Zizyphus structures

In 1963 a group of Swiss authors (12) isolated zizyphine from Zizyphus oenoplia and recognized isoleucine and proline as components. Two years later Zbiral etal. (13) proposed a complete structure which was later revised (14). Pais et al. (15) in an earlier preliminary report suggested the structure of pandamine which had been isolated from Panda oleosa. This was confirmed in 1966, and the structure of the similarly constituted pandamine was reported (17). Shortly thereafter Tschesche and co-workers (18) reported the structure of an alkaloid of this type scutianine-A from Scutia buxifolia. Since then the number of cyclopeptide alkaloids of known structure has risen to more than sixty, a figure which Klein and Rapoport had envisioned in 1968 (20). The workers at Gif-sur-Yvette and at Bonn have been in the forefront of these researches but others have made important contributions (19-26). 

The zizyphine-A type are 13-membered cyclopeptides composed of / -(2-methoxy-5-hydroxyphenyl)vinylamine, 3-hydroxyproline, and another amino acid. The first known representative was described as zizyphine in 1965 and given an open chain structure (13). It was subsequently renamed zizyphine-A in view of a further examination of Zizyphus oenoplia which disclosed other peptide alkaloids (14). 

A number of new 14-membered-ring alkaloids incorporating the p-hydroxy-styrylamine and j8-hydroxyphenylalanine structural features have been isolated and structurally elucidated, mainly by application of high-resolution mass spectrometry. Cre natine A (55) has been obtained from Discaria crenata while alkaloid A, (feretine) (56) and alkaloid A2 (57) have been isolated from Feretia apondanthera. In addition to four known alkaloids, the root bark of Zizyphus nummularia has yielded nummularine-D (58) and nummularine-E (59). ... 

In continuation of their chemical investigation of peptide alkaloids obtained from Zizyphus amphibia (see Vols. 3 and 4 of these Reports), Tschesche and coworkers have elucidated the structures of the new amphibines F (40), G (41), and H (42) by the established spectroscopic and degradative methods. Amphibine I (43), an alkaloid of obvious mixed biogenesis, has been isolated from Z. am-phibia. Interestingly, the aporphine base (—Fnuciferine was also obtained from this species. 

Zizyphine, the major alkaloid from Zizyphus oenoplia, for which a structure containing an unusual diketopiperazine unit had been proposed (see Vol. 1 of these Reports), has been shown to possess the more normal structure (44) on the basis of extensive spectral and degradative evidence. The alkaloid has been... 

From the root bark of Zizyphus lotus, cyclopeptide alkaloids were isolated. The structures of two new compounds, lotusine A (45) and lotusine... 

From the roots of Zizyphus mucronata, in addition to the known alkaloid mucronine D (23), two new cyclopeptide alkaloids 24 and 25 were isolated. The structures were elucidated by ID- and 2D-NMR techniques (48). A new cyclopeptide alkaloid, named mucronine J (53), was isolated together with known alkaloids abyssenine A and mucronine D (23) from the methylene chloride extract of the root bark of Z. mucronata (49). The structure of mucronine J was elucidated by mass spectrometry and ID and 2D-NMR techniques, and the solution conformation is proposed on the basis of NOE experiments in combination with MM2 calculations. Leaves of Zizyphus hysodrica were extracted with methanol and the different alkaloidal fractions gave a new compound, hysodricanine B, which is a cyclopeptide alkaloid (50). 

From the root bark of Zizyphus mauritiana, a new cyclopeptide alkaloid mauritine J (54), together with known alkaloids, was isolated. Its structure was established by homo- and heteronuclear 2D-NMR analysis and compared with that of amphibine E (55) (51). From Zizyphus oenoplea, some cyclopeptide alkaloids were isolated (52-54). 

Sterculiaceae, Asteraceae, Euphorbiaceae, Pandaceae, Menispermaceae, Rubiaceae, and Urticaceae. A general structure of cyclopeptide alkaloids is designated on Figure 29.12. Cyclopeptide alkaloids display a broad spectrum of biological activities, like antibacterial, antifungal, sedative, and antiplasmodial. Both abyssenine A and murconine E were isolated from the roots and stem bark of several Zizyphus-type Rhamnaceae ... 

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