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1.
3Beta-hydroxyolean-12-en-27-oic acid (1), a biologically active, pentacyclic triterpenoid isolated from the rhizomes of Astilbe chinensis, was found to be considerably more cytotoxic toward human colorectal carcinoma (COLO-205) and human cervical squamous carcinoma (HeLa) cells than its congener oleanolic acid (4). This suggests that the position of the COOH group significantly affects the cytotoxicity of oleanane-type pentacyclic triterpene carboxylic acids. To elucidate the underlying biological mechanism responsible for the cytotoxicity of 1, we investigated its growth-inhibitory effect on COLO-205 cells. Compound 1 induced a marked concentration- and time-dependent inhibition of cell proliferation, with the typical morphological characteristics of apoptosis, and under formation of DNA ladders in agarose-gel electrophoresis. Flow-cytometric analysis showed that the cell cycle of COLO-205 cells exposed to 1 was arrested in the G0/G1 phase. Also, 1 increased and decreased the expression of Bax and Bcl-2 proteins, respectively, and lowered the mitochondrial transmembrane potential (delta psi(m)). The peptidic caspase-3 inhibitor NH2-Asp-Glu-Val-Asp-CHO (at 1 microM) could increase the viability of COLO-205 cells previously treated with 1. These results indicate that 1 induces efficient cell apoptosis through down-regulating Bcl-2 expression, up-regulating Bax expression, lowering delta psi(m), and by activating the caspase-3 pathway. 相似文献
2.
Pereira SI Freire CS Pascoal Neto C Silvestre AJ Silva AM 《Phytochemical analysis : PCA》2005,16(5):364-369
The chemical composition of the epicuticular wax from the fruits of Eucalyptus globulus was studied by GC-MS before and after alkaline hydrolysis. The wax had two main components, ursolic acid and tritriacontan-16,18-dione, together with several other triterpenic acids. After alkaline hydrolysis, a large increase in the amounts of triterpenic acids and fatty acids (particularly in hexadecanoic acid) was observed, suggesting that these components were present predominantly in esterified forms in the fruit wax. Six compounds were isolated from the fruits by preparative chromatography, and were identified as 8-desmethyleucalyptin, sesamin, tritriacontan-16,18-dione, ursolic acid, 3beta-hydroxyurs-11-en-13beta(28)-olide (ursolic acid lactone) and 3beta,11alpha-dihydroxyurs-12-en-28-oic acid, the latter of which was identified for the first time. 相似文献
3.
In this paper, five of six samples of 2,3-allenoic acid enantiomers were separated by capillary zone electrophoresis (CZE) using hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and hydroxypropyl-gamma-cyclodextrin (HP-gamma-CD) as chiral selectors. Using HP-beta-CD for chiral separation, three of the six enantiomers were separated. Five experimental conditions including HP-beta-CD concentration, pH, buffer concentration, temperature, and running voltage were investigated for their influence on separation and migration using enantiomers of 2-methyl-4-phenyl-2,3-butadienoic acid (A) and 2-(n-propyl)-4-phenyl-2,3-butadienoic acid (B) as samples. Good separation results were observed when [HP-beta-CD] = 3-12 mmol/L and pH = 7-9 for samples A and B. The temperature range of 15-25 degrees C can be selected for convenience. According to the chiral separation results, HP-beta-CD and HP-gamma-CD should be valuable selectors to separate 2,3-allenoic acids and HP-gamma-CD was suggested to separate the 2,3-allenoic acid samples with a group at 4-position bulkier than phenyl. 相似文献
4.
