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Bioassay-guided analysis of an EtOH extract of Moringa oleifera leaves showing hypotensive activity led to the isolation of two nitrile glycosides, niazirin [1] and niazirinin [2], and three mustard oil glycosides, 4-[(4'-O-acetyl-alpha-L-rhamnosyloxy)benzyl]isothiocyanate [4], niaziminin A, and niaziminin B. Glycoside 2 is a new compound. Niaziminins A and B have previously been obtained from the left extract as a mixture, while compound 4 is new from this source. Structural determination was accomplished by means of spectroscopic methods including appropriate 2D nmr experiments and chemical reactions. This is the first report of the isolation of nitriles, an isothiocyanate, and thiocarbamates from the same plant species. Isothiocyanate 4 and the thiocarbamate glycosides niaziminin A and B showed hypotensive activity while nitrile glycosides 1 and 2 were found to be inactive in this regard.

Mahmoodin [1], a new limonoid, has been isolated from Azadirachta indica (neem) oil, along with seven known tetranortriterpenoids, azadirone, epoxyazadiradione, nimbin, gedunin, azadiradione, deacetylnimbin, and 17-hydroxyazadiradione. A new protolimonoid, naheedin [3], has been obtained from the neem fruits along with azadirachtol. Their structures have been elucidated through chemical and spectral analyses including 2D nmr studies. The absolute configuration of 1 was established by comparison of its cd spectrum with those of the known tetranortriterpenoids. Mahmoodin showed significant antibacterial activity against various Gram-positive and Gram-negative organisms. Four hydrocarbons, icosane, docosane, 2-methyltricosane, and docosene, have also been identified by gc-ms of the EtOH extract of the fruit coats. Only docosane has earlier been reported from neem, while the remaining three are unreported from this plant.