Publications by authors named "Theodora K Kowa"
Article Synopsis
- Antiparasitic drug resistance is a significant issue in controlling malaria and leishmaniasis, particularly affecting disadvantaged populations in remote tropical regions.
- The study focused on evaluating the antimalarial and antileishmanial effects of a methanol extract from a Cameroonian medicinal plant, leading to the isolation of a new compound and several known ones.
- The extracts showed moderate to potent antileishmanial activity, with better effectiveness against multidrug-resistant parasite strains, while being less effective against chloroquine-sensitive strains.
Article Synopsis
- * A novel glucocerebroside called antroklaicerebroside was isolated, along with five previously known compounds, using advanced chromatographic techniques and characterized through NMR, MS, and IR spectroscopy.
- * Several fractions and isolated compounds were tested against chloroquine-resistant and susceptible strains of parasites, showing significant antiparasitic effects, with one compound exhibiting an impressive IC value that surpassed standard reference drugs.
Objective: The present study investigated the effect of the leaves extracts and fractions of on the inhibition of pancreatic lipase, cholesterol esterase, adipocytes lipid uptake, and antithrombotic activity which may be important in atherosclerosis development.
Methods: Aqueous, ethanolic, and hydroethanolic extracts of were prepared by maceration. The hydroethanolic extract was fractionated into -hexane, ethylacetate, and butanol fractions and their inhibition of pancreatic lipase, cholesterol esterase, adipocytes lipid uptake, and antithrombotic activities measured.
Bioassay-guided fractionation of the CHCl-MeOH (1:1) leaves extract of , yielded two new vilasinin-type limonoids named gilgianin A () and gilgianin B (), one new phenyl alkene derivative designated as gilgialkene A (), along with six known compounds: rubescin H (), TS3 (), trichirubine A (), sitosteryl-6'--undecanoate--D-glucoside (), scopoletin (), and octadecane-2-one (). Their structures were elucidated based on spectroscopic analysis and comparison with literature data. Compounds and exhibited the highest antiplasmodial activity with IC values of 1.
View Article and Find Full Text PDFThe phytochemical study of leaves of Funtumia elastica led to the isolation of three undescribed ursane derivatives, funtumic acids A, B and C (1-3), as well as one steroidal alkaloid, elasticine (4) and five other known compounds (5-9). Their structures were elucidated on the basis of NMR, MS, IR, UV spectroscopic data as well as by comparison with the literature. The compound 5-hydroxypyridine-3-carboxamide (9) was isolated for the first time from the Apocynaceae family.
View Article and Find Full Text PDFArticle Synopsis
- Researchers isolated a new limonoid (trigilgianin) and a new phenyl alkene (epoxy gilgialkene) from the stem bark of the Harms tree, along with five known compounds, marking the first time these have been identified in this species.
- The structures of these compounds were determined using spectral studies and comparisons with existing literature.
- Among the isolated compounds, two demonstrated significant antileishmanial activity against the visceral leishmaniasis parasite, exhibiting low cytotoxicity, while one showed moderate activity against promastigotes.
Background: Psorospermun aurantiacum and Hypericum lanceolatum are plants locally used in Cameroon and other parts of Africa for the treatment of gastrointestinal and urinary tract infections, skin infections, venereal diseases, gastrointestinal disorder, infertility, epilepsy as well as microbial infections. The present study was designed in order to investigate the in vitro antimicrobial and radical scavenging activities of the extracts and isolated compounds from the leaves of these plants.
Methods: The plant extract was prepared by maceration in ethyl acetate and methanol and fractionated by column chromatography.
Background: Malaria is a major public health threat in Africa, and traditional medicine continues to play a key role in its control especially in rural areas. A bioassay-guided fractionation was carried out in order to evaluate the anti-malarial potential and the safety of the methanol extract of the Hypericum lanceolatum stem bark.
Methods: The anti-plasmodial activity was assayed by the lactate dehydrogenase method (pLDH) against the multidrug-resistant W2mef laboratory strain, and a field isolate (SHF4) of Plasmodium falciparum.