Chung IM Ali M Ahmad A Chun SC Kim JT Sultana S Kim JS Min SK Seo BR 《Phytochemical analysis : PCA》2007,18(2):133-145
Two new compounds, 14-methyl stigmast-9(11)-en-3alpha-ol-3beta-D-glucopyranoside (1) and cholest-11-en-3beta, 6beta, 7alpha, 22beta-tetraol-24-one-3beta-palmitoleate (2), along with the known compound beta-sitosteryl-3beta-D-glucopyranosyl-6'-linoleiate (3), were isolated from the methanolic extract of rice (Oryza sativa) hulls. The structures of the two new compounds were elucidated using one- and two-dimensional NMR in combination with IR, EI/MS, FAB/MS, HR-EI/MS and HR-FAB/MS. In bioassays with blue-green algae, Microcystis aeruginosa UTEX 2388 and duckweed, Lemna paucicostata Hegelm 381, the efficacy of bioactivity of the two new compounds linearly increased as the concentration increased from 0.3 to 300 IgM. Compared with momilactone A, compounds 1 and 2 showed similar and higher inhibitory activities against the growth of M. aeruginosa at a concentration of 300 microM. However, compound 2 was similar to momilactone A in inhibiting L. paucicostata growth at a concentration of 300 microM. As a result, compound 2 appears to have a strong potential for the environmentally friendly control of weed and algae that are harmful to water-logged rice. 相似文献
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6.
George Flouret Tadeusz Majewski Lajos Balaspiri William Brieher Kevin Mahan Olivier Chaloin Laird Wilson Jirina Slaninová 《Journal of peptide science》2002,8(7):314-326
Twenty analogues were synthesized of [Pmp1, D-Trp2, Arg8]oxytocin, PA, (Pmp = beta,beta-pentamethylene-beta-mercaptopropionic acid), a potent antagonist of the uterotonic effect of oxytocin in the rat (uterotonic test in vitro, pA2 = 7.77) and in the baboon. Systematic substitution of Pmp1 was made with beta-mercaptopropionic acids featuring replacement of the 4-methylene group of the cyclohexyl ring of Pmp with isosteric O, S, NH or with C=O. Since the more hydrophilic NH and C=O substitutions showed a sharply decreased antagonistic potency (rat uterotonic test in vitro), additional modifications were made to reduce their hydrophilicity. Acylation of the NH group with various acyl groups, and ketalization or thioketalization of C=O with more or less bulky substituents led to a partial restoration of potency, the N-carbamyl- and the 2-mercapto-2-adamantaneacetyl analogues being equipotent with PA. Internal cyclization by amidation of the NH-group with Gly-9, resulted in a bicyclic analogue, (cyclo 1-9)[(HN)Pmp1, Gly9]PA which was equipotent with PA. When Pen-6 was introduced into the bicyclic derivative instead of Cys-6, to reduce the flexibility of the rings, the resulting (cyclo 1-9)[(HN)Pmp1, Pen6, Gly9]PA had somewhat better potency (pA2 = 8.17) in the uterotonic test and no detectable activity in the antidiuretic assay. In the case of substitution of PA with beta,beta-(3-thiapentamethylene)-beta-mercaptopropionic acid, (S)Pmp, there was also an increase in inhibitory potency in the uterotonic test (pA2 = 8.08): the analogue had extremely weak antidiuretic activity. To establish the importance of the steric effects of the Pen-6 substitution, analogues [Pen6]PA and [(S)Pmp1, Pen6]PA were made and found to be very potent, with a pA2 of 8.72 and 8.86, respectively. The high potency of the latter analogue and its extremely weak action in the diuretic assay makes it an attractive candidate for studies on the inhibition of the biological effects of oxytocin and for the prevention of preterm labour. 相似文献
7.
The absolute configurations of several 3-hydroxy beta-lactams were assigned by the NMR \"mix and shake\" methodology developed by Riguera and co-workers. The results from the NMR study correlated perfectly with the absolute configurations obtained from X-ray crystallographic structure analyses and chiral-phase HPLC data. 相似文献
8.
Four new compounds, stigmastanol-3beta-p-glyceroxydihydrocoumaroate (1), stigmastanol-3beta-p-butanoxydihydrocoumaroate (2), lanast-7,9(11)-dien-3alpha,15alpha-diol-3alpha-D-glucofuranoside (3) and 1-phenyl-2-hydroxy-3,7-dimethyl-11-aldehydic-tetradecane-2-beta-D-glucopyranoside (4), along with several known compounds were isolated from the methanol extract of hulls of Oryza sativa. The new structures were established by one- and two-dimensional NMR and in combination with IR, EI/MS, FAB/MS and HR-FAB/ MS. Compound (3) strongly inhibited the growth of duckweed (Lemna paucicostata Hegelm 381), whilst compounds (2) and (4) exhibited weak inhibition. 相似文献
9.
