Review on Classification and Nomenclature of Viruses
Solomon Bimrew,
Merkuz Abera
Issue:
Volume 11, Issue 2, April 2023
Pages:
11-23
Received:
31 March 2023
Accepted:
23 April 2023
Published:
10 May 2023
Abstract: Viruses are subcellular, infectious, non-living creatures that can only replicate and metabolize inside the cells of living hosts. Virus taxonomy is the classification of viruses into categories called taxa. The classification and nomenclature recently gained importance due to the exponentially increasing number of new viruses discovered. Hence the current review on classification and nomenclature of virus aimed to provide sufficient and updated information to readers. Current virus classification is increasingly performed using more complex phylogenetic approaches that move researchers closer to a rudimentary understanding of the origin, evolution, relatedness, and diversification of viruses. In the taxonomic hierarchy of virus, the highest taxa are real and the lowest rank is species. To categorize viruses, phenotypic traits like morphology, nucleic acid type, and mechanism of replication, host organisms, and the sort of disease they cause are taken into consideration. Mostly based on 1. Classical- e.g. Animal, plant, or bacterial virus system- e.g. Naked or enveloped virus. 2. Genomic-Baltimore classification by seven categories: I: dsDNA viruses (e.g. Adeno viruses, Herpes viruses, Pox viruses) II: ssDNA viruses (+ strand or "sense") DNA (e.g. Parvo viruses) III: dsRNA viruses (e.g. Reo viruses) IV: (+) ssRNA viruses (+ strand or sense) RNA (e.g. Corona viruses, Picorna viruses, Toga viruses) V: (−) ssRNA viruses (− strand or antisense) RNA (e.g. Orthomyxo viruses, Rhabdo viruses). VI: ssRNA-RT viruses (+ strand or sense) RNA with DNA intermediate in life-cycle (e.g. Retro viruses). VII: dsDNA-RT viruses DNA with RNA intermediate in life-cycle (e.g. Hepadna viruses). 3. Serology (a corona virus). There isn't a standardized format for virus species names yet, in contrast to the binomial nomenclature used for cellular species. The ICTV now requires that a species name comprise as few words as possible while still being distinct, and must not merely contain the term virus and the host. By responding to a series of questions based on contrasting traits, a species can be identified using the dichotomous key method.
Abstract: Viruses are subcellular, infectious, non-living creatures that can only replicate and metabolize inside the cells of living hosts. Virus taxonomy is the classification of viruses into categories called taxa. The classification and nomenclature recently gained importance due to the exponentially increasing number of new viruses discovered. Hence the...
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Improvement of Phenolic Compounds and Antihyperlipidemic Activity of Hibiscus sabdariffa L. Calyxes Powder Using CDS Processing
Linda Stella Mbassi,
Elie Baudelaire Djantou,
Richard Marcel Nguimbou,
Amadou Dicko,
Nicolas Yanou Njintang
Issue:
Volume 11, Issue 2, April 2023
Pages:
24-35
Received:
10 March 2022
Accepted:
11 August 2022
Published:
9 June 2023
Abstract: The aim of this study was to evaluate the effect of controlled differential sieving processing (CDSp) on the content of phenolic compounds and antihyperlipidemic activity of H. sabdariffa calyxes powder. For this, four granulometric classes (<180 μm, 180-212 μm, 212-315 μm, ≥315 μm) were analyzed. Unsieved powder and lyophilized ethanolic extract were used for comparison. First, we identified and quantified the phenolic compounds present in the samples by chromatography in liquid phase coupled to a UV detector and mass spectrometry (LC-MS). Second, we evaluated the antihyperlipidemic activity of the different fractions in adult male rats at a dose of 250 mg/kg and compared them with those of unsieved powder and the ethanolic extract. LC-MS analysis identified seven compounds (quercetin, rutin, catechin, ferrulic acid, p-coumaric acid, protocatechic acid and cafeic acid) in the different sample of H. sabdariffa calyxes powder. The granulometric class 212-315 μm showed the best concentration, higher than those of the other granulometric class and crude powder. This fraction also showed content of phenolic compounds higher than those of ethanolic extract except for p-coumaric acid, and protocatechic acid which were concentrated equally in both samples. Antihyperlipidemic activity were significantly influenced (P <0.05) by particle sizes. The best activity was obtained in the particle size classes of 212-315 µm and <180 µm which were significantly (P <0.05) higher than those of the other fractions and of the unsieved powder to improve the lipid parameters (total cholesterol, LDL-C, HDL-C and triglycerides), transaminases (ALAT and ASAT) and creatine. However, compared to the ethanolic extract, only the granulometric class of 212-315 µm showed a significantly higher activity. CDSp can be an alternative to ethanol extraction and may be an option to improve the content of phenolic compounds and antihyperlipidemic activity of plant powders.
Abstract: The aim of this study was to evaluate the effect of controlled differential sieving processing (CDSp) on the content of phenolic compounds and antihyperlipidemic activity of H. sabdariffa calyxes powder. For this, four granulometric classes (<180 μm, 180-212 μm, 212-315 μm, ≥315 μm) were analyzed. Unsieved powder and lyophilized ethanolic extract were used for comparison. First, we identified and quantified the phenolic compounds present in the samples by chromatography in liquid phase coupled to a UV detector and mass spectrometry (LC-MS). Second, we evaluated the antihyperlipidemic activity of the different fractions in adult male rats at a dose of 250 mg/kg and compared them with those of unsieved powder and the ethanolic extract. LC-MS analysis identified seven compounds (quercetin, rutin, catechin, ferrulic acid, p-coumaric acid, protocatechic acid and cafeic acid) in the different sample of H. sabdariffa calyxes powder. The granulometric class 212-315 μm showed the best concentration, higher than ...
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