Comparative genomic analysis of the Growth-Regulating Factors-Interacting Factors (GIFs) in six Salicaceae species and functional analysis of PeGIF3 reveals their regulatory role in Populus heteromorphic leaves.

BACKGROUND: The growth-regulating factor-interacting factor (GIF) gene family plays a vital role in regulating plant growth and development, particularly in controlling leaf, seed, and root meristem homeostasis. However, the regulatory mechanism of heteromorphic leaves by GIF genes in Populus euphratica as an important adaptative trait of heteromorphic leaves in response to desert environment remains unknown. RESULTS: This study aimed to identify and characterize the GIF genes in P. euphratica and other five Salicaceae species to investigate their role in regulating heteromorphic leaf development. A total of 27 GIF genes were identified and characterized across six Salicaceae species (P. euphratica, Populus pruinose, Populus deltoides, Populus trichocarpa, Salix sinopurpurea, and Salix suchowensis) at the genome-wide level. Comparative genomic analysis among these species suggested that the expansion of GIFs may be derived from the specific Salicaceae whole-genome duplication event after their divergence from Arabidopsis thaliana. Furthermore, the expression data of PeGIFs in heteromorphic leaves, combined with functional information on GIF genes in Arabidopsis, indicated the role of PeGIFs in regulating the leaf development of P. euphratica, especially PeGIFs containing several cis-acting elements associated with plant growth and development. By heterologous expression of the PeGIF3 gene in wild-type plants (Col-0) and atgif1 mutant of A. thaliana, a significant difference in leaf expansion along the medial-lateral axis, and an increased number of leaf cells, were observed between the overexpressed plants and the wild type. CONCLUSION: PeGIF3 enhances leaf cell proliferation, thereby resulting in the expansion of the central-lateral region of the leaf. The findings not only provide global insights into the evolutionary features of Salicaceae GIFs but also reveal the regulatory mechanism of PeGIF3 in heteromorphic leaves of P. euphratica.

The Idesia polycarpa genome provides insights into its evolution and oil biosynthesis.

The deciduous tree Idesia polycarpa can provide premium edible oil with high polyunsaturated fatty acid contents. Here, we generate its high-quality reference genome, which is ∼1.21 Gb, comprising 21 pseudochromosomes and 42,086 protein-coding genes. Phylogenetic and genomic synteny analyses show that it diverged with Populus trichocarpa about 16.28 million years ago. Notably, most fatty acid biosynthesis genes are not only increased in number in its genome but are also highly expressed in the fruits. Moreover, we identify, through genome-wide association analysis and RNA sequencing, the I. polycarpa SUGAR TRANSPORTER 5 (IpSTP5) gene as a positive regulator of high oil accumulation in the fruits. Silencing of IpSTP5 by virus-induced gene silencing causes a significant reduction of oil content in the fruits, suggesting it has the potential to be used as a molecular marker to breed the high-oil-content cultivars. Our results collectively lay the foundation for breeding the elite cultivars of I. polycarpa.

Genome-wide identification and expression analysis of xyloglucan endotransglucosylase/hydrolase genes family in Salicaceae during grafting.

BACKGROUND: Poplar (Populus cathayana)and willow (Salix rehderiana) are important fast-growing trees in China. Grafting plays an important role in improving plant stress resistance and construction of ornamental plants. It is found that willow scions grafted onto poplar rootstocks can form ornamental plants. However, this grafted combination has a low survival rate. Many studies have reported that the xyloglucan endotransglucosylase/hydrolase (XTH) family plays an important role in the healing process of grafts. RESULTS: A total of 38 PtrXTHs and 32 SpuXTHs were identified in poplar and willow respectively, and were classified into three subfamilies. Tandem duplication was the main reason for the expansion of the PtrXTHs. Grafting treatment and Quantitative real time PCR (RT-qPCR) analysis revealed that five XTH genes differentially expressed between self-grafted and reciprocal grafted combinations. Specifically, the high expression levels of SrXTH16, SrXTH17, SrXTH25, PcXTH22 and PcXTH17 may contribute to the high survival rate of the grafted combination with willow scion and poplar rootstock. Subcellular localization identified that the SrXTH16, SrXTH17, SrXTH25, PcXTH17 and PcXTH22 proteins were located on the cell walls. Transcription factors (NAC, MYB and DOF) may regulate the five XTH genes. CONCLUSIONS: This study provides a new understanding of the roles of PcXTH and SrXTH genes and their roles in grafting. Our results will give some hints to explore the molecular mechanisms of PcXTH and SrXTH genes involved in grafting in the future.

