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Didymochlaena truncatula (Sw.) J.Sm. — Habit: Fern. Habitat: LMWF; up to 2 300 m. Distribution: I. Voucher: Kaburia Track, Alt. 2 165 m, 10 Aug. 2015, SAJIT 003913 (HIB). References: Bussmann (1993, 1994), Bussmann & Beck (1995a), Agnew (2013)., Published as part of Zhou, Ya-Dong, Mwachala, Geoffrey, Hu, Guang-Wan & Wang, Qing-Feng, 2022, Annotated checklist of the vascular plants of Mount Kenya, East Africa, pp. 1-108 in Phytotaxa 546 (1) on page 19, DOI: 10.11646/phytotaxa.546.1.1, http://zenodo.org/record/6550464, {"references":["Bussmann, R. W. (1993) The forest of Mt. Kenya (Kenya): A phytosociological approach with special reference to ecological problems. Ph. D. Thesis, Eberhard Karls Universitat Tubingen, Tubingen, 119 pp.","Bussmann, R. W. (1994) The forest of Mt. Kenya (Kenya): Vegetation, ecology, destruction and management of a tropical mountain forest ecosystem. Ph. D. dissertation, Universitat Bayreuth Startseite, Bayreuth, 252 pp.","Bussmann, R. W. & Beck, E. (1995 a) The forests of Mt. Kenya (Kenya), a phytosociological synopsis. Phytocoenologia 25 (4): 467 - 560. https: // doi. org / 10.1127 / phyto / 25 / 1995 / 467","Agnew, A. D. Q. (2013) Upland Kenya wild flowers and ferns, 3 rd edn. Nature Kenya Publications, Nairobi, 733 pp."]}

We provide a synopsis to the family Didymochlaenaceae in Bolivia, comprising the single pantropical species, Didymochlaena truncatula.

Th e phenology of the herbaceous fern Didymochlaena truncatula in a Brazilian submontane tropical rainforest is described. A total of 23 individuals were observed over 18 months (May 2012 to October 2013). Th e number of live leaves, leaf production, leaf mortality, leaf growth, and fertility were recorded monthly and correlated with local rainfall and temperature. Th e D . truncatula plants remained evergreen with a monthly mean of 6.49 0.75 leaves that were produced almost continuously at a rate of 6.13 1.46 leaves plant 1 year 1 . Th is rate was higher than the leaf mortality rate, which was 4.61 1.27 leaves plant 1 year 1 . Monthly leaf growth of the population was correlated with rainfall. Leaf expansion was fastest in the fi rst month after emergence (1.31 1.03 cm day 1 ). Fertility and leaf production intensity were not correlated with climate factors or seasonal variations. However, leaf mortality was negatively correlated with rainfall, causing variations in the number of leaves throughout the year. Th ese results show that the phenological rhythms of D . truncatula were not equally infl uenced by climate variations. Th e phenology of D . truncatula corresponds to the phenology of a small number of aseasonal tropical ferns.

Bioassay-guided fractionation of the EtOH extracts obtained from a plant identified as Didymochlaena truncatula led to the isolation of two cytotoxic alkaloids, camptothecin and 9-methoxycamptothecin. A second plant collection yielded three lignan derivatives, didymochlaenone A (1), didymochlaenone B (2), and (-)-wikstromol, one stilbene, (E)-3-methoxy-5-hydroxystilbene, and two stigmasterol derivatives, stigmast-4-en-3beta-ol and stigmast-4-en-3-one, but no camptothecins, and it is probable that a coding error led to a mistaken identification of the original extract. The structures of the new compounds 1 and 2 were established on the basis of extensive interpretation of one- and two-dimensional NMR spectroscopic data.

Background: Ferns are a group of plants that have been little explored from a chemical and biological perspective but that have interesting potential, occurring in various parts of the world. Objective: This work investigates the chemical profile and the biological effects of ferns from Brazil. Materials and Methods: Analyses were performed using rapid performance liquid chromatography (RP-LC) with a diode array detector (DAD). Extracts were tested for their in vitro antioxidant activity, by the total reactive antioxidant potential method and for their antichemotactic potential, by the Boyden chamber method. Cytotoxic effects were assessed by lactate dehydrogenase levels, while the monoamine oxidase (MAO) assay was carried out using a fluorescence-based method. Results: Different chemical compositions were found for the studied ferns, such as Asplenium gastonis, in which hesperidin was identified in its extract, while A. serra showed the presence of xanthone mangiferin. The most samples with highest antioxidant activity were the Asplenium serra, Lastreopsis amplissima and Cyathea dichromatolepis extracts, at 10 μg/mL. High antichemotactic activity was found for A. serra (94.06%) and Didymochlaena truncatula (93.41%), at 10 μg/mL. The extracts showed no cytotoxicity at the highest concentration. Against MAO-A, D. truncatula (82.61%), Alsophila setosa (82.21%), Cyathea phalerata (74.07%) and C. delgadii (70.32%) were the most active extracts (100 μg/mL). Conclusion: The hypothesis was considered that phenolics and triterpenes are responsible for these pronounced activities.