Diterpene Research Articles

Protection of gastric mucosa against aspirin-induced damage by teprenone

Objective To investigate the protection effects of teprenone in aspirin-induced gastric mucosa injury.Methods From 2008 to 2010,a total of 296 patients who took aspirin for the first time at the Department of Cardiovascular,First Hospital Affiliated to Zhejiang Chinese Medicine University were randomly divided into two groups.There were 166 cases in aspirin group,which took aspirin 100mg daily; 130 cases in aspirin and teprenone group,the aspirin dose equivalent with aspirin group and took teprenone 50mg/time,3 times/day orally.Gastrointestinal symptoms and gastric mucosa injury of patients in these two group were inspected at 3 month,6 month and 1 year.Results A total of 143 cases were recruited in aspirin group and 118 cases in aspirin and teprenone group.After taking medicine for 3 months,the occurrence rate of gastrointestinal symptoms in aspirin group was 1.40 ％.Compared with aspirin and teprenone group,the difference was statistical significant (0,x2 =1.663,P＝ 0.197).Follow up after taking medicine for 6 months,the occurrence rate of gastrointestinal symptoms in aspirin group was 4.96％.Compared with aspirin and teprenone group,the difference was statistical significant (0,x2 ＝6.021,P＝0.014).Follow up after taking medicine for 1 year,the occurrence rate of gastrointestinal symptoms in aspirin group was 20.15 ％.Compared with aspirin and teprenone group,the difference was statistical significant (1.69％,x2 =20.984,P=0.001).Compared with aspirin group,the symptom and endoscopy score of aspirin and teprenone group decreased significantly at follow-up for 6 months and 1 year (P＜0.05; P＜0.01 ).Compared with at 6 month,the symptom and endoscopy score of aspirin group at 1 year increased significantly (P＜0.05 ; P＜0.01).Conclusion Teprenone has certain protection effects in aspirin-induced gastric mucosa injury.Long-term use of conventional doses of aspirin may cause vary degrees of gastric mucosal injury,and the gastric mucosal injury get more severe as the time of taking medicine increases. Key words: Aspirin; Gastric mucosa; Diterpenes; Gastrointestinal agents

Effects of triptolide on lipopolysaccharide-induced acute lung injury in rats

Objective To investigate the effects of triptolide on lipopolysaccharide (LPS)-induced acute lung injury in rats.Methods Sixty-five male SD rats weighing 200-250 g were randomly divided into 5 groups: control group (group C,n =5),LPS group (group L,n =15),different doses of triptolide groups (groups TP1-3,n =15).In group C normal saline was injected iv and 1％ DMSO injected intraperitoneally(ip).In group L LPS 5 mg/kg was injected iv and 1％ DMSO injected ip.In groups TP1-3 LPS 5 mg/kg was injected iv and triptolide 25,50 and 100 μg/kg was injected ip respectively.Blood samples were collected at 1 h before administration and 1,3,6 and 12 h after administration for blood gas analysis.The animals were sacrificed at 12 h after administration.TNF-α concentrations in serum and bronchoalveolar lavage fluid (BALF) were determined by ELISA.The lungs were removed for microscopic examination,evaluation of diffuse alveolar damage (DAD) score and determination of W/D lung weight ratio and the expression of Toll-like receptor4 (TLR4) protein and mRNA.Results Compared with group C,PaO2 was significantly decreased at 3,6 and 12 h after administration,DAD score and W/D lung weight ratio were increased in groups L and TP1-3,TNF-α concentrations in serum and BLAF were increased,expression of TLR4 mRNA and protein was up-regulated in groups L,TP1 and TP2,whlie TNF-α concentrations in serum and BLAF were significantly decreased,expression of TLR4 mRNA and protein was down-regulated in group TP3 ( P ＜ 0.05).Compared with groups L and TP1,PaO2 was significantly increased at 6 and 12 h after administration,DAD score,W/D lung weight ratio and TNF-α concentrations in serum and BLAF were decreased,expression of TLR4 mRNA and protein was down-regulated in groups TP2 and TP3 ( P ＜ 0.05).There was no siginificant difference in blood gas parameters,DAD score and W/D lung weight ratio between group L and group TP1 and between group TP2 and TP3 ( P ＞ 0.05).Compared with group TP2,TNF-α concentrations in serum and BLAF were significantly decreased,expression of TLR4 mRNA and protein was down-regulated in group TP3 (P ＜ 0.05).The lung pathologic injury was reduced in groups TP1-3 as compared with group L.Conclusion Triptolide can attenuate acute lung injury induced by LPS in a dose-dependent manner in rats,and the inhibition of up-regulation of TLR4 expression and release of TNF-α may be involved in the mechanism. Key words: Diterpenes ; Lipopolysaccharides ; Acute lung injury

