Hypoxidaceae. Medicinal uses and the norlignan constituents.

Glycosides of uncommon aglucones, characterized by the Ph-C5-Ph skeleton, were isolated from the rhizomes of some African Hypoxis species. HPLC analysis indicated the occurrence of these compounds in other Hypoxidaceae. On the basis of structural evidence and biogenetic considerations, the aglucones of these glycosides can be considered as norlignans, derived from the union of two phenylpropanoid units in positions alpha, beta' or beta, gamma' and with the loss of the terminal carbon of a chain. Several Hypoxis species are used in traditional medicine as antiinflammatory and antitumor drugs and, recently, preparations based on lipophilic extracts of H. rooperi have been introduced into the market for the treatment of prostatic hypertrophy.

Insect antifeedant activity associated with compounds isolated from species ofLonchocarpus andTephrosia.

The antifeedant activity of a series of 21 chalcones, flavanes, and flavanones isolated from the generaLonchocarpus andTephrosia (Leguminosae) was assessed by behavioral and electrophysiological bioassays against larvae ofSpodoptera littoralis andS. exempta. The antifeedant activity is related to the molecular structure of the compounds, and possible modes of interaction with the insect taste receptors are discussed.

Two New Glucosides from Hypoxis obtusa: Obtuside A and Obtuside B1,5.

From the rhizomes of HYPOXIS OBTUSA two monoglucosides having the same aglycone as hypoxoside, 1-(3',4'- dihydroxyphenyl)-5-(3'',4''-dihydroxyphenyl)-1-pen-ten-4-yne, have been obtained. By methylation followed by hydrogenation they have been transformed into the same compound, 1-(3'-methoxy-4'- O-beta- D-glucopyranosyl-phenyl)-5-(3''-4''-dimethoxyphenyl)-pentane, likewise obtainable through partial hydrolysis of hypoxoside.

Effect of tingenone, a quinonoid triterpene, on growth and macromolecule biosynthesis in Trypanosoma cruzi.

Tingenone and horminone, two natural quinonoid substances, inhibited the in vitro growth of Trypanosoma cruzi, 30 microM drug concentration producing total inhibition of growth. Tingenone inhibited total uptake and incorporation of [3H]thymidine, [3H]uridine, L-[3H]leucine into parasite macromolecules. Other quinonoids assayed were either less effective (abruquinone A) or even quite inactive (visminone B and ferruginin B). Investigation of several mechanisms for the cytotoxic action of tingenone pointed to the interaction with DNA as the most likely factor involved. Tingenone also inhibited the growth of Crithidia fasciculata, but the drug was significantly less active on this organism than on T. cruzi.

A new bisbenzylisoquinoline alkaloid from a peruvian curare.

From a Peruvian curare a new bisbenzylisoquinoline alkaloid, ( R,S)-nor-N (b)-chondrocurine, 1, was isolated together with the known ( R,R)-curine, 2, (R,S)-chondrocurine, 3, and tubocurarine (as chloride), 5. (13)C-NMR data of 1, 2 and of ( R,S)-di-methylchondrocurine, 4, are reported.

Insect antifeedant properties of anthranoids from the genusVismia.

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.

Flavonoids and alkaloids from Strychnos pseudoquina.

From the leaves of Strychnos pseudoquina (Loganiaceae), isorhamnetin (1) and a new biflavone (2) named strychnobiflavone were isolated together with the alkaloids diaboline and 11-methoxydiaboline.

Study of the binding of jatrophone to Escherichia coli s-ribonucleic acid.

The interaction of jatrophone with sRNA from Escherichia coli has been investigated through UV, CD, and 1H NMR measurements. The results obtained show that the interaction with jatrophone increases the stability of the polynucleotide. It appears that the optical properties of jatrophone depend upon the jatrophone/nucleotide ratio. The observed behaviour can only be explained by the existence of different types of interaction between jatrophone and sRNA. Even for a jatrophone/nucleotide ratio as low as 0.17 the 1H NMR spectra show a multiplicity of resonances that can only be explained by the simultaneous existence of two different binding modes involving the jatrophone molecules.

Flavonoids and rotenoids from Tephrosieae and related tribes of leguminosae.

Seeds and/or roots of eleven species of Leguminosae, mainly Tephrosiae, were examined. Prenylated chalcones and flavanones were isolated from Lonchocarpus nitidus and L. neuroscapha seeds; rotenoids from Lonchocarpus spruceanus, Piscidia mollis and a Tephrosia sp.; demethylhomopterocarpin from Canavalia bonariensis (Phaseoleae). No flavonoids or rotenoids were found in L. nelsii, L. rugosus, T. multijuga (seeds), Millettia grandis (Tephrosieae) and in Xeroderris stuhlmanii (Dalbergieae).

Chuchuhuasha - a drug used in folk medicine in the Amazonian and Andean areas. A chemical study of Maytenus laevis.

In the high Amazonian basin a plant named chuchuasha, (or chuchuaso) is used in traditional medicine for several purposes in the form of an alcoholic extract. This plant, a Maytenus species, most probably Maytenus laevis, grows in the subandean region of the Amazonian basin (Peru, Ecuador, Colombia). Antitumor and anti-inflammatory properties were recently attributed to the extracts of the root bark of the plant. The composition of the extract of M. laevis from the Putumayo area of Colombia was studied in order to establish the active principle responsible for these activities. The presence of phenoldienones (tingenone, 22-hydroxytingenone), a catechin (4'-methyl-(-)-epigallocatechin) and proanthocyanidins (Ouratea-proanthocyanidins A and B) was established. The biological activities of these compounds confirm the properties of the extracts of the plant claimed by traditional medicine.