Effect of cornstalk biochar on phytoremediation of Pb-contaminated soil by females and males of Populus deltoides (Salicaceae).

Soil pollution with lead (Pb) has become a serious global concern, adversely affecting the forest ecosystem. This study was conducted to investigate the effects of corn straw on the remediation efficiency of Pb-contaminated soil using Populus deltoides. Female and male P. deltoides cuttings were subjected to soil spiked with 900 mg kg-1 Pb and amended with 5% (v/v) corn straw biochar for 90 days. Under Pb stress, the addition of biochar significantly increased the total biomass accumulation by 29% in females and 26% in males. However, without the addition of biochar, the biomass accumulation was significantly reduced by 11% in females and 3% in males under Pb stress. Females showed a higher uptake and accumulation of Pb in roots and leaves, while males accumulated more Pb in roots and stems and exhibited an increased anti-oxidative capacity. Biochar addition alleviated Pb toxicity in both male and female P. deltoides by immobilizing Pb ion in the soil, reducing Pb uptake and translocation, promoting nutrient uptake, and improving the diversity and stability of the soil bacteria community. Under Pb stress, the relative abundances of metal-resistance bacteria significantly increased, such as the abundance of Bacteroidetes in females and the abundances of Actinobacteria, Firmicutes, and Planctomycetes in males. In brief, the males under biochar addition exhibited promising potential as candidates for phytoremediation of Pb-contaminated soil. This study provides new insights into mechanisms underlying sexually differential responses to Pb stress in the presence of biochar amendment.

Bioactive constituents from Flacourtia vogelii Hook.f. (Flacourtiaceae).

The chemical investigation of the methanolic root extract of Flacourtia vogelii led to the isolation of a new arylbenzoate derivative, vogelinal (1), together with thirteen known compounds (2-14). The structures of the isolates were elucidated by extensive spectroscopic and spectrometric analyses (1D and 2D NMR, ESI-MS) and by comparison with previously reported data. All the compounds were tested for their antioxidant, antifungal and antibacterial activities. Compound 7 exhibited the highest antioxidant potential, with RSa50of 11.80 ± 2.13 µg/mL, RSa50of 42.60 ± 6.32 µg/mL and RC50 of 51.60 ± 7.71 µg/mL for the DPPH, ABTS and FRAP assay, respectively. Compound 13 displayed weak antifungal effect with MIC value of 125 µg/mL against Candida parapsilosis. Compound 8 showed weak antibacterial effect with MIC value of 125 µg/mL, against Shigella dysenteria. The present study, conclude that this species could be a promising source of antioxidant and antibacterial constituents.

A comprehensive study on physicochemical properties, bioactive compounds, and emulsified lipid digestion characteristics of Idesia polycarpa var. Vestita Diels fruits oil.

Idesia polycarpa var. vestita Diels fruits oil (IPO) has the potential to broaden the availability of healthy vegetable oil and relieve pressure on the edible oil supply. In this study, we compared the physicochemical, bioactivity, and digestive properties of IPO, olive oil (OO), and soybean oil (SO) to comprehensively evaluate the edible potential of IPO. The results revealed no significant differences in relative density or refractive index among the three oils. IPO was rich in ß-sitosterol (366.74 mg/100 g), ß-tocopherol (8.42 mg/100 g), and α-tocopherol (37.10 mg/100 g). The digestive properties of IPO emulsion were investigated for the first time using in vitro simulated digestion. The IPO emulsion stood out regarding its free fatty acid release (88.03 %). Finally, the IPO emulsion released mainly unsaturated fatty acids and had a higher monoacylglycerol content. This study provides new insights into IPO as a high-quality edible vegetable oil.

The whole-genome assembly of an endangered Salicaceae species: Chosenia arbutifolia (Pall.) A. Skv.

