Diterpenes of Pinus pinaster aiton with anti-inflammatory, analgesic, and antibacterial activities.

ETHNO-PHARMACOLOGICAL RELEVANCE: The P. pinaster species, known as 'Pino nigral or rodeno', is used in the treatment of colds, asthma, flu, and tuberculosis. AIM OF THE STUDY: This study determined the anti-inflammatory, analgesic, and antibacterial activities of the P. pinaster resin, identifying the compounds with higher biological activity. MATERIALS AND METHODS: A bio-guided isolation of the compounds of P. pinaster was carried out by selecting the most active extracts with anti-inflammatory and analgesic effects in the HBEC3-KT, MRC-5, and THP-1 cell lines. The antibacterial activity was determined against the S. aureus, S. pneumoniae, K. pneumoniae and P. aeruginosa strains. RESULTS: The following compounds were identified by NMR: dehydroabietic acid (1), ( + )-cis-abienol (2), pimaric acid (3), isopimaric acid (4), 7α-hydroxy-dehydroabietic acid (5), 7-oxo-dehydroabietic acid (6), 15-hydroxy-abietic acid (7), 7-oxo-15-hydroxy-dehydroabietic acid (8), 13-oxo-8 (14)-podocarpen-18-oic acid (9), and pinyunin A (10). Regarding their anti-inflammatory activity, all compounds inhibited NF-κB. Compound 9 was the most active (IC50 = 3.90-12.06 µM). Concerning the analgesic activity, all the compounds inhibited NK-1, yet compound 9 was the most active (IC50 = 0.28-0.33 µM). Finally, compounds 6 (MIC = 12.80-25.55 µM) and 9 (MIC = 9.80-24.31 µM) were the most promising antibacterial compounds in all strains. CONCLUSION: This study managed to identify, for the first time, six diterpenes from the resin of P. pinaster, with anti-inflammatory, analgesic, and antibacterial activity. Among the identified compounds, compound 9 was the most active, being considered a promising candidate as an antagonist of the tachykinin NK-1 receptor and as an analgesic agent against inflammation and neuropathic pain. It also had an antibacterial effect against Gram negative bacteria.

Croton tiglium L. seeds ameliorate loperamide-induced constipation via regulating gastrointestinal hormones and gut microbiota before and after processing.

ETHNOPHARMACOLOGICAL RELEVANCE: Crotonis Fructus (CF), the seeds of Croton tiglium L., have been commonly used in the treatment of constipation for more than two thousand years in traditional Chinese medicine (TCM). CF needs to be processed before clinical use and Crotonis Semen Pulveratum (CP) is the processed cream of CF, which could reduce the drastic purgative action and gastrointestinal damages. However, the mechanism of CF and CP in the treatment of constipation is still unclear. AIM OF THE STUDY: This study was to evaluate the effects of CF and CP on loperamide-induced constipation and the underlying mechanism. MATERIALS AND METHODS: The chemical compositions of CF and CP were analyzed by UPLC-Q-TOF-MS. Constipated mouse model was established by loperamide (9.6 mg/kg, b.w., i.g.) for two weeks. After successful modeling, the mice were treated with CF or CP (45.5 and 136.5 mg/kg, b.w., i.g.) once a day for seven days. The physiological status, defecation indices, defecation time, and intestinal propulsion rate in mice were measured. Histopathologic examination and serum biochemical parameters were further estimated. 16S rDNA gene sequencing was carried out to characterize the effects of CF and CP on intestinal microbiome structure. Spearman correlation analysis was also performed to explore the association between gut microbiotic abundance and serum indices. RESULTS: The results verified the therapeutic effects of CF and CP on loperamide-induced constipation. CF and CP could significantly ameliorate the reduction of fecal number, fecal weight, fecal water content, and intestinal propulsion rate in mice with constipation, and the first stool defecation time was also obviously reduced. Moreover, CF and CP could regulate the secretion of gastrointestinal hormones and inflammatory factors induced by constipation. Histopathologic examination showed that CP was superior to CF in relieving pathological injury and inflammatory cell infiltration. According to 16S rDNA sequencing, CF and CP treatment could improve gut microbiota disturbance in mice with constipation and the abundance of opportunistic pathogens such as Parabacteroides, Parasutterella and Bacillus remarkably declined, while the levels of beneficial bacterial such as Candidatus_Arthromitus significantly increased. Besides, CP may play a better role in correcting the intestinal flora disorder than CF, which was more obvious in the high-dose group. In addition, phytochemical analysis revealed the presence of diterpenoids and alkaloids in CF and CP. CONCLUSIONS: CF and CP could ameliorate loperamide-induced constipation by regulating gastrointestinal hormones secretion, reducing the levels of inflammatory cytokines and improving the disturbance of gut microbiota. Moreover, CP was superior to CF in the enrichment of beneficial bacteria and reduction of harmful bacteria and histopathological damage induced by constipation, which may be related to the changes in the species and content of diterpenoids after processing. The study provides new evidence for the processing mechanism and clinical application of CF and CP.

