scholarly journals Glycoalkaloids: Structure, Properties, and Interactions with Model Membrane Systems

Processes ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 513 ◽  
Author(s):  
Bishal Nepal ◽  
Keith J. Stine
Keyword(s):  
Membrane Structure ◽  
Biological Properties ◽  
Model Membrane ◽  
Plant Biology ◽  
Vaccine Adjuvants ◽  
Membrane Systems ◽  
Physical Behavior ◽  
Biological Studies ◽  
Significant Interest ◽  
Structure Properties

The glycoalkaloids which are secondary metabolites from plants have proven to be of significant interest for their biological properties both in terms of their roles in plant biology and the effects they exhibit when ingested by humans. The main feature of the action of glycoalkaloids is their strong binding to 3β-hydroxysterols, such as cholesterol, to form complexes with the consequence that membrane structure is significantly perturbed, and leakage or release of contents inside cells or liposomes becomes possible. The glycoalkaloids have been studied for their ability to inhibit the growth of cancer cells and in other roles such as vaccine adjuvants and as synergistic agents when combined with other therapeutics. The glycoalkaloids have rich and complex physical behavior when interacting with model membranes for which many aspects are yet to be understood. This review introduces the general properties of glycoalkaloids and aspects of their behavior, and then summarizes their effects against model membrane systems. While there are many glycoalkaloids that have been identified, most physical or biological studies have focused on the readily available ones from tomatoes (α-tomatine), potatoes (α-chaconine and α-solanine), and eggplant (α-solamargine and α-solasonine).

scholarly journals Sphingolipid organization in biomembranes: what physical studies of model membranes reveal

1998 ◽  
Vol 111 (1) ◽  
pp. 1-9 ◽  
Author(s):  
R.E. Brown
Keyword(s):  
Signal Transduction ◽  
Model Membrane ◽  
Model Membranes ◽  
Lipid Domains ◽  
Membrane Systems ◽  
Biological Studies ◽  
Physical Interactions

Recent cell biological studies suggest that sphingolipids and cholesterol may cluster in biomembranes to form raft-like microdomains. Such lipid domains are postulated to function as platforms involved in the lateral sorting of certain proteins during their trafficking within cells as well as during signal transduction events. Here, the physical interactions that occur between cholesterol and sphingolipids in model membrane systems are discussed within the context of microdomain formation. A model is presented in which the role of cholesterol is refined compared to earlier models.

Bimolecular and Monomolecular Lipid Films: Selected Area Electron Diffraction

1969 ◽  
Vol 27 ◽  
pp. 338-339
Author(s):  
Robert M. Glaeser ◽  
David W. Deamer
Keyword(s):  
Electron Diffraction ◽  
Membrane Structure ◽  
Molecular Organization ◽  
Membrane Material ◽  
X Ray Diffraction ◽  
Membrane Systems ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Lipid Films ◽  
Ultimate Objective

In the investigation of the molecular organization of cell membranes it is often supposed that lipid molecules are arranged in a bimolecular film. X-ray diffraction data obtained in a direction perpendicular to the plane of suitably layered membrane systems have generally been interpreted in accord with such a model of the membrane structure. The present studies were begun in order to determine whether selected area electron diffraction would provide a tool of sufficient sensitivity to permit investigation of the degree of intermolecular order within lipid films. The ultimate objective would then be to apply the method to single fragments of cell membrane material in order to obtain data complementary to the transverse data obtainable by x-ray diffraction.

Update on Phytochemical and Biological Studies on Rocaglate Derivatives from Aglaia Species

Planta Medica ◽  
2021 ◽  
Author(s):  
Garima Agarwal ◽  
Long-Sheng Chang ◽  
Djaja Doel Soejarto ◽  
A. Douglas Kinghorn
Keyword(s):  
Biological Activities ◽  
Chemical Constituents ◽  
Protein Translation ◽  
Biological Properties ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Eukaryotic Translation ◽  
Ability To Act ◽  
Biological Studies ◽  
Phytochemical Constituents