BACKGROUND: As a fast-growing tree species, Chosenia arbutifolia has a unique but controversial taxonomic status in the family Salicaceae. Despite its importance as an industrial material, in ecological protection, and in landscaping, C. arbutifolia is seriously endangered in Northeast China because of artificial destruction and its low reproductive capability. RESULTS: To clarify its phylogenetic relationships with other Salicaceae species, we assembled a high-quality chromosome-level genome of C. arbutifolia using PacBio High-Fidelity reads and Hi-C sequencing data, with a total size of 338.93 Mb and contig N50 of 1.68 Mb. Repetitive sequences, which accounted for 42.34% of the assembly length, were identified. In total, 33,229 protein-coding genes and 11,474 small noncoding RNAs were predicted. Phylogenetic analysis suggested that C. arbutifolia and poplars diverged approximately 15.3 million years ago, and a large interchromosomal recombination between C. arbutifolia and other Salicaceae species was discovered. CONCLUSIONS: Our study provides insights into the genome architecture and systematic evolution of C. arbutifolia, as well as comprehensive information for germplasm protection and future functional genomic studies.

Evaluation of cultivars diversity and lipid composition properties of Idesia polycarpa var. vestita Diels.

Idesia polycarpa var. vestita Diels is a perennial deciduous tree widely distributed throughout China. Four I. polycarpa fruit of different cultivars with different fruit issues during the growth process were compared, which were on the basis of morphological characteristics and chemical compositions. The influencing factors of oil accumulation in I. polycarpa fruit and the correlation between different components were investigated, and the results revealed a negative correlation between oil content and total sugar (r = -0.930), ash (r = -0.606), and crude fiber (r = -0.952). Except for oil, none of the chemical components changed substantially during the growing phase, and most cultivars showed higher oil content in the pulp portion (14.14-43.99 g/100 g). Linoleic acid was the most abundant fatty acid in I. polycarpa oil (IPO), with values ranging from 52.18% to 66.65% (fruit), 55.44% to 65.15% (pulp), and 68.99% to 78.76% (seed). Principal component analysis revealed that Hubei varieties are more advantageous. Besides, the lipid composition of IPO was identified by ultrahigh-performance liquid chromatography coupled with electrospray ionization Q-Exactive Focus mass spectrometry. The glyceride components of IPO were mostly composed of 22 triacylglycerols, 30 diacylglycerols, and 8 monoacyglycerols. Meanwhile, linoleic acid was mainly distributed in sn-2 and sn-3 positions. PRACTICAL APPLICATION: Morphologic characteristics, chemical compositions, oil fatty acid profiles, and oil correlation factors of I. polycarpa were analyzed. The comprehensive score of oil quality by PCA in Hb fruit was the highest. The glyceride components of I. polycarpa oil were mainly composed of 22 triacylglycerols, 30 diacylglycerols, and eight monoacyglycerols.

Anticancer, antioxidant, antiviral and antimicrobial activities of Kei Apple (Dovyalis caffra) fruit.

Secondary plant metabolites remain one of the key sources of therapeutic agents despite the development of new approaches for the discovery of medicinal drugs. In the current study, chemical analysis, and biological activities of Kei apple (Dovyalis caffra) methanolic extract were evaluated. Chemical analysis was performed using HPLC and GC-MS. Antiviral and anticancer effect were assessed using the crystal violet technique and activity against human liver cells (HepG2), respectively. Antibacterial activity was tested with the disc diffusion method. The obtained results showed that chlorogenic acid (2107.96 ± 0.07 µg/g), catechin (168 ± 0.58 µg/g), and gallic acid (15.66 ± 0.02 µg/g) were the main bioactive compounds identified by HPLC techniques. While, compounds containing furan moieties, as well as levoglucosenone, isochiapin B, dotriacontane, 7-nonynoic acid and tert-hexadecanethiol, with different biological activities were identified by GC-MS. Additionally, inhibition of 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) scavenging was 79.25% at 2000 µg/mL, indicating its antioxidant activity with IC50 of 728.20 ± 1.04 µg/mL. The tested extract exhibited potential anticancer activity (58.90% toxicity) against HepG2 cells at 1000 µg/mL. Potential bacterial inhibition was observed mainly against Escherichia coli and Proteus vulgaris, followed by Staphylococcus aureus and Bacillus subtilis with a diameter of growth inhibition ranging from 13 to 24 mm. While weak activities were recorded for fungi Candida albicans (10 mm). The extract showed mild antiviral activity against human coronavirus 229E with a selective index (SI) of 10.4, but not against human H3N2 (SI of 0.67). The molecular docking study's energy ratings were in good promise with the experiment documents of antibacterial and antiviral activities. The findings suggest that D. caffra juice extract is a potential candidate for further experiments to assess its use as potential alternative therapeutic agent.

