scholarly journals Synthesis of endolides A and B: naturally occurring N-methylated cyclic tetrapeptides

MedChemComm ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 693-698 ◽  
Author(s):  
Emma K. Davison ◽  
Alan J. Cameron ◽  
Paul W. R. Harris ◽  
Margaret A. Brimble
Keyword(s):  
Natural Products ◽  
Solution Phase ◽  
Naturally Occurring ◽  
Cyclic Tetrapeptides ◽  
Cyclic Tetrapeptide

The first syntheses of the bioactive cyclic tetrapeptide natural products, endolides A and B, were accomplished using a solution-phase macrocyclisation reaction; the stereoselectivity of which was found to be reagent-controlled.

scholarly journals Chemical Diversity of Plant Cyanogenic Glycosides: An Overview of Reported Natural Products

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 719
Author(s):  
Meri Yulvianti ◽  
Christian Zidorn
Keyword(s):  
Natural Products ◽  
Plant Species ◽  
Chemical Diversity ◽  
Cyanogenic Glycosides ◽  
Sugar Moiety ◽  
Plant Natural Products ◽  
Naturally Occurring

Cyanogenic glycosides are an important and widespread class of plant natural products, which are however structurally less diverse than many other classes of natural products. So far, 112 naturally occurring cyanogenic glycosides have been described in the phytochemical literature. Currently, these unique compounds have been reported from more than 2500 plant species. Natural cyanogenic glycosides show variations regarding both the aglycone and the sugar part of the molecules. The predominant sugar moiety is glucose but many substitution patterns of this glucose moiety exist in nature. Regarding the aglycone moiety, four different basic classes can be distinguished, aliphatic, cyclic, aromatic, and heterocyclic aglycones. Our overview covers all cyanogenic glycosides isolated from plants and includes 33 compounds with a non-cyclic aglycone, 20 cyclopentane derivatives, 55 natural products with an aromatic aglycone, and four dihydropyridone derivatives. In the following sections, we will provide an overview about the chemical diversity known so far and mention the first source from which the respective compounds had been isolated. This review will serve as a first reference for researchers trying to find new cyanogenic glycosides and highlights some gaps in the knowledge about the exact structures of already described compounds.

Synthesis of O-Phosphotyrosine-Containing Peptides. II. Solution-Phase Synthesis of Asn-Glu-PTyr-Thr-Ala Through Methyl Phosphate Protection

1989 ◽  
Vol 42 (9) ◽  
pp. 1519 ◽  
Author(s):  
RM Valerio ◽  
JW Perich ◽  
EA Kitas ◽  
PF Alewood ◽  
RB Johns
Keyword(s):  
Trifluoroacetic Acid ◽  
Dimethyl Sulfide ◽  
Solution Phase ◽  
High Yield ◽  
Phase Synthesis ◽  
Rous Sarcoma ◽  
Naturally Occurring ◽  
Solution Phase Synthesis ◽  
Sarcoma Virus ◽  
Methyl Phosphate

The PTyr (O-phosphotyrosine) pentapeptide H-Asn-Glu-Tyr(PO3H2)-Thr-Ala-OH.HO2CCF3, which is a naturally occurring sequence from the autophosphorylated Rous sarcoma virus pp60V-SrC, was prepared in high yield by the use of Boc-Tyr(PO3Me2)-OH in the Boc mode of solution-phase peptide synthesis. The protected pentapeptide, Z-Asn-Glu(OBzl)-Tyr(PO3Me2)-Thr(Bzl)-Ala-OBzl, was deprotected by a two-stage procedure which involved initial palladium-catalysed hydrogenolysis followed by the removal of the phosphate methyl groups by the use of one of the following treatments: (A) 10% bromotrimethylsilane/acetonitrile, (B) 1 M bromotrimethylsilane/thioanisole in trifluoroacetic acid, or (C) trifluoromethanesulfonic acid/trifluoroacetic acid/dimethyl sulfide/m-cresol.

scholarly journals Potentially Effective and Safe Anti-Helicobacter pylori Natural Products: Chemometric Study

2020 ◽  
Vol 71 (6) ◽  
pp. 267-273 ◽  
Author(s):  
Branislava D. Kocic ◽  
Dobrila M. Stankovic Dordevic ◽  
Marija V. Dimitrijevic ◽  
Marija S. Markovic ◽  
Dragoljub L. Miladinovic
Keyword(s):  
Helicobacter Pylori ◽  
Antibacterial Activity ◽  
Natural Products ◽  
Chemical Composition ◽  
Essential Oils ◽  
Principal Component ◽  
Synergistic Activity ◽  
Agglomerative Hierarchical Clustering ◽  
Naturally Occurring ◽  
H Pylori

