Polyphenols profiles of fermented and non fermented Cassia obtusifolia leaves and their antifungal activity against Madurella mycetomatis

S Ahmed; KE Ahmed; H Ali; EA Omer; SA Khalid

doi:10.1055/s-0035-1565797

Planta Medica, Inhaltsverzeichnis

Polyphenols profiles of fermented and non fermented Cassia obtusifolia leaves and their antifungal activity against Madurella mycetomatis

S Ahmed ¹, KE Ahmed ², H Ali ³, EA Omer ⁴, SA Khalid ⁴

¹Sinnar University, Faculty of Agriculture, Biotechnology Department, Sinnar, Sudan
²University of Khartoum, Faculty of Agriculture, Food sciences Department, Khartoum, Sudan
³Biochemistry Department Commission for Biotechnology and Genetic Engineering National Center for Research Ministry of Science and Communication, Khartoum, Sudan
⁴University of Khartoum, Faculty of Pharmacy, Department of Pharmacognosy, khartoum, Sudan

Abstract

Cassia obtusifolia (Caesalpiniaceae) is a wild African plant found in wastelands in the rainy season. Its leaves are usually fermented by people from the eastern part of Chad and western Sudan [1].

C. obtusifolia leaves of both intact and fermented forms were dried, ground and extracted with 80% ethanol. The concentrated extract was fractionated sequentially using petroleum ether, chloroform, and ethyl acetate. The extracts of fermented and non-fermented and their respective fractions were screened for their activity against Madurella mycetomatis, the causative agent of mycetoma infection, using a microtitre plate-based assay developed by our group incorporating resazurin as an indicator of measuring cell growth [2].

All tested extracts of both the fermented and non-fermented and their respective fractions exhibited consistently significant activity against M. mycetomatis with MIC of 39.1 µg/mL. Interestingly, however, that analysis by TLC employing Natural Products Reagent (NPR), RP-HPLC and RP-HPLC-DAD coupled with ESI tandem mass spectrometry revealed significant qualitative and quantitative differences of the polyphenols profiles of the fermented and non-fermented leaves of C. obtusifolia.

It was clearly seen that the effect of fermentation resulted in a remarkable chemical transformation of the flavones present in the non-fermented leaves of C. obtusifolia into phenolic acids following fermentation as has been clearly demonstrated by both TLC [3] and RP-HPLC-DAD coupled with ESI tandem mass spectrometry.

References:

[1] Dirar HA, Harper DB, Collins MA J Sci Food and Agric 1985; 36: 881 – 892

[2] Khalid SA. Development of microtiter plate-based method for the determination of the MIC of antimycetomal agents against Madurella mycetomatis. II ResNet NPND workshop on natural products against neglected diseases, 2014, Brazil

[3] Wagner H, Bladt S. 1996; Plant Drug Analysis a Thin Layer Chromatography Atlas, Springer Press, Heidelberg New York.