Species Of Celastraceae Research Articles

Microtropis gulinqingensis, a new dioecious species of Celastraceae from China

A new species of Celastraceae, Microtropis gulinqingensis, is discovered in the dynamic plot of Gulinqing Provincial Nature Reserve, Yunnan Province, China. After two-year observations of 65 individual plants in the field, we found that this species presented unique traits of being dioecious and having highly connate petals in its male flowers. We compared it with similar species and those in Microtropis distributed across the adjacent regions, and the morphological evidence supports the recognition of Microtropis gulinqingensis as a new species. A comprehensive description and photographs of this new species are provided.

Exploring the Anticancer Potential of Phenolic nor-Triterpenes from Celastraceae Species.

To explore new compounds with antitumour activity, fifteen phenolic nor-tripterpenes isolated from Celastraceae species, Maytenus jelskii, Maytenus cuzcoina, and Celastrus vulcanicola, have been studied. Their chemical structures were elucidated through spectroscopic and spectrometric techniques, resulting in the identification of three novel chemical compounds. Evaluation on human tumour cell lines (A549 and SW1573, non-small cell lung; HBL-100 and T-47D, breast; HeLa, cervix, and WiDr, colon) revealed that three compounds, named 6-oxo-pristimerol, demethyl-zeylasteral, and zeylasteral, exhibited significant activity (GI50 ranging from 0.45 to 8.6 µM) on at least five of the cell lines tested. Continuous live cell imaging identified apoptosis as the mode of action of selective cell killing in HeLa cells. Furthermore, their effect on a drug-sensitive Saccharomyces cerevisiae strain has been investigated to deepen on their mechanism of action. In dose-response growth curves, zeylasteral and 7α-hydroxy-blepharodol were markedly active. Additionally, halo assays were conducted to assess the involvement of oxidative stress and/or mitochondrial function in the anticancer profile, ruling out these modes of action for the active compounds. Finally, we also delve into the structure-activity relationship, providing insights into how the molecular structure of these compounds influences their biological activity. This comprehensive analysis enhances our understanding of the therapeutic potential of this triterpene type and underscores its relevance for further research in this field.

Salvadoran Celastraceae Species as a Source of Antikinetoplastid Quinonemethide Triterpenoids

Chagas disease and leishmaniasis are among the most widespread neglected tropical diseases, and their current therapies have limited efficacy and several toxic side effects. The present study reports the chemical and antikinetoplastid profiles of extracts from five Salvadoran Celastraceae species against theTrypanosoma cruzi epimastigotes stage and Leishmania amazonensis and Leishmania donovani promastigote forms. The phytochemical profile evinced the presence of flavonoids, tannins, sterols, and triterpenes as the main components in all plant species, whereas quinonemethide triterpenoids (QMTs) were restricted to the root bark of the studied species. Antikinetoplastid evaluation highlights the root bark extracts from Zinowewia integerrima, Maytenus segoviarum, and Quetzalia ilicina as the most promising ones, exhibiting higher potency against T. cruzi (IC50 0.71–1.58 µg/mL) and L. amazonensis (IC50 0.38–2.05 µg/mL) than the reference drugs, benznidazole (IC50 1.81 µg/mL) and miltefosine (IC50 2.64 µg/mL), respectively. This potent activity was connected with an excellent selectivity index on the murine macrophage J774A.1 cell line. These findings reinforce the potential of QMTs as antikinetoplastid agents for the development of innovative phytopharmaceuticals and the plant species under study as a source of these promising lead compounds.

Contribution to Celastraceae palynology from Cerrado forest fragments: a focus on shape, amb and exine ornamentation

Forest fragments in the Cerrado are areas of prominent biological importance due to their great species richness and biodiversity. These areas host endemic species of Celastraceae, the knowledge of which contributes to the preservation of this biome. This study aims to characterize the pollen morphology of 10 native species of Celastraceae found in forest fragments in the state of São Paulo, Brazil, contributing to the knowledge of the taxa for future taxonomic studies, and providing data for the conservation of the species in the forest areas. The pollen grains were acetolyzed, measured, described qualitatively and illustrated using light microscopy and scanning electron microscopy. The pollen characters referring to the pollen unit, polarity, type and number of apertures are similar in all the species studied. The shape, amb and exine ornamentation of pollen grains are the diagnostic qualitative morphological data for Celastraceae in this study. Microreticulate pollen grains were observed in Celastrus, Hippocratea and Pristimera; reticulate pollen grains with a very thick exine characterize the analyzed species of Plenckia; and reticulate and microreticulate ornamentation was observed among the species of Monteverdia. The results obtained here allow us to distinguish species of the analyzed genera and confirm the pollen diversity previously reported for Celastraceae.

