Insight into neofunctionalization of 2,3-oxidosqualene cyclases in B,C-ring-opened triterpene biosynthesis in quinoa.

Bioactive triterpenes feature complex fused-ring structures, primarily shaped by the first-committed enzyme, 2,3-oxidosqualene cyclases (OSCs) in plant triterpene biosynthesis. Triterpenes with B,C-ring-opened skeletons are extremely rare with unknown formation mechanisms, harbouring unchartered chemistry and biology. Here, through mining the genome of Chenopodium quinoa followed by functional characterization, we identified a stress-responsive and neofunctionalized OSC capable of generating B,C-ring-opened triterpenes, including camelliol A and B and the novel (-)-quinoxide A as wax components of the specialized epidermal bladder cells, namely the quinoxide synthase (CqQS). Protein structure analysis followed by site-directed mutagenesis identified key variable amino acid sites underlying functional interconversion between pentacyclic ß-amyrin synthase (CqbAS1) and B,C-ring-opened triterpene synthase CqQS. Mutation of one key residue (N612K) in even evolutionarily distant Arabidopsis ß-amyrin synthase could generate quinoxides, indicating a conserved mechanism for B,C-ring-opened triterpene formation in plants. Quantum computation combined with docking experiments further suggests that conformations of conserved W613 and F413 of CqQS might be key to selectively stabilizing intermediate carbocations towards B,C-ring-opened triterpene formation. Our findings shed light on quinoa triterpene skeletal diversity and mechanisms underlying B,C-ring-opened triterpene biosynthesis, opening avenues towards accessing their chemistry and biology and paving the way for quinoa trait engineering and quality improvement.

Inhibition of protein tyrosine phosphatase 1B by serratane triterpenes from Huperzia serrata and their molecular docking study.

During the search for protein tyrosine phosphatase 1B (PTP1B) inhibitory compounds from the natural resources, two new serratane triterpenes, 3-O-dihydro-p-coumaroyltohogenol (1) and 21-O-acetyltohogenol (2), along with four known serratane triterpenes (3-6), were isolated from the whole plant of Huperzia serrata. The chemical structures of compounds 1 and 2 were determined by NMR study, HRMS analysis, and chemical modification. All isolates were evaluated for their PTP1B inhibitory activities. Among the isolates, compounds 1, 3, 5 and 6 exhibit moderate inhibitory activities against PTP1B. Kinetic studies demonstrated that they are competitive inhibitors. Molecular docking studies support these experimental results by showing that compounds 1, 3, 5 and 6 interact with the active site of PTP1B, clarifying the structure-activity relationship. This study suggests that serratane triterpenes from H. serrata have potential as starting skeletons for anti-diabetes or anti-obesity agents.

A Review on Ethnobotany, Phytochemistry and Pharmacological Activities of Euphorbia antiquorum L.

Euphorbia antiquorum L. is a small plant in the Euphorbiaceae family that is found primarily in tropical and subtropical Asia. It has a long tradition of being utilized in Chinese, Ayurvedic, and other traditional systems for a variety of ailments. To date, More than 116 bioactive constituents were isolated from Euphorbia antiquorum, with diterpenoids being the most abundant. Extracts and isolated chemicals from various portions of the plant have demonstrated significant pharmacological activities such as anti-inflammatory, analgesic, antidiabetic, anticancer etc. It is necessary to conduct an in-depth investigation of the phytochemicals along with the pharmacological properties of E. antiquorum. This review summarised the knowledge of ethnobotany, phytochemistry and pharmacological activities of the plant which will provide a better understanding to clarify the traditional uses of the species and its relation to modern pharmacology which will ultimately pave the way for its clinical application.

Larvicidal Activity against Spodoptera frugiperda of some Constituents from two Diospyros Species. In silico Pesticide-likeness Properties, Acetylcholinesterase Activity and Molecular Docking.