Activation of the Isotypes of Protein Kinase C-α, β1, β2, γ, Δ, ε and ζ by Mezerein, a Second-stage Tumour-promoting Agent: Correlation with Computer-assisted Molecular Modelling

The second-stage tumour promoter mezerein was compared with the full promoter, tetra-decanoyl phorbol acetate (TPA) and the non-promoter, resiniferatoxin for its ability to activate the isotypes of protein kinase C of the c, n and a groups. Mezerein was a selectively weaker activator of the n-PKC group of isotypes, Δ and e, than TPA whilst resiniferatoxin failed to activate PKC up to maximum concentration of 1000 nM. None of the diterpenes used were found to activate the PKC isotype ζ. These results were correlated with computer generated minimum free energy values (CAMM) and Log D, a measure of their hydrophobicity. There was little difference in minimum free energy values of TPA and mezerein; however mezerein had only about 50% of the hydrophobicity of TPA.

Phytochemical investigation of abietanoid quinones: extraction, structure elucidation, toward systhesis in the laboratory

The rootes of Chinese sage, Salvia miltiorrhiza Bunge (labieteae) are used to prepare an important traditional medicine in the Chinese pharmacoepia, Dan Shen. Indeed, related members of this genus are common traditional medicines throughout the world, making Salvia species the targets of intense phytochemical investigations. The active constituents of these species have been reported to be several abietanoids diterpenes bearing o-quinone or p-quinones. In this report we will present results of our investigation of Salvia species alogwith thesynthesis of some active structures

Gnidilatimonoein from Daphne mucronata induced differentiation and apoptosis in leukemia cell lines

Among various treatments, plants play a crucial role in cancer chemotherapy. Base on literature data, different species of the thymeleaeceae family have been found to be good sources for anticancer agents. Therefore, our laboratory has initiated a research project on evaluating the anticancer properties of the Iranian medical plant, Daphne mucronata (Thymeleaeceae). Gnidilatimonoein is a new diterpene ester compound that is purified from Daphne mucronata with antiproliferative and anti-metastatic effects in different tumor cell lines. Based on the inhibitory role of this agent on the cell cycle progression of K562 cell line, we were interested to check gnidilatimonoein for induction of differentiation and apoptosis in different human leukemia ML-1, HL-60 and K562 cells. Cell viability was determined by trypan blue exclusion method. Cell differentiation was studied in terms of morphology, NBT reduction in leukemia cells (HL-60 and ML-1) and benzidine staining in erythroleukemia (K562) cells. Apoptosis was detected by fluorescence microscopy (Acridine orange/Ethedium bromide double staining), annexineV flow cytometry and DNA electrophoresis. After 48 hours of treatment with 10 µM gnidilatimonoein, 80-70% of HL-60 and ML1 cells showed NBT reduction. Indeed gnidilatimonoein induced monocyte differentiation of myeloid leukemia HL-60 and ML-1 cells but not K562 erythroluekemia cells. In this condition, we observed the growth inhibitory effect (60%) without substantial loss of viability (

Induction of apoptosis by novel inosine monophosphate dehydrogenase, 3-hydrogenkwadaphnin

