Thalictrum minus Ranunculaceae

This example demonstrates how widely chemical profiles can differ between two populations separated by only a matter of kilometers in this case, populations of halictrum minus L. in the Voj vodina area of Serbia (Popovic et al., 1992) (Fig. 2.20). Plants collected at 500 m in the Fruska Gora Mountains (Novi Sad) afforded a comparatively complex mixture of benzylisoquinoline alkaloids that consisted of 

As noted, the alkaloid yield from the Beocin plants was low, which the authors suggested might be caused by the poor soil in which the plants were growing (Popovic et ah, 1992). One could ask whether the soil conditions to which they refer might be influential in the overall alkaloid biosynthetic processes in this species. It would be of interest to see experimental studies aimed at determining the effect of soil components on these processes. In the present case, it may be a lack of, or reduction in the activity of, the oxidase(s) necessary for the dimerization process (required to form the bibenzyldihydroisoquinolines) to occur. It is also possible that the lack of dimeric alkaloids may simply reflect a concentration effect caused by the edaphic conditions. These questions should be accessible to experiment. 

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Thalictrum minus L. var. microphyllum (Ranunculaceae) was the source of the amorphous base (+)-uskudaramine (358), C39H44N208, [a] 5 +84° (c 0.15, MeOH). The structure proof of uskudaramine was simplified by comparison of its properties with those of the isomeric (+)-istanbulamine (173, Section II,C,47), isolated from the same source. Notably, the NMR spectrum of 358 lacks the H-8 (8 6.84) singlet of 173, and its UV spectrum shows not only a bathochromic base shift but also a hyperchromic effect, characteristic of a 3- or 9-hydroxyaporphine. 

Thalictrum glandulosissimum (Finet et Gagnep.) W.T. Wang et S.H. Wang [292] Thalictrum minus L. race B (Ranunculaceae)[360]... 

Thalictrum minus L. var. microphyllum Boiss. (Ranunculaceae)(38,374] Thalictrum minus L. var. minus (Ranunculaceae)[37S]... 

Thalmine Thalictrum cultraium Wall. (Ranunculaceae)[24l] Thalictrum kuhistanicum Ovcz. (Ranunculaceae)(362] Thalictrum minus L. (Ranunculaceae)[366.369,455] C H ,06N, 608.2886... 

There are four alkaloids that constitute this small subgroup. The mono imine [N(2 )] alkaloids thalmethine (98) and O-methylthalmethine (96) have only been isolated from Thalictrum species (Ranunculaceae), with the former reported as a constituent of T. minus, while the latter has been found in T. minus, T. minus var. minus, and T. revolutum. These two alkaloids differ at C(12), where thalmethine is monophenolic. A third N(2 ) imine alkaloid is thalsivasine (380), a constituent of Thalictrum cultratum and Thalictrum minus var. minus. This alkaloid is monophenolic at C(7), instead of C(12). The final alkaloid of this small group is the secobisbenzylisoquinoline alkaloid revolutionone (266) which has only been isolated from Thalictrum revolutum (Ranunculaceae). The alkaloids of this small subgroup appear to be restricted in distribution to the genus Thalictrum. 

The fully methoxylated parent alkaloid of this type group thalfmine (103), as well as its S -demethyl- analog thalmirabine (222), have both been isolated from just two plants, Thalictrum foetidum and T. minus (Ranunculaceae). 

New aporphine-benzylisoquinoline dimers are ( + )-thalirevolutine (38), (-1-)-thalirevoline (39), (-H )-thalilutidine (40), and (-H )-thalilutine (41), all present in Thalictrum revolutum (Ranunculaceae) while (-I- )-thaliadanine (42) is found in Thalictrum minus Race B. Another new alkaloid is thaliadine (43), also located in T. minus Race Thaliadine must be an oxidation product of an aporphine-benzylisoquinoline alkaloid. 

A relevant and very recent development is the isolation and characterization by Beal, Doskotch, and co-workers, of the new alkaloid ( + )-thaliadine from Thalictrum minus L. race B (Ranunculaceae). This alkaloid is accompanied in the plant by such aporphine-benzylisoquinoline dimers as (-h)-adiantifoline, (+)-desmethyladiantifoline, and (-h)-thaliadanine (Sec. 12.1), and must be formed from their oxidative degradation. ... 

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