α,β-Diamino Acids: Biological Significance and Synthetic Approaches

ChemInform ◽  
2005 ◽  
Vol 36 (45) ◽  
Author(s):  
Alma Viso ◽  
Roberto Fernandez de la Pradilla ◽  
Ana Garcia ◽  
Aida Flores
2007 ◽  
Vol 79 (12) ◽  
pp. 2229-2242 ◽  
Author(s):  
El Sayed H. El Ashry ◽  
Mohamed R. E. Aly

The structural diversity as well as the biological significance of N-acetylglucosamine-containing glycans are exemplified. The problem of forming the respective glycosidic bonds of synthetic targets is addressed. Special emphasis has been given to human milk oligosaccharides (HMOs), in view of their biological relevance, and synthetic approaches of selected examples are reported.


2005 ◽  
Vol 105 (8) ◽  
pp. 3167-3196 ◽  
Author(s):  
Alma Viso ◽  
Roberto Fernández de la Pradilla ◽  
Ana García ◽  
Aida Flores

2021 ◽  
Vol 12 (5) ◽  
pp. 6460-6486

Oxazolone is a five-membered heterocyclic compound which is also known as azlactone. It contains one oxygen and one nitrogen as heteroatoms, which exist in five isomeric forms, according to the carbonyl group's location and the double bonds such as: 5 (4)-oxazolones, 5 (2) – oxazolones, 2 (3)-oxazolones, 4 (5)-oxazolones, and 2 (5)-oxazolones. 5 (4)-oxazolones is the most important heterocyclic moiety among all isomeric form of oxazolones. It is classified into two classes: saturated and unsaturated oxazolones. It is synthesized by various synthetic routes. Oxazolones are reported to exhibit various pharmacological activities such as antimicrobial, anti-inflammatory, anticancer, anti-HIV, antiangiogenic, anticonvulsant, sedative, cardiotonic, antidiabetic activity, etc.


2011 ◽  
Vol 111 (2) ◽  
pp. PR1-PR42 ◽  
Author(s):  
Alma Viso ◽  
Roberto Fernández de la Pradilla ◽  
Mariola Tortosa ◽  
Ana García ◽  
Aida Flores

Author(s):  
Vitthal S. Kulkarni ◽  
Wayne H. Anderson ◽  
Rhoderick E. Brown

The biological significance of the sphingomyelins (SM) and monoglycosylated sphingolipids like galactosylceramides (GalCer) are well documented Our recent investigation showed tubular bilayers in the aqueous dispersions of N-nervonoyl GalCer [N-(24:lΔ15,cls) GalCer] (a major fatty acyl moiety of natural GalCer). To determine the influence of lipid head groups on the resulting mesophasic morphology, we investigated microstructural self-assemblies of N-nervonoyl-SM [N-(24:1 Δ15,cls) SM; the second most abundant sphingomyelin in mammalian cell membranes], 1- palmitoyl-2-nervonoyl phosphatidylcholine [PNPC] (the lipid species with the same acyl chain configuration as in N-(24: 1) GalCer) and also compared it with egg-SM by freeze-fracture EM.Procedures for synthesizing and purifying N-(24:1) GalCer, N-(24:1) SM, and PNPC have been reported . Egg-SM was purchased from Avanti Polar Lipids, Alabaster AL. All lipids were >99% pure as checked by thin layer chromatography. Lipid dispersions were prepared by hydrating dry lipid with phosphate buffer (pH 6.6) at 80-90°C (3-5 min), vigorously vortexing (1 min) and repeating this procedure for three times prior to three freeze-thaw cycles.


Author(s):  
Dong Yuming ◽  
Yang Guanglin ◽  
Wu Jifeng ◽  
Chen Xiaolin

On the basis of light microscopic observation, the ultrastructural localization of CEA in gastric cancer was studied by immunoelectron microscopic technique. The distribution of CEA in gastric cancer and its biological significance and the mechanism of abnormal distribution of CEA were further discussed.Among 104 surgically resected specimens of gastric cancer with PAP method at light microscopic level, the incidence of CEA(+) was 85.58%. All of mucinous carcinoma exhibited CEA(+). In tubular adenocarcinoma the incidence of CEA(+) showed a tendency to rising with the increase of degree of differentiation. In normal epithelia and intestinal metaplasia CEA was faintly present and was found only in the luminal surface. The CEA staining patterns in cancer cells were of three types--- cytoplasmic, membranous and weak reactive type. The ultrastructural localization of CEA in 14 cases of gastric cancer was studied by immunoelectron microscopic technique.There was a little or no CEA in the microvilli of normal epithelia. In intestinal metaplasia CEA was found on the microvilli of absorptive cells and among the mucus particles of goblet cells. In gastric cancer CEA was also distributed on the lateral and basal surface or even over the entire surface of cancer cells and lost their polarity completely. Many studies had proved that the alterations in surface glycoprotein were characteristic changes of tumor cells. The antigenic determinant of CEA was glycoprotein, so the alterations of tumor-associated surface glycoprotein opened up a new way for the diagnosis of tumors.


2020 ◽  
Vol 11 (48) ◽  
pp. 7603-7624
Author(s):  
Ismail Altinbasak ◽  
Mehmet Arslan ◽  
Rana Sanyal ◽  
Amitav Sanyal

This review provides an overview of synthetic approaches utilized to incorporate the thiol-reactive pyridyl-disulfide motif into various polymeric materials, and briefly highlights its utilization to obtain functional materials.


This review paper covers the major synthetic approaches attempted towards the synthesis of some Non-Steroidal Anti-Inflammatory Drugs (Naproxen, Ibuprofen and Nabumetone)


1973 ◽  
Vol 74 (Suppl) ◽  
pp. S130-S167 ◽  
Author(s):  
O. P. Samarina ◽  
E. M. Lukanidin ◽  
G. P. Georgiev

ABSTRACT This paper is a review of the data concerning the nature, structural organization, properties and biological significance of the particles, containing mRNA and pre-mRNA (precursor of mRNA), i. e., (1) nuclear pre-mRNA-containing particles (2) free cytoplasmic mRNP (ribonucleoproteins), or informosomes (3) polysome-bound mRNP. Some new data on the comparison of nuclear and cytoplasmic particles, the nature of poly A-containing structures, involvement of informofers in Adenovirusspecific RNA transfer are presented. The general scheme of mRNA transport from nucleus to cytoplasm is discussed.


2010 ◽  
Vol 17 (1) ◽  
pp. 17-30 ◽  
Author(s):  
Katarzyna J. Chwedorzewska

ABSTRACTThe geographic position, astronomic factors (e.g. the Earth’s maximum distance from the Sun during winter), ice cover and altitude are the main factors affecting the climate of the Antarctic, which is the coldest place on Earth. Parts of Antarctica are facing the most rapid rates of anthropogenic climate change currently seen on the planet. Climate changes are occurring throughout Antarctica, affecting three major groups of environmental variables of considerable biological significance: temperature, water, UV-B radiation.Low diversity ecosystems are expected to be more vulnerable to global changes than high diversity ecosystems


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