Discovery of a highly potent and orally available importin-β1 inhibitor that overcomes enzalutamide-resistance in advanced prostate cancer

Nuclear transporter importin-β1 is emerging as an attractive target by virtue of its prevalence in many cancers. However, the lack of druggable inhibitors restricts its therapeutic proof of concept. In the present work, we optimized a natural importin-β1 inhibitor DD1 to afford an improved analog DD1-Br with better tolerability (>25 folds) and oral bioavailability. DD1-Br inhibited the survival of castration-resistant prostate cancer (CRPC) cells with sub-nanomolar potency and completely prevented tumor growth in resistant CRPC models both in monotherapy (0.5 mg/kg) and in enzalutamide-combination therapy. Mechanistic study revealed that by targeting importin-β1, DD1-Br markedly inhibited the nuclear accumulation of multiple CRPC drivers, particularly AR-V7, a main contributor to enzalutamide resistance, leading to the integral suppression of downstream oncogenic signaling. This study provides a promising lead for CRPC and demonstrates the potential of overcoming drug resistance in advanced CRPC via targeting importin-β1.

Improving cancer immunotherapy via co-delivering checkpoint blockade and thrombospondin-1 downregulator

The use of checkpoint-blockade antibodies is still restricted in several malignancies due to the modest efficacy, despite considerable success in anti-tumor immunotherapy. The poor response of cancer cells to immune destruction is an essential contributor to the failure of checkpoint therapy. We hypothesized that combining checkpoint therapy with natural-product chemosensitizer could enhance immune response. Herein, a targeted diterpenoid derivative was integrated with the checkpoint blockade (anti-CTLA-4) to improve immunotherapy using thermosensitive liposomes as carriers. In vivo, the liposomes enabled the co-delivery of the two drug payloads into the tumor. Consequently, the regulatory T cell proliferation was restrained, the cytotoxic T cell infiltration was enhanced, and the profound immunotherapeutic effect was achieved. In addition, the immunotherapeutic effect of another clinically used checkpoint antibody, anti-PD-1, also benefited from the diterpenoid derivative. Of note, our mechanism study revealed that the targeted diterpenoid derivative increased the sensitivity of cancer cells to immune attack via THBS1 downregulation and the resultant destruction of THBS1-CD47 interaction. Collectively, co-delivering THBS1 inhibitor and checkpoint blockade is promising to boost cancer immunotherapy. We first time discovered that THBS1 suppression could strengthen checkpoint therapy.

Two new terpene glycosides from the Alpiniae Oxyphyllae Fructus / 药学学报

Two undescribed terpene glycosides and two compounds were isolated from the n-butanol fraction of Alpiniae Oxyphyllae Fructus by using various chromatographic methods, including MCI Gel, Sephadex LH-20, ODS, silica gel and semi-preparative HPLC. The structures of the isolated compounds were identified by spectroscopy methods (1D, 2D NMR, UV, IR, MS, etc.), and the absolute configuration of the compound 1 was determined by ECD calculation and acid hydrolysis. Compounds 1 and 2 are new compound, and compounds 3 and 4 were isolated from Alpiniae Oxyphyllae Fructus for the first time.

New di-spirocyclic labdane diterpenoids from the aerial parts of Leonurus japonicus / 中国天然药物

Phytochemical investigation on the ethanol extract of a well-known medicinal herb Leonurus japonicus, led to the separation of 18 labdane type diterpenoids (1-18). Through comprehensive spectroscopic analyses and quantum chemical calculations, these compounds were structurally characterized as six new interesting 5,5,5-di-spirocyclic ones (1-6), two new (7 and 8) and six known (13-18) interesting 6,5,5-di-spirocyclic ones, a new rare 14,15-dinor derivative (9), and three new ones incorporating a γ-lactone unit (10-12). An in vitro neuroprotective assay in RSC96 cells revealed that compounds 7 and 12 exhibited neuroprotective activity in a concentration-dependent way, comparable to the reference drug N-acetylcysteine.

