Investigating the chemical diversity and biomedicinal potential of South African actinomycetes for tuberculosis drug discovery
type: CreativeWork
description: The chemical diversity and biomedicinal potential of three South African actinomycetes, Streptomyces speibonae PK-BlueT , Streptomyces africanus CPJVR-H T and Streptomyces pharetrae CZA14T , was investigated. The primary aim was the isolation and structure elucidation of anti-tubercular natural products (NPs), including the re-isolation of the compound named PK-B, reported to be produced by S. speibonae PK-BlueT . Efforts were made to re-isolate the compound named PK-B. However, the results could not be replicated and focus was shifted to the bioassay-guided isolation of antimycobaterial compounds from the three actinobacteria. Culture conditions were optimised for antimycobacterial activity of S. speibonae PK-BlueT extracts by testing against the MTB analogue Mycobacterium aurum A+ (a non-pathogenic, fast-growing mycobacterium that has a similar antibiotic susceptibility to Mycobacterium tuberculosis). Bioactive crude extracts were prioritised for liquid-liquid partitioning and dereplication by LR LC-MS, followed by prefractionation and purification using a combination of HPLC and benchtop column chromatography. Structure elucidation of isolated compounds was achieved using NMR, LCMS and GC-MS data. Bioassays against M. aurum A+ were implemented at every stage of the isolation process to make sure that the isolated compounds had antimycobacterial activity. This strategy led to the isolation of four known compounds, the alkaloid N-phenylpyridin-2- aminium (3.1), a 1:1 mixture of the long-chain fatty acids (LCFAs) n-hexadecanoic acid (3.2) and 14-methylpentadecanoic acid (3.3), and the isoflavone 7-hydroxy-3-(4-hydroxyphenyl)- 4H-chromen-4-one (3.4), from S. speibonae PK-BlueT cultures. Of the four isolated compounds, only 3.1 has not previously been reported from a natural source. The approach of using M. aurum A+ in searching for anti-tubercular compounds was vindicated as 3.1, the mixture of 3.2 and 3.3, and 3.4, in addition to inhibiting the growth of M. aurum A+…
abstract: The chemical diversity and biomedicinal potential of three South African actinomycetes, Streptomyces speibonae PK-BlueT , Streptomyces africanus CPJVR-H T and Streptomyces pharetrae CZA14T , was investigated. The primary aim was the isolation and structure elucidation of anti-tubercular natural products (NPs), including the re-isolation of the compound named PK-B, reported to be produced by S. speibonae PK-BlueT . Efforts were made to re-isolate the compound named PK-B. However, the results could not be replicated and focus was shifted to the bioassay-guided isolation of antimycobaterial compounds from the three actinobacteria. Culture conditions were optimised for antimycobacterial activity of S. speibonae PK-BlueT extracts by testing against the MTB analogue Mycobacterium aurum A+ (a non-pathogenic, fast-growing mycobacterium that has a similar antibiotic susceptibility to Mycobacterium tuberculosis). Bioactive crude extracts were prioritised for liquid-liquid partitioning and dereplication by LR LC-MS, followed by prefractionation and purification using a combination of HPLC and benchtop column chromatography. Structure elucidation of isolated compounds was achieved using NMR, LCMS and GC-MS data. Bioassays against M. aurum A+ were implemented at every stage of the isolation process to make sure that the isolated compounds had antimycobacterial activity. This strategy led to the isolation of four known compounds, the alkaloid N-phenylpyridin-2- aminium (3.1), a 1:1 mixture of the long-chain fatty acids (LCFAs) n-hexadecanoic acid (3.2) and 14-methylpentadecanoic acid (3.3), and the isoflavone 7-hydroxy-3-(4-hydroxyphenyl)- 4H-chromen-4-one (3.4), from S. speibonae PK-BlueT cultures. Of the four isolated compounds, only 3.1 has not previously been reported from a natural source. The approach of using M. aurum A+ in searching for anti-tubercular compounds was vindicated as 3.1, the mixture of 3.2 and 3.3, and 3.4, in addition to inhibiting the growth of M. aurum A+…
author: De Cerf, Christopher
language: eng
date published: 2018
date modified: 2026-07-22T22:22:52Z
provider: University of Cape Town
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Department of Chemistry

PropertyValue
property ID: Handle
value: http://hdl.handle.net/11427/29612