This report informs for the first time the chemical constituents of Diospyros xolocotzii and Diospyros digyna, the pesticidal and the acetylcholinesterase (AChE) inhibition potential of some compounds calculated by in silico approaches, the larvicidal activity against Spodoptera frugiperda of available compounds, the AChE inhibition of selected compounds, and the results of the molecular docking of the most active ones with this receptor. From the aerial parts of D. xolocotzii were isolated pentacyclic triterpenes (1-4, 6, 10, 11-13), phytosterols (15-17), and isodiospyrin (18), whereas the analysis of aerial parts of D. digyna conducted to the isolation of pentacyclic triterpenes (4, 5, 7-9, 11-14), (4S)-shinanolone (19), and scopoletin (20). For comparison purposes, origanal (21) was chemically prepared from 11. The in silico analysis showed that the tested compounds have pesticide potential. The larvicidal activities of 11>13>12 indicated that the increase of the oxidation degree at C-28 increases their bioactivity. Compounds 11 and 21 presented the higher inhibition in the acetylcholinesterase assay, and the higher binding energies, and for the interactionswith AChE by molecular docking. Both Diospyros species are sources of triterpenes with pesticidal potential and the molecular changes in lupane triterpenes correlate with the observed bioactivity and molecular docking.

Two new baccharane triterpenes isolated from Rhus chinensis.

Two new baccharane triterpenes, 17,24-epoxy-23-en-baccharan-3-one (1) and 17,24(S)-epoxy-25-en-21-hydroxy-baccharan-3-one (2) were isolated from Rhus chinensis Mill. The structures were established on the basis of UV, IR, HR-ESI-MS, 1D and 2D NMR spectroscopy and X-ray diffraction analysis.

Two new oleanane triterpenes from Maytenus hookeri.

Two new triterpenes mayteneri A (1), mayteneri B (2), and seven known compounds (3-9) were isolated from stems of Maytenus hookeri Loes. The chemical structures of compounds 1 and 2 were established by 1D, 2D NMR, HRESIMS analysis, and calculating electronic circular dichroism (ECD). The structures of known compounds 3-9 were determined by comparison of their spectral with those reported. Compounds 4-7 showed significant inhibitory activity for NLRP3 inflammasome, with the IC50 values of 2.36-3.44 µM.

Ceanothanes Derivatives as Peripheric Anionic Site and Catalytic Active Site Inhibitors of Acetylcholinesterase: Insights for Future Drug Design.

Alzheimer's disease (AD) is a multifactorial and fatal neurodegenerative disorder. Acetylcholinesterase (AChE) plays a key role in the regulation of the cholinergic system and particularly in the formation of amyloid plaques; therefore, the inhibition of AChE has become one of the most promising strategies for the treatment of AD, particularly concerning AChE inhibitors that interact with the peripheral anionic site (PAS). Ceanothic acid isolated from the Chilean Rhamnaceae plants is an inhibitor of AChE through its interaction with PAS. In this study, six ceanothic acid derivatives were prepared, and all showed inhibitory activity against AChE. The structural modifications were performed starting from ceanothic acid by application of simple synthetic routes: esterification, reduction, and oxidation. AChE activity was determined by the Ellmann method for all compounds. Kinetic studies indicated that its inhibition was competitive and reversible. According to the molecular coupling and displacement studies of the propidium iodide test, the inhibitory effect of compounds would be produced by interaction with the PAS of AChE. In silico predictions of physicochemical properties, pharmacokinetics, drug-likeness, and medicinal chemistry friendliness of the ceanothane derivatives were performed using the Swiss ADME tool.

Study of Pentacyclic Triterpenes from Lyophilised Aguaje: Anti-Inflammatory and Antioxidant Properties.

Mauritia flexuosa (M. flexuosa), commonly known as Aguaje or Moriche palm, is traditionally recognised in South America for its medicinal properties, particularly for its anti-inflammatory and antioxidant effects. However, the bioactive compounds responsible for these effects have not been thoroughly investigated. This study aims to isolate and characterise pentacyclic triterpenoid compounds from M. flexuosa and to evaluate their therapeutic potential. Using various chromatographic and spectroscopic techniques including Nuclear Magnetic Resonance (NMR) and Mass Spectrometry (MS), three pentacyclic triterpenoid compounds were successfully isolated. Among them, compound 1 (3,11-dioxours-12-en-28-oic acid) exhibited notable bioactivity, significantly inhibiting the activation of Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB) (IC50 = 7.39-8.11 µM) and of Nitric Oxide (NO) (IC50 = 4.75-6.59 µM), both of which are key processes in inflammation. Additionally, compound 1 demonstrated potent antioxidant properties by activating the antioxidant enzyme Superoxide Dismutase (SOD) (EC50 = 1.87 µM) and the transcription factor Nuclear factor erythroid 2-related factor 2 (Nrf2) (EC50 = 243-547.59 nM), thus showing its potential in combating oxidative stress. This study is the first to isolate and characterise the three compounds from M. flexuosa, suggesting that compound 1 could be a promising candidate for the development of safer and more effective therapies for inflammatory and oxidative stress-related diseases.

