scholarly journals Decoding the Membrane Activity of the Cyclotide Kalata B1

2011 ◽  
Vol 286 (27) ◽  
pp. 24231-24241 ◽  
Author(s):  
Sónia Troeira Henriques ◽  
Yen-Hua Huang ◽  
K. Johan Rosengren ◽  
Henri G. Franquelim ◽  
Filomena A. Carvalho ◽  
...  
Keyword(s):  
Lipid Membranes ◽  
Cyclic Peptides ◽  
Cell Membranes ◽  
Hydrophobic Interactions ◽  
Biological Activities ◽  
Large Family ◽  
Kalata B1 ◽  
Raft Domains ◽  
Anti Hiv

Cyclotides, a large family of cyclic peptides from plants, have a broad range of biological activities, including insecticidal, cytotoxic, and anti-HIV activities. In all of these activities, cell membranes seem likely to be the primary target for cyclotides. However, the mechanistic role of lipid membranes in the activity of cyclotides remains unclear. To determine the role of lipid organization in the activity of the prototypic cyclotide, kalata B1 (kB1), and synthetic analogs, their bioactivities and affinities for model membranes were evaluated. We found that the bioactivity of kB1 is dependent on the lipid composition of target cell membranes. In particular, the activity of kB1 requires specific interactions with phospholipids containing phosphatidylethanolamine (PE) headgroups but is further modulated by nonspecific peptide-lipid hydrophobic interactions, which are favored in raft-like membranes. Negatively charged phospholipids do not favor high kB1 affinity. This lipid selectivity explains trends in antimicrobial and hemolytic activities of kB1; it does not target bacterial cell walls, which are negatively charged and lacking PE-phospholipids but can insert in the membranes of red blood cells, which have a low PE content and raft domains in their outer layer. We further show that the anti-HIV activity of kB1 is the result of its ability to target and disrupt the membranes of HIV particles, which are raft-like membranes very rich in PE-phospholipids.

scholarly journals LITHISTID SPONGES DERIVED COMPOUNDS AND THEIR IMPORTANCE IN BIOLOGICAL RESEARCH - A REVIEW

2018 ◽  
Vol 11 (6) ◽  
pp. 57
Author(s):  
Abirla M ◽  
Brindha Devi P
Keyword(s):  
Antifungal Activity ◽  
Cyclic Peptides ◽  
Therapeutic Potential ◽  
Biological Activities ◽  
Natural Compounds ◽  
Biomedical Science ◽  
Biological Research ◽  
Bacterial Origin ◽  
Anti Hiv

Lithistid sponges have an important source of complex natural compounds with biological activities. The lithistid sponges are of interest to biomedical science because of the great variety of pharmaceutically relevant biological activities of their chemical extracts and are considered as economically important. The compounds identified in these sponges have therapeutic potential and have been frequently hypothesized to contain compounds of bacterial origin. The peptides identified from these lithistid sponges are found to be the sources of antifungal activity. The active agents of these sponges also have cytotoxic and immunosuppressive activities. Many of the cyclic peptides of lithistid represent the anti-HIV activity. The different structure and biological activities of the compounds derived from these sponges have more chemical aspects too.

Role of hydrophobic interactions in the fusion activity of influenza and sendai viruses towards model membranes

1994 ◽  
Vol 14 (1) ◽  
pp. 15-24 ◽  
Author(s):  
João Ramalho-Santos ◽  
Ricardo Negrão ◽  
Maria da Conceição Pedroso de Lima
Keyword(s):  
Lipid Membranes ◽  
Hydrophobic Interactions ◽  
Polymer Concentration ◽  
Viral Envelope ◽  
Fusion Process ◽  
Fusion Activity ◽  
Enveloped Viruses ◽  
Model Lipid Membranes ◽  
Poly Ethylene

We have studied the role of hydrophobic interactions in the fusion activity of two lipid enveloped viruses, influenza and Sendai. Using the fluorescent probe ANS (1-aminonaphtalene-8-sulfonate) we have shown that low-pH-dependent influenza virus activation involves a marked increase in the viral envelope hydrophobicity. The effect of dehydrating agents on the fusion activity of both viruses towards model lipid membranes was studied using a fluorescence dequenching assay. Dehydrating agents such as dimethylsulfoxide and dimethylsulfone greatly enhanced the initial rate of the fusion process, the effect of dimethylsulfone doubling that of dimethylsulfoxide. The effect of poly(ethylene glycol) on the fusion process was found to be dependent on the polymer concentration and molecular weight. In general, similar observations were made for both viruses. These results stress the importance of dehydration and hydrophobic interactions in the fusion activity of influenza and Sendai viruses, and show that these factors may be generally involved in membrane fusion events mediated by many other lipid enveloped viruses.

