A [1] and B [2], have been isolated from the aerial parts of Ziziphus lotus, together with the known alkaloids sanjoinenine [3], sanjoinine F [4], and frangufoline [51• Ziziphus lotus Lam. (Rhamnaceae) is a small tree that is widely distributed in the Jordan Valley. The genus Ziziphus comprises several species that are used in indigenous medicine for the treatment of various diseases (1-5). We report here the first chemical investigations of Z. lotus, yielding two new 14-membered frangulanine-type (6) cyclopeptide alkaloids from an extract of the aerial pans of Z. lotus. The new compounds, lotusanine A [1} and lotusanine B [2] were isolated along with the known alkaloids, sanjoinenine {31 (7), sanjoinine F [4] (7), and frangufoline [51 (8) (Table 1). Characterization of these compounds was achieved with the help of spectroscopic studies, especially mass spectrometry, which permitted conclusions to be drawn about the structural units (amino acids and styryl moiety) present in the compound and the manner in which they are linked (6,9).
RESULTS AND DISCUSSIONCc of an alkaloidal fraction of the C6H6 extract of Z. lotus (see Experimental) gave an amorphous solid, lotusanine A [1]. The uv spectrum of 1 showed only terminal absorption. The ir spectrum exhibited bands for NH-(3260 cm '), amide carbonyls
The isolation for the first time from the genus Artemisia (Compositae) of the known flavanone, 7-O-methyleriodictyol (7-methoxy-5,3',4'-trihydroxy-flavanone), its identification, and its biological effects on rat isolated smooth muscles are described. 7-O-Methyleriodictyol (10(-7) M to 3 x 10(-4) M) caused concentration-dependent inhibition of the amplitude of the phasic contractions and reduced the tone of the ileum, the uterus, and the urinary bladder. It also caused relaxation of the phenylephrine-precontracted pulmonary artery and the acetylcholine-precontracted trachea. The flavanone also shifted to the right the acetylcholine concentration-effect curve on the ileum and the oxytocin concentration-effect curve on the uterus. The maximum contractions induced by acetylcholine or oxytocin were also inhibited by 7-O-methyleriodictyol. These antispasmodic effects are partly consistent with the use of A. monosperma in folk medicine for certain gastrointestinal disorders.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.