In silico investigation of Komaroviquinone as a potential inhibitor of SARS-CoV-2 main protease (Mpro): Molecular docking, molecular dynamics, and QM/MM approaches.

COVID-19 has highlighted the urgent need for new therapeutic agents to combat the spread of the virus. The main protease of SARS-CoV-2 (Mpro) has emerged as a promising target. In this study, we conducted an in silico investigation to explore the potential of Komaroviquinone, an icetexane diterpene, as a therapeutic agent against COVID-19. We employed molecular docking, molecular dynamics, and QM/MM methodologies to compare the binding affinity, molecular interactions, and stability of Komaroviquinone and the FDA-approved antiviral drug Nirmatrelvir with the SARS-CoV-2 Mpro protein. The study demonstrated that Komaroviquinone exhibits strong interaction with Mpro, with a binding energy comparable to Nirmatrelvir. The ADMET analysis revealed that Barbatusol, Brussonol, and Komaroviquinone possess superior solubility, permeability, and intestinal absorption compared to Nirmatrelvir, as well as more favorable distribution properties and lower toxicity profiles. Notably, Nirmatrelvir displayed toxicity and hepatotoxicity, which were not present in the natural compounds. Thus, it is suggested that Komaroviquinone may be a promising candidate for the development of effective and safer therapeutic agents against COVID-19. Experimental validation is necessary to confirm its potential as a treatment for the disease.

Discovery of highly functionalized grayanane diterpenoids from the flowers of Rhododendron molle as potent analgesics.

A systematical investigation on the chemical constituents of the flowers of Rhododendron molle (Ericaceae) led to the isolation and characterization of thirty-eight highly functionalized grayanane diterpenoids (1-38), including twelve novel analogues molleblossomins A-L (1-12). Their structures were elucidated by comprehensive methods, including 1D and 2D NMR analysis, calculated ECD, 13C NMR calculations with DP4+ probability analysis, and single crystal X-ray diffraction. Molleblossomins A (1), B (2), and E (5) are the first representatives of 2ß,3ß:9ß,10ß-diepoxygrayanane, 2,3-epoxygrayan-9(11)-ene, and 5,9-epoxygrayan-1(10),2(3)-diene diterpenoids, respectively. Molleblossomins G (7) and H (8) represent the first examples of 1,3-dioxolane-grayanane conjugates furnished with the acetaldehyde and 4-hydroxylbenzylidene acetal moieties, respectively. All grayanane diterpenoids 1-38 were screened for their analgesic activities in the acetic acid-induced writhing model, and all of them exhibited significant analgesic activities. Diterpenoids 6, 13, 14, 17, 20, and 25 showed more potent analgesic effects than morphine at a lower dose of 0.2 mg/kg, with the inhibition rates of 51.4%, 68.2%, 94.1%, 66.9%, 97.7%, and 60.0%, respectively. More importantly, even at the lowest dose of 0.04 mg/kg, rhodomollein X (14), rhodojaponin VI (20), and rhodojaponin VII (22) still significantly reduced the number of writhes in the acetic acid-induced pain model with the percentages of 61.7%, 85.8%, and 64.6%, respectively. The structure-activity relationship was summarized and might provide some hints to design novel analgesics based on the functionalized grayanane diterpenoids.

Improved production of Taxol® precursors in S. cerevisiae using combinatorial in silico design and metabolic engineering.

