Modified Zeolites

Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving the silicon framework intact as confirmed via X-ray fluorescence and diffraction. SEM images on calcined and HCl treated NV-Na were obtained. BET surface area analysis confirmed an increase in surface area for the two zeolites after treatment, NM-Ca 20.0(1) to 111(4) m2/g and NV-Na 19.0(4) to 158(7) m2/g. 29Si and 27Al MAS NMR were performed on the natural and treated NV-Na zeolite, and the data for the natural NV-Na zeolite suggested a Si:Al ratio of 4.33 similar to that determined by X-Ray fluorescence of 4.55. Removal of lead ions from solution decreased from the native NM-Ca, 0.27(14), NV-Na, 1.50(17) meq/g compared to the modified zeolites, 30 min HCl treated NM-Ca 0.06(9) and NV-Na, 0.41(23) meq/g, and also decreased upon K+ ion pretreatment in the HCl modified zeolites.

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Structural Study of an Unusual Diels-Alder Adduct

Australian Journal of Chemistry ◽

10.1071/ch9922089 ◽

1992 ◽

Vol 45 (12) ◽

pp. 2089 ◽

Cited By ~ 4

Author(s):

EL Ghisalberti ◽

BW Skelton ◽

AH White

Keyword(s):

Single Crystal ◽

Diffraction Study ◽

Structural Study ◽

Spectroscopic Studies ◽

Diels Alder ◽

X Ray Diffraction ◽

X Ray ◽

Naturally Occurring ◽

Chemical Evidence ◽

Alder Adduct

The structure of the compound obtained on heating the naturally occurring clerodane furanoditerpene (1) had been formulated as (2) on the basis of spectroscopic studies. A single-crystal X-ray diffraction study on the dihydro derivative of (2) has confirmed this and provides support for the stereochemistry previously assigned to (1) on the basis of chemical evidence.

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Synergistic interaction of renewable nipagin and eugenol for high performance aromatic copoly(ether ester) materials

10.21203/rs.3.rs-706272/v1 ◽

2021 ◽

Author(s):

Keling Hu ◽

Huachao Sui ◽

Dongping Zhao

Keyword(s):

High Performance ◽

Synergistic Interaction ◽

Differential Scanning Calorimetric ◽

Gravimetric Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Molecular Weights ◽

Chemical Structures ◽

Naturally Occurring ◽

Ether Ester

Abstract Naturally occurring nipagin and eugenol were used as the collaborative starting materials for poly(ether ester) materials. In this study, two series of nipagin and eugenol-derived copoly(ether ester)s, PHN11-xE1x and PHN11-xE2x (x = 0%, 5%, 10%, 15%, 20%), were prepared with renewable 1,6-hexanediol as a comonomer. The nipagin-derived component acts as the renewable surrogate of petroleum-based dimethyl terephthalate (DMT), while the eugenol-derived component acts as the cooperative property modifier of parent homopoly(ether ester) PHN1. 1,6-Hexanediol was chosen as the spacer because of its renewability and short chain to enhance the glass transition temperatures (Tgs) of materials. The molecular weights and chemical structures were confirmed by gel permeation chromatograph (GPC), NMR and FTIR spectroscopies. Thermal and crystalline properties were studied by thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC) and wide-angle X-ray diffraction (WXRD). The tensile assays were conducted to evaluate the mechanical properties. The results suggest that properties of such kind of poly(ether ester)s can be finely tuned by the relative content of two components. Synergistic interaction of two structurally distinctive parts endows the materials with high performance.