Combined analysis of transcriptomics and metabolomics revealed complex metabolic genes for diterpenoids biosynthesis in different organs of Anoectochilus roxburghii / 中草药·英文版

OBJECTIVE@#Diterpenoids with a wide variety of biological activities from Anoectochilus roxburghii, a precious medicinal plant, are important active components. However, due to the lack of genetic information on the metabolic process of diterpenoids in A. roxburghii, the genes involved in the molecular regulation mechanism of diterpenoid metabolism are still unclear. This study revealed the complex metabolic genes for diterpenoids biosynthesis in different organs of A. roxburghii by combining analysis of transcriptomics and metabolomics.@*METHODS@#The differences in diterpenoid accumulation in roots, stems and leaves of A. roxburghii were analyzed by metabonomic analysis, and its metabolic gene information was obtained by transcriptome sequencing. Then, the molecular mechanism of differential diterpenoid accumulation in different organs of A. roxburghii was analyzed from the perspective of gene expression patterns.@*RESULTS@#A total of 296 terpenoid metabolites were identified in the five terpenoid metabolic pathways in A. roxburghii. There were 38, 34, and 18 diterpenoids with different contents between roots and leaves, between leaves and stems, and between roots and stems, respectively. Twenty-nine metabolic enzyme genes with 883 unigenes in the diterpenoid synthesis process were identified, and the DXS and FDPS in the terpenoid backbone biosynthesis stage and CPA, GA20ox, GA3ox, GA2ox, and MAS in the diterpenoid biosynthesis stage were predicted to be the key metabolic enzymes for the accumulation of diterpenoids. In addition, 14 key transcription factor coding genes were predicted to be involved in the regulation of the diterpenoid biosynthesis. The expression of genes such as GA2ox, MAS, CPA, GA20ox and GA3ox might be activated by some of the 14 transcription factors. The transcription factor NTF-Y and PRE6 were predicted to be the most important transcription factors.@*CONCLUSION@#This study determined 29 metabolic enzyme genes and predicted 14 transcription factors involved in the molecular regulation mechanism of diterpenoid metabolism in A. roxburghii, which provided a reference for the further study of the molecular regulation mechanism of the accumulation of diterpenoids in different organs of A. roxburghii.

Three new diterpenoids from whole herb of Carpesium cernuum / 中国中药杂志

The study investigated the chemical constituents from the whole herb of Carpesium cernuum. Three new diterpenoids were isolated from the whole herb of C. cernuum by column chromatography on silica gel, Sephadex LH-20, and semi-preparative HPLC. Their structures were identified by MS, NMR and other spectral techniques. The isolates were identified as(5Z)-2-oxo-2, 10, 14-trimethylhexadeca-5, 13-diene-11α, 18-diol(1),(2E, 10E)-7-[(acetyloxy)methyl]-3, 11, 15-trimethylhexadeca-2, 10, 14-triene-1, 12α-diol(2),(2E, 6Z)-3, 11, 15-trimethylhexadeca-2, 6, 14-triene-1, 12α, 19-triol(3), respectively. The cytotoxic activity of compounds 1-3 were investigated with DU-145, MCF-7, and A549 cells by MTT. The results showed that compound 1 and 3 had certain inhibitory effects on MCF-7 cells, with the inhibition rates of 45.06% and 29.40%, respectively.

Progress in antitumor activity of diterpenoid alkaloids in plants of Aconitum / 中国中药杂志

Small-molecule compounds with rich sources have diverse structures and activities. The active ingredients in traditional Chinese medicine(TCM) provide new sources for the discovery of new antitumor drugs. Aconitum plants as Chinese medicinal plants have the effects of dispelling wind, removing dampness, warming meridian, and relieving pain. They are mainly used to treat inflammation, pain, rheumatism, and tumors, improve heart function, and dilate blood vessels in clinical practice. Diterpenoid alkaloids are the main active components of Aconitum plants, including C20-, C19-, C18-diterpenoid alkaloids and bis-diterpenoid alkaloids. Stu-dies have demonstrated that diterpenoid alkaloids can effectively treat lung cancer, liver cancer, breast cancer, colon cancer and other cancers. Diterpenoid alkaloids are considered as the most promising natural compounds against cancers. In this review, we summarized the chemical structures and antitumor activities of C20-, C19-, C18-diterpenoid alkaloids and bis-diterpenoid alkaloids extracted from plants of Aconitum, aiming to provide reference for further development of diterpenoid alkaloids from Aconitum as antitumor drugs.