Cold Resistance of Euonymus japonicus Beihaidao Leaves and Its Chloroplast Genome Structure and Comparison with Celastraceae Species.

Euonymus japonicus Beihaidao is one of the most economically important ornamental species of the Euonymus genus. There are approximately 97 genera and 1194 species of plants worldwide in this family (Celastraceae). Using E. japonicus Beihaidao, we conducted a preliminary study of the cold resistance of this species, evaluated its performance during winter, assembled and annotated its chloroplast genome, and performed a series of analyses to investigate its gene structure GC content, sequence alignment, and nucleic acid diversity. Our objectives were to understand the evolutionary relationships of the genus and to identify positive selection genes that may be related to adaptations to environmental change. The results indicated that E. japonicus Beihaidao leaves have certain cold resistance and can maintain their viability during wintering. Moreover, the chloroplast genome of E. japonicus Beihaidao is a typical double-linked ring tetrad structure, which is similar to that of the other four Euonymus species, E. hamiltonianus, E. phellomanus, E. schensianus, and E. szechuanensis, in terms of gene structure, gene species, gene number, and GC content. Compared to other Celastraceae species, the variation in the chloroplast genome sequence was lower, and the gene structure was more stable. The phylogenetic relationships of 37 species inferred that members of the Euonymus genus do not form a clade and that E. japonicus Beihaidao is closely related to E. japonicus and E. fortunei. A total of 11 functional positive selected genes were identified, which may have played an important role in the process of Celastraceae species adapting to environmental changes. Our study provides important genetic information to support further investigations into the phylogenetic development and adaptive evolution of Celastraceae species.

The complete chloroplast genome of Euonymus alatus (Celastraceae)

Euonymus alatus, Celastraceae, is a deciduous tree species valued for its ornamental and medicinal properties. Here, the species’ whole chloroplast genome sequence was generated by assembling the Illumina paired-end sequencing reads. The circular genome was 157,611 bp in length, exhibiting a typical quadripartite structure with a large single-copy (LSC: 85,892 bp), a small single-copy (SSC: 18,419 bp), and a pair of inverted repeat regions (IRA and IRB: each of 26,650 bp). The chloroplast genome encoded 131 genes, including 87 protein-coding (78 protein-coding gene species), 36 transfer RNA (29 tRNA species), and 8 ribosomal RNA genes (4 rRNA species). The overall GC content was 37.3%, while the corresponding values of the LSC, SSC and IR regions were 35.1, 31.7 and 42.7%, respectively. Phylogenetic analysis of 12 species complete chloroplast genomes suggested that E. alatus was relatively close to E. japonicus. This complete chloroplast genome is expected to provide valuable insight into further phylogenetic reconstruction of the Celastraceae species.

Pentacyclic Triterpenoids Isolated from Celastraceae: A Focus in the 13C-NMR Data.

The Celastraceae family comprises about 96 genera and more than 1.350 species, occurring mainly in tropical and subtropical regions of the world. The species of this family stand out as important plant sources of triterpenes, both in terms of abundance and structural diversity. Triterpenoids found in Celastraceae species display mainly lupane, ursane, oleanane, and friedelane skeletons, exhibiting a wide range of biological activities such as antiviral, antimicrobial, analgesic, anti-inflammatory, and cytotoxic against various tumor cell lines. This review aimed to document all triterpenes isolated from different botanical parts of species of the Celastraceae family covering 2001 to 2021. Furthermore, a compilation of their 13C-NMR data was carried out to help characterize compounds in future investigations. A total of 504 pentacyclic triterpenes were compiled and distinguished as 29 aromatic, 50 dimers, 103 friedelanes, 89 lupanes, 102 oleananes, 22 quinonemethides, 88 ursanes and 21 classified as others.

Probing the functions of friedelane-type triterpene cyclases from four celastrol-producing plants.

