General structure and heterogeneity of immunoglobulins

1966 ◽  
Vol 166 (1003) ◽  
pp. 114-123 ◽  
Keyword(s):  
Chemical Structure ◽  
Biological Activities ◽  
General Structure ◽  
Structural Features ◽  
Chain Structure ◽  
Biological Properties ◽  
Peptide Chain ◽  
Myeloma Proteins ◽  
General Configuration ◽  
Detailed Chemical

The general configuration of immunoglobulins and the chemical relationships that exist between different classes of antibodies have become clear during recent years. On the other hand, the structural features which determine various biological activities of these complex molecules have not been elucidated and, in particular, the basis of combining specificity is not understood. The problem of relating biological activity to chemical structure is complicated by the size of antibody molecules (molecular weight 150 000 or more) and more particularly by the remarkable heterogeneity of their constituent peptide chains. As a result of this complexity, variations in the structure of immunoglobulins cannot be ascribed with certainty to particular biological properties and it has proved impossible to establish the detailed chemical structure of specific antibodies. These difficulties have stimulated renewed interest in the proteins found in multiple myelomatosis and certain related pathological conditions. Individual myeloma proteins have the same general configuration as antibody molecules, but their peptide chain structure is sufficiently homogeneous to permit of detailed chemical analysis. In this paper the general structure of different classes of antibody will be described and their peptide chain structure compared with that of myeloma proteins; several detailed reviews of this subject have been published recently (Cohen & Porter 1964; Franklin 1964; Nisonoff & Thorbecke 1964; Fleischman 1966).

scholarly journals Structural Analysis of Fucoidans

2008 ◽  
Vol 3 (10) ◽  
pp. 1934578X0800301 ◽  
Author(s):  
Maria I. Bilan ◽  
Anatolii I. Usov
Keyword(s):  
Biological Activity ◽  
Structural Analysis ◽  
Charge Density ◽  
Brown Algae ◽  
Uronic Acid ◽  
Chemical Structure ◽  
Biological Activities ◽  
Biological Properties ◽  
Sulfated Polysaccharides ◽  
New Information

Sulfated polysaccharides of brown algae (“fucoidans”) constitute a wide variety of biopolymers from simple sulfated fucans up to complex heteropolysaccharides composed of several neutral monosaccharides, uronic acid and sulfate. The increased interest in this class of polysaccharides is explained by their high and versatile biological activities, and hence, by their possible use in new drug design. Structural analysis of several fucoidans demonstrates that their biological properties are determined not only by charge density, but also by fine chemical structure, although distinct correlations between structure and biological activity cannot be formulated at present. The aim of this review is to describe the methods of structural analysis currently used in fucoidan chemistry, and to discuss some new information on the structures of fucoidans presented in recent publications.

scholarly journals Effect of the Modifications on the Physicochemical and Biological Properties of β-Glucan—A Critical Review

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 57 ◽  
Author(s):  
Hongjie Yuan ◽  
Ping Lan ◽  
Yan He ◽  
Chengliang Li ◽  
Xia Ma
Keyword(s):  
Food Processing ◽  
Triple Helix ◽  
Functional Foods ◽  
Physiological Function ◽  
Biological Activities ◽  
Structural Features ◽  
Biological Properties ◽  
Enzymatic Modification ◽  
Anti Oxidant

β-Glucan exhibits many biological activities and functions such as stimulation of the immune system and anti-inflammatory, anti-microbial, anti-infective, anti-viral, anti-tumor, anti-oxidant, anti-coagulant, cholesterol-lowering, radio protective, and wound healing effects. It has a wide variety of uses in pharmaceutical, cosmetic, and chemical industries as well as in food processing units. However, due to its dense triple helix structure, formed by the interaction of polyhydroxy groups in the β-d-glucan molecule, it features poor solubility, which not only constrains its applications, but also inhibits its physiological function in vivo. One aim is to expand the applications for modified β-glucan with potential to prevent disease, various therapeutic purposes and as health-improving ingredients in functional foods and cosmetics. This review introduces the major modification methods required to understand the bioactivity of β-glucan and critically provides a literature survey on the structural features of this molecule and reported biological activity. We also discuss a new method to create novel opportunities to exploit maximally various properties of β-glucan, namely ultrasound-assisted enzymatic modification.

scholarly journals An Overview of Bioactive 1,3-Oxazole-Containing Alkaloids from Marine Organisms

2021 ◽  
Vol 14 (12) ◽  
pp. 1274
Author(s):  
Jinyun Chen ◽  
Sunyan Lv ◽  
Jia Liu ◽  
Yanlei Yu ◽  
Hong Wang ◽  
...  
Keyword(s):  
Nitrogen Atom ◽  
Chemical Synthesis ◽  
Biological Activities ◽  
Structural Features ◽  
Biological Properties ◽  
Therapeutic Agents ◽  
Marine Organisms ◽  
Chemical Structures ◽  
First Time ◽  
Oxazole Derivatives