Today’s medical word is highly dependent on severel natural products (e.g. taxol) in fighting different kinds of cancer and in constantly working to found new compounds. In this respect, 3-hydrogenkwadaphnin is a new diterpene ester isolated from Dendrostellera lessertii (Thymelaceae). It has been previously shown that this new compound has high anti-tumor activity and the capability of arresting the growing leukemic cells at G1/S phase of their progression cycle, which finally leads to cell death. Further studies revealed 3-hydrogenkwadaphnin decreased both DNA synthesis and inosine monophosphate dehydrogenase (IMPDH) activity in K562 and HL-60 cells. Here we decided to interrogate the mechanism (s) and mode of cytotoxic effects of this compound. Inosine monophosphate dehydrogenase is the key regulatory and the rate-limiting enzyme of the de novo biosynthetic pathway of purines. Apparently, the activity of this enzyme significantly increases in tumor cells in proportion to the proliferation. We hypothesized that inhibition of IMPDH and consequently depletion of guanine nucleotide pool is responsible of cytotoxic effect with characteristic of apoptosis. HL-60 and K562 leukemia cells were treated with increasing doses of 3-hydrogenkwadaphnin. Thereafter, the mode of its cytotoxic action was determined by Acridine orange/Ethedium bromide double staining, DNA fragmentation, sub-G1 flow cytometry and electron microscopic. Involvement of guanine nucleotide pool was tested by co-provision of guanosine and deoxyguanosine that replead GTP and dGTP pool size, respectively. 3-hydrogenkwadaphnin at low doses (10 nM) enhanced fragment of the apoptotic HL-60 cells within 72 hours of treatment. Higher doses (25 nM) led to rapid induction of apoptosis, which could be detected as early as 24 h. The majority (85%) of the treated HL-60 cells died by apoptosis, 72 hours after exposure to 3-hydrogenkwadaphnin. Althought K562 cells are generally more resistant to a variety of apoptotic stimuli, to our surprising 3-hydrogenkwadaphnin was equally effective in this cell line as compared to HL-60. 3-hydrogenkwadaphnin-induced apoptosis was almost totally prevented by supplementation with guanosine, but not with adenosine or deoxyguanosine, indicating the specific effect of 3-hydrogenkwadaphnin in reducing the pool size of GTP. The results indicate that 3-hydrogenkwadaphnin decreases GTP pool size and depletion of this pool, and not dGTP, is probably the cause of cell death through apoptosis. Induction of apoptosis is a major goal of chemotherapy. GTP depletion induced apoptosis is selective for tumor cells; thereby 3-hydrogenkwadaphnin could be presented as a powerful drug for treatment of cancer, especially leukemia.

Gnidilatimonoein from Daphne mucronata inhibits DNA synthesis in human cancer cell lines

The anticancer agents from plant sources usually exert their action through a wide range of mechanisms. As part of our studies of plants for new anticancer agents with emphasis on Thymelaeaceae family, we examined the cytotoxicity and anti-tumor activity of the water extract of D. mucronata leaves against induced breast tumor in rats. In the current study, we were interested to obtain some knowledge about the mode of action of the new compound. Cytotoxicity evaluation of gnidilatimonoein, the most active isolated diterpene ester from Daphne mucronata, revealed strong antiproliferative activity among several different human cancer cell lines (K562, CCRF-CEM, HL-60, MOLT-4 leukemia cell lines, and LNCaP-FGC-10 a prostate cancer cell line) and a mouse BALB/C fibrosarcoma cell line (WEHI-164). Using flow cytometry technique, it was found that treatment of the most responsive cells (K562) with gnidilatimonoein inhibited the progression of cells through G1 phase by almost 15% compared to the untreated cells. The population of the treated cells in the S and G2 phases was reduced by 8.3% and 5.4%, respectively. Based on the extent of [3H]-thymidine and [3H]-uridine incorporation into DNA and RNA, respectively, the major metabolic effects of gnidilatimonoein were found to be mainly on DNA and to a less extent on RNA synthesis. Additionally, the activity of inosine-5';-monophosphate dehydrogenase (IMPDH), under the effects of genidilatimonoein, was reduced in the treated cells by 44%. These data strongly suggest that the purine biosynthetic pathway is significantly affected by gnidilatimonoein. Our data indicates that gnidilatimonoein can inhibit the cell proliferation through DNA synthesis inhibition. These effects are mainly achieved through reduction of IMPDH activity.

Discrimination of coffee species using kahweol and cafestol: effects of roasting and of defects

The two most commercialized coffee species worldwide are: Coffea arabica L. (arabica) and Coffea canephora Pierre ex A. Froehner (robusta). Since these coffees differ in their commercial value and acceptability, adulteration and mislabeling are major concerns. The diterpenes kahweol and cafestol are considered potential indicators of conilon coffee addition, as they are present in different contents in the species. The degree of roasting and the presence of defective beans may affect the theor of several coffee constituents. The aim of this work was to evaluate the possibility of discriminating the coffee species arabica and robusta through their kahweol and cafestol contents. Samples of arabica, robusta, and of their blends, with different amounts of defects and degrees of roasting (light, medium and dark) were studied. After direct saponification and extraction with terc-butyl methyl ether, the samples were analyzed by reverse-phase HPLC with UV detection. The kahweol content varied between 661 and 923 mg/100 g in the arabica coffee, and its presence was not observed in the conilon. Cafestol ranged from 360 to 478 mg in arabica, and from 163 to 275 mg/100 g in conilon coffee. The addition of conilon coffee reduced diterpene contents, but this effect varied according to the amount of defects and roasting degrees. A higher intensity roast did not affect diterpene degradation. No differences in the kahweol and cafestol levels, comparing defective or regular beans, were observed. In the analysis of coffee samples with different degrees of roasting and defects, the parameters kahweol and cafestol showed potential for discriminating between the species.

