Bioactive Dimeric Acylphloroglucinols from the Mexican Fern Elaphoglossum paleaceum.

Two new prenylated acylphloroglucinols, paleacenins A (1) and B (2), were isolated from the rhizome n-hexane and chloroform extracts of the fern Elaphoglossum paleaceum. Both compounds were found to possess the same geranylated filicinic acid moiety but have a different phloroglucinol ring substituent. Their structures were determined using H and C NMR spectroscopic, HRMS, and ECD analysis.

Anticholinesterase activity and identification of huperzine A in three Mexican lycopods: Huperzia cuernavacensis, Huperzia dichotoma and Huperzia linifolia (Lycopodiaceae).

Huperzine A (Hup A), the alkaloid produced by the Chinese medicinal plant Huperzia serrata, has been documented to be a promising agent for the treatment of Alzheimer's disease due to its potent acetylcholinesterase inhibitory (AChEI) activity. The search for anticholinesterase natural products, as well as for alternative sources of Hup A in Mexican lycopods, prompted us to investigate these plants. The action of methanolic and alkaloidal extracts of three Huperzia species (H.

Observations of the spore, gametophyte and young sporophyte of Pteridium caudatum (L.) Maxon using scanning electron microscopy.

This paper describes the development of the sexual phase of the invasive fern, Pteridium caudatum, from spore germination to young sporophyte formation. Spores samples for gametophyte cultures were taken from various sporophytes and then sown on mineral agar with Thompson's media. Gametophytes were maintained under fluorescent light on a 12h light, 12h dark cycle at 24-25°C.

Gametophyte morphology of Platycerium andinum Baker and Platycerium wandae Racif.

This paper describes the morphology of the sexual phase and spores of Platycerium andinum and Platycerium wandae. Spores were sown in Thompson's media and the cultures were kept at 24-25 degrees C, with 12h light/darkness photoperiod. Developmental phases were fixed in FAA and processed for observation with the scanning electron microscope.

Developmental gametophyte morphology of seven species of Thelypteris subg. Cyclosorus (Thelypteridaceae).

The morphogenesis of the sexual phase of seven species of Thelypteris subg. Cyclosorus (Thelypteridaceae) is described and compared. Spores of all species are monolete, ellipsoid and have positive photoblastism.

[Gametophyte morphogenesis of Mexican species of Pleopeltis (Polypodiaceae, subfamily Pleopeltoideae)].

The development and morphology of the gametophytes of seven species of ferns from genus Pleopeltis are described and compared. The spore germination is Vittaria-type in P. astrolepis, P.