AbstractWith about 120 species, Aglaia is one of the largest genera of the plant family Meliaceae (the mahogany plants). It is native to the tropical rainforests of the Indo-Australian region, ranging from India and Sri Lanka eastward to Polynesia and Micronesia. Various Aglaia species have been investigated since the 1960s for their phytochemical constituents and biological properties, with the cyclopenta[b]benzofurans (rocaglates or flavaglines) being of particular interest. Phytochemists, medicinal chemists, and biologists have conducted extensive research in establishing these secondary metabolites as potential lead compounds with antineoplastic and antiviral effects, among others. The varied biological properties of rocaglates can be attributed to their unusual structures and their ability to act as inhibitors of the eukaryotic translation initiation factor 4A (eIF4A), affecting protein translation. The present review provides an update on the recently reported phytochemical constituents of Aglaia species, focusing on rocaglate derivatives. Furthermore, laboratory work performed on investigating the biological activities of these chemical constituents is also covered.

scholarly journals Cytotoxic Agents in the Minor Alkaloid Groups of the Amaryllidaceae

Planta Medica ◽  
2021 ◽  
Author(s):  
Jerald J. Nair ◽  
Johannes van Staden
Keyword(s):  
Cancer Cells ◽  
Cancer Cell Line ◽  
Structural Features ◽  
Biological Properties ◽  
Cytotoxic Agents ◽  
Plant Family ◽  
Structure Activity ◽  
Significant Interest ◽  
Different Types ◽  
Minor Alkaloid

AbstractOver 600 alkaloids have to date been identified in the plant family Amaryllidaceae. These have been arranged into as many as 15 different groups based on their characteristic structural features. The vast majority of studies on the biological properties of Amaryllidaceae alkaloids have probed their anticancer potential. While most efforts have focused on the major alkaloid groups, the volume and diversity afforded by the minor alkaloid groups have promoted their usefulness as targets for cancer cell line screening purposes. This survey is an in-depth review of such activities described for around 90 representatives from 10 minor alkaloid groups of the Amaryllidaceae. These have been evaluated against over 60 cell lines categorized into 18 different types of cancer. The montanine and cripowellin groups were identified as the most potent, with some in the latter demonstrating low nanomolar level antiproliferative activities. Despite their challenging molecular architectures, the minor alkaloid groups have allowed for facile adjustments to be made to their structures, thereby altering the size, geometry, and electronics of the targets available for structure-activity relationship studies. Nevertheless, it was seen with a regular frequency that the parent alkaloids were better cytotoxic agents than the corresponding semisynthetic derivatives. There has also been significant interest in how the minor alkaloid groups manifest their effects in cancer cells. Among the various targets and pathways in which they were seen to mediate, their ability to induce apoptosis in cancer cells is most appealing.

scholarly journals Development of Spanish Broom and Flax Dressings with Glycyrrhetinic Acid-Loaded Films for Wound Healing: Characterization and Evaluation of Biological Properties

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1192
Author(s):  
Angela Abruzzo ◽  
Concettina Cappadone ◽  
Valentina Sallustio ◽  
Giovanna Picone ◽  
Martina Rossi ◽  
...  
Keyword(s):  
Wound Healing ◽  
Drug Loading ◽  
Healing Process ◽  
In Vitro Release ◽  
Sodium Hyaluronate ◽  
Biological Properties ◽  
Glycyrrhetinic Acid ◽  
Wound Dressings ◽  
Biological Studies

The selection of an appropriate dressing for each type of wound is a very important procedure for a faster and more accurate healing process. So, the aim of this study was to develop innovative Spanish Broom and flax wound dressings, as alternatives to cotton used as control, with polymeric films containing glycyrrhetinic acid (GA) to promote wound-exudate absorption and the healing process. The different wound dressings were prepared by a solvent casting method, and characterized in terms of drug loading, water uptake, and in vitro release. Moreover, biological studies were performed to evaluate their biocompatibility and wound-healing efficacy. Comparing the developed wound dressings, Spanish Broom dressings with GA-loaded sodium hyaluronate film had the best functional properties, in terms of hydration ability and GA release. Moreover, they showed a good biocompatibility, determining a moderate induction of cell proliferation and no cytotoxicity. In addition, the wound-healing test revealed that the Spanish Broom dressings promoted cell migration, further facilitating the closure of the wound.