Triterpenes are among the most diverse plant natural products, and their diversity is closely related to various triterpene skeletons catalyzed by different 2,3-oxidosqualene cyclases (OSCs). Celastrol, a friedelane-type triterpene with significant bioactivities, is specifically distributed in higher plants, such as Celastraceae species. Friedelin is an important precursor for the biosynthesis of celastrol, and it is synthesized through the cyclization of 2,3-oxidosqualene, with the highest number of rearrangements being catalyzed by friedelane-type triterpene cyclases. However, the molecular mechanisms underlying the catalysis of friedelin production by friedelane-type triterpene cyclases have not yet been fully elucidated. In this study, transcriptome data of four celastrol-producing plants from Celastraceae were used to identify a total of 21 putative OSCs. Through functional characterization, the friedelane-type triterpene cyclases were separately verified in the four plants. Analysis of the selection pressure showed that purifying selection acted on these OSCs, and the friedelane-type triterpene cyclases may undergo weaker selective restriction during evolution. Molecular docking and site-directed mutagenesis revealed that changes in some amino acids that are unique to friedelane-type triterpene cyclases may lead to variations in catalytic specificity or efficiency, thereby affecting the synthesis of friedelin. Our research explored the functional diversity of triterpene synthases from a multispecies perspective. It also provides some references for further research on the relative mechanisms of friedelin biosynthesis.

The Methionine 549 and Leucine 552 Residues of Friedelin Synthase from Maytenus ilicifolia Are Important for Substrate Binding Specificity.

Friedelin, a pentacyclic triterpene found in the leaves of the Celastraceae species, demonstrates numerous biological activities and is a precursor of quinonemethide triterpenes, which are promising antitumoral agents. Friedelin is biosynthesized from the cyclization of 2,3-oxidosqualene, involving a series of rearrangements to form a ketone by deprotonation of the hydroxylated intermediate, without the aid of an oxidoreductase enzyme. Mutagenesis studies among oxidosqualene cyclases (OSCs) have demonstrated the influence of amino acid residues on rearrangements during substrate cyclization: loss of catalytic activity, stabilization, rearrangement control or specificity changing. In the present study, friedelin synthase from Maytenus ilicifolia (Celastraceae) was expressed heterologously in Saccharomyces cerevisiae. Site-directed mutagenesis studies were performed by replacing phenylalanine with tryptophan at position 473 (Phe473Trp), methionine with serine at position 549 (Met549Ser) and leucine with phenylalanine at position 552 (Leu552Phe). Mutation Phe473Trp led to a total loss of function; mutants Met549Ser and Leu552Phe interfered with the enzyme specificity leading to enhanced friedelin production, in addition to α-amyrin and β-amyrin. Hence, these data showed that methionine 549 and leucine 552 are important residues for the function of this synthase.

Chemodiversity of Essential Oils from Nine Species of Celastraceae.

Extracts and compounds obtained from several species of Celastraceae family are reported as potential sources of drugs due to their diverse pharmacological properties. Nevertheless, essential oil composition from these species is still little known. This work aimed at the analysis of essential oils obtained from different Brazilian Celastraceae species. A total of seventeen oils were obtained using hydrodistillation process and analyzed by gas chromatography/mass spectrometry (GC/MS). Principal component analysis (PCA) allowed the identification of a chemical composition pattern among the analyzed essential oils. Some compounds were more frequent among Celastraceae species, such as cis- and trans-linalool oxide (14/17 oil samples), nerylacetone (13/17), linalool (11/17), β-ionone (10/17), α-ionone (9/17), nerolidol (10/17), decanal (10/17), and dodecanoic acid (10/17). These results contribute to the chemophenetics of Celastraceae species.

Structural Requirements for Antimicrobial Activity of Phenolic Nor-Triterpenes from Celastraceae Species

The emergence of pathogenic bacteria-resistant strains is a major public health issue. In this regard, natural product scaffolds offer a promising source of new antimicrobial drugs. In the present study, we report the antimicrobial activity against Gram-positive and Gram-negative bacteria and the yeast Candida albicans of five phenolic nor-triterpenes (1–5) isolated from Maytenus blepharodes and Maytenus canariensis in addition to four derivatives (6–9), three of them reported for the first time. Their stereostructures have been elucidated on the basis of spectroscopic analysis, including one-dimensional (1D) and two-dimensional (2D) NMR techniques, spectrometric methods, and comparison with data reported in the literature. To understand the structural basis for the antimicrobial activity of this type of compounds, we have performed an in-depth study of the structure–activity relationship (SAR) of a series of previously reported phenolic nor-triterpenes. The SAR analysis was based on the skeleton framework, oxidation degree, functional groups, and regiosubstitution patterns, revealing that these aspects modulate the antimicrobial activity.

Development and Validation of an HPLC-PDA Method for Biologically Active Quinonemethide Triterpenoids Isolated from Maytenus chiapensis.

