The chemical nature of supercritical gas extracts from low-rank U. K. coals

Two processes are being developed by the National Coal Board for producing liquids from coal. Both involve extraction of the coal to produce an extract, freed from mineral matter, which is then catalytically hydrocracked. This approach is particularly suitable for producing transport fuels and chemical feedstocks. One process uses as solvent a process-derived liquid. The other uses a compressed supercritical gas to extract the more hydrogen-rich parts of the coal, leaving a reactive char which can provide the necessary hydrogen, heat and power for the process. As part of the development programme, extracts have been prepared by gas extraction over a range of conditions, and their chemical structures investigated by elemental and spectroscopic analysis. The average structures so derived consist of small aromatic clusters joined by methylene, ether and diphenyl linkages. Extracts produced by the liquid solvent route contain larger aromatic clusters.

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Two antibacterial and PPARα/γ-agonistic unsaturated keto fatty acids from a coral-associated actinomycete of the genus Micrococcus

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.16.29 ◽

2020 ◽

Vol 16 ◽

pp. 297-304 ◽

Cited By ~ 1

Author(s):

Amit Raj Sharma ◽

Enjuro Harunari ◽

Naoya Oku ◽

Nobuyasu Matsuura ◽

Agus Trianto ◽

...

Keyword(s):

Fatty Acids ◽

Spectroscopic Analysis ◽

Culture Broth ◽

Peroxisome Proliferator ◽

Simulation Studies ◽

Fish Pathogen ◽

Chemical Structures ◽

Agonistic Activity ◽

Isoform Specificity ◽

Peroxisome Proliferator Activated Receptors

A pair of geometrically isomeric unsaturated keto fatty acids, (6E,8Z)- and (6E,8E)-5-oxo-6,8-tetradecadienoic acids (1 and 2), were isolated from the culture broth of an actinomycete of the genus Micrococcus, which was associated with a stony coral, Catalaphyllia sp. Their chemical structures were elucidated by spectroscopic analysis including NMR and MS, with special assistance of spin system simulation studies for the assignment of an E geometry at C8 in 2. As metabolites of microbes, compounds 1 and 2 are unprecedented in terms of bearing a 2,4-dienone system. Both 1 and 2 showed antibacterial activity against the plant pathogen Rhizobium radiobacter and the fish pathogen Tenacibaculum maritimum, with a contrasting preference that 1 is more effective to the former strain while 2 is so to the latter. In addition, compounds 1 and 2 displayed agonistic activity against peroxisome proliferator-activated receptors (PPARs) with an isoform specificity towards PPARα and PPARγ.

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Chemical Derivatization and Characterization of Novel Antitrypanosomals for African Trypanosomiasis

Molecules ◽

10.3390/molecules26154488 ◽

2021 ◽

Vol 26 (15) ◽

pp. 4488

Author(s):

Aboagye Kwarteng Dofuor ◽

Temitayo Samson Ademolue ◽

Cynthia Mmalebna Amisigo ◽

Kwaku Kyeremeh ◽

Theresa Manful Gwira

Keyword(s):

Structural Modification ◽

Spectroscopic Analysis ◽

Microscopic Analysis ◽

The Novel ◽

Chemical Derivatization ◽

African Trypanosomiasis ◽

Chemical Structures ◽

Normal Ratio

The search for novel antitrypanosomals and the investigation into their mode of action remain crucial due to the toxicity and resistance of commercially available antitrypanosomal drugs. In this study, two novel antitrypanosomals, tortodofuordioxamide (compound 2) and tortodofuorpyramide (compound 3), were chemically derived from the natural N-alkylamide tortozanthoxylamide (compound 1) through structural modification. The chemical structures of these compounds were confirmed through spectrometric and spectroscopic analysis, and their in vitro efficacy and possible mechanisms of action were, subsequently, investigated in Trypanosoma brucei (T. brucei), one of the causative species of African trypanosomiasis (AT). The novel compounds 2 and 3 displayed significant antitrypanosomal potencies in terms of half-maximal effective concentrations (EC50) and selectivity indices (SI) (compound 1, EC50 = 7.3 μM, SI = 29.5; compound 2, EC50 = 3.2 μM, SI = 91.3; compound 3, EC50 = 4.5 μM, SI = 69.9). Microscopic analysis indicated that at the EC50 values, the compounds resulted in the coiling and clumping of parasite subpopulations without significantly affecting the normal ratio of nuclei to kinetoplasts. In contrast to the animal antitrypanosomal drug diminazene, compounds 1, 2 and 3 exhibited antioxidant absorbance properties comparable to the standard antioxidant Trolox (Trolox, 0.11 A; diminazene, 0.50 A; compound 1, 0.10 A; compound 2, 0.09 A; compound 3, 0.11 A). The analysis of growth kinetics suggested that the compounds exhibited a relatively gradual but consistent growth inhibition of T. brucei at different concentrations. The results suggest that further pharmacological optimization of compounds 2 and 3 may facilitate their development into novel AT chemotherapy.