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Microbialite-like structures in Cladophora sp. (Ulvophyceae) mats from a subtropical Andean basin: ecological implications

Revista de Biología Tropical ◽

10.15517/rbt.v67i1.31542 ◽

2019 ◽

Vol 67 (1) ◽

Author(s):

Hugo R. Fernández ◽

Ana Lucia Gonzalez Achem ◽

Marcela Correa ◽

Virginia H. Albarracín

Keyword(s):

Organic Pollution ◽

Biological Factors ◽

X Ray Diffraction ◽

Calcite Precipitation ◽

Annual Cycles ◽

X Ray ◽

Naturally Occurring ◽

Ecological Implications ◽

First Time ◽

Solubility Equilibrium

The solubility equilibrium of calcite is influenced by physicochemical, climatic and biological factors. Annual cycles of exceptionally prolonged drought, in conjunction with naturally occurring diffuse organic pollution, generate the unique conditions for the precipitation of lithified carbonate structures (microbialites). The aim of this article is to analyze the possible implications of calcite precipitation produced in mats of Cladophora sp. in an Andean subtropical basin, considering it is the first time this phenomenon is described for the region. We collected samples from selected sites at the Lules River Basin, in four sampling dates between the years 2003 and 2004, within a monitoring work of 15 years. Samples were analyzed using an electron microscope and X-ray diffraction analysis. We found that Gomphonema sp. attached to Cladophora sp. contributes to precipitation of calcite and formation of microbialite like structures, in the studied area. This work presents an initial discussion of the discovery of microbialites-like structures attached to Cladophora sp. mats in a subtropical Andean stream and the environmental conditions that lead to their production, as well as the possible ecological implications of these microbialites.

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The Seven Last Infra-Uranium Elements to Be Discovered

The Periodic Table ◽

10.1093/oso/9780190914363.003.0016 ◽

2019 ◽

Author(s):

Eric Scerri

Keyword(s):

Periodic Table ◽

Atomic Weight ◽

Weak Acid ◽

Ray Method ◽

Natural Sources ◽

Transuranium Elements ◽

X Ray ◽

Naturally Occurring ◽

Missing Element

The term “infra-uranium,” meaning before uranium, is one that I have proposed by contrast to the better-known term transuranium elements that are discussed in the following chapter. The present chapter concerns the last seven elements that formed the missing gaps in the old periodic table that ended with the element uranium. After Moseley developed his X-ray method, it became clear that there were just seven elements yet to be isolated among the 92 naturally occurring elements or hydrogen (#1) to uranium (#92). This apparent simplicity is somewhat spoiled by the fact that, as it turned out, some of these seven elements were first isolated from natural sources following their being artificially created, but this raises more issues that are best left to the next chapter of this book. The fact remains that five of these seven elements are radioactive, the two exceptions being hafnium and rhenium, the second and third of them to be isolated. The first of the seven final infra-uranium elements to be discovered was protactinium, and it was one of the lesser-known predictions made by Mendeleev. In his famous 1896 paper, Mendeleev indicated incorrect values for both thorium (118) and uranium (116). (See figure 1.6.) A couple of years later, he corrected both of these values and showed a missing element between thorium and uranium (figure 4.4). In doing so, Mendeleev added the following paragraph, in which he made some specific predictions. . . . Between thorium and uranium in this series we can further expect an element with an atomic weight of about 235. This element should form a highest oxide R2O5, like Nb and Ta to which it should be analogous. Perhaps in the minerals which contain these elements a certain amount of weak acid formed from this metal will also be found.. . . The modern atomic weight for eka-tantalum or protactinium is 229.2. The apparent inaccuracy in Mendeleev’s prediction is not too surprising, however, since he never knew that protactinium is a member of only four “pair reversals” in the entire periodic table.

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Bioactive Butyrolactones from Fungi

Australian Journal of Chemistry ◽

10.1071/ch02154 ◽

2002 ◽

Vol 55 (10) ◽

pp. 625 ◽

Cited By ~ 12

Author(s):

J. Hargreaves ◽

J. Park ◽

E. L. Ghisalberti ◽

K. Sivasithamparam ◽

B. W. Skelton ◽

...

Keyword(s):

Single Crystal ◽

X Ray ◽

Naturally Occurring

Investigation of a strain of an Acremonium sp fungus has led to the isolation of two butyrolactones not previously described as naturally occurring. The structures were deduced primarily by spectroscopic means, and, in the case of (2), confirmed by a single-crystal X-ray study.