Oleanolic Acid Dimers with Potential Application in Medicine-Design, Synthesis, Physico-Chemical Characteristics, Cytotoxic and Antioxidant Activity.

The present work aimed to obtain a set of oleanolic acid derivatives with a high level of cytotoxic and antioxidant activities and a low level of toxicity by applying an economical method. Oleanolic acid was alkylated with α,ω-dihalogenoalkane/α,ω-dihalogenoalkene to obtain 14 derivatives of dimer structure. All of the newly obtained compounds were subjected to QSAR computational analysis to evaluate the probability of the occurrence of different types of pharmacological activities depending on the structure of the analysed compound. All dimers were tested for cytotoxicity activity and antioxidant potential. The cytotoxicity was tested on the SKBR-3, SKOV-3, PC-3, and U-87 cancer cell lines with the application of the MTT assay. The HDF cell line was applied to evaluate the tested compounds' Selectivity Index. The antioxidant test was performed with a DPPH assay. Almost all triterpene dimers showed a high level of cytotoxic activity towards selected cancer cell lines, with an IC50 value below 10 µM. The synthesised derivatives of oleanolic acid exhibited varying degrees of antioxidant activity, surpassing that of the natural compound in several instances. Employing the DPPH assay, compounds 2a, 2b, and 2f emerged as promising candidates, demonstrating significantly higher Trolox equivalents and highlighting their potential for pharmaceutical and nutraceutical applications. Joining two oleanolic acid residues through their C-17 carboxyl group using α,ω-dihalogenoalkanes/α,ω-dihalogenoalkenes resulted in the synthesis of highly potent cytotoxic agents with favourable SIs and high levels of antioxidant activity.

Phytochemical and Micro-Morphological Characterization of Atraphaxis pyrifolia Bunge Growing in the Republic of Kazakhstan.

Atraphaxis pyrifolia is a native species of Central Asia, known for curing several disorders. The species has little knowledges about its chemical composition and any information about its morphological characteristics despite its importance in traditional Asian medicine. This is one of the first approaches to the phytochemical and morphological characterization of this species. Micro-morphology was performed on the stem, and leaf parts of this plant to profile the morpho-anatomical characters using brightfield, fluorescence, polarized and scanning electron microscopy. Leaves were extracted with hexane and methanol. The hexane extract was analyzed using GC-MS analysis revealing the major presence of γ-sitosterol and nonacosane. The methanolic extract was submitted to Vacuum Liquid Chromatography and Sephadex LH-20. HPTLC, HR-ESI-MS and NMR techniques were used to identify the main compounds. Four glycosylated flavonoids were isolated: 8-O-acetyl-7-O-methyl-3-O-α-l-rhamnopyranosylgossypetin (Compound 1), and 7-O-methyl-3-O-α-l-rhamnopyranosylgossypetin (Compound 3), and two other compounds reported for the first time in the literature (Compounds 2 and 4). The findings presented herein furnish pertinent information essential for the identification and authentication of this medicinal plant. Such insights are invaluable for facilitating robust quality control measures and serve as a foundational framework for subsequent endeavours in metabolic, pharmacological, and taxonomical analyses.

Exploring the Potential of Oleanolic Acid Dimers-Cytostatic and Antioxidant Activities, Molecular Docking, and ADMETox Profile.