Extraction of Phenolic Compounds from Populus Salicaceae Bark.

Lignocellulosic residues have the potential for obtaining high value-added products that could be better valorized if biorefinery strategies are adopted. The debarking of short-rotation crops yields important amounts of residues that are currently underexploited as low-grade fuel and could be a renewable source of phenolic compounds and other important phytochemicals. The isolation of these compounds can be carried out by different methods, but for attaining an integral valorization of barks, a preliminary extraction step for phytochemicals should be included. Using optimized extraction methods based on Soxhlet extraction can be effective for the isolation of phenolic compounds with antioxidant properties. In this study, poplar bark (Populus Salicaceae) was used to obtain a series of extracts using five different solvents in a sequential extraction of 24 h each in a Soxhlet extractor. Selected solvents were put in contact with the bark sample raffinate following an increasing order of polarity: n-hexane, dichloromethane, ethyl acetate, methanol, and water. The oily residues of the extracts obtained after each extraction were further subjected to flash chromatography, and the fractions obtained were characterized by gas chromatography coupled with mass spectrometry (GC-MS). The total phenolic content (TPC) was determined using the Folin-Ciocalteu method, and the antioxidant activity (AOA) of the samples was evaluated in their reaction with the free radical 2,2-Diphenyl-picrylhydrazyl (DPPH method). Polar solvents allowed for higher individual extraction yields, with overall extraction yields at around 23% (dry, ash-free basis). Different compounds were identified, including hydrolyzable tannins, phenolic monomers such as catechol and vanillin, pentoses and hexoses, and other organic compounds such as long-chain alkanes, alcohols, and carboxylic acids, among others. An excellent correlation was found between TPC and antioxidant activity for the samples analyzed. The fractions obtained using methanol showed the highest phenolic content (608 µg of gallic acid equivalent (GAE)/mg) and the greatest antioxidant activity.

Synthesis, structural revision, and tyrosinase inhibitory activity of proposed phloretin-4-O-ß-D-glucopyranoside from Homalium stenophyllum.

Phloretin-4-O-ß-D-glucopyranoside (1), isolated from Homalium stenophyllum, was synthesized for the first time through aldol condensation and Schmidt glycosylation reactions aiming to develop a novel hydrophilic tyrosinase inhibitor. However, the specific rotation of synthetic 1 was found to be negative and different from that reported for natural product 1. Thus, L-glucoside 2 was chemically synthesized using the established synthetic route of 1, suggesting that the configuration of the natural product 1 was the same as that of 2, as their specific rotation and spectroscopic data were also the same. In addition, the evaluation of the inhibitory activity of 1 and 2 against tyrosinase indicated that 2 was 1.4 times more potent than 1, but they were both relatively weak. Therefore, the enantiomeric analogues 1 and 2 were proved to be unique tyrosinase inhibitors due to the chiral recognition from the tyrosinase active site.

Perspectives on Populus spp. (Salicaceae) bud extracts as antioxidant and anti-inflammatory agents.

Hydroalcoholic extracts obtained from buds of P. nigra, P. deltoides and P. trichocarpa were characterized by HPLC-DAD-MS analysis and subsequently evaluated in vitro for their antioxidant and anti-inflammatory activities. ABTS and DPPH assays evidenced that P. nigra showed the best antioxidant activity in line with its highest total phenolic content. The analysis of the anti-inflammatory activity clearly demonstrated that all extracts suppressed the production of key pro-inflammatory cytokines (IL-6, Il-1ß and TNF-α) and HMGB1 inflammatory danger signal. These results show antioxidant and critical anti-inflammatory activities mediated by the extracts, emphasising their potentiality as therapeutic agents.