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Chemical constituents of Euphorbia tirucalli L.

Science and Technology Development Journal - Natural Sciences ◽

10.32508/stdjns.v2i5.781 ◽

2019 ◽

Vol 2 (5) ◽

pp. 76-82

Author(s):

Dung Thi Kim Le ◽

Hao Xuan Bui ◽

Tuyet Thi Anh Nguyen ◽

Tuyen Nguyen Kim Pham ◽

Huy Thuc Duong

Keyword(s):

Thin Layer ◽

Gallic Acid ◽

Spectroscopic Analysis ◽

Chemical Constituents ◽

Normal Phase ◽

Chemical Structures ◽

Euphorbia Tirucalli ◽

Arjunolic Acid ◽

First Time ◽

Layer Chromatography

Euphorbia tirucalli has not been chemically studied much in Vietnam. This research described the isolation and elucidation of compounds isolated from the plant collected in Binh Thuan. Multiple chromatographic methods were applied, including normal phase silica gel column chromatography and thin-layer chromatography. Seven compounds were isolated and their chemical structures were elucidated by spectroscopic analysis as well as comparing their data with the ones in the literature. They are arjunolic acid (1), eriodictyol (2), quercitrin (3), afzelin (4), scopoletin (5), 3,3′,4- trimethylellagic acid (6), and gallic acid (7). Among them, compound 1 a major component was isolated for the first time in Euphorbia genus, while three compounds 2, 4, and 5 were isolated from this species for the first time.

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Molecular Structure of Nitrogen in Coal from XANES Spectroscopy

Applied Spectroscopy ◽

10.1366/0003702934067991 ◽

1993 ◽

Vol 47 (8) ◽

pp. 1268-1275 ◽

Cited By ~ 52

Author(s):

Oliver C. Mullins ◽

Sudipa Mitra-Kirtley ◽

Jan Van Elp ◽

Stephen P. Cramer

Keyword(s):

Aromatic Amines ◽

Fossil Fuel ◽

Lone Pair ◽

Low Rank ◽

Model Compounds ◽

X Ray ◽

Chemical Structures ◽

Pyridine Nitrogen ◽

Low Levels ◽

X Ray Absorption

Five major nitrogen chemical structures, present in coals of varying ranks, have been quantitatively determined with the use of nitrogen x-ray absorption near-edge spectroscopy (XANES). Similar studies of the sulfur chemical structures of coals have been performed for the last ten years; nitrogen studies on these fossil-fuel samples have only recently been realized. XANES spectra of coals exhibit several distinguishable resonances which can be correlated with characteristic resonances of particular nitrogen chemical structures, thereby facilitating analysis of these complicated systems. Many model compounds have been examined; for some, the relative peak positions are explained in terms of the orbital description of the lone pair of electrons. All features in the XANES spectra of coals have been accounted for; thus, all the major structural groups of nitrogen present in coals have been determined. A wide variety of aromatic nitrogen compounds is found in the coals; no evidence of saturated amine is found. Pyrroles, pyridines, pyridones, and aromatic amines are found in coal; of these, pyrrolic structures are the most prevalent. Pyridine nitrogen is prevalent in all except low-rank coals. The low pyridine content in low-rank (high-oxygen) coals correlates with a large pyridone content. This observation suggests that, with increasing maturation of coal, the pyridone loses its oxygen and is transformed into pyridine. Aromatic amines are present at low levels in coals of all rank. The spectral effects of aromatic amines are shown by comparing the XANES spectra of coal and petroleum asphaltenes.

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Cytotoxic Polyketides from the Marine Sponge-Derived Fungus Pestalotiopsis heterocornis XWS03F09

Molecules ◽

10.3390/molecules24142655 ◽

2019 ◽

Vol 24 (14) ◽

pp. 2655 ◽

Cited By ~ 2

Author(s):

Lei ◽

Zhou ◽

Hu ◽

Niu ◽

...

