Presence of Inulin-Type Fructo-Oligosaccharides and Shift from Raffinose Family Oligosaccharide to Fructan Metabolism in Leaves of Boxtree (Buxus sempervirens)

Pharmacological and phytochemical properties of the genus Buxus: A review

BACKGROUND

Buxus plants have been used in traditional medicine for a very long time. The Buxus genus has been used to cure a variety of illnesses.

OBJECTIVE

This review aimed to provide a literature review on the genus Buxus including its biological and phytochemical properties.

MATERIALS AND METHODS

The current study was conducted using several scientific databases. Correct plant names were verified from plantlist.org. The results of this search were interpreted, analyzed, and documented based on the obtained bibliographic information.

RESULTS

Within all the species of the family Buxaceae, 5 species of the genus Buxus are reported to be antibacterial, 3 species have been found to be antioxidant, 5 species are cytotoxic, 1 species is anti-inflammatory, 1 species is antidiabetic, and 4 species are antifungal. Alkaloids, terpenoids, tannins, flavonoids, peptides, and phenolic compounds are the main chemical components of this genus. The study of >11 Buxuss pecies has identified >201 compounds. Pharmacological research has demonstrated that crude extracts and some pure compounds obtained from Buxus have several pharmacological activities such as antibacterial, antioxidant, cytotoxic, anti-inflammatory, antidiabetic, and antifungal. Based on the study of the phytochemistry of Buxus species, it was concluded that all the studied plants have active compounds, among which 55 molecules showed interesting activities.

CONCLUSIONS

The numerous traditional uses of Buxus species have been supported by several studies. Before Buxus plants can be fully employed clinically, further research is necessary.

Comparative metabolomics reveals how the severity of predation by the invasive insect Cydalima perspectalis modulates the metabolism re-orchestration of native Buxus sempervirens

The recent biological invasion of box tree moth Cydalima perspectalis on Buxus trees has a major impact on European boxwood stands through severe defoliation. This can hinder further regrowth and threaten survival of populations. In a mesocosm approach and controlled larval density over a 2-month period, responses of B. sempervirens essential and specialized metabolites were characterized using metabolomics, combining 1H-NMR and LC-MS/MS approaches. This is the first metabolome depiction of major Buxus responses to boxwood moth invasion. Under severe predation, remaining green leaves accumulate free amino acids (with the noticeable exception of proline). The leaf trans-4-hydroxystachydrine and stachydrine reached 10-13% and 2-3% (DW), while root content was lower but also modulated by predation level. Larval predation promoted triterpenoid and (steroidal) alkaloid synthesis and diversification, while flavonoids did not seem to have a relevant role in Buxus resistance. Our results reveal the concomitant responses of central and specialized metabolism, in relation to severity of predation. They also confirm the potential of metabolic profiling using 1H-NMR and LC-MS to detect re-orchestration of metabolism of native boxwood after severe herbivorous predation by the invasive box-tree moth, and thus their relevance for plant-insect relationships and ecometabolomics.

Application of ATR-FTIR spectroscopy for profiling of non-structural carbohydrates in onion (Allium cepa L.) bulbs

Qualitative and quantitative composition of non-structural carbohydrates comprising glucose, fructose, sucrose and fructooligosaccharides (FOS) is one of the key determinants of market suitability, storability and technological processability of onions. To develop a cost-effective and rapid tool for carbohydrate profiling, applicability of attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy of onion juice was investigated with special regard to FOS patterns. As reference, detailed carbohydrate profiles of onion juices were generated by high-performance liquid chromatography coupled with evaporative light scattering detection (HPLC-ELSD). Hierarchical cluster analysis (HCA) of ATR-FTIR spectra was successfully applied for classifying onions into fresh market, storage and dehydrator type according to HPLC-ELSD profiles. A bootstrapping method for automatized test-set validation by projection to latent structures (PLS) algorithms using HPLC and ATR-FTIR spectroscopy data was developed. Model statistics showed promising perspectives for reliable quantification of individual saccharides and sum parameters. The presented methodology allows estimating the nutritional and pre-biotic value directly during cultivation and processing.

Chemical Structure and Localization of Levan, the Predominant Fructan Type in Underground Systems of Gomphrena marginata (Amaranthaceae)

Gomphrena marginata Seub. (Amaranthaceae) is an endemic species from Brazilian campos rupestres with a fructan accumulating underground reserve system. Analyses of high performance anion exchange chromatography (HPAEC-PAD) revealed the presence of the soluble carbohydrates glucose, fructose, sucrose, 1-kestose, 6-kestose, nystose and fructans with degree of polymerization (DP) up to approximately 40 fructose units. Data of ¹H and ¹³C Nuclear Magnetic Resonance (NMR) spectroscopy, including Heteronuclear Single-Quantum Correlation (HSQC) and Heteronuclear Multiple-Bonds Correlation (HMBC) showed the presence of β (2,6) linkages, characteristic of the linear molecule of levan-type fructan(2,6). These results confirmed previous studies suggesting that the reserve carbohydrate in the underground system of this species was levan-type fructans, similar to that of G. macrocephala. Structural analyses of the thickened underground system using light microscopy revealed a mixed origin system consisting mainly of a gemmiferous tuberous root with the upper region formed by short branched stems, both presenting vascular cylinders with unusual growth patterns. Fructan spherocrystals were visualized under polarized light and scanning electron microscopy (SEM) mostly in the cortex and vascular cylinder in both thickened stem and root. In addition to data reported in the literature concerning the occurrence of fructans in the Amaranthaceae, the results presented here suggest that fructans are a trait in this family while the levan-type fructan prevail in Gomphrena species.

The fructan syndrome: Evolutionary aspects and common themes among plants and microbes

Fructans are multifunctional fructose-based water soluble carbohydrates found in all biological kingdoms but not in animals. Most research has focused on plant and microbial fructans and has received a growing interest because of their practical applications. Nevertheless, the origin of fructan production, the so-called "fructan syndrome," is still unknown. Why fructans only occur in a limited number of plant and microbial species remains unclear. In this review, we provide an overview of plant and microbial fructan research with a focus on fructans as an adaptation to the environment and their role in (a)biotic stress tolerance. The taxonomical and biogeographical distribution of fructans in both kingdoms is discussed and linked (where possible) to environmental factors. Overall, the fructan syndrome may be related to water scarcity and differences in physicochemical properties, for instance, water retaining characteristics, at least partially explain why different fructan types with different branching levels are found in different species. Although a close correlation between environmental stresses and fructan production is quite clear in plants, this link seems to be missing in microbes. We hypothesize that this can be at least partially explained by differential evolutionary timeframes for plants and microbes, combined with potential redundancy effects.