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Kopsia teoi

Yet another new group of alkaloids, kopsinitarines A - D (257 - 260), were obtained from Kopsia teoi which are characterized by formation of a cage-like structure as a consequence of formation of oxo and carbonyl bridges across C(17) and C(5) and across C(16) and C(6) respectively [170,171]. [Pg.372]

Only one bisindole alkaloid, nitaphylline (313), was isolated from Kopsia teoi which otherwise provided a large number of new indoles. Nitaphylline [155,186] was shown to be a bisindole constituted from union of two kopsingine moieties. The mass-spectrum showed a molecular ion at m/z 910 with a significant peak at ndi 455 suggesting symmetrical cleavage of... [Pg.388]

A similar study of the anti-hypertensive activity of the alkaloids of Kopsia teoi were also carried out which were also prompted by positive results from preliminary screening of alkaloidal extracts. The major aspidofractinine alkaloid kopsingine (191) was found to produce dose-related decreases in mean arterial blood pressure and heart rate in anaesthetized spontaneously hypertensive rats (SHR) which were similar to those elicited in normotensive controls. The same depressor response was shown by the 12-demethoxy derivative (kopsaporine, 192) and the semisynthetic 14,15-dihydto derivative of kopsingine 252, indicating that minor modifications to the basic structure of kopsingine do not significantly alter... [Pg.417]

Melodinus reticulatus Kopsia hainanensis Kopsia hainanensis Catharanthus longiolius Catharanthus ovalis Melodinus fusiformis Melodinus guillauminii Melodinus insulae-pinorum Melodinus morsei Melodinus insulae-pinorum Kopsia teoi Kopsia teoi... [Pg.15]

Methylenedioxy-kopsaporine Kopsia teoi Kopsia singapurensis... [Pg.17]

Mersingine B Kopsia teoi seco-Kopsiiie/Gniticosine albdoids L 243b 188,189... [Pg.20]

Didehydro-17a-hydroxykopsinine (162) is one of several new bases from Kopsia teoi (84,163,164). Its presumed 16-epimer 163 was later isolated from the stem bark of the same plant, but the relationship between the... [Pg.41]

Methylenedioxykopsaporine (198) has been isolated from the leaves of Kopsia teoi 83) and from the trunk bark of K. singapurensis Ridley 176), in which it occurs together with four alkaloids closely related to the kopsidines these are the singapurensines A-D (199-202). [Pg.49]

The remaining two alkaloids in this group, mersingines A (243a) and B (243b), also from Kopsia teoi (188,189), are regarded as artifacts, the consequence of using ammonia in the extraction process. They are presumably derived from kopsinitarines B (240) and C (241), via ammonolysis of the isomeric a-ketols. [Pg.55]

Nitaphylline (572), was the only bisindole isolated from Kopsia teoi which otherwise provided a large number of new indole alkaloids. The mass spectrum... [Pg.283]

See other pages where Kopsia teoi is mentioned: [Pg.294]    [Pg.370]    [Pg.7]    [Pg.14]    [Pg.17]    [Pg.17]    [Pg.17]    [Pg.17]    [Pg.17]    [Pg.18]    [Pg.18]    [Pg.18]    [Pg.18]    [Pg.19]    [Pg.19]    [Pg.20]    [Pg.20]    [Pg.20]    [Pg.41]    [Pg.45]    [Pg.45]    [Pg.55]   
See also in sourсe #XX -- [ Pg.283 ]



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