Isolation and Antimicrobial Activities of Phytochemicals from Parinari curatellifolia (Chrysobalanaceae)

Abstract

The widespread use of antimicrobial agents to treat infectious diseases has led to the emergence of antibiotic resistant pathogens. Plants have played a central role in combating many ailments in humans, and Parinari curatellifolia has been used for medicinal purposes. Seven extracts from P. curatellifolia leaves were prepared using serial exhaustive extraction of nonpolar to polar solvents. The microbroth dilution method was used to evaluate antimicrobial bioactivities of extracts. Five of the extracts were significantly active against at least one test microbe. Mycobacterium smegmatis was the most susceptible to most extracts. The methanol and ethanol extracts were the most active against M. smegmatis with an MIC of 25 µg/mL. The hexane extract was the most active against Candida krusei with an MIC of 25 µg/mL. None of the extracts significantly inhibited growth of Klebsiella pneumoniae and Staphylococcus aureus. Active extracts were selected for fractionation and isolation of pure compounds using gradient elution column chromatography. TLC analyses was carried out for pooling fractions of similar profiles. A total of 43 pools were obtained from 428 fractions. Pools 7 and 10 were selected for further isolation of single compounds. Four compounds, Pc4963r, Pc4962w, Pc6978p, and Pc6978o, were isolated. Evaluation of antimicrobial activities of Pc4963r, Pc4962w, and Pc6978p showed that the compounds were most active against C. krusei with MFC values ranging from 50 to 100 µg/mL. Only Pc6978p was shown to be pure. Using spectroscopic analyses, the structure of Pc6978p was determined to be β-sitosterol. The antifungal effects of β-sitosterol were evaluated against C. krusei in vitro and on fabrics. Results showed that β-sitosterol reduced the growth of C. krusei attached to Mendy fabric by 83%. Therefore, P. curatellifolia can be a source of lead compounds for prospective development of novel antimicrobial agents. Further work needs to be done to improve the antifungal activity of the isolated compound using quantitative structure-activity relationships.

In vitro antiplasmodial evaluation of ethanolic and n-hexane extracts of Parinari curatellifolia stem bark

“…Recently, some compounds have been isolated from different parts of P. curatellifolia. For example, β-sitosterol which was isolated from the leaves of P. curatellifolia was reported to reduce the growth of Candida krusei by 83% [38] while toddalolactone and 10-hydroxy-13-methoxy-9-methyl-15-oxo-20-norkaur-16-en-18-oic acid ι-lactone isolated from the root of P. curatellifolia demonstrated antimicrobial activity against Candida albicans, Cryptococcus neoformans and Aspergillus niger [39]. These compounds may also exhibit antiplasmodial activity against P. falciparum and may be responsible for the antiplasmodial activity of this plant recorded in this study.…”

An Evaluation of the Antibacterial Activity of Pterocarpus tinctorius Bark Extract against Enteric Bacteria That Cause Gastroenteritis

“…This may be attributed to the fact that the methanolic subextract contains small amounts of active compounds. This further suggests that some of the compounds found in the methanolic subextract (M1) may have caused an antagonistic effect on the active compounds that possess antibacterial activity against tested bacteria [ 43 ]. However, ciprofloxacin and nalidixic acid are pure compounds that have no other compounds that can cause antagonistic effects to the active compound.…”

Antimalarial effect of ethanol extract of Parinari curatellifolia stem-bark in Plasmodium berghei-NK 65 infected mice.

“…The plant extract's wide range of secondary metabolites may explain why it is used in ethnomedicine to treat a number of illnesses in Africa, such as malaria, fever, toothaches, fractures, pneumonia, cancer, in ammation, bacterial infections, and diabetes Kuntze et al, 2017;Mawire et al, 2021). Alkaloids are class of small nitrogen-containing organic molecules found in plants.…”