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.

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.

Induction effects of rabdosin B on differentiation of human promyelocytic leukemia HL-60 cells / 中草药

Objective To investigate the characteristics and mechanism of spironolactone ent-kaurane diterpene type diterpene rabdosin B (RB) induced HL-60 differentiation into mature granulocytes. Methods The effects of RB on proliferation, cell cycle, NBT reducing power, phagocytosis, and cell surface antigen CD11b expression of HL-60 were detected by trypan blue staining, Giemsa staining, NBT reducing power assay, and flow cytometry, respectively. Results RB inhibited the proliferation of HL-60 cells at the concentration of 1.0, 3.0, and 5.0 μmol/L, which resulted in the arrest of G0/G1 phase, increased the ratio of renal nucleated and lobate nucleus, and markedly enhanced the NBT reducing power and phagocytic capacity and the significant increase of CD11b positive cell rate. Further tests showed that the active oxygen scavenger NAC (300 μmol/L), NADPH oxidase inhibitor APO (100 μmol/L), and DPI (0.1 μmol/L) not only significantly inhibited the intracellular ROS upregulation induced by RB, but also inhibited various features of RB induced HL-60 cell differentiation. Conclusion RB can increase the activity of NADPH oxidase in HL-60 cells, increase the intracellular ROS concentration, and induce the differentiation of HL-60 cells to mature granulocytes.

A new ent-kaurane diterpenoid from Isodon eriocalyx / 中草药

To study the chemical constituents from the stems and leaves of Isodon eriocalyx. Methods The chemical constituent of I. eriocalyx was separated and purified by chromatographic methods and structurally elucidated by physicochemical characteristics and spectral data. Results One new compound was isolated from the stems and leaves of I. eriocalyx, and it was identified as 15β-acetoxy-1α-hydroxy-7α,20-epoxy-ent-kaur-16-en-6-one (1). Conclusion Compound 1 is a new ent-kaurane diterpenoid named as eriocalyxin H.

Scopariusols L-T, nine new ent-kaurane diterpenoids isolated from Isodon scoparius / 中国天然药物

Nine new ent-kaurane diterpenoids, named scopariusols L-T (1-9), were isolated from the aerial parts of Isodon scoparius. Their structures were characterized mainly by analyzing the NMR and HR-ESI-MS data, and the absolute configuration of 1 was determined by single-crystal X-ray diffraction. Compound 1 was active against five human tumor cell lines (HL-60, SMMC-7721, A-549, MCF-7, and SW-480), and it also inhibited NO production in LPS-stimulated RAW264.7 cells, with an IC value of 0.6 μmol·L.

Scopariusols L-T, nine new ent-kaurane diterpenoids isolated from Isodon scoparius / 中国天然药物

Nine new ent-kaurane diterpenoids, named scopariusols L-T (1-9), were isolated from the aerial parts of Isodon scoparius. Their structures were characterized mainly by analyzing the NMR and HR-ESI-MS data, and the absolute configuration of 1 was determined by single-crystal X-ray diffraction. Compound 1 was active against five human tumor cell lines (HL-60, SMMC-7721, A-549, MCF-7, and SW-480), and it also inhibited NO production in LPS-stimulated RAW264.7 cells, with an IC value of 0.6 μmol·L.

Antitumor activityand mechanism of JD20,a newly synthetic analog of natural ent-kaurane diterpenoid / 中国药理学与毒理学杂志

OBJECTIVE To study the anti-tumor activity and molecular mechanism of natural diter-pene derivative JD20 in vitro. METHODS Screening the sensitive of gastric carcinoma cell lines to JD20 by cytotoxicity test for 24 h.Cell morphology was evaluated by using DAPI.After staining of can-cer cells with PI or annexin V-FITC/PI respectively,the cell cycle and apoptosis induced by JD20 were detectded by flow cytometry. The change in cell membrane potential was detected by JC-1 test kit. Western blot method was used to detect the apoptosis-related protein. RESULTS The novel natural kaurane diterpene derivative JD20 had a significant inhibitory effect on tumor cells and was particularly active on gastric cancer cell lines HGC-27 (IC50=4.72 ± 1.37 μmol·L- 1) and MGC-803 (IC50=7.36 ± 0.86 μmol·L-1).Further studies found that JD20 resulted in thecell cycle arrest in the G2/M phase,and induced a significant apoptosis in HGC-27. In addition, JD20 also caused the drop of mitochondrial membrane potential of HGC-27 within a short time (3 h). Furthermore, the Western blotting analysis showed that JD20 could induce the up-regulation of p53,Bax and Bim protein expression in gastric can-cer cells,and the releasing of cytochrome c from the mitochondria into the cytoplasm,as well as the ac-tivation of casepase-9/3.CONCLUSION The natural kaurane diterpene derivative JD20 can inhibit the proliferation of various human cancer cells by blocking the cell cycle and inducing apoptosis, and its mechanism of inducing apoptosis may be related to the mitochondria-mediated apoptosis pathway.