1,3-Oxazole chemicals are a unique class of five-membered monocyclic heteroarenes, containing a nitrogen atom and an oxygen. These alkaloids have attracted extensive attention from medicinal chemists and pharmacologists owing to their diverse arrays of chemical structures and biological activities, and a series of 1,3-oxazole derivatives has been developed into therapeutic agents (e.g., almoxatone, befloxatone, cabotegravir, delpazolid, fenpipalone, haloxazolam, inavolisib). A growing amount of evidence indicates that marine organisms are one of important sources of 1,3-oxazole-containing alkaloids. To improve our knowledge regarding these marine-derived substances, as many as 285 compounds are summarized in this review, which, for the first time, highlights their sources, structural features and biological properties, as well as their biosynthesis and chemical synthesis. Perspective for the future discovery of new 1,3-oxazole compounds from marine organisms is also provided.

Combined strong anion-exchange HPLC and PAGE approach for the purification of heparan sulphate oligosaccharides

2001 ◽  
Vol 354 (1) ◽  
pp. 141-147 ◽  
Author(s):  
Romain R. VIVÈS ◽  
Sarah GOODGER ◽  
David A. PYE
Keyword(s):  
Anion Exchange ◽  
Biological Activities ◽  
Heparan Sulphate ◽  
Structural Features ◽  
Biological Properties ◽  
Cellular Functions ◽  
Structural Isomers ◽  
Wide Range ◽  
Strong Anion Exchange ◽  
Anion Exchange Hplc

Heparan sulphates are highly sulphated linear polysaccharides involved in many cellular functions. Their biological properties stem from their ability to interact with a wide range of proteins. An increasing number of studies, using heparan sulphate-derived oligosaccharides, suggest that specific structural features within the polysaccharide are responsible for ligand recognition and regulation. In the present study, we show that strong anion-exchange HPLC alone, a commonly used technique for purification of heparan sulphate-derived oligosaccharides, may not permit the isolation of highly pure heparan sulphate oligosaccharide species. This was determined by PAGE analysis of hexa-, octa- and decasaccharide samples deemed to be pure by strong anion-exchange HPLC. In addition, subtle differences in the positioning of sulphate groups within heparan sulphate hexasaccharides were impossible to detect by strong anion-exchange HPLC. PAGE analysis on the other hand afforded excellent resolution of these structural isomers. The precise positioning of specific sulphate groups has been implicated in determining the specificity of heparan sulphate interactions and biological activities; hence, the purification of oligosaccharide species that differ in this way becomes an important issue. In this study, we have used strong anion-exchange HPLC and PAGE techniques to allow production of the homogeneous heparan sulphate oligosaccharide species that will be required for the detailed study of structure/activity relationships.

Diverse chemical and biological potentials of various pyridazine and pyridazinone derivatives

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Heterocyclic Compounds ◽  
Biological Activities ◽  
Wide Spectrum ◽  
Biological Properties ◽  
Industrial Chemical ◽  
Anti Inflammatory ◽  
Pyridazinone Derivatives

A series of heterocyclic compounds incorporating pyridazine moiety were for diverse biological activities. Pyridazines and pyridazinones derivatives showed wide spectrum of biological activities such as vasodialator, cardiotonic, anticonvulsant, antihypertensive, antimicrobial, anti-inflammatory, analgesic, anti-feedant, herbicidal, and various other biological, agrochemical and industrial chemical activities. The results illustrated that the synthesized pyridazine/pyridazine compounds have diverse and significant biological activities. Mechanistic insights into the biological properties of pyridazinone derivatives and various synthetic techniques used for their synthesis are also described.

Tamarix articulata (T. articulata) - An Important Halophytic Medicinal Plant with Potential Pharmacological Properties

2019 ◽  
Vol 20 (4) ◽  
pp. 285-292 ◽  
Author(s):  
Abdullah M. Alnuqaydan ◽  
Bilal Rah
Keyword(s):  
Medicinal Plant ◽  
Biological Activities ◽  
Wide Spectrum ◽  
Biological Properties ◽  
In Vivo Model ◽  
Drug Candidate ◽  
Phytochemical Analysis ◽  
Pharmacological Properties