Homalium zeylanicum attenuates streptozotocin-induced hyperglycemia and cellular stress in experimental rats via attenuation of oxidative stress imparts inflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: Homalium zeylanicum (Gardner) Benth (Salicaceae) leaves are being used as folklore medicine to treat diabetes by the local folk of Andhra Pradesh, India. The medicinal claim of this plant with hypoglycaemic effects was initially studied by the authors. Results demonstrated the important antioxidant activities of the hydroalcohol fraction of leaves of H. zeylanicum leaves (HAHZL) were positively correlated with phenols and flavonoids contents. AIM OF THE STUDY: Based on the previous findings, additional research is needed to examine the efficacy of using HAHZL to treat hyperglycemia. We therefore investigated in vitro and in vivo glycemic response of HAHZL, and evaluation of possible mechanism of bioactive molecules in mitigating streptozotocin-induced cellular stress in experimental rats via attenuation of oxidative stress imparts inflammation. METHODS: GC-MS/MS analysis of HAHZL was carried out to identify bioactive constituents. In vitro antidiabetic (α-glucosidase, α-amylase) and anti-inflammatory activities were investigated. HFD/low-STZ-prompted diabetic Wistar rats were administered with HAHZL (300 and 400 mg/kg; oral) for 28 days. Blood serum, oxidative stress, inflammation, DNA damage, and antidiabetic markers of pancreas and liver were determined. Histopathological studies of liver and pancreas were performed to assess the protective role of HAHZL. RESULTS: GC-MS/MS study revealed 7 bioactive compounds e.g., Phenol, 4-ethenyl-, acetate (28.68%), hydroquinone (9.10%), n-hexadecanoic acid (0.55%), phytol (0.57%), arbutin (17.65%), Vitamin E (1.04%), ß-Sitosterol (1.54%) which possess antioxidant, anti-inflammatory and anti-diabetic activities. HAHZL showed significant in vitro glycemic response as evidenced by the inhibition of α-amylase, and α-glucosidase activities. Lineweaver-Burk plot revealed that HAHZL exhibited competitive and mixed competitive inhibition towards α-amylase and α-glucosidase, respectively. HAHZL at 400 mg/kg modulated the pathophysiology associated with HFD/STZ-induced type2 diabetes mellitus and significantly (p < 0.001) improved antihyperglycemic (SG, SI, HOMA-IR, and HbA1C), antidyslipidemic (TC, HDL-C, LDL-C, and TG), antioxidative (MDA, SOD, CAT, GSH, and 8-OHdG) and anti-inflammatory (TNF-α, and CRP) markers in serum, pancreas and liver. In vitro and in vivo test results were corroborated by the improvement of pancreatic and hepatic tissue architecture in diabetic rats. CONCLUSION: HAHZL bearing bioactive components phenol, 4-ethenyl-,acetate, hydroquinone, n-hexadecanoic acid, arbutin, phytol, vitamin E and ß-sitosterol balanced glycemic level by normalising the levels of glycaemic indices, lipid profile, pancreas and liver functional markers in STZ-induced T2DM rats.

Frequent ploidy changes in Salicaceae indicates widespread sharing of the salicoid whole genome duplication by the relatives of Populus L. and Salix L.

BACKGROUNDS: Populus and Salix belong to Salicaceae and are used as models to investigate woody plant physiology. The variation of karyotype and nuclear DNA content can partly reflect the evolutionary history of the whole genome, and can provide critical information for understanding, predicting, and potentially ameliorating the woody plant traits. Therefore, it is essential to study the chromosome number (CN) and genome size in detail to provide information for revealing the evolutionary process of Salicaceae. RESULTS: In this study, we report the somatic CNs of seventeen species from eight genera in Salicaceae. Of these, CNs for twelve species and for five genera are reported for the first time. Among the three subfamilies of Salicaceae, the available data indicate CN in Samydoideae is n = 21, 22, 42. The only two genera, Dianyuea and Scyphostegia, in Scyphostegioideae respectively have n = 9 and 18. In Salicoideae, Populus, Salix and five genera closely related to them (Bennettiodendron, Idesia, Carrierea, Poliothyrsis, Itoa) are based on relatively high CNs from n = 19, 20, 21, 22 to n = 95 in Salix. However, the other genera of Salicoideae are mainly based on relatively low CNs of n = 9, 10, 11. The genome sizes of 35 taxa belonging to 14 genera of Salicaceae were estimated. Of these, the genome sizes of 12 genera and all taxa except Populus euphratica are first reported. Except for Dianyuea, Idesia and Bennettiodendron, all examined species have relatively small genome sizes of less than 1 pg, although polyploidization exists. CONCLUSIONS: The variation of CN and genome size across Salicaceae indicates frequent ploidy changes and a widespread sharing of the salicoid whole genome duplication (WGD) by the relatives of Populus and Salix. The shrinkage of genome size after WGD indicates massive loss of genomic components. The phylogenetic asymmetry in clade of Populus, Salix, and their close relatives suggests that there is a lag-time for the subsequent radiations after the salicoid WGD event. Our results provide useful data for studying the evolutionary events of Salicaceae.

