Search Results (5)

The recently developed phenoplast-related polymer, poly(benzofuran-co-arylacetic acid), presents a versatile molecular structure containing lactone and carboxylic acid functionalities that offer significant flexibility in creating cured materials with tailored properties for diverse applications, wherein also the thermal conductivity is an important factor. This study analyses the possibility of forming amide moieties of poly(benzofuran-co-arylacetic acid) with diamines resulting in cross-linked products in order to control its thermal properties. The cross-linking process is achieved by utilizing three distinct diamines, 1,6-diaminohexane, p-xylylenediamine, and 4,7,10-trioxa-1,13-tridecanediamine, each possessing different degrees of polarity, flexibility, and reactivity. The resulting cross-linked zwitterionic poly(benzofuran-co-arylacetic acids) were structurally and morphologically characterized. By means of measuring the thermal conductivity and diffusivity of the materials, the possibility of adjusting the thermal properties of the cross-linked products by choosing appropriate linkers was determined. A case was developed where the thermal conductivity and diffusivity increased with temperature, a hardly found property in the cross-linking of polymers being important for many practical applications. Full article

This study investigated the chemical phenotypical variability of Piper lhotzkyanum Kunth (Piperaceae), a shrub found in Brazilian tropical forests, over time (different periods of the day and seasons) and under natural conditions. For this, essential oils (EOs) from the leaves were collected in different seasons and times of the day and analyzed by gas chromatography coupled with mass spectrometry, and gas chromatography coupled with a flame ionization detector. The indices were applied to evaluate the chemical diversity as well as the dynamics of redox of the mixtures. The results showed that the EOs were dominated by non-oxygenated sesquiterpenes, with β-elemene, E-caryophyllene, and α-zingiberene being the main compounds identified in all collections. Temporal and seasonal analyses revealed important fluctuations in the chemical composition, redox, and chemical diversity indices of the species. A correlation between climatic factors and the variation in redox and chemical diversity was observed, highlighting the chemical phenotypic plasticity P. lhotzkyanum. This study resolves a previously unanswered question by confirming that natural light does not produce interconversion of major compounds. The adaptation capacity of this species to the environmental changes suggests new cultivation strategies to maximize the quality of EO and promote a more sustainable future in partnership with nature. Full article

Lamium amplexicaule L. (Family: Lamiaceae) is a cosmopolitan weed whose eradication is challenging. The phenoplasticity of this species is related to its heteroblastic inflorescence, which has not received adequate research worldwide in its morphological and genetic aspects. This inflorescence hosts two flower types, a cleistogamous (CL: closed flower) and a chasmogamous (CH: opened flower). This species subjected to detailed investigation is a model species to clarify: (1) the existence of the CL and CH flowers in relation to the time and individual plants. (2) the predominant flower morphs in Egypt. (3) the morphological and genetic variability between these morphs. Among the novel data retrieved from this work is the Presence of this species in three distinct morphs coexisting during winter. These morphs showed remarkable phenoplasticity, particularly in flower organs. Significant differences were observed between the three morphs in pollen fertility, nutlets productivity and sculpture, flowering time, and seed viability. These differences were extended to the genetic profile of these three morphs assessed by the inter simple sequence repeats (ISSRs) and start codon targeted (SCoT). This work highlights the urgent need to study the heteroblastic inflorescence of crop weeds to facilitate its eradication. Full article

This study tested the hypothesis that “clonal chemical heritability is a crucial factor for the conservation of chemical uniformity of Piper essential oils in controlled monoclonal cultivation”. We asexually propagated first and second-generation clones of two medicinal and aromatic species, Piper gaudichaudianum Kunth and Piper mollicomum Kunth (Piperaceae), for use as experimental models since they show high chemical plasticity in the wild. Leaves from wild specimens of both species, and their respective cultivated specimens, were hydrodistilled in a Clevenger-type apparatus to produce essential oils (EOs). EOs were chemically characterised by GC-MS and GC-FID. The analysis identified 63 compounds in EO of P. mollicomum, which were predominantly monoterpenes, and 59 in EO of P. gaudichaudianum, which were predominantly sesquiterpenes. Evaluation of chemical diversity and oxi-reduction indices showed a loss of chemical homology across the intergenerational cline. Chemometric analysis indicated higher chemical plasticity between wild and intergenerational specimens of P. mollicomum, than for P. gaudichaudianum. EO compounds were significantly less oxidized throughout the generations in both species. Therefore, while clonal heritability is crucial to chemical homology, significant chemical plasticity is likely to occur when cultivated from wild specimens. Full article

The highly aromatic Australian mint bushes from the genus Prostanthera Labill. produce a high yield of essential oil on hydrodistillation. Together with its rich history, horticultural potential, iconic flowers, and aromatic leaves, it achieves high ornamental and culinary value. Species in the genus express highly diverse and chemically unique essential oils that demonstrate intra- and inter-specific patterns that have inspired taxonomic reinterpretation for over a hundred years. Previous studies have conveyed that phenoplastic expression of volatiles creates chemotypes within taxa, adding complexity to chemophenetic exploration. The current study chemically characterised essential oils from 64 highly aromatic specimens, representative of 25 taxa, giving yields as high as >2% g/g. The chemical profiles of essential oils are diverse, but generally include 1,8-cineole and signatory compounds such as sesquiterpene oxides, caryophyllene oxide, kessane and cis-dihydroagarofuran; sesquiterpene alcohols, globulol, epiglobulol, maaliol, prostantherol, spathulenol and ledol; and monoterpene derivatives of common scaffolds, borneol, bornyl acetate, bornanone, linalool and linalyl acetate. As in previous studies, analysis of chemical data confirms that the chemistry strongly agrees with taxonomic classifications. Importantly, as in classical taxonomy, the current chemical study complemented morphological analysis but conveys chemovariation, obscuring the taxonomic agreement. Nevertheless, variation within taxa may be due to environmental factors, meaning that cultivation of species in gardens will create different chemical profiles as compared to those published here. Full article