Keyword(s):

Marine Sponge ◽

Spectroscopic Analysis ◽

Fermentation Broth ◽

Human Cancer ◽

Optical Rotation ◽

Cytotoxic Activities ◽

Human Cancer Cell Lines ◽

Chemical Structures ◽

Ic50 Values ◽

New Compounds

Four new compounds, including two new polyketides, heterocornols M and N (1, 2), and a pair of epimers, heterocornols O and P (3, 4), were isolated from the fermentation broth of the marine sponge-derived fungus Pestalotiopsis heterocornis XWS03F09, together with three known compounds (5–7). The new chemical structures were established on the basis of a spectroscopic analysis, optical rotation, experimental and calculated electronic circular dichroism (ECD). All of the compounds (1–7) were evaluated for their cytotoxic activities, and heterocornols M-P (1–4) exhibited cytotoxicities against four human cancer cell lines with IC50 values of 20.4–94.2 μM.

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A formula for the mineral matter to ash ratio for low rank coals

Fuel ◽

10.1016/0016-2361(83)90261-2 ◽

1983 ◽

Vol 62 (1) ◽

pp. 94-97 ◽

Cited By ~ 4

Author(s):

V GRAY

Keyword(s):

Low Rank ◽

Mineral Matter ◽

Low Rank Coals

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The effect of mineral matter on the physical and chemical activation of low rank coal and biomass materials

Fuel ◽

10.1016/j.fuel.2006.03.005 ◽

2006 ◽

Vol 85 (12-13) ◽

pp. 1763-1771 ◽

Cited By ~ 97

Author(s):

D VAMVUKA ◽

S TROULINOS ◽

E KASTANAKI

Keyword(s):

Chemical Activation ◽

Low Rank ◽

Mineral Matter ◽

Low Rank Coal ◽

Biomass Materials ◽

Physical And Chemical

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Triazoles with long chain alkyl groups as a potential biological compounds

International Journal of Research in Pharmaceutical Sciences ◽

10.26452/ijrps.v10i3.1475 ◽

2019 ◽

Vol 10 (3) ◽

Author(s):

Salih Mahdi Salman

Keyword(s):

Spectroscopic Analysis ◽

Hydroxyl Group ◽

Medical Applications ◽

Methyl Glycoside ◽

Chemical Structures ◽

Alkyl Groups ◽

Biological Compounds ◽

Antibacterial And Antifungal ◽

Long Chain ◽

Propargyl Ester

New series of four compounds was synthesized from multi hydroxyl group compounds such as methyl glycoside by coupling with long-chain alky propargyl ester ( C10, C12, C14 and unsaturated C18) via click chemistry after activation the hydroxyl at C6 position by chlorination with N-chlorosuccinimide NCS and functionalized with sodium azide NaN3. The chemical structures and the purity of the resulting triazoles derivatives was confirmed by elemental analysis (CHN) and spectroscopic analysis 1H NMR & 13C NMR. The biological activity for the target compounds was investigated, and they show good antibacterial and antifungal properties against some selected gram-posative and fungi, which make them suitable for medical applications.

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Phenolic compounds from the lichen Parmotrema tinctorum

Science and Technology Development Journal ◽

10.32508/stdj.v24i1.2490 ◽

2021 ◽

Vol 24 (1) ◽

pp. 1842-1846

Author(s):

Huynh Bui Linh Chi ◽

Van Muoi Bui ◽

Thi Quynh Nhu Phan ◽

Kim Phi Phung Nguyen

Keyword(s):

Inhibitory Activity ◽

Spectroscopic Analysis ◽

Published Data ◽

Anticancer Activities ◽

Chemical Structures ◽

Diphenyl Ethers ◽

Pure Compounds ◽

First Time ◽

Parmotrema Tinctorum ◽

Gyrophoric Acid

Introduction: The metabolites of lichens concentrated depsidones, depsides, and diphenyl ethers were possessed antibiotic, antifungal, antiviral, antitumor, and anticancer activities. Parmotrema tinctorum (Despr. ex Nyl.) Hale, a species of foliose lichen, is widely distributed in Lam Dong province, Vietnam. Herein, this paper describes the isolation and structure elucidation of seven compounds isolated from this lichen. Methods: Phytochemical investigations of the ethyl acetate extract of the lichen P. tinctorum led to the isolation of seven pure compounds. Their chemical structures were elucidated by extensive HR-ESI-MS and NMR spectroscopic analysis and comparison with previously published data. Results: Seven compounds, namely orcinol (1), orsellinic acid (2), methyl orsellinate (3), methyl heamatomate (4), lecanorin (5), lecanoric acid (6), and gyrophoric acid (7). These compounds were determined the α-glucosidase inhibitory activity. Conclusions: Compound 7 was determined for the first time in P. tinctorum, and this was also the first time these compounds were determined the α-glucosidase inhibitory activity.

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