New reports of cyanolipids from sapindaceous plants

Several previously uninvestigated species of the Sapindaceae were examined and found to contain cyanolipids and cyanogenic compounds. Several species from the Melianthaceae, Meliosmaceae and Hippocastanaceae were devoid of these substances.     

Chemical constituents of Cardiospermum corindum L. and their distribution in Sapindaceae

Phytochemical investigation on the aerial parts of Cardiospermum corindum L. led to the isolation of two triterpenes [friedelin (1) and friedelinol (2)], two coumarins, [umbelliferone (4) and scopoletin (5)], three methoxylated flavones [umuhengerin (3), luteolin 3’,4’-dimethyl ether (6) and chrysoeriol (7)], one non-cyanogenic glucoside [epidermin (8)] and one cyclitol [(L)-quebrachitol (9)]. To our knowledge, 2, 3, 6 and 8 were isolated for the first time within Sapindaceae. Of these classes of metabolites, the distribution of methoxylated flavonoids in Cardiospermum is reviewed, including the new records, indicating that polymethoxylated flavonoid (3) may be value as chemotaxonomic markers for this genus.     

The abrupt climate change at the Eocene–Oligocene boundary and the emergence of South-East Asia triggered the spread of sapindaceous lineages

Background and Aims

Paleoclimatic data indicate that an abrupt climate change occurred at the Eocene–Oligocene (E–O) boundary affecting the distribution of tropical forests on Earth. The same period has seen the emergence of South-East (SE) Asia, caused by the collision of the Eurasian and Australian plates. How the combination of these climatic and geomorphological factors affected the spatio-temporal history of angiosperms is little known. This topic is investigated by using the worldwide sapindaceous clade as a case study.

Methods

Analyses of divergence time inference, diversification and biogeography (constrained by paleogeography) are applied to a combined plastid and nuclear DNA sequence data set. Biogeographical and diversification analyses are performed over a set of trees to take phylogenetic and dating uncertainty into account. Results are analysed in the context of past climatic fluctuations.

Key Results

An increase in the number of dispersal events at the E–O boundary is recorded, which intensified during the Miocene. This pattern is associated with a higher rate in the emergence of new genera. These results are discussed in light of the geomorphological importance of SE Asia, which acted as a tropical bridge allowing multiple contacts between areas and additional speciation across landmasses derived from Laurasia and Gondwana.

Conclusions

This study demonstrates the importance of the combined effect of geomorphological (the emergence of most islands in SE Asia approx. 30 million years ago) and climatic (the dramatic E–O climate change that shifted the tropical belt and reduced sea levels) factors in shaping species distribution within the sapindaceous clade.     

Gender expression and inflorescence structure of Pappea capensis Eckl. and Zeyh. (Sapindaceae)

Gender and the structure of the inflorescence and flowers of Pappea capensis (Sapindaceae) are investigated in a locality around Pretoria (22-27°S and 25-32°E). The trees flower over a long period (December to April) and are basically monoecious, starting with male flowers followed by female flowers towards the end of the flowering period, although some trees may be predominantly male and some predominantly female. The inflorescence is a reduced thyrse with small flowers. Male flowers have five ephemeral petals, eight stamens and a rudimental pistil. Female flowers comprise a 3-lobed ovary, a single style and stigma and eight staminodes.     

A new cycloartane-type triterpene and a new eicosanoic acid ester from fruits of Paullinia pinnata L.

A phytochemical study of the MeOH-soluble portion from the CH₂Cl₂/MeOH extract of the fruits of Paullinia pinnata resulted in the isolation of a new triterpenoid, cyclopinnatol (1), and a new eicosanoic acid ester, paulliniester (2), together with five known compounds including cycloart-22(E)-ene-3β,25-diol (3), cycloartenol (4), β-sitosterol (5), betulonic acid (6) and oleanonic acid (7). The structures of the new compounds were elucidated by spectroscopic analyses (NMR and MS) and comparisons with published data. Cyclopinnatol (1) and the MeOH-soluble portion exhibited significant and weak antibacterial activities against Staphylococcus aureus, with MICs of 32 and 50 μg/mL, respectively.     

