25 mL of CH2C12 was added at 0 °C, over a period of 0.5 h, a solution of 4-phenylbenzoyl chloride (0.83 g, 5.0 mmol) in 5 mL of CH2C12. The reaction mixture was stirred at 0 °C for 2 h and then allowed to warm to 25 °C over 14 h. It was then evaporated, the residue was dissolved in 20 mL of CH2C12 and washed with 1 X 10 mL of 1 N NaOH and 2 X 10 mL of 10% HC1, and the organic phase was dried and evaporated to leave 750 mg of residue. Chromatography (Si02, 5% acetone/CH2Cl2) afforded 30d, pure

Saponins of DuPuits and Lahontan alfalfa cultivars were extracted and fractionated by preparative thin‐layer chromatography. The ten relatively well‐defined saponin fractions obtained from each cultivar were chemically characterized by major aglycone and carbohydrate moieties. Lahontan contained considerably more soyasapogenol A than DuPuits, but medicagenic acid predominated in DuPuits. The near absence of medicagenic acid from Lahontan fractions was the most significant difference in composition of Lahontan and DuPuits saponins. Based on mass‐spectrometric analyses, four unidentified sapogenins were classified as the same pentacyclic triterpenoids as medicagenic acid or soyasapogenol. Six Lahontan fractions incorporated varying quantities of galactose, which was present in only two DuPuits fractions, but more arabinose was found in DuPuits than in Lahontan saponins. Simplified saponins of DuPuits and Lahontan were then bioassayed by survival of potato leafhopper (Empoasca fabae (Harris)), survival of pea aphid (Acyrthosiphon pisutn (Harris)), hemolysis of human blood cells, and inhibition of Trichoderma viride Pers. ex Fr. A crude‐saponin mixture and a commercially available saponin from Yucca sp. were included in all assays as controls. Certain fractions containing medicagenic acid were responsible for toxic properties in all assays. Presence or absence of medicagenic acid seemed to explain most of the differences in biological activity of DuPuits and Lahontan cultivars. However, medicagenic acid apparently is, not the only acid sapogenin strongly active toward pathogens. An unidentified acid sapogenin chemically related to medicagenic acid inhibited fungal growths markedly, but did not affect insects tested. Potato leafhopper and pea aphid appeared to be appropriate test insects for saponin differentiation. Zusammenfassung BIOLOGISCHE WIRKSAMKEIT VON SAPON1NFRAKTIONEN DER LUZERNESORTEN DUPUITS UND LAHONTAN Saponine sind Glykoside, welche auch in Luzerne (Medicago sativa L.) vorkommen. Obschon sie biologisch ungewöhnlich, wirksam sind, ist deren Bedeutung für die Pflanzen noch nicht abgeklärt. Unsere Untersuchungen bezweckten herauszufinden, ob es die gleichen oder verschiedene Saponine sind, welche für die unterschiedliche biologische Wirksamkeit verschiedener Saponingemische, wie sie in bestimmten Luzernesorten vorkommen, verantwortlich sind; ferner ob und wie jene in Zusammenhang mit der relativen Resistenz oder Anfälligkeit dieser Sorten gegenüber Krankheiten oder Schädlinge gebracht werden können. In der vorliegenden interdisziplinären Zusammenarbeit wurden die gereinigten Saponine der Luzeraesorten DuPuits und Lahontan zuerst charakterisiert und dann, in den folgenden drei Abschnitten, ihre biologische Wirksamkeit gegenüber 2 Insektenarten und einem Pilz, sowie die haemolytische Wirkung auf menschliches Blut dargestellt. Die Saponine der Sorten DuPuits und Lahontan wurden nach der Extraktion mithilfe präparativer Dünnschichtchromatographie fraktionniert. Die 10 verhältnismässig gut definierten Saponinfra...

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The resolution of several antimalarial agents via pi-complex formation with alpha-(2,4,5,7-tetranitro-9-fluorenylideneaminooxy) propionic acid (TAPA) is reported. Since this represents the first use of this agent for the resolution of amines, some details of the separations are presented. The method proved successful for resolving weakly alkaline amines that did not form stable salts with common resolving acids, highly insoluble amines that did not form soluble salts with usual resolving acids, and amines that did not form crystalline salts with commonly available resolving acids. The optical isomers of several antimalarial agents were evaluated against Plasmodium berghei in the mouse. None of the optically active forms showed any significant differences. The curative activity of (+)- and (-)-primaquine against Plasmodium cynomolgi in the rhesus monkey was essentially identical; however, significant differences in toxicity were noted.