Evidence of Antiproliferative Activity in the Liverwort Isotachis serrulata from Southern Ecuador

Natural products from bryophytes represent an underexplored source of structurally diverse bioactive compounds. In this study, extracts of Isotachis serrulata collected in southern Ecuador were evaluated for antiproliferative activity against five human tumor cell lines. Sequential extraction and chromatographic fractionation yielded six fractions, among which fraction IsF5 displayed the most notable activity, particularly against lung (SW1573) and breast (T-47D) cancer cell lines, with GI50 values within the moderate activity range according to National Cancer Institute criteria. Phytochemical investigation of IsF5 revealed the presence of two glycosylated aromatic constituents, tentatively assigned as tachioside and isotachioside, based on comparative 1H and 13C NMR spectroscopic analysis. These compounds were obtained as a mixture and were not evaluated individually due to limited material. Additionally, species distribution modeling using MaxEnt indicated that I. serrulata is primarily associated with humid montane and páramo ecosystems in the southern, central and northern Andes of Ecuador, where elevation and precipitation variables strongly influence its distribution. This study provides the first integrated assessment of the antiproliferative activity, chemical profiling, and ecological distribution of I. serrulata.