BACKGROUND: Integrated metabolic engineering approaches that combine system and synthetic biology tools enable the efficient design of microbial cell factories for synthesizing high-value products. In this study, we utilized in silico design algorithms on the yeast genome-scale model to predict genomic modifications that could enhance the production of early-step Taxol® in engineered Saccharomyces cerevisiae cells. RESULTS: Using constraint-based reconstruction and analysis (COBRA) methods, we narrowed down the solution set of genomic modification candidates. We screened 17 genomic modifications, including nine gene deletions and eight gene overexpressions, through wet-lab studies to determine their impact on taxadiene production, the first metabolite in the Taxol® biosynthetic pathway. Under different cultivation conditions, most single genomic modifications resulted in increased taxadiene production. The strain named KM32, which contained four overexpressed genes (ILV2, TRR1, ADE13, and ECM31) involved in branched-chain amino acid biosynthesis, the thioredoxin system, de novo purine synthesis, and the pantothenate pathway, respectively, exhibited the best performance. KM32 achieved a 50% increase in taxadiene production, reaching 215 mg/L. Furthermore, KM32 produced the highest reported yields of taxa-4(20),11-dien-5α-ol (T5α-ol) at 43.65 mg/L and taxa-4(20),11-dien-5-α-yl acetate (T5αAc) at 26.2 mg/L among early-step Taxol® metabolites in S. cerevisiae. CONCLUSIONS: This study highlights the effectiveness of computational and integrated approaches in identifying promising genomic modifications that can enhance the performance of yeast cell factories. By employing in silico design algorithms and wet-lab screening, we successfully improved taxadiene production in engineered S. cerevisiae strains. The best-performing strain, KM32, achieved substantial increases in taxadiene as well as production of T5α-ol and T5αAc. These findings emphasize the importance of using systematic and integrated strategies to develop efficient yeast cell factories, providing potential implications for the industrial production of high-value isoprenoids like Taxol®.

Unraveling Connective Tissue Growth Factor as a Therapeutic Target and Assessing Kahweol as a Potential Drug Candidate in Triple-Negative Breast Cancer Treatment.

Triple-negative breast cancer (TNBC) is characterized by aggressive behavior and limited treatment options, necessitating the identification of novel therapeutic targets. In this study, we investigated the clinical significance of connective tissue growth factor (CTGF) as a prognostic marker and explored the potential therapeutic effects of kahweol, a coffee diterpene molecule, in TNBC treatment. Initially, through a survival analysis on breast cancer patients from The Cancer Genome Atlas (TCGA) database, we found that CTGF exhibited significant prognostic effects exclusively in TNBC patients. To gain mechanistic insights, we performed the functional annotation and gene set enrichment analyses, revealing the involvement of CTGF in migratory pathways relevant to TNBC treatment. Subsequently, in vitro experiments using MDA-MB 231 cells, a representative TNBC cell line, demonstrated that recombinant CTGF (rCTGF) administration enhanced cell motility, whereas CTGF knockdown using CTGF siRNA resulted in reduced motility. Notably, rCTGF restored kahweol-reduced cell motility, providing compelling evidence for the role of CTGF in mediating kahweol's effects. At the molecular level, kahweol downregulated the protein expression of CTGF as well as critical signaling molecules, such as p-ERK, p-P38, p-PI3K/AKT, and p-FAK, associated with cell motility. In summary, our findings propose CTGF as a potential prognostic marker for guiding TNBC treatment and suggest kahweol as a promising antitumor compound capable of regulating CTGF expression to suppress cell motility in TNBC. These insights hold promise for the development of targeted therapies and improved clinical outcomes for TNBC patients.

Inhibitory efficiency of Andrographis paniculata extract on viral multiplication and nitric oxide production.