The presented work aimed to explore the potential of oleanolic acid dimers (OADs): their cytostatic and antioxidant activities, molecular docking, pharmacokinetics, and ADMETox profile. The cytostatic properties of oleanolic acid (1) and its 14 synthesised dimers (2a-2n) were evaluated against 10 tumour types and expressed as IC50 values. Molecular docking was performed with the CB-Dock2 server. Antioxidant properties were evaluated with the CUPRAC method. ADMETox properties were evaluated with the ADMETlab Manual (2.0) database. The results indicate that the obtained OADs can be effective cytostatic agents, for which the IC50 not exceeded 10.00 for many tested cancer cell lines. All OADs were much more active against all cell lines than the mother compound (1). All dimers can inhibit the interaction between the 1MP8 protein and cellular proteins with the best results for compounds 2f and 2g with unsaturated bonds within the linker. An additional advantage of the tested OADs was a high level of antioxidant activity, with Trolox equivalent for OADs 2c, 2d, 2g-2j, 2l, and 2m of approximately 0.04 mg/mL, and beneficial pharmacokinetics and ADMETox properties. The differences in the DPPH and CUPRAC assay results obtained for OADs may indicate that these compounds may be effective antioxidants against different radicals.

Olea europaea L. Leaves as a Source of Anti-Glycation Compounds.

High concentrations of advanced glycation end products (AGEs) have been linked to diseases, including diabetic complications. The pathophysiological effects of AGEs are mainly due to oxidative stress and inflammatory processes. Among the proteins most affected by glycation are albumin, the most abundant circulating protein, and collagen, which has a long biological half-life and is abundant in the extracellular matrix. The potential cellular damage caused by AGEs underscores the importance of identifying and developing natural AGE inhibitors. Indeed, despite initial promise, many synthetic inhibitors have been withdrawn from clinical trials due to issues such as cytotoxicity and poor pharmacokinetics. In contrast, natural products have shown significant potential in inhibiting AGE formation. Olea europaea L. leaves, rich in bioactive compounds like oleuropein and triterpenoids, have attracted scientific interest, emphasizing the potential of olive leaf extracts in health applications. This study investigates the anti-glycation properties of two polyphenol-rich extracts (OPA40 and OPA70) and a triterpene-enriched extract (TTP70) from olive leaves. Using in vitro protein glycation methods with bovine serum albumin (BSA)-glucose and gelatin-glucose systems, this study assesses AGE formation inhibition by these extracts through native polyacrylamide gel electrophoresis (N-PAGE) and autofluorescence detection. OPA40 and OPA70 exhibited strong, dose-dependent anti-glycation effects. These effects were corroborated by electrophoresis and further supported by similar results in a gelatin-glucose system. Additionally, TTP70 showed moderate anti-glycation activity, with a synergistic effect of its components. The results support the real possibility of using olive leaf bioproducts in ameliorating diabetic complications, contributing to sustainable bio-economy practices.

Acetylation of Oleanolic Acid Dimers as a Method of Synthesis of Powerful Cytotoxic Agents.

Oleanolic acid, a naturally occurring triterpenoid compound, has garnered significant attention in the scientific community due to its diverse pharmacological properties. Continuing our previous work on the synthesis of oleanolic acid dimers (OADs), a simple, economical, and safe acetylation reaction was performed. The newly obtained derivatives (AcOADs, 3a-3n) were purified using two methods. The structures of all acetylated dimers (3a-3n) were determined based on spectral methods (IR, NMR). For all AcOADs (3a-3n), the relationship between the structure and the expected directions of pharmacological activity was determined using a computational method (QSAR computational analysis). All dimers were also tested for their cytotoxic activity on the SKBR-3, SKOV-3, PC-3, and U-87 cancer cell lines. HDF cell line was applied to evaluate the Selectivity Index of the tested compounds. All cytotoxic tests were performed with the application of the MTT assay. Finally, all dimers of oleanolic acid were subjected to DPPH and CUPRAC tests to evaluate their antioxidant activity. The obtained results indicate a very high level of cytotoxic activity (IC50 for most AcOADs below 5.00 µM) and a fairly high level of antioxidant activity (Trolox equivalent in some cases above 0.04 mg/mL).

Mexican Coccoloba uvifera L. Leaf and Fruit Extracts: Identification of Pentacyclic Triterpenes and Volatile Profile by GC-MS.

