Cryptolepis sanguinolenta (Lindl.) Schlechter (Periplocaceae) is a medicinal plant used in some African countries against infectious and parasitic diseases. Six of its constituent alkaloids have been isolated from the root bark, identified spectroscopically as cryptoquindolinine (1), quindoline (2), neocryptolepine (3), cryptolepine (4), 11‐hydroxycryptolepine (5) and biscryptolepine (6), and their interaction with the xanthine‐xanthine oxidase enzyme system has been tested. Compound 5 has been shown to inhibit xanthine oxidase and act as a scavenger of superoxide anions. Alkaloids 1–4 and 6 were devoid of effect in both assays at the highest test concentration of 100 mM. These findings suggest the importance, in the manifestation of both activities, of the hydroxyl group present in 5 but not in the other alkaloids.

A significant effect is found when various ratios of CH 4 /H 2 and CH 4 /N 2 are used for the synthesis of multiwalled carbon nanotube (MWNT) bundles on nickel-doped MgMoO 4 (Ni/Mo/MgO) as a catalyst. The absorption of hydrogen makes the nickel-molybdenum nanoparticles highly dispersed on the porous MgO, and the synergism of nickel-molybdenum has the effect that sufficient carbon atoms are rapidly dissolved in the molten nickel-molybdenum nanoparticles, leading to a high yield of MWNTs. The phase transformations of the catalysts and the formation mechanism of the MWNT bundles on Ni/Mo/ MgO catalyst are also presented.