Background: Quinonemethide triterpenoids, known as celastroloids, constitute a relatively small group of biologically active compounds restricted to the Celastraceae family and, therefore, they are chemotaxonomic markers for this family. Among this particular type of metabolite, pristimerin and tingenone are considered traditional medicines in Latin America. The aim of this study was the isolation of the most abundant celastroloids from the root bark of Maytenus chiapensis, and thereafter, to develop an analytical method to identify pristimerin and tingenone in the Celastraceae species. Methods: Pristimerin and tingenone were isolated from the n-hexane-Et2O extract of the root bark of M. chiapensis through chromatographic techniques, and were used as internal standards. Application of a validated RP HPLC-PDA method was developed for the simultaneous quantification of these two metabolites in three different extracts, n-hexane-Et2O, methanol, and water, to determine the best extractor solvent. Results: Concentration values showed great variation between the solvents used for extraction, with the n-hexane–Et2O extract being the richest in pristimerin and tingenone. Conclusions: M. chiapensis is a source of two biologically active quinonemethide triterpenoids. An analytical method was developed for the qualification and quantification of these two celastroloids in the root bark extracts of M. chiapensis. The validated method reported herein could be extended and be useful in analyzing Celastraceae species and real commercial samples.

HPLC profile and simultaneous quantitative analysis of tingenone and pristimerin in four Celastraceae species using HPLC-UV-DAD-MS

A validated method for the identification and authentication of tingenone and pristimerin was developed using HPLC. The chromatographic profile analysis was combined with simultaneous quantification in Crossopetalum rhacoma Crantz, Cassine xylocarpa Vent, Semialarium mexicanum (Miers) Mennega (known as cancerina), and Maytenus phyllanthoides Benth, through microwave-assisted extraction. The HPLC profiles of the four analyzed species showed three similar signals, which corresponded to the main chemotaxonomic markers of the Celastraceae family: quinonemethide triterpenes. HPLC profile analysis was used as a tool to identify the relationship with the quinonemethide triterpenes, for establishing the taxonomic position of some species whose placement in, or within, the Celastraceae family is uncertain.

<p><strong><em>Microtropis</em></strong><strong> <em>cerocarpa</em> (Celastraceae), a new species from southern Vietnam</strong></p>

Microtropis cerocarpa, a new species of Celastraceae, is described and illustrated. The species was discovered in 2012 during a botanical survey of the Chu Yang Sin National Park (Dak Lak province, southern Vietnam); additional collections were obtained there in 2018. Microtropis cerocarpa possesses dense glomerate sessile inflorescence with sessile flowers which allows placing this species into sect. Microtropis. Within this section it is most similar to M. obscurinervia, M. rhynchocarpa and M. wui. The new species differs from related species mainly by large thick leaves 23.5–39 cm long and 13–22 cm wide with very short petiole (subsessile) and cordate base, fruit with short rostrum of 1–2 mm long at apex, and immature fruit surface with a pronounced white wax coating in the form of granules. Microtropis cerocarpa is an easily recognized tree with remarkable robust habit and large leaves. A description of the vegetation in the area inhabited by M. cerocarpa is provided. The data on species diversity of Microtropis in Vietnam are summarized and an identification key is compiled.

Cytotoxic Triterpenes from Salacia crassifolia and Metabolite Profiling of Celastraceae Species.

The new pentacyclic triterpene 11β-hydroxypristimerin (1), along with the known metabolites pristimerin (2), 6-oxopristimerol (3) and vitideasin (4), were isolated from a Salacia crassifolia root wood extract, following a bioassay-guided fractionation approach. Both the extract and the purified triterpenes displayed pronounced cytotoxic activity against human cancer cell lines. The NCI-60 cell line screen revealed that compound 2 was the most active, with a mean GI50 of 0.17 μM, while compound 1 had a mean GI50 of 8.7 μM. A COMPARE analysis of the screening results showed that pristimerin is likely to be the main compound responsible for the cytotoxic activity of the extract (mean GI50 of 0.3 μg·mL−1). A targeted search for pristimerin and related derivatives using LC-MS/MS revealed the presence of pristimerin (2) and 6-oxopristimerol (3) in all Celastraceae species examined and in all plant parts tested, while vitideasin (4) was only detected in the genus Salacia.