Background:Tamarix Articulata (T. articulata), commonly known as Tamarisk or Athal in Arabic region, belongs to the Tamaricaece species. It is an important halophytic medicinal plant and a good source of polyphenolic phytochemical(s). In traditional medicines, T. articulata extract is commonly used, either singly or in combination with other plant extracts against different ailments since ancient times.Methods:Electronic database survey via Pubmed, Google Scholar, Researchgate, Scopus and Science Direct were used to review the scientific inputs until October 2018, by searching appropriate keywords. Literature related to pharmacological activities of T. articulata, Tamarix species, phytochemical analysis of T. articulata, biological activities of T. articulata extracts. All of these terms were used to search the scientific literature associated with T. articulata; the dosage of extract, route of administration, extract type, and in-vitro and in-vivo model.Results:Numerous reports revealed that T. articulata contains a wide spectrum of phytochemical(s), which enables it to have a wide window of biological properties. Owing to the presence of high content of phytochemical compounds like polyphenolics and flavonoids, T. articulata is a potential source of antioxidant, anti-inflammatory and antiproliferative properties. In view of these pharmacological properties, T. articulata could be a potential drug candidate to treat various clinical conditions including cancer in the near future.Conclusion:In this review, the spectrum of phytochemical(s) has been summarized for their pharmacological properties and the mechanisms of action, and the possible potential therapeutic applications of this plant against various diseases discussed.

The Molecular Diversity Scope of Urazole in the Synthesis of Organic Compounds

2019 ◽  
Vol 16 (7) ◽  
pp. 953-967 ◽  
Author(s):  
Ghodsi M. Ziarani ◽  
Fatemeh Mohajer ◽  
Razieh Moradi ◽  
Parisa Mofatehnia
Keyword(s):  
Biological Activities ◽  
Biological Properties ◽  
Biologically Active ◽  
Microtubule Assembly ◽  
Heterocyclic Molecules ◽  
Biological Perspective ◽  
Highly Active ◽  
Anti Inflammatory ◽  
High Yields ◽  
Short Time

Background: As a matter of fact, nitrogen as a hetero atom among other atoms has had an important role in active biological compounds. Since heterocyclic molecules with nitrogen are highly demanded due to biological properties, 4-phenylurazole as a compound containing nitrogen might be important in the multicomponent reaction used in agrochemicals, and pharmaceuticals. Considering the case of fused derivatives “pyrazolourazoles” which are highly applicable because of their application for analgesic, antibacterial, anti-inflammatory and antidiabetic activities as HSP-72 induction inhibitors (I and III) and novel microtubule assembly inhibitors. It should be mentioned that spiro-pyrazole also has biological activities like cytotoxic, antimicrobial, anticonvulsant, antifungal, anticancer, anti-inflammatory, and cardiotonic activities. Objective: Urazole has been used in many heterocyclic compounds which are valuable in organic syntheses. This review disclosed the advances in the use of urazole as the starting material in the synthesis of various biologically active molecules from 2006 to 2019. Conclusion: Compounds of urazole (1,2,4-triazolidine-3,5-dione) are the most important molecules which are highly active from the biological perspective in the pharmaceuticals as well as polymers. In summary, many protocols for preparations of the urazole derivatives from various substrates in multi-component reactions have been reported from different aromatic and aliphatic groups which have had carbonyl groups in their structures. It is noted that several catalysts have been synthesized to afford applicable molecules with urazole scaffolds. In some papers, being environmentally friendly, short time reactions and high yields are highlighted in the protocols. There is a room to synthesize new catalysts and perform new reactions by manipulating urazole to produce biologically active compounds, even producing chiral urazole component as many groups of chiral urazole compounds are important from biological perspective.

Synthesis and biological properties of cholecystokinin heptapeptide analogues containing D- and L-forms of tert-leucine or neopentylglycine in position 5

1991 ◽  
Vol 56 (10) ◽  
pp. 2209-2217 ◽  
Author(s):  
Jan Hlaváček ◽  
Jana Pírková ◽  
Jan Pospíšek ◽  
Jiřina Slaninová ◽  
Lenka Maletínská
Keyword(s):  
Gall Bladder ◽  
Solid Phase ◽  
Biological Activities ◽  
Biological Properties ◽  
Phase Synthesis ◽  
Structural Modifications ◽  
Bladder Contraction ◽  
Anorectic Effect ◽  
Carboxy Terminal ◽  
Anorectic Activity

Using solution or solid-phase synthesis we prepared the cholecystokinin fragment Boc-CCK-7 (Boc-Tyr-(SO3-.Na+)-Met-Gly-Trp-Met-Asp-PheNH2) and its four analogues in which the methionine moiety (Met) in the carboxy-terminal part is replaced by tert-leucine (Tle) or neopentylglycine (Neo) residue or D-enantiomers of these non-coded amino acids. These structural modifications led to reduction of the studied biological activities (gall bladder contraction, anorectic activity, analgetic and sedation activity) of all prepared analogues except Boc[Neo5]-CCK-7 which, being less analgetically active, retains full gall bladder and sedation activity of CCK-8. Moreover, its anorectic activity is substantially higher (400%). This analogue is very interesting particularly for its selectively increased (4x) anorectic effect compared with that of CCK-8.

Sign in / Sign up

Export Citation Format

Share Document