Vascular activity of a natural diterpene isolated from Croton zambesicus and of a structurally similar synthetic trachylobane

The aim of this study was to determine the vasorelaxant activity of a natural diterpene extracted from Croton zambesicus, ent-18-hydroxy-trachyloban-3-one (DT6), and a synthetic diterpene of similar structure, ent-trachyloban-14,15-dione (DT10) in rat aorta. DT6 and DT10 inhibited aorta contraction in a concentration-dependent manner. Both were more potent inhibitors of KCl-evoked contraction than noradrenaline-evoked contraction. Nitric oxide (NO) synthase inhibition did not significantly affect DT6 effect whereas it significantly decreased DT10 inhibitory potency. In fura-2 loaded aorta rings, DT10 simultaneously inhibited KCl-evoked contraction and cytosolic calcium increase in a concentration-dependent manner. Furthermore, DT10 significantly inhibited calcium channel current recorded by the patch-clamp technique in human neuroblastoma cells SH-SY5Y. However, despite potentiation of 8-bromo-cGMP-response, DT6 and DT10 as verapamil depressed acetylcholine-evoked relaxation, DT6 being the most potent, while only DT6 and DT10 depressed SNAP-evoked relaxation. In conclusion, these data suggest that vasorelaxant activity of diterpenes (DT) is associated with the blockade of L-type voltage-operated calcium channels. Inhibition of NO-dependent relaxation by DT could be related to a decrease in NO availability.

Tonantzitlolone and other Diterpenes from Stillingia sanguinolenta

AbstractCembrene A (1), two novel diterpenes 2 and 3 with the rare flexibilane skeleton, two new pimaranes 4 and 5, sevenkauranes 6–12 (9 and 12 new), three known atisanes 13–15, a new trachylobane 16, and the new pentacyclic diterpene sanguinolane 17 with a novel skeleton were obtained from Stillingia sanguinolenta. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Relationships Among Resin-Producing Detarieae s.l. (Leguminosae) as Inferred by Molecular Data

The tribe Detarieae s.l. (Caesalpinioideae: Leguminosae) contains a large number of genera that produce resins, but which previously had been placed in differrent generic groups. To test the monophyly of the resin-producing Detarieae and to examine phylogenetic relationships among these genera, we analyzed sequences from the chloroplast trnL intron and trnL-F spacer for more than 80 taxa and from the nuclear ribosomal Internal Transcribed Spacers (ITS) for over 50 taxa. The two chloroplast regions were highly congruent, but incongruent with the nuclear ITS data. Incongruence may be the result of hybridization, particularly in the Colophospermum and Hardwickia polyploid lineage. Resin-producing taxa are scattered among two clades, the Prioria and Detarieae s.s. clades, which together are monophyletic, but only with weak support. This group is characterized by the ability to produce bicyclic diterpenes. The phylogenetic relationships as inferred from molecular data resolved the intergeneric affinities but the main clades obtained are different from the groupings proposed by classifications based primarily on morphological characters. Based on these analyses, we propose new generic groupings that correspond to the Prioria s.s., Hardwickia, Hymenaea, Eperua s.s. and Detarium clades.

Study on the diterpenes and their bioactivities in Croton plant

Study on the diterpenes and their bioactivities in Croton plant

Three Novel 5(6→7)Abeoabietane‐Type Diterpenes from the Bark of Taiwania cryptomerioides.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Chemosystematic Investigations of Irregular Diterpenes (I) and (II) in Anisotome and Related New Zealand Apiaceae.

Chemosystematic Investigations of Irregular Diterpenes (I) and (II) in Anisotome and Related New Zealand Apiaceae.

Three novel 5(6-->7)abeoabietane-type diterpenes from the bark of Taiwania cryptomerioides.