The susceptibility of Helicobacter pylori to three essential oils (EOs), 12 naturally occurring monoterpene hydrocarbons, oxygenated and phenolic monoterpenes and three reference antibiotics were studied. Classification and comparison of essential oils and monoterpenes on the basis of their chemical composition and antibacterial activity were made by the utilization of principal component analyses (PCA) and agglomerative hierarchical clustering (AHC). The most abundant compound in the Thymus glabrescens Willd. and Thymus pulegioides L. EOs is geraniol (33.8% and 52.5%), while the main constituent in Satureja kitaibelii Wierzb. ex Heuff. EO is limonene (16,1%). The compound that was the most active against H. pylori was carvacrol. EOs of T. glabrescens and S. kitaibelii exhibit higher antibacterial ability in comparison with all monoterpenes, except carvacrol, probably based on the concept of synergistic activity of essential oil components. PCA separated essential oils based on chemical composition and explain 96.5% of the total variance in the first two principal components. Essential oils, phenolic monoterpenes and two antibiotics were classified in the same sub-cluster within AHC analyses. EOs of T. glabrescens and S. kitaibelii can be used to treat infections caused by H. pylori, as a potentially effective, cheap and safe natural products. Further research of antibacterial activity of selected monoterpenes, essential oils and standard antibiotic combinations, as well as clinical study are required.

Aryne-based strategy in the total synthesis of naturally occurring polycyclic compounds

2018 ◽  
Vol 47 (21) ◽  
pp. 8030-8056 ◽  
Author(s):  
Hiroshi Takikawa ◽  
Arata Nishii ◽  
Takahiro Sakai ◽  
Keisuke Suzuki
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Polycyclic Compounds ◽  
Total Syntheses ◽  
Naturally Occurring

This review has outlined the strategies and tactics of using arynes in the total syntheses of polycyclic natural products.

scholarly journals First total synthesis of versicotide A, B and C

RSC Advances ◽  
2020 ◽  
Vol 10 (71) ◽  
pp. 43653-43659
Author(s):  
Laura Posada ◽  
Danilo Davyt ◽  
Gloria Serra
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Anthranilic Acid ◽  
Solution Phase ◽  
Fmoc Spps

Versicotides A–C, natural products containig anthranilic acid and NMe-Ala, were prepared by Fmoc/SPPS and solution phase macrocyclization.

scholarly journals Nanosystems for the Encapsulation of Natural Products: The Case of Chitosan Biopolymer as a Matrix

Pharmaceutics ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 669 ◽  
Author(s):  
Anastasia Detsi ◽  
Eleni Kavetsou ◽  
Ioanna Kostopoulou ◽  
Ioanna Pitterou ◽  
Antonella Rozaria Nefeli Pontillo ◽  
...  
Keyword(s):  
Natural Products ◽  
Review Article ◽  
Modified Chitosan ◽  
The Past ◽  
Natural Extracts ◽  
Naturally Occurring ◽  
Natural Polysaccharide ◽  
Low Toxicity ◽  
Valuable Compounds ◽  
Chitosan Biopolymer

Chitosan is a cationic natural polysaccharide, which has emerged as an increasingly interesting biomaterialover the past few years. It constitutes a novel perspective in drug delivery systems and nanocarriers’ formulations due to its beneficial properties, including biocompatibility, biodegradability and low toxicity. The potentiality of chemical or enzymatic modifications of the biopolymer, as well as its complementary use with other polymers, further attract the scientific community, offering improved and combined properties in the final materials. As a result, chitosan has been extensively used as a matrix for the encapsulation of several valuable compounds. In this review article, the advantageous character of chitosan as a matrix for nanosystemsis presented, focusing on the encapsulation of natural products. A five-year literature review is attempted covering the use of chitosan and modified chitosan as matrices and coatings for the encapsulation of natural extracts, essential oils or pure naturally occurring bioactive compounds are discussed.

Chemical and Functional Diversity of Natural Products from Plant Associated Endophytic Fungi

2009 ◽  
Vol 4 (11) ◽  
pp. 1934578X0900401 ◽  
Author(s):  
Vijay C. Verma ◽  
Ravindra N. Kharwar ◽  
Gary A. Strobel
Keyword(s):  
Natural Products ◽  
Biological Activity ◽  
Functional Diversity ◽  
Bioactive Compounds ◽  
Endophytic Fungi ◽  
Host Plants ◽  
Fungal Endophytes ◽  
Sources Identification ◽  
Naturally Occurring

This review describes examples of naturally occurring bioactive compounds obtained from fungal endophytes from various host plants. The main topics addressed are sources, identification, biological activity, biosynthesis, and ecological and chemosystematic significance of those bioactive compounds whose sources were well defined.

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