How does Amphotericin B Work?: Studies on Model Membrane Systems

1993 ◽  
Vol 3 (3) ◽  
pp. 377-408 ◽  
Author(s):  
Scott C. Hartsel ◽  
Christopher Hatch ◽  
Woubeshet Ayenew
Keyword(s):  
Amphotericin B ◽  
Model Membrane ◽  
Membrane Systems

scholarly journals Origanum vulgare ssp. vulgare: Chemical Composition and Biological Studies

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 2077 ◽  
Author(s):  
Ilioara Oniga ◽  
Cristina Pușcaș ◽  
Radu Silaghi-Dumitrescu ◽  
Neli-Kinga Olah ◽  
Bogdan Sevastre ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Salmonella Enteritidis ◽  
Biological Properties ◽  
Gamma Glutamyl Transferase ◽  
Reducing Ability ◽  
Biological Studies ◽  
Antioxidant And Antimicrobial Activity ◽  
Agar Well Diffusion Assay ◽  
New Research ◽  
Glutamyl Transferase

The biological properties and main phenolic compounds of the O. vulgare L. ssp. vulgare extract are described in the present paper. The polyphenolic compounds were analyzed by chromatographic and spectrophotometric techniques. The antioxidant potential was evaluated using several methods: CUPRAC (cupric ion reducing antioxidant capacity), FRAP (ferric reducing ability of plasma), inhibition of lipid peroxidation catalyzed by cytochrome c, and superoxide (SO) scavenging assays. The antimicrobial activity of the oregano extract was evaluated by means of agar-well diffusion assay. The hepatoprotective effect of the O. vulgare extract on CCl4-induced hepatotoxicity was evaluated in rats. Liver injury was estimated by determination of alanine aminotransaminase (ALT), aspartate aminotransaminase (AST), gamma-glutamyl transferase GGT, total protein and albumin concentrations, glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA). These values were improved by the administration of oregano extract. A specific phenolic profile was evidenced by these data, with large amounts of rosmarinic and chlorogenic acids. The oregano extract showed very strong antioxidant activity in good agreement with the phenolic content. Antimicrobial activity was good, especially against Salmonella enteritidis and Aspergillus niger strains. The high hepatoprotective, antioxidant and antimicrobial activity, along with polyphenol-rich content, can support the use of O. vulgare in therapy. We also expect our results to open new research directions for designing important new drug products, using indigenous plant material.

Community detection in complex networks by using membrane algorithm

2018 ◽  
Vol 29 (01) ◽  
pp. 1850003 ◽  
Author(s):  
Chuang Liu ◽  
Linan Fan ◽  
Zhou Liu ◽  
Xiang Dai ◽  
Jiamei Xu ◽  
...  
Keyword(s):  
Network Analysis ◽  
Complex Networks ◽  
Community Detection ◽  
Membrane Structure ◽  
Superior Performance ◽  
Membrane Systems ◽  
Membrane Algorithm ◽  
Differential Evolutionary Algorithm ◽  
Network Modularity

Community detection in complex networks is a key problem of network analysis. In this paper, a new membrane algorithm is proposed to solve the community detection in complex networks. The proposed algorithm is based on membrane systems, which consists of objects, reaction rules, and a membrane structure. Each object represents a candidate partition of a complex network, and the quality of objects is evaluated according to network modularity. The reaction rules include evolutionary rules and communication rules. Evolutionary rules are responsible for improving the quality of objects, which employ the differential evolutionary algorithm to evolve objects. Communication rules implement the information exchanged among membranes. Finally, the proposed algorithm is evaluated on synthetic, real-world networks with real partitions known and the large-scaled networks with real partitions unknown. The experimental results indicate the superior performance of the proposed algorithm in comparison with other experimental algorithms.

scholarly journals Iron Mediated Interaction of Alpha Synuclein with Lipid Rafts in Model Membrane Systems

2018 ◽  
Vol 114 (3) ◽  
pp. 244a
Author(s):  
Loredana Casalis ◽  
Fabio Perissinotto ◽  
Denis Scaini
Keyword(s):  
Lipid Rafts ◽  
Alpha Synuclein ◽  
Model Membrane ◽  
Membrane Systems
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