Among-population variation in drought responses is consistent across life stages but not between native and non-native ranges.

Understanding how widespread species adapt to variation in abiotic conditions across their ranges is fundamental to ecology. Insight may come from studying how among-population variation (APV) in the common garden corresponds with the environmental conditions of source populations. However, there are no such studies comparing native vs non-native populations across multiple life stages. We examined APV in the performance and functional traits of 59 Conyza canadensis populations, in response to drought, across large aridity gradients in the native (North America) and non-native (Eurasia) ranges in three experiments. Our treatment (dry vs wet) was applied at the recruitment, juvenile, and adult life stages. We found contrasting patterns of APV in drought responses between the two ranges. In the native range, plant performance was less reduced by drought in populations from xeric than mesic habitats, but such relationship was not apparent for non-native populations. These range-specific patterns were consistent across the life stages. The weak adaptive responses of non-native populations indicate that they can become highly abundant even without complete local adaptation to abiotic environments and suggest that long-established invaders may still be evolving to the abiotic environment. These findings may explain lag times in invasions and raise concern about future expansions.

Cytotoxic Homoisoflavones from the Bulbs of Bellevalia eigii.

Eight new and 10 known compounds were isolated from an organic extract of the bulbs of Bellevalia eigii as part of a search for anticancer leads from native plants of Jordan. Of these, the series of 16 homoisoflavonoids (1-16) comprise the seven new analogues 7-O-methyl-3'-hydroxy-3,9-dihydropunctatin (3), 6-hydroxy-7-O-methyl-3,9-dihydropunctatin (6), 7,4'-di-O-methyl-3'-hydroxy-3,9-dihydropunctatin (9), 7-O-methylpunctatin (10), 7-O-methyl-3'-hydroxypunctatin (13), 5-hydroxy-7,8-dimethoxychroman-4-one (14), and 7-O-methyl-8-demethoxy-3-hydroxy-3,9-dihydropunctatin (15). The known ferulic acid-derived acrylamide (17) and the new methylthioacrylate bellegimycin (18) are also reported. The structures were elucidated using a set of spectroscopic and spectrometric techniques; the absolute configurations of compounds 1-9, 15, and 16 were determined using ECD spectroscopy, while a modified Mosher's ester method was used for compound 18. Optical rotation data for the known compounds 1, 2, and 8 are reported here for the first time. The cytotoxic activities of all compounds were evaluated using the MDA-MB-435 (melanoma) and HT-29 (colon) cancer cell lines. Compounds 4 and 9 were the most potent on the latter cell line, with IC50 values of 1.0 and 1.1 µM, respectively. Compounds 1-18 were assessed for antimicrobial activity using a collection of bacteria and fungi; compounds 4 and 12 showed promising activity against the bacterium Mycobacterium smegmatis with MIC values of 17 and 24 µg/mL, respectively.

UPLC-HRESI-MS and GC-MS analysis of the leaves of Nicotiana glauca.

The alkaloid-rich fraction obtained by fractionation of the crude methanolic extract of the leaves of wild tobacco tree Nicotiana glauca Graham (Solanaceae) was analyzed using UPLC-MS and GC-MS. Anabasine, a piperidine alkaloid, was identified as the major constituent with approximately 60 % (m/m) of the alkaloid-rich fraction. In addition to anabasine, six secondary metabolites were identified using high-resolution UPLC-MS. Anabasine was quantified in the leaves to be 1 mg g-1 dry plant material. The GC-MS analysis revealed five compounds with anabasine as the major component, while nicotine was not detected. Moreover, GC-MS was used for the analysis of the volatile oil that was obtained by hydro-distillation from the leaves of N. glauca. The volatile plant oil was found to be rich in oxygenated sesquiterpenes (e.g., ß-bisabolol) and carboxylic acids and esters (e.g., ethyl linoleate and hexadecanoic acid), whereas anabasine was not detected.

Homoisoflavonoids from the bulbs of Bellevalia longipes and an assessment of their potential cytotoxic activity.