This study tested the hypothesis that 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] plays a role in human umbilical vein endothelial cells (HUVEC) cultures. HUVEC were incubated with 10 or 100 nM 1,25(OH)(2)D(3) for 24 h, in the absence or presence of 40 ng/ml tumor necrosis factor-alpha (TNF-alpha) or 2 ng/ml interleukin-1alpha (IL-1alpha). 1,25(OH)(2)D(3) did not affect HUVEC viability and proliferation, while TNF-alpha, alone or in combination with the hormone, significantly inhibited HUVEC viability. [(3)H]thymidine incorporation in HUVEC treated with TNF-alpha or IL-1alpha significantly decreased, in the absence or in the presence of the hormone, while the levels of vitamin D receptor markedly increased in the presence of 1,25(OH)(2)D(3) alone or associated with TNF-alpha or IL-1alpha, in comparison to the control. The noteworthy increase in protein levels of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) induced by TNF-alpha was significantly decreased after incubation of the cells with 1,25(OH)(2)D(3), this effect not being seen on E-selectin expression. Neither apoptosis nor nuclear translocation of NF-kappaB, induced in HUVEC by TNF-alpha was influenced by 1,25(OH)(2)D(3) treatment. 相似文献
10.
A facile synthesis of 3R,5R-dihydroxy-L-homoproline as idulonic acid mimic, of which the carboxyl and 3-hydroxyl groups were protected, was attained using L-threonine aldolase-catalyzed reaction. Idulonic acid is a key acidic sugar of the b-FGF binding domain in heparin and heparan sulfate. Moreover, the synthetic precursor of N-acetyl-4-deoxy-D-mannosamine, which is a potent inhibitor of NeuAc synthase, was prepared from the side product of the enzymatic aldol condensation. 相似文献
11.
Peganum harmala L. is a traditional Chinese and Uygur medicine used to treat cancer. Bioactivity‐guided fractionation was applied to determine the cytotoxic constituents from P. harmala. A novel triterpenoid and a phenolic glycoside were isolated and identified, as well as seven known compounds. The novel metabolites were elucidated to be 3α‐acetoxy‐27‐hydroxyolean‐12‐en‐28‐oic acid methyl ester ( 1 , OA) and N‐acetyl‐9‐syringinoside ( 9 ). Some compounds exhibited potent cytotoxicity against human tumor cells. Among them, OA showed the highest cytotoxicity against human lung cancer cells A549 with an IC50 value of 8.03 ± 0.81 μm . OA had a potent anti‐NSCLC cell activity by interfering with the epidermal growth factor receptor (EGFR) activation and its downstream signaling, and could exert an antiproliferative effect by inactivation of EGFR‐driven antiapoptotic pathway followed by the release of mitochondrial cytochrome c, which might prove to be a promising leading compound for the development of an anti‐lung cancer drug. 相似文献
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13.
A new bisabolane-type sesquiterpene, trichoderic acid (1), and a new acorane-type sesquiterpene, 2β-hydroxytrichoacorenol (2), along with three known compounds, cyclonerodiol (3), cyclonerodiol oxide (4), and sorbicillin (5), were isolated from the culture broth of Trichoderma sp. PR-35, an endophytic fungus isolated from Paeonia delavayi. Their structures were elucidated on the basis of their IR, MS, and 1D- and 2D-NMR analyses. The antibacterial and antifungal activities of 1-5 towards various types of bacteria and fungi were tested. Most of the compounds showed moderate or weak antimicrobial activities in an agar-diffusion assay. 相似文献
14.