Fragmentation pathways of five characteristic diterpenoid compounds in Isodon coetsa / 中草药

Objective To study the fragmentation pathways of five 7,20-cyclo-ent-kaurane diterpenoid compounds (rabdocoetsin B, megathyrin B, rabdocoetsin A, enanderianin N, and megathyrin A) in Isodon coetsa. Methods The samples were analyzed by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS2). According to the fragment in MS2 of five compounds, the possible fragmentation pathways of these diterpenoid compounds were inducted. Results In negative mode, the typical fragmentation pathways of these compounds in high-quality areas were mainly loss of substituents on C-1, C-7, and the oxygen bridge on C-20. The fragmentation pathways were different as a result of the difference of the substituents on C-1. The fragment, which in medium and low quality areas, suggested that fracture order of these compounds were A ring to B and then to C ring. Conclusion The study on fragmentation pathways contributed to the structural identification of 7,20-cyclo-ent-kaurane diterpenoid compounds.

Chemical constituents from Pteris dispar and their anti-tumor activity in vitro / 中国中药杂志

The dried whole plant of Pteris dispar were milled and extracted with 95% EtOH. The resulting dried extract was isolated by kinds of chromatographic column, including polyamide, Sephadex LH-20, preparative HPLC. As a result, ten diterpenes were isolated from the plant. By analyzing of ESI-MS and NMR spectroscopic data, the structures were established as geopyxin B(1), geopyxin E(2), ent-11α-hydroxy-18-acetoxykaur-16-ene(3), ent-14β-hydroxy-18-acetoxykaur-16-ene(4), neolaxiflorin L(5), ent-3β,19-dihydroxy-kaur-16-ene(6), ent-3β-hydroxy-kaur-16-ene(7), 7β,17-dihydroxy-16α-ent-kauran-19-oic acid 19-O-β-D-glucopyranoside ester(8), crotonkinin C(9)and crotonkinin C(10). Compounds 1-10 were obtained from P. dispar for the first time. Compounds 1 and 2 showed moderate activities against Bel-7402 with IC₅₀ values of 7.50 and 10.60 μmol•L⁻¹, and against HepG2 with IC₅₀ values of 6.68,11.80 μmol•L⁻¹, respectively.

A new diterpenoid from Isodon nervosus / 中草药

Objective: To study the chemical constituents from the stems and leaves of Isodon nervosus. Methods: The chemical constituent was isolated and purified by chromatographic methods and structurally identified by physicochemical characteristics and spectral data. Results: One new compound was isolated from 95% ethanol extract of I. nervosus, the structure was identified as 15α,20β/α-dihydroxy-6β-methoxy-6,7-seco-6,20-epoxy-1α,7-olide-ent-kaur-16-ene. Conclusion: A new diterpenoid was identified and named as rabdonervosin K.

Structure-based drug design studies of the interactions of ent-kaurane diterpenes derived from Wedelia paludosa with the Plasmodium falciparum sarco/endoplasmic reticulum Ca2+-ATPase PfATP6

Malaria is responsible for more deaths around the world than any other parasitic disease. Due to the emergence of strains that are resistant to the current chemotherapeutic antimalarial arsenal, the search for new antimalarial drugs remains urgent though hampered by a lack of knowledge regarding the molecular mechanisms of artemisinin resistance. Semisynthetic compounds derived from diterpenes from the medicinal plant Wedelia paludosa were tested in silico against the Plasmodium falciparum Ca2+-ATPase, PfATP6. This protein was constructed by comparative modelling using the three-dimensional structure of a homologous protein, 1IWO, as a scaffold. Compound 21 showed the best docking scores, indicating a better interaction with PfATP6 than that of thapsigargin, the natural inhibitor. Inhibition of PfATP6 by diterpene compounds could promote a change in calcium homeostasis, leading to parasite death. These data suggest PfATP6 as a potential target for the antimalarial ent-kaurane diterpenes.

Inhibitory activity of kaurane-type diterpenes isolated from Acanthopanax senticosus Harms on protein tyrosine phosphatase 1B / 中国药学杂志

OBJECTIVE: To study the constituents isolated from Acanthopanax senticosus Harms and their inhibitory activity on protein tyrosine phosphatase 1B(PTP1B). METHODS: Kaurane-type diterpenes with PTP1 B inhibitory activity were obtained by bio-assay-guided fractionation. RESULTS Nine compounds were identified as 17-isobutyryloxy-16αH-kauran-19-oic acid(1), 17-hydrox-y-16αH-kauran-19-oic acid(2), 17-acetoxy-18-isobutyryloxy-16αH-kauran-19-oic acid (3), ent-kaur-16-en-19-oic acid (4), ent-kaur-16-en-19-oic acid (kaurenoic acid 5), 4-epirulopezol(6), 16α-hydroxy-ent-kauran-19-oic acid(7), 16αH, 17-isovaleryloxy-ent-kauran-19-oic acid(8) and 16α-hydroxy-17-isovaleryloxyent-kauran-19-oic acid(9). CONCLUSION: Compounds 1-3, 5 and 6 are obtained from the plant for the first time. Compounds 1,3-6 and 8 exhibite inhibitory effects on PTP1 B with IC50 values ranging from (5.6 ± 0.8) to (22.8 ± 1.2) μmol · L-1.

