A new 13-membered cyclopeptide alkaloid, sativanine-E (l), carrying a short side chain, has been isolated from Zizyphus sativa (Rhamnaceae). The structure was obtained by spectral evidence and hydrolysis. Zizyphus sativa Gaertn. (Rhamnaceae) is a small tree native to the Hazara District of Pakistan, where it grows wild in the hilly areas ( 1). The bark of this plant is used to heal ulcers and wounds. The gum is used to treat eye disease while the syrup of the dried fruit is used for bronchitis (2). In our earlier communications, we reported the isolation and characterization of several cyclopeptide alkaloids from the bark of this plant (3-6). This paper describes the isolation and structure determination of a new alkaloid, sativanine-E (l), from the same source. Sativanine-E (1) is a 13-membered cyclopeptide alkaloid containing a short side chain like nummularine-C (2) (7).The ir spectrum of 1 exhibited bands for -NH, secondary amide, -OCH,, -NMe, >C=C :, and aryl ether, typical for cyclopeptide alkaloids. The uv spectrum showed absorption maxima at 321 and 268 nm characteristic of the styrylamine chromophore in the 13-membered cyclopeptide alkaloids (8), and shoulders observed at 289, 282, and 272 nm were typical for a tryptophan unit (9). The 'H-nmr spectrum confirmed the presence of an N,N-dimethyl group, a -0Me group, and a cis-styrylamine moiety. The two (D,O exchangeable) NH signals were recognized at 8.07 and 8.43 ppm. The cis-olefin proton, adjacent to the aromatic ring of the 13-membered ring system, appeared as a doublet at 5.92 ppm (J=9 Hz). The two doublets at 0.91 and 0.97 ppm (J=7 Hz each) were assigned to the two methyl groups of leucine. The presence of leucine was confirmed by paper chromatography of the hydrolysate of 1 in comparison with an authentic sample of leucine.The molecular formula of 1 was determined by high resolution ms to be C33H41N5O5. The ms of 1 resembled that of the 13-membered cyclopeptide alkaloid, nummularine-C (2), and the 14-membered cyclopeptide alkaloid, mauritine-C (3) (10), containing a short side chain. The principal fragmentations observed are listed in Table 1, and the assignments are depicted in Scheme 1. The identity of each fragment was substantiated by high resolution ms, and various fragments are represented as usual (6).α-Cleavage yielded the two most intense ions, a at m/z 187 and b at m/z 457. The fragment a disintegrated further into ions m/z 144 and m/z 130, typical for tryptophan derivatives (11). Due to the short side chain, the ions C, d, e, and m are absent (6). The typical fragments for hydroxyproline m/z 96 and 68, leucine m/z 86 and a methoxy styrylamine group m/z 165 revealed the identity of the units that formed the 13-membered ring; and f m/z 401, g m/z 400, h m/z374, i m/z 373, Q m/z 181, r m/z 259, s m/z 233, and u m/z 304 suggest their linkage (Scheme 1). From these data, structure 1 was established for sativanine-E.