Oxidative stress has been considered as a major cause of cellular injuries in a variety of clinical abnormalities, especially prominent in neural diseases. One of the effective ways to prevent the reactive oxygen species (ROS) mediated cellular injury is dietary or pharmaceutical augmentation of some free radical scavenger. Water-soluble amino-fullerene derivative is a novel compound that behaves as a free radical scavenger with excellent biocompatibility. In the present study, we synthesized a novel beta-alanine C(60) derivative. The product was characterized by FT-IR, (1)H NMR, (13)C NMR, LC-MS and elemental analysis. We investigated the protective effect on hydrogen peroxide-induced oxidative stress and apoptotic death in cultured rat pheochromocytoma (PC12) cells. PC12 cells treated with hydrogen peroxide underwent apoptotic death determined by MTT, flow cytometry analysis and PI/Hoechst 33342 staining. Moreover, the scavenging ability of beta-alanine C(60) derivative to reactive oxygen species both in vivo and in vitro of PC12 cells was measured. The results suggest that beta-alanine C(60) derivative has the potential to prevent oxidative stress-induced cell death without evident toxicity. Hence, on the basis of the above-mentioned studies, we can hypothesize that the protective effect of beta-alanine C(60) derivative on H(2)O(2) induced apoptosis is related to their known scavenger activity toward ROS. 相似文献
15.
The cellular and molecular mechanisms that mediate vascular calcification remain poorly understood. In our previous study, oxysterol cholestane-3beta, 5alpha, 6beta-triol (Triol) was shown to promote vascular smooth muscle cells (VSMCs) calcification. In this study, by using direct coculture, non-contact transwell coculture, and culture with conditioned media, we investigated the roles of endothelial cells (ECs) and macrophages in the regulation of VSMCs calcification in the absence or presence of Triol. In vitro calcification was induced by incubation of VSMCs with beta-glycerophosphate. The results showed that ECs inhibited VSMCs calcification, as manifested by the reduction of calcium deposition in extracellular matrix. This effect of ECs on calcification was via the secreted soluble factors. Furthermore, the stimulation of ECs by Triol had no influence on ECs inhibition of calcification. On the other hand, macrophages promoted VSMCs calcification via the secreted soluble factors such as reactive oxygen species, which was further enhanced by Triol. Our results supported the roles for ECs and macrophages in vascular calcification, modulated by oxysterols in atherosclerotic plaque. 相似文献
16.
In this paper circadian changes in the liver enzyme activities of rat housed under highly standardized conditions with 12:12 hour light-dark cycle are shown. Activities of acid phosphatase, arylsulphatase, β-galactosidase and β-N-acetyl-d-glucosaminidase in microsomal and lysosomal fractions and crude homogenate were estimated every 4 hr during one 24-hr period. The enzyme activities were related to 1 mg of protein, 1 mg of DNA and 1 g fresh tissue. Daily changes of enzyme activities were found. In case of activity calculated per 1 mg DNA two maxima at 0500 and at 2100 hr were observed, while activity calculated per 1 mg protein showed one maximum at 0500 hr. Activity calculated per 1 g fresh tissue showed the maximum at 0500 hr for each enzyme only in microsomal fraction. As far as acrophase table is concerned for all enzymes and fractions the acrophase occurred during the night. The obtained results are discussed in relation to lysosomal enzymes synthesis process as well as different reference values. 相似文献
17.
Cytosolic phospholipase A(2)alpha (cPLA(2)alpha) is a rate-limiting key enzyme that releases arachidonic acid (AA) from membrane phospholipid for the production of biologically active lipid mediators including prostaglandins, leukotrienes and platelet-activating factor. cPLA(2)alpha is translocated to nuclear envelope in response to intracellular calcium increase and the enzyme is also present inside the cell nucleus; however, the biological function of cPLA(2)alpha in the nucleus remains unknown. Here we show a novel role of cPLA(2)alpha for activation of peroxisome proliferator-activated receptor-delta (PPARdelta) and beta-catenin in the nuclei. Overexpression of cPLA(2)alpha in human cholangiocarcinoma cells induced the binding of PPARdelta to beta-catenin and increased their association with the TCF/LEF response element. These effects are inhibited by the cPLA(2)alpha siRNA and inhibitors as well as by siRNA knockdown of PPARdelta. Overexpression of PPARdelta or treatment with the selective PPARdelta ligand, GW501516, also increased beta-catenin binding to TCF/LEF response element and increased its reporter activity. Addition of AA and GW501516 to nuclear extracts induced a comparable degree of beta-catenin binding to TCF/LEF response element. Furthermore, cPLA(2)alpha protein is present in the PPARdelta and beta-catenin binding complex. Thus the close proximity between cPLA(2)alpha and PPARdelta provides a unique advantage for their efficient functional coupling in the nucleus, where AA produced by cPLA(2)alpha becomes immediately available for PPARdelta binding and subsequent beta-catenin activation. These results depict a novel interaction linking cPLA(2)alpha, PPARdelta and Wnt/beta-catenin signaling pathways and provide insight for further understanding the roles of these key molecules in human cells and diseases. 相似文献
18.