Andrographis paniculata (Burm. F.) Nees is a medicinal plant previously reported with broad-spectrum antivirals but the mode of inhibition remains elusive. The objective of this study was to identify the most active fraction from A. paniculata ethanol extract (APE, APE-2A, APE-2B and APE-2C) and dry powder extract (APSP) against influenza A (H3N2), representing RNA viruses, and herpes simplex virus-1 (HSV-1), representing DNA viruses. The results showed that the fractions APSP, APE, APE-2B, and APE-2C directly neutralized the HSV-1 and influenza A (H3N2) when incubated at room temperature for 60 min before infecting the cells. The results also showed that the additional APE-2A fraction also directly neutralized the influenza A (H3N2), but not the HSV-1. The APE, APE-2B and APE-2C inhibited the HSV-1 by more than 0.5 log when the fractions were introduced after infection. Similarly, the APSP and APE inhibited the influenza A (H3N2) more than 0.5 log after infection. Only 50 µg/mL APE-2C inhibited the viruses greater than 0.5 log. In addition, A. paniculata extracts were also evaluated for their interfering capacities against nitric oxide (NO) production in LPS-activated RAW 264.7 macrophages. As well, APE-2C potently inhibited NO production at the IC50 of 6.08 µg/mL. HPLC and LC-MS analysis indicated that the most actively antiviral fractions did not contain any andrographolide derivatives, whereas the andrographolide-rich fractions showed moderate activity.

Diterpenes and triterpenes show potential as biocides against pathogenic fungi and oomycetes: a screening study.

OBJECTIVES: The aim was to screen di- and triterpenes as potential biocides against fungal pathogens (Alternaria sp., Fusarium avenaceum, F. sambucinum, Botrytis cinerea, Botryotina fuckeliana, Mycocentrospora acerina, Cylindrocarpon sp.) and oomycetes (Phytophthora cactorum, P. fragariae). Results We measured the antifungal activity of terpenes by estimating the growth area, ergosterol content and level of lipid peroxidation. Fungi and oomycetes were grown on solid media in Petri dishes. As a positive control, we used a common synthetic fungicide, fosetyl-Al. Di- and triterpenes showed promising potential as biocides against most of the studied species. The responses of fungi and oomycetes were dependent on the specific type of terpenes and identity of the fungi. Compared to synthetic fungicide, terpenes were equally effective as antifungal agents and even more effective for some species, especially for oomycetes. The terpene mode of action includes inhibition of ergosterol synthesis and increased lipid peroxidation. Conclusions Di- and triterpenes, natural compounds that are very abundant in northern countries, are excellent candidates for biocides.

Diterpenes stability of commercial blends of roasted and ground coffees packed in copolymer coupled with aluminium and eco-friendly capsules.

Diterpenes are group of compounds of the terpenic fraction of roasted coffee and account for about 7-20 % (w/w) of the lipid fraction. Several parameters can influence their occurrence in coffee beans and beverages including species and post-harvest processing. Diterpenes in coffee have been studied extensively, but to the best of the authors' knowledge, there is no information in the literature on their stability over time. Coffee is a relatively stable product under optimal temperature, humidity and oxygen conditions. However, during storage it can undergo a series of chemical and physical reactions that alter its flavour and lead to rancidity, mainly due to the oxidative reactions that take place on the lipid fraction. In this study, the effect of long-term storage on the diterpene content of different commercial coffee blends and packaging is analysed and critically discussed. The Results show that the storage influences the internal environment of the capsules with an increase in moisture and a decrease in pH favouring more reactive conditions, especially for Eco capsules. Relative stability over time is observed for cafestol and kahweol. dehydro derivatives show a degradation up to T60 independently on the blends and packaging, which is not related to their precursors. The permeability of packaging and blends affect the modification of these components: while a drastic oxidation process takes place in Arabica eco compatible capsules (PC) when acidity and moisture increase, in Arabica/Robusta eco compatible capsules (IC) as well as in Arabica/Robusta and Arabica standard capsules (IS and PS) the peroxides tend to increase resulting in an autocatalytic propagation.

Chemical profile of the Anatolian Sideritis species with bioactivity studies.

CONTEXT: The genus Sideritis L. (Lamiaceae) is represented by 46 species in Turkey with an 79% endemism ratio, 42 of 46 belonging to the section Empodoclia. OBJECTIVE: In this review article, Sideritis species growing in Turkey have been evaluated for phytochemical constituents and biological activities. METHODS: The data for the isolates, components and extracts of the Anatolian Sideritis species and their bioactivity studies were retrieved from the main databases WoS, Scopus and PubMed from 1975 until 31 December 2022. RESULTS: In this review article, terpenoids, flavonoids, phenolics and other secondary metabolites isolated from Turkish Sideritis species were reported. Anatolian Sideritis species, which primarily consist of monoterpenes and sesquiterpenes, were studied in detail. Sideritis plants are represented by 46 species in Turkey, and 25 of them were investigated for their diterpenoids through isolation or LC-MS studies. Most of the diterpenoids of Turkish Sideritis species have ent-kaurene skeleton, among them linearol, siderol, 7-epicandicandiol and sideridiol were found to be the main compounds. Exceptionally, labdane, pimarane and beyerene diterpenoids were only found in a few species. For phenolics and flavonoids, only 12 species were investigated until now, and they were found to be rich in phenylethanoid glycosides and flavonoid glycosides. In terms of activity, most of the species were tested for antioxidant activity, followed by antimicrobial and anti-ulcer/anti-inflammatory activities. Their cytotoxic, enzyme inhibitory, antinociceptive and antistress activities were less frequently studied. CONCLUSIONS: Sideritis species should be considered promising therapeutic agents in the treatment of upper respiratory tract and ulcer/inflammatory diseases.