Mexican Coccoloba uvifera fruit contains polyphenols, flavonoids, and anthocyanins, while in the leaves, lupeol, α- and ß-amyrin have been previously identified by HPLC. However, the low resolution by HPLC of pentacyclic triterpenes (PTs) is a limitation. Moreover, the volatile profile of C. uvifera fruit is still unknown. Therefore, this study aimed to identify PTs in C. uvifera leaf and fruit extracts by CG-MS analysis and to determine the volatile profile of C. uvifera pulp by headspace solid-phase microextraction. The results showed trimethylsilylated compounds of standards lupeol, α- and ß-amyrin, indicating that the silylation reaction was suitable. These trimethylsilylated compounds were identified in leaf and fruit extracts. The fruit volatile profile revealed the presence of 278 esters, 20 terpenes, 9 aldehydes, 5 alcohols, and 4 ketones. The fruit showed a high content of esters and terpenes. Due to their flavour properties, esters are essential for the food, cosmetics, and pharmaceutics industries. Moreover, terpenes in the fruit, such as menthone, ß-elemene, junipene, and ß-caryophyllene have the potential as anticancer and phytopathogen agents. The results indicated that GC-MS is an alternative to HPLC approaches for identifying PTs. Besides, identifying volatile compounds in the fruit will increase the value of this plant and expand its application. Identifying PTs and volatile compounds in Mexican C. uvifera leads to a better understanding of the potential benefits of this plant. This would increase the consumption of Mexican C. uvifera fresh or as functional ingredients in nutraceutical or pharmaceutical products.

[Research progress on chemical constituents from Kadsura genus and its pharmacological activities and clinical application].

The 29 plant species in the Kadsura genus of the Schisandraceae family are mainly distributed in eastern and southeas-tern Asia. Ten species of plants in this genus are distributed in China, some of which are folk medicinal plants with activating blood circulation, relieving pain, dispelling wind, and dehumidifying effects. Their main constituents are lignans and triterpenes. The current pharmacology and clinical studies have shown that their extracts and constituents have anti-rheumatoid arthritis, liver protection, antioxidation, anti-inflammatory, and other biological activities. The rheumatologic and liver diseases can also be treated with the plants in the clinic. The new chemical constituents reported in the last decade(2012 to date) from the plants of Kadsura genus in China, as well as their pharmacological effects and clinical applications in recent years were reviewed, so as to provide a theoretical basis for further research on the genus.

Neuroprotective, neurogenic, and anticholinergic evidence of Ganoderma lucidum cognitive effects: Crucial knowledge is still lacking.

Ganoderma lucidum is a mushroom that has been widely used for centuries in Asian countries for its antiaging properties. It is popularly known as "Ling Zhi," "Reishi," and "Youngzhi," and because of its benefits, it is known as the "immortality mushroom." Pharmacological assays have revealed that G. lucidum ameliorates cognitive impairments through inhibition of ß-amyloid and neurofibrillary tangle formation, antioxidant effect, reduction of inflammatory cytokine release and apoptosis, genic expression modulation, among other activities. Chemical investigations on G. lucidum have revealed the presence of metabolites such as triterpenes, which are the most explored in this field, as well as flavonoids, steroids, benzofurans, and alkaloids; in the literature, these have also been reported to have mnemonic activity. These properties of the mushroom make it a potential source of new drugs to prevent or reverse memory disorders, as actual medications are able to only alleviate some symptoms but are unable to stop the progress of cognitive impairments, with no impact on social, familiar, and personal relevance. In this review, we discuss the cognitive findings of G. lucidum reported in the literature, converging the proposed mechanisms through the several pathways that underlie memory and cognition processes. In addition, we highlight the gaps that deserve particular attention to support future studies.

The saponin bomb: a nucleolar-localized ß-glucosidase hydrolyzes triterpene saponins in Medicago truncatula.

Plants often protect themselves from their own bioactive defense metabolites by storing them in less active forms. Consequently, plants also need systems allowing correct spatiotemporal reactivation of such metabolites, for instance under pathogen or herbivore attack. Via co-expression analysis with public transcriptomes, we determined that the model legume Medicago truncatula has evolved a two-component system composed of a ß-glucosidase, denominated G1, and triterpene saponins, which are physically separated from each other in intact cells. G1 expression is root-specific, stress-inducible, and coregulated with that of the genes encoding the triterpene saponin biosynthetic enzymes. However, the G1 protein is stored in the nucleolus and is released and united with its typically vacuolar-stored substrates only upon tissue damage, partly mediated by the surfactant action of the saponins themselves. Subsequently, enzymatic removal of carbohydrate groups from the saponins creates a pool of metabolites with an increased broad-spectrum antimicrobial activity. The evolution of this defense system benefited from both the intrinsic condensation abilities of the enzyme and the bioactivity properties of its substrates. We dub this two-component system the saponin bomb, in analogy with the mustard oil and cyanide bombs, commonly used to describe the renowned ß-glucosidase-dependent defense systems for glucosinolates and cyanogenic glucosides.