Diterpenoids from Rabdosia flexicaulis / 中国中药杂志

The genus Rabdosia is famous for the abundance of diverse and novel ent-kaurane diterpenoids. However, only a few ent-kauranoids have been discovered from R. flexicaulis since the investigation on its chemical constituents is not systematic. To find novel bioactive diterpenoids, the ethyl acetate extract of the above ground part of R. flexicaulis in Daofu County, Sichuan Province was obtained by column chromatography. One new compound and five known ones were identified as flexicaulin E(1), forrestin B(2), inf-lexarabdonin D(3), 7α-hydroxydehydroabietic acid(4), 15-hydroxydehydroabietic acid(5), and pomiferin F(6) by spectral techniques. Compounds 1-3 were the ent-kaurane diterpenoids isolated from this species for the first time. Compounds 4-6, aromatic abie-tanoids, were isolated from the genus Rabdosia for the first time.

Anti-dengue virus activity of natural podocarpane-type diterpenoid in vitro / 药学学报

Dengue virus (DENV) is the most rapidly transmitted mosquito-borne pathogen, which is the main cause of seasonal outbreaks of dengue fever and dengue hemorrhagic fever in tropical and subtropical regions, and may cause serious life-threatening diseases. There is an urgent need to develop effective vaccines or antiviral therapies. In this paper, we found that a podocarpane-type diterpenoid, (3α,5β,10α)-13-methoxypodocarpa-8,11,13-triene-3,12-diol (MPTD), isolated from the stems and leaves of Aleurites moluccana, showed good effect against DENV. The anti-DENV activity of MPTD against four different DENV serotypes was studied by plaque assay. The cytotoxicity of MPTD in Vero and Huh7 cells was tested by MTT assay. qRT-PCR and Western blot assays were used to investigate the anti-DENV activity of MPTD at RNA and protein levels, respectively. The results showed that MPTD greatly reduced the virus titer in DENV infected Vero cells, and its 50% effective concentration (EC50) for DENV (1–4) were 2.72 ± 0.39, 10.99 ± 5.18, 18.72 ± 0.21, and 0.48 ± 0.28 μmol·L-1, respectively. The results showed that MPTD inhibits DENV RNA level and the expression of E protein. In addition, MPTD may inhibit the early stage of DENV replication and exert antiviral activity. Further studies showed that the inhibitory effect of MPTD against DENV infection is not targeting the viral entry stage. Therefore, MPTD has a significant anti-dengue virus effect, and is an anti-DENV compound with potential application value.

Diterpenoid alkaloids from roots of Aconitum kongboense / 中国中药杂志

The chemical constituents from the roots of Aconitum kongboense were studied. Twenty-five diterpenoid alkaloids were isolated from the 95% methanol extract of the roots of A. kongboense by silica gel, reverse-phase silica gel and basic alumina column chromatography. They included a new aconitine-type diterpenoid alkaloid, named as kongboensenine(1), and twenty-four known ones(2-25), i.e., acotarine F(2), acotarine G(3), 14-acetyltalatisamine(4), talatisamine(5), indaconitine(6), yunaconitine(7), chasmanine(8), 6-epi-foresticine(9), homochasmanine(10), 8-deacetyl-yunaconitine(11), chasmaconitine(12), ajaconine(13), franchetine(14), ezochasmanine(15), crassicautine(16), 14-O-deacylcrassicausine(17), genicunine A(18), falconeridine(19), sachaconitine(20), liljestrandisine(21), 8-methyl-14-acetyltalatisamine(22), kongboendine(23), 14-benzoylchasmanine(24) and pseudaconine(25). Their structures were elucidated by common spectroscopic methods including high-resolution electrospray ionization mass spectrometry(HR-ESI-MS) and nuclear magnetic resonance(NMR) techniques. Compounds 2-4, 10, 13, 15-19 and 21-22 were isolated from this plant for the first time. Experimental results showed that all compounds did not have a significant inhibitory activity against acetylcholinesterase(AChE).