Constituintes químicos e avaliação das atividades antibacteriana e antiedematogênica de Aloysia gratissima (Gillies & Hook.) Tronc. e Aloysia virgata (Ruiz & Pav.) Pers., Verbenaceae / Chemical composition and evaluation of antibacterial and antiedematogenic Activities of Aloysia gratissima (Gillies & Hook.) Tronc. e Aloysia virgata (Ruiz & Pav.) Pers., Verbenaceae

O estudo químico de Aloysia gratissima (Gillies & Hook.) Tronc. e Aloysia virgata (Ruiz & Pav.) Pers., Verbenaceae, resultou no isolamento de quatorze substâncias. Suas estruturas foram determinadas com base nos dados de IV, RMN de ¹H e de 13C uni e bidimensionais e comparação com dados da literatura. A atividade antibacteriana do extrato bruto das folhas e caules e das frações de A. virgata, bem como as substâncias hoffmaniacetona e seu monoacetato, verbascosídeo e arenariosídeo, foram avaliadas através do método de bioautografia e a atividade antiedematogênica foi avaliada pelo modelo de edema de orelha induzido para os extratos brutos e frações metanólicas de A. gratissima e A. virgata..

Phytochemical study of Aloysia gratissima (Gillies & Hook.) Tronc. e Aloysia virgata (Ruiz & Pav.) Pers., Verbenaceae, afforded fourteen compounds. The structures were established using IR, 1D and 2D NMR and by comparison of its spectroscopic data to those of literature. The antibacterial activity of the crude extract from the leaves and branches and the fractions from the crude extract of A. virgata, besides the isolated compounds hoffmaniacetone, hoffmaniacetone monoacetate, verbascoside and arenarioside were evaluated by means of bioautography and the antiedematogenic activity was evaluated using induced ear oedema model to the crude extracts and methanol fractions for A. gratissima and A. virgata.

One new ent-kaurane glycoside from stems of Acanthopanax gracilistylus / 中草药

Objective: To study the chemical constituents from the stems of Acanthopanax gracilistylus. Methods: The chemical constituents of the plant were isolated and purified by column chromatography and their structures were elucidated on the basis of physico-chemical properties and spectral data. Results: A new ent-kaurane glycoside, named kaurane acid glycoside A (16α, 17-dihydroxy-ent-kauran-19-oic 19-[β-D-glucopyranosyl-(1→2)-β-D- glucopyranosyl] ester) (1), was isolated from the n-butanol part. Conclusion: Compound 1 is a new one.

A New ent-Kaurane Glycoside from the Stems of Acanthopanax gracilistylus / 中草药·英文版

Objective To study the chemical constituents from the stems of Acanthopanax gracilistylus.Methods Thechemical constituents of the plant were isolated and puried by column chromatography and their structures wereelucidated on the basis of physicochemical properties and spectral data.Results A new ent-kaurane glycoside,named kaurane acid glycoside A { 16α,17-dihydroxy-ent-kauran-19-oic 19-[β-D-glucopyranosyl-(1→2)-β-Dglucopyranosyl]ester}(1),was isolated from the n-butanol part.Conclusion Compound 1 is a new one.

Preliminary studies on the volatile constitution of Mikania species / Estudos preliminares dos constituintes voláteis de espécies de Mikania

Volatile oils obtained from the aerial parts of three Mikania species plants were analyzed by GC-MS and NMR. Forty-six terpenes among monoterpenes, sesquiterpenes and diterpenes were identified by this methodology. The analysis classified Mikania hookriana as diterpene producer as the majority Mikania species occurring in Brazil.

Óleos voláteis obtidos das partes aéreas de plantas de três espécies de Mikania foram analisados por CG-EM e RMN. Quarenta e seis terpenos, entre monoterpenos, sesquiterpenos e diterpenos, foram identificados. A análise classificou Mikania hookeriana como produtora de diterpenos, de acordo com a maioria das espécies de Mikania que ocorrem no Brasil.

Studies on chemical constituents from leaves of Smallanthus sonchifolius / 中草药

Objective To study the chemical composition from leaves of Smallanthus sonchifolius.Methods Some chromatography methods were used in the isolation procedure,while the structures were determined on the aids of NMR and MS spectral analyses.Results A new compound,together with five known compounds,was isolated from the ethanolic extract of the leaves.The new compound is characterized as 5,8-dihydroxyl-(5H,8H)-?-ionol(Ⅰ).Other compounds are obtained for the first time from the title plant and identified as ent-kaurane-3?,16?,17-triol(Ⅱ),entkaurane-16?,17-diol-19-oic acid(Ⅲ),3,4-dihydroxybenzaldehyde(Ⅳ),1-pentacosanol(Ⅴ),and 1-octacosanol(Ⅵ),respectively.Conclusion Compounds Ⅰ-Ⅵ are isolated from the plants of genus Smallanthus for the first time.Compound Ⅰ is a ?-ionol derivate firstly isolated from genus Smallanthus.It is named as sonchifolol.