Mitochondria-targeted pentacyclic triterpenoid carbon dots for selective cancer cell destruction via inducing autophagy, apoptosis, as well as ferroptosis.

Natural products have been an important database for anti-cancer drug development. However, low water solubility and poor biocompatibility limit the efficacy of natural products. Carbon dots (CDs), as an emerging 0D material, have unique properties in bioimaging, water solubility and biocompatibility. Here, we prepared three pentacyclic triterpenoids (PTs) included glycyrrhetinic acid (GA), ursolic acid (UA) and oleanolic acid (OA), which have anticancer activity but poor water solubility, as raw materials into CDs to improve disadvantages. Our data indicated that the active surface groups of all three CDs were largely preserved and were able to excite green fluorescence. Their carboxyl edges not only exhibited excellent water solubility, but also specifically targeted tumor cell mitochondria due to high sensitivity to ROS-induced damage and high internal oxidative stress. In cancer cells, the PT-CDs induced cell death through three pathways (apoptosis, ferroptosis, and autophagy), which is essentially the same way their raw materials induce death, but the effect was much stronger than raw materials. Notably, functionalized PT-CDs also exhibited extremely low toxicity. In summary, PT-CDs not only have improved water solubility and biocompatibility, but also retain the structure of their raw materials well and exert better efficacy, which provides new ideas for the development of anti-cancer natural product drugs.

Phenolic and quinone methide nor-triterpenes as selective NLRP3 inflammasome inhibitors.

Dysregulated inflammasome activity, particularly of the NLRP3 inflammasome, is associated with the development of several inflammatory diseases. The study of molecules directly targeting NLRP3 is an emerging field in the discovery of new therapeutic compounds for the treatment of inflammatory disorders. Friedelane triterpenes are biologically active phytochemicals having a wide range of activities including anti-inflammatory effects. In this work, we evaluated the potential anti-inflammatory activity of phenolic and quinonemethide nor-triterpenes (1-11) isolated from Maytenus retusa and some semisynthetic derivatives (12-16) through inhibition of the NLRP3 inflammasome in macrophages. Among them, we found that triterpenes 6 and 14 were the most potent, showing markedly reduced caspase-1 activity, IL-1ß secretion (IC50 = 1.15 µM and 0.19 µM, respectively), and pyroptosis (IC50 = 2.21 µM and 0.13 µM, respectively). Further characterization confirmed their selective inhibition of NLRP3 inflammasome in both canonical and non-canonical activation pathways with no effects on AIM2 or NLRC4 inflammasome activation.

Analysis of 14 terpenoids and sterols and variety discrimination of Codonopsis Radix using ultra-high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry.

Recently, we confirmed that the 95% ethanol-extracted fraction of Codonopsis Radix, which contains several triterpenoids and sterols, possesses pharmacological activities. However, due to the low content and diverse types of triterpenoids and sterols, their similar structures, lack of ultraviolet absorption, and difficulty in obtaining controls, few studies have so far assessed their contents in Codonopsis Radix. We accordingly constructed an ultra-high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry technique for the simultaneous quantitative determination of 14 terpenoids and sterols. Separation was performed on the Waters Acquity UPLC HSS T3 C18 column (100 × 2.1 mm, 1.8 µm) with 0.1% formic acid (A) and 0.1% formic acid in methanol (B) as mobile phase under gradient elution. The determination coefficients for each of the matrix calibration curves were ≥0.9925. The average recovery ranged from 81.25% to 118.05%, with relative standard deviations of <4%. The contents of 14 components in 23 batches were quantified and further analyzed through chemometrics. Linear discriminant analysis can distinguish sample varieties. The quantitative analysis method can accurately determine the contents of 14 components and thereby provide the chemical basis for the quality control of Codonopsis Radix. It also could be a valuable approach for the classification of different Codonopsis Radix varieties.