Anti-rheumatoid arthritis potential of diterpenoid fraction derived from Rhododendron molle fruits / 中国天然药物

Rhododendron molle G. Don is first recorded in Shengnong's Herbal Classic, and its fruits, which are termed as Liuzhouzi, are often used to treat rheumatoid arthritis in Chinese folk. During our ongoing investigation to develop a safer and potential new arthritis therapy, a process for the preparation of diterpenoid fraction from Rhododendron mollefruits was established. In order to evaluate the main components and the anti-rheumatoid arthritis effect of the diterpenoid fraction, phytochemical and pharmacological experiments were used. As the result, the main components of diterpenoid fraction were identified as rhodojaponin III (1), rhodojaponin VI (2), 2-O-methylrhodojaponin (3), and 5'-β-D-glucopyranosy-loxyjasmonic acid (4). These four components constitute greater than 95% of diterpenoid fraction using area normalization method of HPLC-ELSD. The results of CIA rat experiment showed that high dose of diterpenoid fraction (0.6 mg·kg

Research progress on structure and activity of C19 diterpeneoid alkaloids from Aconiti Lateralis Radix Praeparata / 中草药

Aconiti Lateralis Radix Praeparata (Fuzi in Chinese) is a commonly used Chinese materia medica in clinic, with the effects in rescuing from collapse by restoring yang, eliminating cold to stop pain, warming yang and transforming qi. C19 diterpenoid alkaloids from Fuzi can be divided into three types: diester type, monoester type and amine alcohol type, which can lead to neurotoxicity and cardiotoxicity while exerting anti-inflammatory, analgesic, anti-tumor and other pharmacodynamic effects. In this paper, the chemical structure, pharmacology and toxicological effects of C19 diterpene alkaloids of Fuzi were systematically combed, in order to provide a theoretical basis for safer and more effective use of Fuzi in clinic.

Non-diterpenoid alkaloids in aerial parts of Aconitum carmichaelii / 中草药

Objective: To study the chemical constituents in the aerial parts of Aconitum carmichaelii. Methods: The air-dried arial parts of A. carmichaelii were powdered and extracted with methanol by percolation extraction. After the removal of solvent under reduced pressure, the crude extract was dissolved in 1.5% HCl solution, and then extracted by ethyl acetate to obtain the total crude extract. The compounds were isolated and purified by column chromatography and identified by spectral analyses (MS, 13C-NMR, and 1H-NMR). Results: Fifteen compounds were isolated from A. carmichaelii and characterized as indol-3-carboxylic acid (1), corchoionol C (2), β-sitosterol-3-O-β-D-glucoside-6’-palmitate (3), (+)-pinoresinol (4), (+)-N-formylnorglaucine (5), oxoglaucidaline (6), glaucine (7), (+)-cataline (8), kaempferol-7-O-α-L-rhamnofuranoside (9), kaempferol-3-O-β-(2″-acetyl)-galactopyranoside (10), megastigmane (11), kaempferol-7-O-α-L-arabinoside (12), kaempferol-3-O-β-D-xylopyranoside (13), kaempferol-3-O-β-D- glucopyranoside (14), and quercetin-3-O-β-D-galactopyranoside (15). Conclusion: All compounds are isolated from aerial parts of A. carmichaelii for the first time, and compounds 1-3,5-6,8-15 are isolated from this plant for the first time.

A new neo-clerodane diterpenoid from Salvia tiliifolia / 中草药

Objective: To study the chemical constituents of the aerial parts of Salvia tiliifolia. Methods: The compounds were isolated and purified by various modern chromatographies, and their structures were identified by spectroscopic data. Results: Two compounds were isolated from the acetone extract of the aerial parts of S. tiliifolia, which were elucidated as 1-(furan-3-yl)-8- (2-oxo- 2,5-dihydrofuran-3-yl)-1,7,8,9-tetrahydronaphtho[1,2-c]furan-3,6-dione (1) and dugesin B (2). Conclusion: Compound 1 is a new clerodane diterpene with no cytotoxicity, named as 1-keto-tilifodiolide.