New Cyclopiane Diterpenes and Polyketide Derivatives from Marine Sediment-Derived Fungus Penicillium antarcticum KMM 4670 and Their Biological Activities.

Two new cyclopiane diterpenes and a new cladosporin precursor, together with four known related compounds, were isolated from the marine sediment-derived fungus Penicillium antarcticum KMM 4670, which was re-identified based on phylogenetic inference from ITS, BenA, CaM, and RPB2 gene regions. The absolute stereostructures of the isolated cyclopianes were determined using modified Mosher's method and quantum chemical calculations of the ECD spectra. The isolation from the natural source of two biosynthetic precursors of cladosporin from a natural source has been reported for the first time. The antimicrobial activities of the isolated compounds against Staphylococcus aureus, Escherichia coli, and Candida albicans as well as the inhibition of staphylococcal sortase A activity were investigated. Moreover, the cytotoxicity of the compounds to mammalian cardiomyocytes H9c2 was studied. As a result, new cyclopiane diterpene 13-epi-conidiogenone F was found to be a sortase A inhibitor and a promising anti-staphylococcal agent.

Indole Diterpenes from Mangrove Sediment-Derived Fungus Penicillium sp. UJNMF0740 Protect PC12 Cells against 6-OHDA-Induced Neurotoxicity via Regulating the PI3K/Akt Pathway.

In our chemical investigation into Penicillium sp. UJNMF0740 derived from mangrove sediment, fourteen indole diterpene analogs, including four new ones, are purified by multiple chromatographic separation methods, with their structures being elucidated by the analyses of NMR, HR-ESIMS, and ECD data. The antibacterial and neuroprotective effects of these isolates were examined, and only compounds 6 and 9 exhibited weak antibacterial activity, while compounds 5, 8, and 10 showed protective effects against the injury of PC12 cells induced by 6-hydroxydopamine (6-OHDA). Additionally, compound 5 could suppress the apoptosis and production of reactive oxygen species (ROS) in 6-OHDA-stimulated PC12 cells as well as trigger the phosphorylation of PI3K and Akt. Taken together, our work enriches the structural diversity of indole diterpenes and hints that compounds of this skeleton can repress the 6-OHDA-induced apoptosis of PC12 cells via regulating the PI3K/Akt signaling pathway, which provides evidence for the future utilization of this fascinating class of molecules as potential neuroprotective agents.

Tonantzitlolone B Modulates the Endogenous Opioid System to Promote Antinociception in Mice.

Tonantzitlolone B (TZL-B) is a diterpene isolated from the roots of Stillingia loranthacea. Its antinociceptive effects were investigated in male Swiss mice using the following models of pain: formalin test, inflammation induced by Complete Freund's Adjuvant (CFA), tail flick test, and cold plate test. The influence of TZL-B on the opioid system was assessed in vivo, using opioid antagonists; in silico, investigating the chemical similarity among TZL-B and opioid agonists; and ex vivo, measuring preproenkephalin (PENK) gene expression in the spinal cord by RT-qPCR. TZL-B (10-1000 µg/kg) promoted antinociception in the four experimental models without impairing mice's motor function. TZL-B did not alter paw edema during CFA-induced inflammation. The antinociceptive effects of TZL-B in the tail flick and cold plate tests were diminished by the opioid antagonists naloxone (5 mg/kg), NOR-BNI (0.5 mg/kg), naltrindole (3 mg/kg), and CTOP (1 mg/kg), indicating the involvement of κ-, δ-, and µ-opioid receptors. TZL-B showed no significant chemical similarity to opioid agonists, but the treatment with TZL-B (1000 µg/kg) increased PENK gene expression in the spinal cord of mice. These data suggest that TZL-B promotes antinociception by enhancing the transcription of PENK, hence modulating the endogenous opioid system.