Determination of cyanolipids in seed oils of the sapindaceae by means of their NMR spectra

Analysis of the NMR spectra has been developed as a method for the measurement of the type and amount of cyanolipids in seed oils. The cyanolipids of 6 species of Sapindaceae are reported.     

A species well travelled – the Dodonaea viscosa (Sapindaceae) complex based on phylogenetic analyses of nuclear ribosomal ITS and ETSf sequences

Aim To determine the evolutionary history of the widely studied, cosmopolitan polymorphic species Dodonaea viscosa (hop bush, varnish tree). Location All continents except Antarctica, extending from 44° S (in the South Island of New Zealand) to 33° N (in California and Arizona). Methods For 50 samples across the worldwide distribution, Bayesian analyses of nuclear ribosomal transcribed spacers (ITS 1, ITS 2 and partial ETS) were performed. The alignment was partitioned by secondary structure and analysed using separate models of sequence evolution for each spacer’s stem and loop partition. Bayesian relaxed‐clock estimations of divergence times were used to investigate the tempo of the transoceanic dispersal history of Dodonaea viscosa. Results The widely distributed Dodonaea viscosa evolved in Australia from its most recent common ancestor in the Late Pliocene to Early Pleistocene and subsequently split into two distinct, geographically based, intraspecific lineages. There are a number of regional subclades that are also supported by specific molecular elements. Main conclusions Dodonaea viscosa is not an old lineage, as has often been speculated based primarily on its vast distribution. It diverged from its most recent common ancestor and subsequently dispersed and established around the world within the last 2 Myr. Two distinct lineages within Dodonaea viscosa, which have been shaped by Quaternary climatic change, have separate dispersal histories. The molecular investigations have identified that, although there are least two evolutionary lineages within the complex, they do not correlate with any distinct morphological subunits. It is proposed that Dodonaea viscosa (including D. biloba and D. procumbens) be recognized as an ochlospecies.     

GENETIC DIFFERENTIATION OF FITNESS-ASSOCIATED TRAITS AMONG RAPIDLY EVOLVING POPULATIONS OF THE SOAPBERRY BUG

In this study we used reciprocal rearing experiments to test the hypothesis that there is a genetic basis for the adaptive differences in host-use traits among host-associated soapberry bug populations (described in Carroll and Boyd 1992). These experiments were conducted on two host races from Florida, in which differences in beak length and development were found between natural populations on a native host plant species and those on a recently introduced plant species (colonized mainly post-1950). Performance was generally superior on the host species from which each lab population originated (i.e., on the “Home” host species): in analysis of variance, there was significant population-by-host interaction for size, development time, and growth rate. These results indicate that the population differences in nature are evolved rather than host induced. Increased performance on the introduced host was accompanied by reduced performance on the native host, a pattern that could theoretically promote further differentiation between the host races.     

Chemical Composition of Magonia pubescens Essential Oils and Gamma-Radiation Effects on Its Constituents and Cytotoxic Activity in Leukemia and Breast Cancer Model

Magonia pubescens A. St.-Hil. is a Brazilian species often used in ethnopharmacology for wound and pain healing and seborrhea treatment. For the first time, essential oils (EOs) obtained from M. pubescens inflorescences were studied. The plant materials (Montes Claros, Brazil, 2018) were submitted to different gamma-radiation doses and their chemical compositions were analyzed by GC/MS and GC-FID. The cytotoxic activity of the EOs was evaluated against K562 and MDA-MB-231 cancer cell lines. A total of 30 components were identified, being 24 compounds detected for the first time in M. pubescens. The main obtained components were hotrienol (35.9 %), cis-linalool oxide (17.0 %) and trans-linalool oxide (10.2 %). The chemical composition of the EO was slightly affected by the applied radiation doses. Irradiated and non-irradiated EOs showed cytotoxic activity against both cell lines and the non-irradiated EO sample was the most active against the K562 cell lines (IC₅₀=22.10±1.98).