Three new 5(6-->7)abeoabietane diterpenes with the uncommon skeleton of fused 6-5-6 rings were isolated from the bark of Taiwania cryptomerioides designated as taiwaniaquinone F (8), taiwaniaquinol C (9) and taiwaniaquinol D (10). Meanwhile, two known compounds, taiwaniaquinones A (1) and D (4), were also obtained. Their structures were determined principally from spectral evidence.

On the Ent -Kaurene Diterpenes from Sideritis Athoa

The structure of a diterpene, which has been isolated form Sideritis athoa , has been corrected from 3 g ,18-dihydroxy- ent -kaur-16-ene to 1 f ,18-dihydroxy- ent -kaur-16-ene (canadiol).

Synthesis of Diterpene β-Carbolines

Synthesis of Diterpene β-Carbolines

Long-term effects of triptolide on spermatogenesis, epididymal sperm function, and fertility in male rats.

Prior studies had suggested that triptolide, a diterpene triepoxide isolated from a Chinese medicinal plant, might be an attractive candidate as a post-testicular male contraceptive agent. Despite the promise that triptolide would not affect testis function, nagging concerns remained that a delayed onset of testicular effect might exist. The objectives of this study were to assess the effects of relatively longer treatment duration of triptolide on fertility, spermatogenesis, and epididymal sperm pathophysiology; and to evaluate the reversibility of these effects after the cessation of treatment. Adult male Sprague-Dawley rats were fed daily with either 30% gum acacia as a vehicle control (n = 12) or 100 microg/kg body weight (BW) of triptolide for 82 days (n = 12) followed by a recovery period of up to 14 weeks (n = 6). At the end of the treatment period, all rats treated with triptolide were sterile. Cauda epididymal sperm content decreased by 84.8% and sperm motility was reduced to zero. In addition, virtually all cauda epididymal sperm in the triptolide-treated group exhibited severe structural abnormalities. The most striking changes observed were head-tail separation, premature chromatin decondensation of sperm nuclei, a complete absence of the plasma membrane of the entire middle and principle pieces, disorganization of the mitochondrial sheath, and aggregation of many sperm tails. Longer treatment duration of triptolide also affected spermatogenesis, with marked variability in the response of individual animals. The degree of damage ranged from apparently normal-looking seminiferous tubules to flattened seminiferous epithelium lined by a single layer of cells consisting of Sertoli cells and a few spermatogonia. Affected tubules exhibited intraepithelial vacuoles of varying sizes, multinucleated giant cells, germ cell exfoliation, and tubular atrophy. Recovery occurred as early as 6 weeks after cessation of treatment. By 14 weeks, 4 out of 6 triptolide-treated males were fertile and the females that were impregnated by 3 out of 4 triptolide-treated male rats produced apparently normal litters. These results suggest that triptolide has 2 phenotypic effects on mature and maturing germ cells. The first action appears earlier and manifests mainly in epididymal sperm. The second action presumably is directly on germ cells in testis and causes a variable impairment of spermatogenesis that may not be completely reversible. It is unclear if the earlier effect is a delayed manifestation of subtle testicular injury or post-testicular action.

Chlorosphaeropsidone and Epichlorospaeropsidone, Two New Chlorinated Dimedone Methyl Ethers Isolated from Liquid Cultures of "Sphaeropsis sapinea" f. sp. "cupressi"

Two new dimedone methyl ethers, named chlorosphaeropsidone and epichlorosphaeropsidone were isolated from the culture filtrates of Sphaeropsis sapinea f. sp. cupressi, the causal agent of a canker of Italian cypress (Cupressus sempervirens L.). The same fungus also produced various phytotoxic metabolites: three pimarane diterpenes (sphaeropsidins A, B and C) and two dimedone methyl ethers (sphaeropsidone and episphaeropsidone). Chlorosphaeropsidone and epichlorosphaeropsidone were characterized using chemical and spectroscopic methods as two 6-chloro-4,5-dihydroxy-3-methoxycyclohex-2-en-1-ones epimers at C-6. Their relative and absolute configurations were established by NMR, X-ray analysis and circular dichroism. Assayed on host plants they did not show phytotoxic activity. Comparison with other sphaeropsidones suggested that this might result from opening of the epoxy ring.

A New Diglycoside of Diterpene from Ageratina vacciniaefolia

From leaves and flowers of Ageratina vacciniaefolia [1-7] we have isolated several compounds: a flavonoid, a diterpene [8] and a new compound identified as b-D-glucopyranosil ester of (-)17-(bglucopiranosyloxyl)- 16-hydroxy-kauran-19-oic acid (see the formula).[...]