Cryptic Isomerization in Diterpene Biosynthesis and the Restoration of an Evolutionarily Defunct P450.

Biosynthetic modifications of the 6/10-bicyclic hydrocarbon skeletons of the eunicellane family of diterpenoids are unknown. We explored the biosynthesis of a bacterial trans-eunicellane natural product, albireticulone A (3), and identified a novel isomerase that catalyzes cryptic isomerization in the biosynthetic pathway. We also assigned functions of two cytochromes P450 that oxidize the eunicellane skeleton, one of which was a naturally evolved non-functional P450 that, when genetically repaired, catalyzes allylic oxidation. Finally, we described the chemical susceptibility of the trans-eunicellane skeleton to undergo Cope rearrangement to yield inseparable atropisomers.

Functional Characterization of ent-Copalyl Diphosphate Synthase and Kaurene Synthase Genes from Coffea arabica L.

The biochemical profile of coffee beans translates directly into quality traits, nutraceutical and health promoting properties of the coffee beverage. Ent-kaurene is the ubiquitous precursor for gibberellin biosynthesis in plants, but it also serves as an intermediate in specialized (i.e., secondary) diterpenoid metabolism that leads to a diversity of more than 1,000 different metabolites. Nutraceutical effects on human health attributed to diterpenes include antioxidant, anticarcinogenic, and anti-inflammatory properties. Cafestol (CAF) and kahweol (KAH) are two diterpenes found exclusively in the Coffea genus. Our objective was to identify and functionally characterize genes involved in the central step of ent-kaurene production. We identified 17 putative terpene synthase genes in the transcriptome of Coffea arabica. Two ent-copalyl diphosphate synthase (CaCPS) and three kaurene synthase (CaKS) were selected and manually annotated. Transcript expression profiles of CaCPS1 and CaKS3 best matched the CAF and KAH metabolite profiles in different tissues. CaCPS1 and CaKS3 proteins were heterologously expressed and functionally characterized. CaCPS1 catalyzes the cyclization of geranylgeranyl diphosphate (GGPP) to ent-copalyl diphosphate (ent-CPP), which is converted to ent-kaurene by CaKS3. Knowledge about the central steps of diterpene formation in coffee provides a foundation for future characterization of the subsequent enzymes involved in CAF and KAH biosynthesis.

TMT-based quantitative proteomics reveals the targets of andrographolide on LPS-induced liver injury.

BACKGROUND: Andrographolide (Andro) is a diterpenoid derived from Andrographis paniculate, which has anti-inflammatory, antibacterial, antiviral and hepatoprotective activities. Gram-negative bacterial infections can cause varying degrees of liver injury in chickens, although Andro has been shown to have a protective effect on the liver, its underlying mechanism of action and effects on liver proteins are not known. METHODS: The toxicity of Andro on the viability of leghorn male hepatoma (LMH) cells at different concentrations and times was analyzed by CCK-8 assays. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in the culture supernatants were measured using an automatic biochemical analyzer to evaluate the protective effect of androscopolide on LPS-induced injury of LMH cells. Subsequently, TMT proteomics analysis were performed on the negative control group (NC group), LPS, and LPS-Andro groups, and bioinformatics analysis was performed on the differentially expressed proteins (DEPs). RESULTS: It was found that Andro reduced ALT and AST levels in the cell supernatant and alleviated LPS-induced injury in LMH cells. Proteomic analysis identified 50 and 166 differentially expressed proteins in the LPS vs. NC group and LPS-Andro vs. LPS group, respectively. Andro may be involved in steroid metabolic processes, negative regulation of MAPK cascade, oxidative stress, and other processes to protect against LPS-induced liver injury. CONCLUSIONS: Andro protects against LPS-induced liver injury, HMGCS1, HMGCR, FDPS, PBK, CAV1, PRDX1, PRDX4, and PRDX6, which were identified by differential proteomics, may be the targets of Andro. Our study may provide new theoretical support for Andro protection against liver injury.