Mechanism of wangzaozin A, an ent-kaurane diterpene, on cytoskeletal rearrangement and migration inhibition of A549 cells / 中草药

Objective: To investigate the mechanism of cytoskeletal recombination and migration inhibition induced by wangzaozin A, ent-kaurane diterpenoid, in A549 cells. Methods: The effects of wangzaozin A on cytotoxicity, cell morphology, cytoskeleton and protein expression as well as cell migration were detected in A549 cells by using MTT, microscope observation, Western blotting, immunofluorescence assay and scratch assay. Results: Wangzaozin A induced significant changes in cell morphology at 24, 48 and 72 h, including increased pseudopods, stretched pseudopods and flattened nucleus in A549 cells. Moreover, microtubules and keratin fibers networks in A549 cells also showed obvious rearrangement, which indicated the cytoskeleton had gone through a continuous recombination process. Further, wangzaozin A significantly increased the phosphorylation of extracellular regulated protein kinase (ERK), microtubule-associated protein 4 (MAP4), keratin 8 (K8) (P < 0.05, 0.01), while wangzaozin A-induced phosphorylation of MAP4 and K8 were suppressed in A549 cells treated with ERK inhibitors U0126 (P < 0.05, 0.01); Wangzaozin A inhibited the migration of A549 cells with a correlation between concentration and time. Conclusion: Wangzaozin A can upregulate the phosphorylation of MAP4 and K8 by activating ERK signaling pathway, which can significantly increase the dynamics of MTs and KFs, disturb the dynamic balance of the cytoskeleton, and inhibit the migration of A549 cells.

Antinociceptive grayanane-derived diterpenoids from flowers of

Twelve new grayanoids (-) along with five known compounds were isolated from flowers of . Their structures were fully characterized using a combination of spectroscopic analyses, computational calculations, and single crystal X-ray diffraction. Rhomollone A () possesses an unprecedented 5/6/6/5 tetra-cyclic ring system (B- grayanane) incorporating a cyclopentene-1,3-dione scaffold. Rhodomollein XLIII () is a dimeric grayanoid, containing a novel 14-membered heterocyclic ring with a symmetry axis. The antinociceptive activities of compounds , , , , and - were evaluated by an acetic acid-induced writhing test. Among them, compounds , , , and displayed significant antinociceptive activities at a dose of 20 mg/kg with inhibition rates ranging from 41.9% to 91.6%. Compounds and inhibited 46.0% and 39.4% of the acetic acid-induced writhes at a dose of 2 mg/kg, while compound inhibited 34.3% of the writhes at a dose of 0.4 mg/kg.

A new briarane-type diterpenoid from the South China Sea gorgonian Junceella fragilis / 药学学报

The chemical constituents of gorgonian Junceella fragilis Ridley, collected from Ximao Island, the South China Sea, were investigated. A new briarane-type diterpenoid, named fragilide Y (1), together with five known compounds (2–6), namely fragilide D (2), cholesterol (3), ergosterol peroxide (4), 2'-deoxythymidine (5) and cis-thyminenol (6), were isolated from the acetone extract of J. fragilis. The structure of the new compound 1 was elucidated by extensive spectroscopic analysis, while the known compounds were identified by comparison with the reported data. In bioassay, none of these compounds displayed obvious anti-inflammatory and cytotoxic effects.

The crucial role of metabolic regulation in differential hepatotoxicity induced by furanoids in Dioscorea bulbifera / 中国天然药物

Diterpenoid lactones (DLs), a group of furan-containing compounds found in Dioscorea bulbifera L. (DB), have been reported to be associated with hepatotoxicity. Different hepatotoxicities of these DLs have been observed in vitro, but reasonable explanations for the differential hepatotoxicity have not been provided. Herein, the present study aimed to confirm the potential factors that contribute to varied hepatotoxicity of four representative DLs (diosbulbins A, B, C, F). In vitro toxic effects were evaluated in various cell models and the interactions between DLs and CYP3A4 at the atomic level were simulated by molecular docking. Results showed that DLs exhibited varied cytotoxicities, and that CYP3A4 played a modulatory role in this process. Moreover, structural variation may cause different affinities between DLs and CYP3A4, which was positively correlated with the observation of cytotoxicity. In addition, analysis of the glutathione (GSH) conjugates indicated that reactive intermediates were formed by metabolic oxidation that occurred on the furan moiety of DLs, whereas, GSH consumption analysis reflected the consistency between the reactive metabolites and the hepatotoxicity. Collectively, our findings illustrated that the metabolic regulation played a crucial role in generating the varied hepatotoxicity of DLs.

