Fungi wat plante aanval, lei tot groot verliese in plantproduksie en ook tot verliese in
opbrengs nadat die produkte geoes is. Die beheer van hierdie fungi deur chemiese fungisiede
lewer komplikasies vanweë menslike en omgewingstoksisiteit. Die koste en die ontwikkeling
van weerstand deur plantpatogeniese fungi teen fungisiede lewer ook probleme. Sekondêre
plantmetaboliete het ‘n goeie potensiaal as antifungusverbindings. Die doel van die studie was
om die aktiwiteit van Tecoma stans-ekstrakte en - fraksies te bepaal en om die aktiewe verbinding
te isoleer deur die bioaktiwiteit van fraksies gedurende die fraksionering te bepaal. Die
dichlorometaanfraksie het die hoogste aktiwiteit gehad en die geïsoleerde verbinding se struktuur
is bepaal as oleanolsuur. Die antifungusaktiwiteit is teen tien belangrike plantfunguspatogene
bepaal (Aspergillus niger, Aspergillus parasiticus, Collectotrichum gloeosporoides, Fusarium oxysporium,
Penicillum expansum, Penicillum janthinellum, Pythium ultimum, Phytophthora nicotiana, Trichoderma
harzianum en Rhizoctonia solani). Die gemiddelde minimum inhiberende konsentrasie was
130 μg/mL. Die DCM-ekstrak en oleanolsuur was minder toksies as die positiewe kontrole
berberien teen Vero-selle met LC50 waardes van 0.413 mg/mL, 0.129 mg/mL en 15.48 μg/mL
onderskeidelik. Die selektiwiteitindeks van 20 met verskeie fungi dui op moontlike relatiewe
veiligheid om onder gekontroleerde toestande selfs vir eetbare produkte te gebruik. Die groot
massa plantmateriaal wat van hierdie indringerplant beskikbaar is, mag tot ‘n kommersieel
bruikbare produk lei in die bekamping van fitopatogeniese fungi.
NAVORSING KORRELASIE : Hierdie artikel is die vertaalde weergawe en is beskikbaar gestel om ‘n
breër lesersgroep te bereik. Die oorspronklike Engelse artikel is beskikbaar hier: https://doi.
org/10.4102/satnt.v36i1.1489
Plant pathogenic fungi are a major cause of reduced plant
production and post-harvest losses of plant produce. The control of these fungi by some synthetic
fungicides is complicated by human and environmental toxicity, the development of resistance by
some fungi and high costs, thus prompting the investigation of other means of fungal control. Plant
secondary metabolites have a good potential as antifungal agents. The aim of this study is to
investigate the potential use of Tecoma stans as a plant-derived fungicide by determining the
antifungal activity of extracts, isolating the bioactive compound and testing the toxicity of both the
extract and the isolated compound. In bioassay-guided fractionation of the leaves of the T. stans
dichloromethane (DCM) extract contained one major compound that was isolated and characterised
as oleanolic acid. The DCM extract and oleanolic acid were active against 10 tested plant fungal
pathogens (Aspergillus niger, Aspergillus parasiticus, Collectotrichum gloeosporoides, Fusarium
oxysporium, Penicillum expansum, Penicillum janthinellum, Pythium ultimum, Phytophthora nicotiana,
Trichoderma harzianum and Rhizoctonia solani) with an average minimal inhibitory concentration of
130 μg/mL. The DCM extract and oleanolic acid were toxic to Vero cells with an LC50 of 0.413 mg/
mL and 0.129 mg/mL respectively, when compared with berberine, a toxic compound with LC50 of
15.48 μg/mL. Oleanolic acid was more toxic than the crude extract, supporting the potential use of
plant extracts for controlling plant fungal pathogens. The selectivity indices of 20 with several
fungi indicated that extracts could possibly be used under controlled conditions against infections
of certain fungal pathogens, even on edible plants. The large quantities available of this invasive
plant species could lead to a commercially useful product in controlling plant fungal pathogens.
RESEARCH CORRELATION : This article is the translated version, made available to provide access to
a larger readership, of which the original English article is available here: https://doi.
org/10.4102/satnt.v36i1.1489