Distinct sesquiterpene pyridine alkaloids from in Salvadoran and Peruvian Celastraceae species

As part of a bioprospecting program aimed at the discovery of undescribed natural products from Salvadoran and Peruvian flora, the phytochemical investigations of four Celastraceae species, Celastrus vulcanicola, Maytenus segoviarum, Maytenus jeslkii, and Maytenus cuzcoina, were performed. The current study reports the isolation and structural characterization of five previously undescribed macrolide sesquiterpene pyridine alkaloids, named vulcanicoline-A, cuzcoinine, vulcanicoline-B, jelskiine, and vulcanicoline-C, along with sixteen known alkaloids. The structures of the alkaloids were established by spectrometric and extensive 1D and 2D NMR spectroscopic analysis, including COSY, HSQC, HMBC, and ROESY experiments. The absolute configurations of alkaloids were proposed based on optical rotation sign, and biogenetic considerations. This study represents the first phytochemical analysis of Maytenus segoviarum.

Pentacyclic Triterpenoids from Maytenus cuzcoina

Phytochemical analysis of the root bark extract of Maytenus cuzcoina (Celastraceae) led to the isolation and characterization of sixteen triterpenoids with a 6/6/6/6/6 pentacyclic system, including the new 22α-hydroxy-29-methoxy-3β-tetradecanoate-olean-12-ene, and 3β,24β-epoxy-29-methoxy-2α,3α,6α- -trihydroxy-D:A-friedelane that is reported for the first time as a natural product. This is the first instance of the isolation of a tetradecanoate triterpene ester from a Celastraceae species. The structures were elucidated on the basis of spectrometric and spectroscopic methods, including ID and 2D NMR techniques.

Bioactive diterpenoids from Celastraceae species

Celastraceae species have a long tradition of use in folk medicine and agriculture. Intensive research into this family has resulted in the isolation of a large number of secondary metabolites with a wide range of bioactivity, with the most characteristic being the dihydro-β-agarofuran sesquiterpenes and the quinomethide triterpenoids. Despite diterpenoids not often being found in Celastraceae species, the novelty of their structures and their biological activities has stimulated their research. There are several reviews covering studies on Tripterigium wilfordii, a traditional Chinese medicine, and their metabolites, but none focusing on bioactive diterpenoids isolated from other Celastraceae species. This review focuses on diterpenes isolated from Celastraceae species, and their skeleton diversity, species sources, and tested biological activities are discussed. The literature from January 2000 to October 2016 is reviewed, and 64 references are cited. A total of 118 isolated diterpenoids possessing twelve different skeletons are included and classified by the following tested biological activity: cytotoxicity, anti-inflammatory, antitumour-promotion, anti-HIV, immunosuppressant, reversal multi-drug resistance, and antifeedant. This compliance information will be helpful in further research into diterpene Celastraceae isolation, biological activity determination and structure specific modifications.

Employing Two-stage Derivatisation and GC-MS to Assay for Cathine and Related Stimulant Alkaloids across the Celastraceae.

Catha edulis (qat, khat, mirra) is a woody plant species that is grown and consumed in East Africa and Yemen for its stimulant alkaloids cathinone, cathine and norephedrine. Two Celastraceae species, in addition to qat, have been noted for their stimulant properties in ethnobotanical literature. Recent phylogenetic reconstructions place four genera in a clade sister to Catha edulis, and these genera are primary candidates to search for cathine and related alkaloids. Determine if cathine or related alkaloids are present in species of Celastraceae other than Catha edulis. Leaf samples from 43 Celastraceae species were extracted in water followed by basification of the aqueous extract and partitioning with methyl-t-butyl ether to provide an alkaloid-enriched fraction. The extract was derivatised in a two-stage process and analysed using GC-MS for the presence of cathine. Related alkaloids and other metabolites in this alkaloid-enriched fraction were tentatively identified. Cathinone, cathine and norephedrine were not detected in any of the 43 Celastraceae species assayed other than Catha edulis. However, the phenylalanine- or tyrosine-derived alkaloid phenylethylamine was identified in five species. Nine species were found to be enriched for numerous sterol- and terpene-like compounds. These results indicate that cathine is unique to Catha edulis, and not the compound responsible for the stimulant properties reported in related Celastraceae species. Copyright © 2017 John Wiley & Sons, Ltd.

ChemInform Abstract: Dihydro‐β‐agarofuran Sesquiterpenes from Celastraceae Species as Antitumor‐Promoting Agents: Structure—Activity Relationship.

AbstractFive dihydro‐β‐agarofuran sesquiterpenes, chiapene A (Ia), chiapene B (Ib), chiapene C (II), chiapene D (III), and chiapene E (IV) are isolated from Maytenus chiapensis and tested for their inhibitory effects on Epstein—Barr virus early antigen activation.