Jar-TTA, a natural diterpenoid derivatives, induces apoptosis in human esophageal cancer cells through dual inhibition of glycolysis and oxidative phosphorylation / 中国药理学通报

Aim To investigate the effects of Jar-TTA in dual inhibition of glycolysis/oxidative phosphoryla-tion in human esophageal cancer cells and explore the related molecular mechanism. Methods The effect of Jar-TTA on the esophageal cancer cell EC 109 and KYSE-150 viability was examined using MTT assay. The effect of Jar-TTA in apoptosis morphology and mitochondrial membrane potential ( MMP) was observed by a fluorescence microscopy. The apoptosis of cell lines treated with Jar-TTA, the quantitative analysis of MMP falling, as well as the glucose uptake was ana-lyzed by flow cytometry. The mitochondrial OXPHOS and glycolysis of EC 109 cells in response to Jar-TTA were analyzed using a Seahorse XFp extracellular flux analyzer by real-time measurements of the oxygen consumption rate (OCR, indicative of mitochondrial OXPHOS) and extracellular acidification rate(ECAR, indicative of glycolysis). The expression of the proteins related with glycolysis were detected by Western blot. Results Jar-TTA caused strong antiproliferation in EC 109 and KYSE-150 cells in a concentration-dependent manner. 2 , 4 and 8 jimol • L"1 Jar-TTA treat-ments of EC 109 cells for 24 h resulted in a significant increase of early apoptosis population up to (27. 9 ± 6. 1)%, (71.1 ±9.3)% and (65. 0 ±9.5)%, respectively , compared to control treated cells (5. 6 ± 3.2)%. The mitochondrial OXPHOS and glycolysis were significantly inhibited in EC 109 incubated by 4 and 8 p,mol • L"1 Jar-TTA for 2 h. In addition, Jar-TTA induced the drop of MiMP. Furthermore, the glucose uptake and the expression of GLUT4 and LDHA were distinctly inhibited in EC 109 treated by Jar-TTA. Conclusions Jar-TTA induces apoptosis of human e-sophageal cancer cells through dual inhibition of glycolysis and oxidative phosphorylation, which is related with the drop of MMP collapse, the decrease of glucose uptake and the down-regulation of GLUT4 and LDHA in EC 109 treated by Jar-TTA.

A new monoterpenoid glycoside from aerial parts of Siegesbeckia pubescens / 中草药

Objective: To study the chemical constituents of the aerial parts of Siegesbeckia pubescens. Methods: A systematic separation of chemical constituents was conducted. Detailed chemical investigation of S. pubescens led to the isolation of six compounds by comprehensive chromatographic Methods: (Extraction, Silic gel C.C, Sephadex LH-20, ODS C. C). The structures of them were fully determined based on spectroscopic analysis including IR, HR-ESI-MS, ESI-MS, 1H-NMR, 13C-NMR, DEPT, HSQC, and HMBC spectrum. Results: A total of six compounds were isolated from the fraction of n-butanol extract of S. pubescens including one new monoterpenoid glycoside named (2Z,5E)-7-hydroxy-3,7-dimethyl-2,5-octadiene-1-O-[α-L-rhamnpyranosyl (1→6)]-β-D-glucopyranoside (1), four known diterpenoid glucosides named pubeside D (2), ent-15,16,19-trihydroxypimar- 8(14)-en-2-one-19-O-β-glucopyranoside (3), ent-15,16-dihydroxypimar-8(14)-en-2-one-19-oic-β-glucopyranoside (4), and neodarutoside (5), and eleutherazine B (6). Conclusion: Compound 1 is a new compound, named as siegeside F, and compound 6 is isolated from this species for the first time.