Search results for "natural product"

Isomotiol, a new triterpene from strychnos potatorum

1978

Isomotiol (fern-8-en-3β-ol) was isolated from the leaves of Strychnos potatorum; it was not known previously as a natural product, but it has been obtained by acidic isomerization of compounds with a fern-7-ene or a fern-9(11)-ene skeleton. From the leaves and the bark mixtures of sitosterol, stigmasterol and campesterol were also isolated.

ChemInform Abstract: Synthesis of Plagiochiline N from Santonin.

2010

This article reports the transformation of O-acetylisophotosantonin, obtained by photochemical rearrangement of santonin, into plagiochiline N, an ent-2,3-secoaromadendrane isolated from Plagiochila ovalifolia. The synthesis was carried out in a sequence involving as the key steps (a) the substitution of the lactone moiety by a gem-dimethylcyclopropane ring through a synthetic intermediate having a C(6)-C(7) double bond and (b) the ozonolysis of the C(2)-C(3) bond followed by cyclization to the dihydropyran ring characteristic of plagiochiline N. Spectroscopic data of the synthetic product fully coincided with the reported data for the natural product.

Synthesis of Natural Products By Rhodium-Mediated Intramolecular C-H Insertion

1998

The strategic advantages of the Rh-mediated intramolecular C–H insertion, which has been used as the key step in several natural product syntheses, are described here. The most recent such synthesis is the elegant route to (+)-morphine shown below.

Synthesis of Enantiopure 6,11‐Methylene Lipoxin B4Methyl Ester

2021

Artesunate – An anti-malarial natural product derivative for cancer therapy

2015

Chemistry of glycopeptides

1999

For a long time, peptides and proteins on the one hand and carbohydrates on the other have been considered separate classes of natural products. The rather strict distinction between these major fields of natural product chemistry is still apparent not only in the organisation of chemistry text books but also in the different approaches to immunological and cell biological recognition phenomena.

ChemInform Abstract: A Decade of Advance in the Asymmetric Vinylogous Mannich Reaction

2016

When the principle of vinylogy is applied to imines as electrophiles, the so-called vinylogous Mannich reaction (VMR), γ-aminocarbonyl (such as butenolides) and β-aminocarbonyl compounds are generated in a very efficient manner. The asymmetric version of this vinylogous Mannich reaction gives access to highly functionalized chiral synthons, which are suitable for further transformations. The versatility of this methodology is exemplified with the synthesis of several alkaloids and natural products. 1 Introduction 2 Asymmetric Vinylogous Mannich Reactions (VMR) with 2-Silyl­oxyfurans and 2-Silyloxypyrroles 3 Asymmetric VMR with Acyclic Silyl Dienolates and Silyl Dienol Ketene Acetals 4 Asymm…

Activation of Mitochondria-Driven Pathways by Artemisinin and Its Derivatives

2014

Mitochondria have recently emerged as promising agents for cancer therapy. Of particular interest and potential clinical relevance are agents that target these organelles, promoting cell death. There are literally thousands of compounds that act on mitochondria and destabilise them. Of these, naturally occurring compounds are particularly interesting, since they are often more ‘biocompatible’; besides, natural compounds can be lead drugs for the design of novel and more efficient anti-cancer agents. In this paper, we focus on the natural product artemisin and its semisynthetic derivatives, and document the molecular mechanism of their activity and their potential use as clinically relevant …

Crystal structure and absolute configuration of (4S,5R,6S)-4,5,6-trihydroxy-3-methylcyclohex-2-enone (gabosine H)

2017

The absolute configuration of the title compound, determined as 4S,5R,6S on the basis of the synthetic pathway, was confirmed by single-crystal X-ray diffraction. The mol­ecule is formed by a substituted six-membered cyclo­hexene ring adopting an envelope conformation and substituted by carbonyl, methyl and hydroxyl groups. The supra­molecular structure is mainly built by a combination of O—H⋯O and weaker C—H⋯O hydrogen bonds.

Cyclodextrins: heterocyclic molecules able to perform chiral recognition (Part II)

2006

The present paper collects the most significant advances appeared since late 1998 up to June 2005 in the field of applications of natural and modified cyclodextrins as chiral selectors, with particular regard for pharmaceuticals and natural products.