No abstract

Twenty-four analogues of D-glutamic acid were tested as substrates or inhibitors of the D-glutamate-adding enzyme from Escherichia coli. The best substrates were, in decreasing order of specific activity, D-erythro-4-methylglutamic acid, D-erythro-3-methylglutamic acid, DL-homocysteic acid, (+/-)-trans-1-amino-3-carboxy-cyclopentanecarboxylic acid and (+/-)-trans-1-amino-3-carboxy-cyclohexanecarboxylic acid. Among the different stereoisomers, only the D-erythro isomers for methylglutamic acids, and the trans isomers for the cyclic analogs, were substrates. Apart from the D-erythro-3- and 4-methylglutamic acids and DL-homocysteic acid, none of the examined compounds significantly inhibited the addition of radioactive D-glutamic acid to UDP-N-acetylmuramyl-L-alanine.

Cryptolepis sanguinolenta extracts are currently used by African herbalists to cure malaria but the compounds involved in its antimalarial activity have not been identified. Two alkaloids, cryptolepine and isocryptolepine, have been isolated from the roots of C. sanguinolenta and their antimalarial activity evaluated. Both alkaloids possess intrinsic inhibitory activity against the human malaria parasite, Plasmodium falciparum in vitro, whatever the chloroquine‐resistance status of the strains used. Cryptolepine was slightly more efficient for parasite killing with an IC50 in the range of 0.2 to 0.6 μMSC compared with an IC50 of about 0.8 μMSC for isocryptolepine. The antimalarial activity of cryptolepine was confirmed in vivo on the rodent malarial parasites Plasmodium vinckei petteri and Plasmodium berghei ANKA.

Cryptolepis sanguinolenta extracts are currently used by African herbalists to cure malaria but the compounds involved in its antimalarial activity have not been identified. Two alkaloids, cryptolepine and isocryptolepine, have been isolated from the roots of C. sunguinolenta and their antimalarial activity evaluated. Both alkaloids possess intrinsic inhibitory activity against the human malaria parasite, Plasmodium fakiparum in vitro, whatever the chloroquine-resistance status of the strains used. Cryptolepine was slightly more efficient for parasite killing with an ICs in the range of 0.2 to 0.6 p~ compared with an ICso of about 0.8 PM for isocryptolepine. The antimalarial activity of cryptolepine was confirmed in vivo on the rodent malarial parasites Plasmodium vinckei petleri and Plasmodium berghei ANKA.