Seven undescribed homoisoflavonoids were identified from the bulbs of Bellevalia longipes Post (Asparagaceae) as well as thirteen known and one natural homoisoflavonoid that had been reported as a synthetic product previously. A general approach for recognizing homoisoflavonoids via NMR spectroscopy data were presented. The undescribed compounds were: 8-dehydroxy-5-O-demethyl-6-hydroxyscillapersicone, 6-methoxyscillapersicone, 5-O-demethyl-6-methoxyscillapersicone, 8-O-methylscillapersicone, 4'-O-methylscillapersicone, 4',8-O,O-dimethylscillapersicone, 3'-O-methylscillapersicone, and 3-hydroxy-desmethylophiopogonanone A. Structures were determined based on analysis of HRMS and NMR data, while absolute configurations were assigned using ECD spectroscopy. Human cancer cell lines were used to assess the cytotoxic activities of the isolated compounds, where 3-dehydroxy-3'-hydroxyeucomol showed IC50 values of 0.62 µM, 5.36 µM, and 2.52 µM, when tested against MDA-MB-435 (melanoma), MDA-MB-231 (breast), and OVCAR3 (ovarian) cells, respectively.

Acquisition and evolution of enhanced mutualism-an underappreciated mechanism for invasive success?

Soil biota can determine plant invasiveness, yet biogeographical comparisons of microbial community composition and function across ranges are rare. We compared interactions between Conyza canadensis, a global plant invader, and arbuscular mycorrhizal (AM) fungi in 17 plant populations in each native and non-native range spanning similar climate and soil fertility gradients. We then grew seedlings in the greenhouse inoculated with AM fungi from the native range. In the field, Conyza plants were larger, more fecund, and associated with a richer community of more closely related AM fungal taxa in the non-native range. Fungal taxa that were more abundant in the non-native range also correlated positively with plant biomass, whereas taxa that were more abundant in the native range appeared parasitic. These patterns persisted when populations from both ranges were grown together in a greenhouse; non-native populations cultured a richer and more diverse AM fungal community and selected AM fungi that appeared to be more mutualistic. Our results provide experimental support for evolution toward enhanced mutualism in non-native ranges. Such novel relationships and the rapid evolution of mutualisms may contribute to the disproportionate abundance and impact of some non-native plant species.

Phenethyisoquinoline alkaloids from the leaves of Androcymbium palaestinum.

Thirteen compounds were isolated from the methanolic extract of the leaves of Androcymbium palaestinum Baker (Colchicaceae). Of these, three were new, two were new natural products, and eight were known. The new isolated compounds were (+)-1-demethylandrocine (5), (-)-andropalaestine (8), and (+)-2-demethyl-ß-lumicolchicone (10), while the new natural products were (+)-O-methylkreysigine-N-oxide (3) and (+)-O,O-dimethylautumnaline (9). Moreover, two known compounds are reported for the first time from this species, specifically (-)-colchicine (11) and (-)-3-demethyldemecolcine (13). The structures of the isolated compounds were elucidated using a series of spectroscopic and spectrometric techniques, principally HRESIMS, 1D-NMR (1H and 13C NMR) and 2D-NMR (COSY, edited-HSQC, and HMBC). ECD spectroscopy was used for assigning the absolute configurations of compounds 3, 5, and 10. The cytotoxic activities of the isolated compounds were evaluated using the MDA-MB-435 (melanoma), MDA-MB-231 (breast), and OVCAR3 (ovary) cancer cell lines. Compound 11 was the most potent against all tested cell lines, with IC50 values of 12, 95 and 23 nM, respectively.

Cytotoxic homoisoflavonoids from the bulbs of Bellevalia flexuosa.

Four new homoisoflavonoids, 7-O-methyl-8-demethoxy-3'-hydroxy-3,9-dihydropunctatin (4), 6-hydroxy-8-demethoxy-4'-O-methyl-3,9-dihydropunctatin (8), 7,4'-O-dimethyl-8-demethoxy-3,3'-dihydroxy-3,9-dihydropunctatin (13), and 7-O-methyl-3-hyroxy-3,9-dihydropunctatin (14) were identified from a chloroform extract of the bulbs of Bellevalia flexuosa, along with 13 known analogues. The structures were determined by analysis of HRMS and NMR data, while ECD spectroscopy enabled the assignment of the absolute configurations of the new compounds 4, 8, 13 and 16. The cytotoxic activities of the isolated compounds (1-17) were evaluated using a panel of human cancer cell lines. Compounds 2 and 7 were the most potent against the MDA-MB-435 (melanoma) cancer cell line with IC50 values of 1.6 and 2.0 µM, respectively, and were essentially equipotent against the OVCAR3 (ovarian) cancer cell line with IC50 values of 9.5 and 10.8 µM, respectively. However, compound 7, with an IC50 value of 3.6 µM, was the most potent against the MDA-MB-231 (breast) cancer cell line.