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Characterization of chitin preparations using powder and film X-ray diffraction methods

Powder Diffraction ◽

10.1017/s0885715612000978 ◽

2013 ◽

Vol 28 (1) ◽

pp. 44-48 ◽

Cited By ~ 6

Author(s):

Jeffrey R. Deschamps

Keyword(s):

Diffraction Pattern ◽

Purification Procedure ◽

Limited Extent ◽

X Ray Diffraction ◽

X Ray ◽

Naturally Occurring ◽

Natural Polysaccharide ◽

Different Sources

Chitin is a natural polysaccharide found in many diverse phyla and almost always occurs in association with protein. In this study the chitin polymer is characterized by X-ray diffraction from its naturally occurring unprocessed state through various steps used in the purification procedure. In addition, the effect of different treatments on the final product is examined. These studies show that native chitin has a characteristic diffraction pattern that is not altered by the mild treatments used to isolate relatively pure chitin. Chitins prepared from different sources exhibit the same characteristic diffraction pattern. In addition, chitin films prepared using non-degrading solvents retain most of the characteristic patterns. De-acylation of chitin to produce chitosan results in large changes to the diffraction pattern. To a very limited extent features present in the diffraction pattern of native chitin can be recovered by re-acylation of chitosan.

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Highly Substituted Benzophenone Aldehydes and Eremophilane Derivatives from the Deep-Sea Derived Fungus Phomopsis lithocarpus FS508

Marine Drugs ◽

10.3390/md16090329 ◽

2018 ◽

Vol 16 (9) ◽

pp. 329 ◽

Cited By ~ 9

Author(s):

Jian-Lin Xu ◽

Hong-Xin Liu ◽

Yu-Chan Chen ◽

Hai-Bo Tan ◽

Heng Guo ◽

...

Keyword(s):

Cytotoxic Activity ◽

Cell Lines ◽

A549 Cell ◽

Marine Sediment ◽

Deep Sea ◽

Crystallographic Analysis ◽

X Ray ◽

Naturally Occurring ◽

Ic50 Values ◽

New Compounds

Five new benzophenone derivatives named tenellones D–H (1–5), sharing a rare naturally occurring aldehyde functionality in this family, and a new eremophilane derivative named lithocarin A (7), together with two known compounds (6 and 8), were isolated from the deep marine sediment-derived fungus Phomopsis lithocarpus FS508. All of the structures for these new compounds were fully characterized and established on the basis of extensive spectroscopic interpretation and X-ray crystallographic analysis. Compound 5 exhibited cytotoxic activity against HepG-2 and A549 cell lines with IC50 values of 16.0 and 17.6 μM, respectively.

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An Expeditious Total Synthesis of 5′-Deoxy-toyocamycin and 5′-Deoxysangivamycin

Molecules ◽

10.3390/molecules24040737 ◽

2019 ◽

Vol 24 (4) ◽

pp. 737 ◽

Cited By ~ 4

Author(s):

Xiangyou Dong ◽

Jie Tang ◽

Chen Hu ◽

Jiang Bai ◽

Haixin Ding ◽

...

Keyword(s):

Total Synthesis ◽

Diffraction Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Naturally Occurring ◽

Benzoyl Group

In present paper, an expeditious total synthesis of naturally occurring 5′-deoxytoyocamycin and 5′-deoxysangivamycin was accomplished. Because of the introduction of a benzoyl group at N-6 of 4-amino-5-cyano-6-bromo-pyrrolo[2,3-d]pyrimidine, a Vorbrüggen glycosylation with 1,2,3-tri-O-acetyl-5-deoxy-β-D-ribofuranose afforded a completely regioselective N-9 glycosylation product, which is unambiguously confirmed by X-ray diffraction analysis. All of the involved intermediates were well characterized by various spectra.

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