scholarly journals The role of the cyclic peptide backbone in the anti-HIV activity of the cyclotide kalata B1

FEBS Letters ◽  
2004 ◽  
Vol 574 (1-3) ◽  
pp. 69-72 ◽  
Author(s):  
Norelle L. Daly ◽  
Kirk R. Gustafson ◽  
David J. Craik
Keyword(s):  
Cyclic Peptide ◽  
Peptide Backbone ◽  
Kalata B1 ◽  
Anti Hiv

scholarly journals Small molecules and cell differentiation in Dictyostelium discoideum

2019 ◽  
Vol 63 (8-9-10) ◽  
pp. 429-438 ◽  
Author(s):  
Tsuyoshi Araki ◽  
Tamao Saito
Keyword(s):  
Cell Differentiation ◽  
Secondary Metabolites ◽  
Small Molecules ◽  
Biological Activities ◽  
Large Family ◽  
Paracrine Signalling ◽  
Pheromonal Communication ◽  
Signalling Compounds

Dictyostelium is a microorganism found in soils that are known as the battle fields of chemical warfare. Genome analysis of Dictyostelium revealed that it has great potential for the production of small molecules, including secondary metabolites such as polyketides and terpenes.Polyketides are a large family of secondary metabolites which have a variety of structures. In accordance with their structural variety, polyketides have a plethora of biological activities, including antimicrobial, antifungal, and antitumor activities. Unsurprisingly, they have exceptional medical importance. Polyketides in nature work as protective compounds and /or function in pheromonal communication. Terpenes belong to another family of structurally diverse secondary metabolites which play roles in ecological interactions, including defence against predators and formation of mutually beneficial alliance with other organisms. Polyketides and terpenes work as intra- or inter-species signalling compounds, i.e. they play the role of a chemical language. However, in Dictyostelium, they work as paracrine signalling compounds which control the organism’s multicellular morphogenesis. This review is primarily focused on the small molecules that regulate pattern formation in the slug stage of the organism and their biosynthetic pathways. Current in vivo understandings of polyketide DIF-1 induced cell differentiation and DIF-1-dependent/independent pathways are also discussed.

Synthesis and Biological Activity of Quaternary Quinolinium Salts: A Review

2020 ◽  
Vol 23 (21) ◽  
pp. 2271-2294 ◽  
Author(s):  
Divya Utreja ◽  
Shivali Sharma ◽  
Akhil Goyal ◽  
Komalpreet Kaur ◽  
Sonia Kaushal
Keyword(s):  
Tyrosine Kinases ◽  
Biological Activities ◽  
Polymeric Materials ◽  
Tubulin Polymerization ◽  
Quinoline Derivatives ◽  
Heterocyclic Chemistry ◽  
Biological Profile ◽  
Drug Candidates ◽  
Anti Hiv ◽  
Quinolinium Salts

Heterocyclic chemistry is the only branch of chemistry that has applications in varied areas such as dyes, photosensitizers, coordination compounds, polymeric materials, biological, and many other fields. Quinoline and its derivatives have always engrossed both synthetic chemists and biologists because of their diverse chemical and pharmacological properties as these ring systems can be easily found in various natural products, especially in alkaloids. Among alkaloids, quinoline derivatives i.e. quinolinium salts have attracted much attention nowadays owing to their diverse biological profile such as antimicrobial, antitumor, antifungal, hypotensive, anti-HIV, analgesics and anti-inflammatory, etc. Quinoline and its analogs have recently been examined for their modes of function in the inhibition of tyrosine kinases, proteasome, tubulin polymerization, topoisomerase, and DNA repair. These observations have been guiding scientists for the expansion of new quinoline derivatives with improved and varied biological activities. Quinolinium salts have immense possibilities and scope to investigate these compounds as potential drug candidates. Therefore, we shall present a concise compilation of this work to aid in present knowledge and to help researchers explore an interesting quinoline class having medicinal potential.

