High impact information on Cycas

• We report the characterization of an ortholog of the AG gene, named Cycas AGAMOUS (CyAG), from the primitive gymnosperm Cycas edentata [1].
• On the basis of conserved primary and secondary structure the second intervening sequence interrupting the Cycas rps3 gene has been classified as a group II intron [2].
• Despite remarkable size heterogeneity, the Cycas rps3i1 can be shown to be homologous to the group IIA introns present within the rps3 gene of algae and land plants, including Magnolia and Helianthus [2].
• Beta-N-Methylamino-L-alanine, a component of the neurotoxic Cycas circinalis plant, activates an ionic current which is antagonized by extracellular Ca2+ but not by the excitatory amino acid receptor antagonists D,L-2-amino-5-phosphonovalerate (10-100 microM) or 6-cyano-7-nitroquinoxaline-2,3-dione (1-10 microM) [3].
• Medicinal use of untreated cycad seed (Cycas sp.) has also been linked with ALS foci in Japan (oral use) and Guam (topical use), with the additional consumption on Guam of food items prepared from Cycas sp. seed or animals that consume cycad seed components [4].

Associations of Cycas with chemical compounds

• In addition to the excitatory and putative neurotoxin beta-N-methylamino-L-alanine (BMAA), the known neurotoxin beta-N-oxalylamino-L-alanine (BOAA) was detected from the seeds of Macrozamia moorei and M. communis, and delta-N-oxalyl-ornithine was obtained from the Cycas revoluta seeds [5].
• Our chemical studies on Cycas circinalis seeds from Guam has provided two new nonprotein amino acids, N-(3'-one-5'-methyl)-hexylalanine and leucine betaine [6].
• Chemical investigation on the constituents of the cones of Cycas beddomei has resulted in the isolation of a new biflavonoid, 2,3-dihydro-4'''-O-methyl amentoflavone, along with 2,3,2'',3''-tetrahydro hinokiflavone, 2,3,2'',3''-tetrahydro amentoflavone, 2,3-dihydro amentoflavone [7].
• Recently, two mannose-specific lectins having tandem repeat-type structures were discovered in Castanea crenata (angiosperm) and Cycas revoluta (gymnosperm) [8].
• For this purpose, we compared the dissociation constants (K(d)) of Castanea crenata agglutinin (CCA) and Cycas revoluta leaf lectin (CRLL) by using 102 pyridylaminated and 13 p-nitrophenyl oligosaccharides with a recently developed automated system for frontal affinity chromatography [8].

Gene context of Cycas

• In our quest to identify tropical plants that contain inhibitors of the cytochrome P-450 aromatase and thus may be efficacious in treating estrogen-dependent tumors, we have screened extracts from 5 species of cycad folia encompassing 3 genera: Cycas cairnsiana F [9].

References