Phenyl glycosides from the leaves of Flacourtia indica (Burm. f.) Merr (Salicaceae).

Thirteen phenolic glycosides, together with fourteen various known compounds, were isolated from the methanolic extract of leaves of Flacourtia indica. Twelve of these were composed of gentisyl or salicyl alcohols, glycosylated on the phenol and acylated on the primary alcohol with various more or less oxidized forms of pyrocatechuic acid. A number of positions on the glucose or on the acid were further acylated by benzoic or cinnamic acid. In addition to these, a glucoside of a phenyl propanoid was also isolated. The gross structures were elucidated by spectroscopic means including 1D and 2D NMR experiments and HR-ESI-MS analyses. Several of these structures, for example, xylosmin, were previously described but it proved extremely difficult to conclude on their exact identity with the absence of clear data on absolute configuration in the literature.

Chloroplast genomes in Populus (Salicaceae): comparisons from an intensively sampled genus reveal dynamic patterns of evolution.

The chloroplast is one of two organelles containing a separate genome that codes for essential and distinct cellular functions such as photosynthesis. Given the importance of chloroplasts in plant metabolism, the genomic architecture and gene content have been strongly conserved through long periods of time and as such are useful molecular tools for evolutionary inferences. At present, complete chloroplast genomes from over 4000 species have been deposited into publicly accessible databases. Despite the large number of complete chloroplast genomes, comprehensive analyses regarding genome architecture and gene content have not been conducted for many lineages with complete species sampling. In this study, we employed the genus Populus to assess how more comprehensively sampled chloroplast genome analyses can be used in understanding chloroplast evolution in a broadly studied lineage of angiosperms. We conducted comparative analyses across Populus in order to elucidate variation in key genome features such as genome size, gene number, gene content, repeat type and number, SSR (Simple Sequence Repeat) abundance, and boundary positioning between the four main units of the genome. We found that some genome annotations were variable across the genus owing in part from errors in assembly or data checking and from this provided corrected annotations. We also employed complete chloroplast genomes for phylogenetic analyses including the dating of divergence times throughout the genus. Lastly, we utilized re-sequencing data to describe the variations of pan-chloroplast genomes at the population level for P. euphratica. The analyses used in this paper provide a blueprint for the types of analyses that can be conducted with publicly available chloroplast genomes as well as methods for building upon existing datasets to improve evolutionary inference.

Phenolic glycosides from the stems of Homalium stenophyllum.

The phytochemical investigation of the stems of Homalium stenophyllum afforded seven new phenolic glycosides (1-5 and 8-9) and two known compounds (6 and 7). Their structures were elucidated by comprehensive analyses of NMR spectroscopic, mass spectrometric data and chemical hydrolysis. Additionally, their anti-inflammatory activities against the NO production in LPS-induced macrophages were evaluated.

Relationships between topographic factors, soil and plant communities in a dry Afromontane forest patches of Northwestern Ethiopia.

Plant community types are influenced by topographic factors, the physical and chemical properties of soil. Therefore, the study was carried out to investigate the relationships of soil and topographic factors on the distribution of species and plant community formation of the Dega Damot district in Northwestern Ethiopia. Vegetation and environmental data were collected from 86 plots (900 m2). Agglomerative hierarchical cluster analysis and redundancy analysis (RDA) with R software were used to identify plant communities and analyze the relationship between plant community types and environmental variables. Five plant community types were identified: Erica arborea-Osyris quadripartita, Discopodium penninervium-Echinops pappii, Olea europaea -Scolopia theifolia, Euphorbia abyssinica-Prunus africana, Dodonaea anguistifolia-Acokanthera schimperi. The RDA result showed that the variation of species distribution and plant community formation were significantly related to altitude, organic matter, moisture content, slope, sand, pH, EC, total nitrogen and phosphorus. Our results suggest that the variation of plant communities (Community 1, 2, 3, and 4) were closely related to environmental factors, including altitude, moisture content, OM, slope, sand, pH, EC, soil nitrogen, and phosphorus, among which altitude was the most important one. However, all the measured environmental variables are not correlated to Dodonaea anguistifolia-Acokanthera schimperi community type. Therefore, it can be concluded that some other environmental variables may influence the species composition, which is needed to be further investigated.

