Daniel Bisrat

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A phytochemical investigation of the leaf exudate of Aloe marlothii has resulted in the isolation of a new chromone (7-O-methylaloeresin A) and a new anthrone (5-hydroxyaloin A 6'-O-acetate). Furthermore 7-O-methylaloesin was isolated as a natural product for the first time from the leaf exudate of Aloe rupestris. The structure elucidation of these(More)
In Ethiopian traditional medicine, the leaves of Otostegia integrifolia Benth. are used for the treatment of several diseases including malaria. In an ongoing search for effective, safe and cheap antimalarial agents from plants, the 80% methanol leaf extract O. integrifolia was tested for its in vivo antimalarial activity, in a 4-day suppressive assay(More)
In the search for new antimicrobial and antioxidant compounds from plants, the latex of the medicinal plant Aloe harlana Reynolds from Ethiopia was subjected to bioassay-guided fractionation, which led to the isolation of two known compounds, anthrone (aloin) and chromone (7-O-methylaloeresin A). The latex and its two constituents were assessed for their(More)
BACKGROUND Health seeking behavior of people around the globe is affected by different socio-cultural and economic factors. In Ethiopia, people living in rural areas in particular, are noted for their use of medicinal plants as a major component of their health care option. This study was conducted to document ethnopharmacological information of the Hamer(More)
BACKGROUND Malaria is one of the major obstacles to the socioeconomic development of several developing countries. Adequate treatment of the disease is becoming increasingly difficult due to the worsening problems of drug resistance in many parts of the world. Therefore, increased efforts in antimalarial drug discovery are urgently needed. OBJECTIVES This(More)
Phytochemical investigation of the leaf latex of Aloe trichosantha by preparative TLC gave two closely related anthrones, aloin A/B (1) and aloin-6'-O-acetate A/B (2). The identity of the compounds was established from HRESI-MS, 1H, 13C, DEPT, HMQC and HMBC spectral and chemical data. Whilst aloin A/B occurs in several Aloe species, aloin-6'-O-acetate A/B(More)
An experiment was conducted to determine the effects of harvesting age and plant population density on agronomic and chemical characters of Artemisia (Artemisia annua L.) during 2009. Four levels of harvesting age and five levels of population density were arranged in split plot design with three replications. Harvesting age was assigned to main plots and(More)
Free radical scavenging activity-guided investigation of the acetone extract of Plectranthus punuctatus (L'Her) (Lamiaceae) resulted in the isolation of a novel diterpenoid 3,11,12,14,19-pentahydroxy-5,8,11,13-abietatraen-7-pyran[4,6]-16-dione whose structure was elucidated based on spectral evidence. The isolated compound showed a significant antioxidant(More)
BACKGROUND The incidents of drug resistant microorganisms and the need of treatments for newly emerging pathogens are of great concern to the global community. Our ability to treat infectious diseases is dependent on the development of new pharmaceuticals, and one potential source being medicinal plants with traditional claims. The leaves of Aloe(More)
BACKGROUND There is an urgent need for the development of new, cheap, safe and highly effective drugs against African trypanosomiasis that affects both man and livestock in sub-Saharan Africa including Ethiopia. In the present study the exudate of Aloe gilbertii, an endemic Aloe species of Ethiopia, aloin, aloe-emodin and rhein were tested for their in(More)