Year: 2013
Type: dissertation
Abstract: White birches (Betula spp.) are utilized in huge quantities in the forest industry in northern latitudes of the world and low-value side-stream birch bark is burnt for energy. Outer birch bark is rich in (up to 30% dry weight) triterpene betulin and it can be easily isolated by solvent extraction. Betulin could be used as such or as starting material for more valuable products, fine chemicals and pharmaceuticals. In this work two sets of betulin derivatives were synthesized and screened as antiviral, antileishmanial and antibacterial agents. First set includes relatively easily synthesizable betulin derivatives, such as esters and various oxidation products. Second set includes novel heterocyclic betulin derivatives, where triazolo ring is fused by Diels-Alder reaction to the lupane skeleton of betulin. In the biological assays against human pathogens Semliki Forest virus; L. donovani parasites, which cause tropical disease leishmaniasis; and Gram-negative bacteria Chlamydia pneumoniae, several betulin derivatives displayed low-micromolar 50% growth inhibition values in vitro. In addition, most of the derivatives showed low cytotoxicity against the host cell lines.
Source: Työväentutkimus Vuosikirja
Author: Sami Alakurtti
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1527292439