Rearrangement of the Tetra- and Tricyclic Skeletons of Pepluanol B to Access the Core Structures of Tigliane- and Myrsinane-Type Euphorbia Diterpenes.

Pepluanol B is a new Euphorbia diterpene with an unprecedented tetracyclic backbone. However, its biogenetic relationship with known Euphorbia diterpenes is unclear. We report herein that its ß-hydroxyl ketone motif could undergo a base-promoted retro-aldol/aldol process in two pathways and afford the skeletons of tigliane- and myrsinane-type Euphorbia diterpenes through the formation of the C8-C14 and C7-C13 bonds, respectively. The retro-aldol/aldol cascade indicates that pepluanol B is possibly a biosynthetic precursor of lathyranes and other relevant dipterpenes.

Biosynthesis of Phomactin Platelet Activating Factor Antagonist Requires a Two-Enzyme Cascade.

Phomactin diterpenoids possess a unique bicyclo[9.3.1]pentadecane skeleton with multiple oxidative modifications, and are good platelet-activating factor (PAF) antagonists that can inhibit PAF-induced platelet aggregation. In this study, we identified the gene cluster (phm) responsible for the biosynthesis of phomactins from a marine fungus, Phoma sp. ATCC 74077. Despite the complexity of their structures, phomactin biosynthesis only requires two enzymes: a type I diterpene cyclase PhmA and a P450 monooxygenase PhmC. PhmA was found to catalyze the formation of the phomactatriene, while PhmC sequentially catalyzes the oxidation of multiple sites, leading to the generation of structurally diverse phomactins. The rearrangement mechanism of the diterpene scaffold was investigated through isotope labeling experiments. Additionally, we obtained the crystal complex of PhmA with its substrate analogue FGGPP and elucidated the novel metal-ion-binding mode and enzymatic mechanism of PhmA through site-directed mutagenesis. This study provides the first insight into the biosynthesis of phomactins, laying the foundation for the efficient production of phomactin natural products using synthetic biology approaches.

[Research progress in tigliane-type macrocyclic diterpenoids].

Tigliane type macrocyclic diterpenoids with special structures and diverse bioactivities are mainly extracted from plants of Euphorbiaceae and Thymelaeaceae. According to the different functional groups, they can be classified into types of phorbol esters, C-4 deoxyphorbol esters, C-12 deoxyphorbol esters, C-16 or C-17 substituted phorbol esters and others. Most of them present promising antiviral activities and cytotoxic activities and are expected to be developed as candidates for anti-AIDS, anti-tuberculosis, and anti-tumor clinical trials, demonstrating great potential for the application in healthcare. This paper reviews 115 novel tigliane-type diterpenoids discovered since 2013 and summarize their chemical structures and bioactivities, aiming to lay a foundation for further development and utilization of these compounds and provide new ideas for the development of clinical drugs.

[Research progress in clinical application and pharmacological effect of Yiyi Fuzi Baijiang Powder].

Yiyi Fuzi Baijiang Powder(YFBP), originating from Synopsis of the Golden Chamber, is a classic prescription composed of Coicis Semen, Aconiti Lateralis Radix Praeparata, and Patriniae Herba for the treatment of abscesses and pus discharge. This article presented a systematic analysis of the clinical application of YFBP, including the indicated diseases, the number of cases, efficacy, dosage, administration methods, and compatibility with other drugs. The analysis reveals that YFBP has a wide range of clinical applications. It is commonly used, often with modifications or in combination with western medicine, for diseases in the fields of gastroente-rology, gynecology, urology, dermatology, and others. And most of the Traditional Chinese Medicine(TCM) evidence involved in these diseases are damp-heat evudence. The prescription shows rich variations in clinical administration methods, and most of which are the treatment of aqueous decoction of it. The therapeutic effect is also significant, and the total effective rate of clinical treatment is re-latively high. Additionally, this article summarized the pharmacological research on YFBP and found that it possessed various pharmacological effects, including anti-inflammatory, antioxidant, anticancer, and immune-modulating properties. Finally, correlation analysis was conducted on the main diseases, TCM types, prescription doses, pharmacological effects and action targets of YFBP, which to show the relationship between these five aspects in a visual form, reflecting the relationship between its clinical application and modern pharmacological effects. These findings provide a reference basis for further development and research on YFBP.