Scientific publications 2008

Natural Products for Neglected Diseases: A Review by Ioset JR. Current Organic Chemistry 2008 May; 12 (8): 643-666.
Neglected diseases are responsible for high mortality and morbidity each year in low-income countries. Due to the lack of vaccines and of safe, effective and affordable treatments, there is an urgent need to reinforce the existing therapeutic arsenal against these killers. One of the main opportunities is through the discovery of new molecules from natural origin. The gaps identified in the R&D process aiming to deliver new medicines for neglected diseases however also apply to natural products. A key review of the most promising antiprotozoal molecules recently discovered from natural resources is presented here together with a critical update on their current development status.
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New lycorine-type alkaloid from Lycoris traubii and evaluation of antitrypanosomal and antimalarial activities of lycorine derivatives by Toriizuka Y, Kinoshita E, Kogure N, Kitajima M, Ishiyama A, Otoguro K, Yamada H, Omura S, Takayama H. Bioorg Med Chem. 2008 Dec 15; 16(24): 10182-9. Epub 2008 Oct 30.
A new lycorine derivative LT1 was isolated from the aerial part and bulbs of Lycoris traubii Hayward (Amaryllidaceae). Its structure including absolute configuration was established by spectroscopic analysis and semi-synthesis to be 1-O-(30S)-hydroxybutanoyllycorine. Some lycorine ester derivatives including LT1 were examined for their inhibitory activity against Trypanosoma brucei brucei, the parasite associated with sleeping sickness, and against Plasmodium falciparum, the causative agent of malaria.
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In Vitro and in Vivo Antitrypanosomal Activitiy of Two Microbial Metabolites, KS-505a and Alazopeptin by Ishiyama A, Otoguro K, Namatame M, Nishihara A, Furusawa T, Masuma R, Shiomi K, Takahashi Y, Ichimura M, Yamada H, Omura S. J Antibiot (Tokyo). 2008 Oct; 61(10): 627-32.
The group’s ongoing screening program to discover new antitrypanosomal antibiotics has been evaluating compounds isolated from soil microorganisms as well as investigating the antibiotic libraries of the Kitasato Institute for Life Sciences and BioFrontier Laboratories of Kyowa Hakko Kogyo Co. Ltd. Two compounds, KS-505a and alazopeptin, were discovered that exhibit moderate antitrypanosomal characteristics. The in vitro and in vivo antitrypanosomal activities are reported and cytotoxicities of KS-505a and alazopeptin compared with some commonly-used antitrypanosomal drugs. This is the first report of in vitro and in vivo antitrypanosomal activities of either KS-505a or alazopeptin.
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