Structure and Activity of Pentacyclic Triterpenes Codrugs. A Review

2021 ◽  
Vol 21 ◽  
Author(s):  
Justyna Żwawiak ◽  
Anna Pawełczyk ◽  
Dorota Olender ◽  
Lucjusz Zaprutko
Keyword(s):  
Biological Activities ◽  
Anticancer Activities ◽  
Drug Molecule ◽  
Pentacyclic Triterpene ◽  
Formation Pathway ◽  
Chemical Systems ◽  
Drug Molecules ◽  
Wide Range ◽  
Anti Hiv ◽  
Structure And Activity

: Triterpenes are a wide and important group of compounds that have several promising pharmacological properties, such as hepatoprotective, anti-inflammatory, anti-HIV, antioxidant, or anticancer activities. Such potent substances can be successfully incorporated in more complex chemical systems e.g. codrugs or pro-drugs that have better pharmacological profile. The codrug is connected with a drug formation pathway to chemically cohere at least two drug molecules to improve positive therapeutic efficiency or decrease side effects. The codrug can be cleaved in the organism to generate effective compounds previously used as substrates. This article presents an overview of codrugs that consist of pentacyclic triterpene moiety that is chosen as a basic codrug moiety due to their wide range of vital activities and another drug molecule fragment. It was found that triterpenoid codrugs are characterized by a wide range of biological activities. However, most of them have anticancer potency.

Antimicrobial Potential of Benzimidazole Derived Molecules

2019 ◽  
Vol 19 (8) ◽  
pp. 624-646 ◽  
Author(s):  
Yogita Bansal ◽  
Manjinder Kaur ◽  
Gulshan Bansal
Keyword(s):  
Biological Activities ◽  
Benzimidazole Derivative ◽  
Structural Similarity ◽  
Living System ◽  
Axial Ligand ◽  
Benzimidazole Derivatives ◽  
Research Groups ◽  
Structural Resemblance ◽  
Privileged Structure ◽  
Anti Hiv

Structural resemblance of benzimidazole nucleus with purine nucleus in nucleotides makes benzimidazole derivatives attractive ligands to interact with biopolymers of a living system. The most prominent benzimidazole compound in nature is N-ribosyldimethylbenzimidazole, which serves as an axial ligand for cobalt in vitamin B12. This structural similarity prompted medicinal chemists across the globe to synthesize a variety of benzimidazole derivatives and to screen those for various biological activities, such as anticancer, hormone antagonist, antiviral, anti-HIV, anthelmintic, antiprotozoal, antimicrobial, antihypertensive, anti-inflammatory, analgesic, anxiolytic, antiallergic, coagulant, anticoagulant, antioxidant and antidiabetic activities. Hence, benzimidazole nucleus is considered as a privileged structure in drug discovery, and it is exploited by many research groups to develop numerous compounds that are purported to be antimicrobial. Despite a large volume of research in this area, no novel benzimidazole derived compound has emerged as clinically effective antimicrobial drug. In the present review, we have compiled various reports on benzimidazole derived antimicrobials, classified as monosubstituted, disubstituted, trisubstituted and tetrasubstituted benzimidazoles, bisbenzimidazoles, fused-benzimidazoles, and benzimidazole derivative-metal complexes. The purpose is to collate these research reports, and to generate a generalised outlay of benzimidazole derived molecules that can assist the medicinal chemists in selecting appropriate combination of substituents around the nucleus for designing potent antimicrobials.

Synthetic Strategies, Chemical Reactivities and Biological Activities of 3-Thioxo-1,2,4-Triazin-5-Ones and Their Derivatives

2019 ◽  
Vol 16 (4) ◽  
pp. 308-322
Author(s):  
Mohammad S.T. Makki ◽  
Reda M. Abdel-Rahman ◽  
Abdulrahman S. Alharbi
Keyword(s):  
Biological Activities ◽  
Biological Evaluation ◽  
Literature Survey ◽  
Recent Advances ◽  
Nucleophilic Reagents ◽  
Anti Hiv ◽  
Biological Field

In recent years, a very interest in the synthesis of functionalized 3-thioxo-1,2,4-triazin-5- ones and their derivatives as vital probes has been increased, due to the important, applications of the medicinal, pharmacological, and biological field as a drug, semi drug, and bioactive systems. The present work review outlines extensive recent advances literature survey on the synthesis of sulfurbearing 1,2,4-triazin-5-one derivatives has been reconsidered. Also, the behavior of these family towards electrophilic and nucleophilic reagents in different media and conditions reported. The biological evaluation of the most synthesized systems included anticancer, anti-HIV, antimicrobial as well as their enzymatic effects (cellobiase produced by fungi) have been reported. The reactivity of these systems depends on the polarity of solvent, temperature, molarity as well as a type of tautomeric present.

Modeling Anti-HIV Compounds: The Role of Analogue-Based Approaches

2012 ◽  
Vol 8 (3) ◽  
pp. 224-248 ◽  
Author(s):  
Hemant Kumar Srivastava ◽  
Mohammed H. Bohari ◽  
G. Narahari Sastry
Keyword(s):  
Anti Hiv
Sign in / Sign up

Export Citation Format

Share Document