Identification of flavonoid-3-O-glycosides from leaves of Casearia arborea (Salicaceae) by UHPLC-DAD-ESI-HRMS/MS combined with molecular networking and NMR.

INTRODUCTION: Casearia is an essential source of cytotoxic highly oxidised clerodane diterpenes, in addition to phenolics, flavonoids, and glycoside derivatives. Here we identify flavonoid-3-O-glycoside derivatives in the ethyl acetate (EtOAc) fraction of the methanolic extract from leaves C. arborea leaves. OBJECTIVE: To characterise the EtOAc phase from the methanolic extract of C. arborea leaves using ultra-high-performance liquid chromatography diode array detector high-resolution tandem mass spectrometry (UHPLC-DAD-HRMS/MS) and molecular networking-based dereplication. Methodology We identified compounds not annotated in the GNPS platform by co-injection of standards in HPLC-DAD or by isolation and characterisation of the metabolites using nuclear magnetic resonance (NMR) spectroscopy. A workflow on the GNPS platform aided the organisation of spectral data and dereplication by annotations. We subjected the EtOAc phase to HPLC-DAD analysis using standard compound co-injection to corroborate the GNPS annotations. We isolated unidentified compounds with semi-preparative HPLC-DAD for structural identification using NMR. RESULTS: We annotated a molecular family of flavonoid-3-O-glycosides in the molecular networking created using the GNPS platform. These included avicularin, cacticin, isoquercitrin, quercitrin, rutin, and a quercetin-3-O-pentoside cluster. We confirmed the annotations with standard compounds using HPLC-DAD co-injection analysis, besides identifying quercetin-3-O-robinobioside and kaempferol. We isolated three flavonoid-3-O-pentosides and characterised them using one- and two-dimensional NMR; we identified them as reynoutrin, guaijaverin, and avicularin. CONCLUSION: This work describes the isolation of kaempferol and nine known flavonoid-3-O-glycosides from the polar fraction of the methanolic extract (EtOAc) from C. arborea leaves using molecular networking to guide the chromatographic procedures. We identified eight compounds for the first time in Casearia that amplify and reinforce the genus' chemotaxonomy with the presence of glycosylated flavonoids.

Effect of alcoholic and acetous fermentations on the phenolic acids of Kei-apple (Dovyalis caffra L.) fruit.

BACKGROUND: The Kei apple is a tree found on the African continent. Limited information exists on the effect of alcoholic and acetous fermentation on the phytochemicals of Kei apple. The fruit has increased concentrations of l-malic, ascorbic, and phenolic acids among other compounds. Juice was co-inoculated with Schizosaccharomyces pombe (Sp) and Saccharomyces cerevisiae (Sc) to induce alcoholic fermentation (AF). Acetous fermentation followed AF, using an acetic acid bacteria (AAB) consortium. RESULTS: Saccharomyces cerevisiae + Sp wines and vinegars had the highest pH. Total acidity, soluble solids and l-malic acid decreased during AF and acetous fermentation, and was highest in Sc wines and vinegars. Volatile acidity (VA) concentration was highest in Sp vinegars but was not significantly different from Sc and Sc + Sp vinegars. Gallic acid was highest in Sp wines and vinegars, whereas syringic acid was highest in Sc wines and vinegars. The Sc + Sp wines were highest in caffeic, p-coumaric, and protocatechuic acids. Schizosaccharomyces pombe vinegars were highest in caffeic and p-coumaric acids. Highest concentrations of ferulic and sinapic acids were found in Sp and Sc wines, respectively. Chlorogenic acid was most abundant phenolic acid in both wines and vinegars. CONCLUSION: Saccharomyces cerevisiae + Sp and Sc fermentation had a positive effect on most phenolic acids; Sc + AAB had an increased effect on syringic and chlorogenic acids, whereas Sp + AAB resulted in an increase in gallic, caffeic, and p-coumaric acids. The AAB selected had minimal performance with respect to VA production in comparison to commercial vinegars. Acetic acid bacteria selection for acetous fermentation should therefore be reconsidered and the decrease of certain phenolic acids during acetous fermentation needs to be investigated. © 2021 Society of Chemical Industry.