The protein ER-alpha has been exhaustively characterized in estrogen-sensitive tissues and cell lines. However, little is known regarding the expression and cellular distribution of the newly identified ER-beta protein. We first quantified the specific estradiol binding site content in the estrogen-responsive cell lines MCF-7 (mammary) and SHM (myometrial). In the two cell types, these sites were associated to the expression of both ER-alpha and -beta isoforms. Native ER-beta was visualized to reside inside the nucleus by means of conventional indirect immunofluorescence. The cells expressed ER-beta as a tight approximately 50 kDa triplet when resolved by sodium dodecyl sulfate-polyacrylamide gels (SDS-PAGE) and blotted using antibodies mapping different domains of the cloned ER-beta version. When the cells were subjected to homogenization and differential centrifugation, a substantial proportion of ER-beta immunolabeling was localized at membrane subfractions. ER-beta expression and partitioning was confirmed by Ligand blotting assays using estrogen derivatives coupled to different macromolecular tags. However, ER-alpha was expressed as the major estrogen binding protein in both cell lines. Similar localization experiments were performed on HeLa cells (cervix). Though usually considered ER-negative, this cell line displayed basal significant estrogen binding capacity and co-expression of both ER isoforms. Taken as a whole, the results indicate that ER-beta could be expressed as functional estrogen binding proteins among a dominant population of ER-alpha sites in the cell lines under study. 相似文献
19.
The alpha-subunit of dystroglycan, a member of the dystrophin associated protein complex, binds to extracellular laminin-alpha2, while its beta-subunit interacts with cytoskeletal dystrophin. The exact biological role of dystroglycan, especially during human skeletal muscle development, has not been fully explored. Here, we analysed the distribution and expression characteristics of both dystroglycan subunits and laminin-alpha2 in primary human skeletal muscle cells. During development, expression levels of all three proteins increased with differentiation. The proteins were relocated from the sarcoplasm to the sarcolemma. The size of alpha-dystroglycan decreased from 150-220 kDa at the proliferation stage to 100-120 kDa at the late developmental stage. Both alpha- and beta-dystroglycan were involved in forming a complex with their respective partners laminin-alpha2 and dystrophin/utrophin. Our data show that, during development, cells may employ tightly regulated post-translational species-specific modification to produce different isoforms of alpha-dystroglycan to participate in appropriate functions. 相似文献
20.
Bingling Dai Tianfeng Yang Yujiao Ma Nan Ma Xianpeng Shi Dongdong Zhang Jie Zhang Yanmin Zhang 《Journal of cellular and molecular medicine》2018,22(5):2955-2959
Looking for novel, effective and less toxic therapies for cervical cancer is of significant importance. In this study, we reported that HMQ‐T‐F2(F2) significantly inhibited cell proliferation and transplantable tumour growth. Mechanistically, HMQ‐T‐F2 inhibited HeLa cell growth through repressing the expression and nuclear translocation of β‐catenin, enhancing Axin expression, as well as downregulating the Wnt downstream targeted proteins. Knock‐down of a checkpoint β‐catenin by siRNA significantly attenuated HeLa cell proliferation. Furthermore, XAV939, an inhibitor of β‐catenin, was used to treat HeLa cells and the results demonstrated that HMQ‐T‐F2 inhibited proliferation and migration via the inhibition of the Wnt/β‐catenin pathway. 相似文献