Chromosome Numbers and Other Karyological Data of Four Stemona Species (Stemonaceae) from Thailand

Hartl, Markus; Kiehn, Michael

doi:10.3767/000651904x484405

Cited by 3 publications

(2 citation statements)

References 7 publications

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“…In this connection it should be pointed out that S. curtisii, a species widely distributed in southern Thailand, also deviated by its chromosome number 2n = 13-16, whereas the other Stemona species were shown to have the same chromosome number 2n = 14 (Oginuma et al 2001;Hartl and Kiehn 2004). Pronounced chemical differences were also observed in S. aphylla, demonstrating infraspecific variability between different localities as well as different individuals within the same population.…”

Section: Chemotaxonomymentioning

confidence: 99%

Structural classification and biological activities of Stemona alkaloids

Greger

2019

Phytochem Rev

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Stemona alkaloids represent a unique class of natural products exclusively known from the three genera Stemona, Stichoneuron, and Croomia of the monocotyledonous family Stemonaceae. Structurally they are characterized by a central pyrroloazepine core usually linked with two butyrolactone rings. The great diversity, comprising 215 derivatives, is created by the formation of additional CC linkages and oxygen bridges together with ring cleavages and eliminations of the lactone rings. Based on biosynthetic considerations they can be grouped into three structural types represented by the croomine, stichoneurine, and protostemonine skeleton. Due to the formation of characteristic terminal lactone rings and the central pyrrolidine ring pandanamine and pandamarilactonine, isolated from Stichoneuron calcicola, were suggested to represent biogenetic precursors. The taxonomically complex S. tuberosa group can be clearly segregated by the formation of stichoneurines, while the other Stemona species are characterized by protostemonine derivatives. Croomine derivatives are more widespread found in both groups and in the genus Croomia. Of chemotaxonomic significance are the different transformations of protostemonine into stemofolines with a cage-type structure or into pyridoazepines characterized by a six-membered piperidine ring. Stimulated by the great interest in the antitussive activity of Stemona alkaloids, differences in transport mechanisms and potencies via different administrative routes were investigated. Follow-up studies on the significant insecticidal activities focused on the mode of action by using biochemical and electrophysiological approaches. Screening for acetylcholinesterase inhibitory properties revealed a much higher potency for stemofoline derivatives compared to pyridoazepines, but showed also significant activity for isomers of stenine with a stichoneurine skeleton. Evaluating synergistic growth inhibitory effects with cancer chemotherapeutic agents stemofoline exhibited the most potent effect in the reversal of permeability glycoprotein-mediated multidrug resistance. The anti-inflammatory activity of some derivatives was identified as an inhibition of the expression of inflammatory mediators. Comparing the diverse bioactivities of Stemona alkaloids stemofoline-type derivatives are the most versatile compounds representing promising lead structures for further development as commercial agents in agriculture and medicine.

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Section: Chemotaxonomymentioning

confidence: 99%

Structural classification and biological activities of Stemona alkaloids

Greger

2019

Phytochem Rev

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“…At the other end of the scale, larger genomes may be found in Stemonaceae in which chromosomes may reach 7 μm in some species, although the highest chromosome number so far reported is 2n = 24 [86]. Triuridaceae may also contain large genomes as this family contains species with chromosomes up to 17 μm in Sciaphila dolichostyla [87] although, like Stemonaceae, chromosome numbers do not exceed 2n = 48.…”

Section: Pandanalesmentioning

confidence: 99%

Genome Size Dynamics and Evolution in Monocots

et al. 2010

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Monocot genomic diversity includes striking variation at many levels. This paper compares various genomic characters (e.g., range of chromosome numbers and ploidy levels, occurrence of endopolyploidy, GC content, chromosome packaging and organization, genome size) between monocots and the remaining angiosperms to discern just how distinctive monocot genomes are. One of the most notable features of monocots is their wide range and diversity of genome sizes, including the species with the largest genome so far reported in plants. This genomic character is analysed in greater detail, within a phylogenetic context. By surveying available genome size and chromosome data it is apparent that different monocot orders follow distinctive modes of genome size and chromosome evolution. Further insights into genome size-evolution and dynamics were obtained using statistical modelling approaches to reconstruct the ancestral genome size at key nodes across the monocot phylogenetic tree. Such approaches reveal that while the ancestral genome size of all monocots was small (1C = 1.9 pg), there have been several major increases and decreases during monocot evolution. In addition, notable increases in the rates of genome size-evolution were found in Asparagales and Poales compared with other monocot lineages.

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