Isoflavones from Calpurnia Aurea subsp. aurea and their anticancer activity.

Background: Calpurnia aurea is an African medicinal plant used in many countries in Africa to treat a range of medical conditions or disorders. Extracts of the plant were shown to be active in antibacterial and antioxidant assays as well as against lice, ticks and maggots. The aim of the study was to isolate the phytochemical constituents from the plant and to test them in appropriate bioassays dependent on the compounds isolated in order to provide a rationale for the use of the plant in ethno-medicine or to provide some information on its constituents.

Antiprotozoal screening of 60 South African plants, and the identification of the antitrypanosomal germacranolides schkuhrin I and II.

Two hundred and seven extracts were prepared from sixty plants from South Africa and screened for in vitro activity against Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani, and Plasmodium falciparum. For the 21 extracts which inhibited the growth of one or more parasites with more than 95 % at 10 µg/mL, the IC50 values against all four protozoal parasites and cytotoxic IC50 values against L6 myoblasts were determined. Amongst the most notable results are the activities of Psoralea pinnata (IC50 of 0.

Quinolizidine alkaloids from Sophora velutina subsp. zimbabweensis (Fabaceae: Sophoreae).

Three novel quinolizidine alkaloids, N-methylenehydroxycytisine (1), 6,7-dihydroxylupanine (2), and velutinine (3) have been isolated from the fruits and pods (1 and 2) and stem bark (3) of Sophora velutina subsp. zimbabweensis along with the known quinolizidine alkaloids, 7-hydroxylupanine (4), thermopsine (5), N-methylcytisine (6), cytisine (7), an aromatic ester, methyl-3-(3',4'-dimethoxyphenyl)-2-propenoate (8) and the triterpenoids, lup-20(29)-ene-3beta-ol (9) and 12-oleanen-3-one (10). Compounds 6 and 10 showed good antibacterial activity against E.

The antimicrobial, antioxidative, anti-inflammatory activity and cytotoxicity of different fractions of four South African Bauhinia species used traditionally to treat diarrhoea.

Ethnopharmacological Importance: Many Bauhinia species, including those indigenous to South Africa, are used in traditional medicine across the world for treating ailments such as gastrointestinal tract (GIT) disorders, diabetes, infectious diseases and inflammation.

Aims: Several relevant aspects of different fractions of leaf extracts of Bauhinia bowkeri (BAB), Bauhinia galpinii (BAG), Bauhinia petersiana (BAP), and Bauhinia variegata (BAV) used in South African traditional medicine to alleviate diarrhoea related symptoms were evaluated.

Materials And Methods: The antioxidative activities of the extracts were determined using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS(+)) radical scavenging and ferric reducing antioxidant power (FRAP) methods.

In vitro screening of traditional South African malaria remedies against Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani, and Plasmodium falciparum.

Three hundred extracts were prepared from plants traditionally used in South Africa to treat malaria and screened in vitro for activity against Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani, and Plasmodium falciparum. For the 43 extracts which inhibited the growth of one or more parasites to more than 95 % at 9.7 µg/mL, the IC₅₀ values against all four protozoal parasites and cytotoxic IC₅₀s against rat myoblast L6 cells were determined.

Bufadienolides from Drimia macrocentra and Urginea riparia (Hyacinthaceae: Urgineoideae).

The bufadienolides, rubellin and riparianin were isolated from the bulbs of Drimia macrocentra and Urginea riparia (Hyacinthaceae) respectively. Rubellin and riparianin contain a carbohydrate moiety doubly linked to the bufadienolide aglycone at the C-2 and C-3 positions. Riparianin showed moderate activity when tested against MCF7 (breast), TK10 (renal) and UACC62 (melanoma) cell lines.

Eucosterol-type nortriterpenoids from Merwilla natalensis.

The bulbs of Merwilla natalensis have yielded two known homoisoflavanones, the known spirocyclic homoisoflavanone, scillascillin, four known nortriterpenoids, and the new nortriterpenoid, (22R,23S)-17alpha,23-epoxy-22,29-dihydroxy-27-nor-lanost-8-en-3,24-dione (1), bisnortriterpenoid, (22R,23S)-17alpha,23-epoxy-3beta,22,24xi-trihydroxy-27,28-bisnor-lanost-8-ene (2), and trisnortriterpenoid, (23S)-17alpha,23-epoxy-3beta,24xi-dihydroxy-27,28,29-trisnor-lanost-8-ene (3). The structures of 1-3 were determined by spectroscopic methods.