Synthesis and Cytotoxicity Assessment of Novel 7-O- and 14-O-Derivatives of Glaucocalyxin A.

BACKGROUND: Rabdosia japonica has been historically used in China as a popular folk medicine for the treatment of cancer, hepatitis, and gastricism. Glaucocalyxin A (GLA), an ent-kaurene diterpene isolated from Rabdosia japonica, is one of the main active ingredients showing potent inhibitory effects against several types of tumor cells. To the best of our knowledge, studies regarding the structural modification and Structure- Activity Relations (SAR) of this compound have not yet been reported. OBJECTIVE: The aim of this study was to discover more potent derivatives of GLA and investigate their SAR and cytotoxicity mechanisms. METHODS: Novel 7-O- and 14-O-derivatives of GLA were synthesized by condensation of acids or acyl chloride. The anti-tumor activities of these derivatives against various human cancer cell lines were evaluated in vitro by MTT assays. Apoptosis assays of compound 17 (7,14-diacylation product) were performed on A549 and HL-60 cells by flow cytometry and TUNNEL. The acute toxicity of this compound was tested on mice, at the dose of 300mg per kg body weight. RESULTS: Seventeen novel 7-O- and 14-O-derivatives of GLA (1-17) were synthesized. These compounds showed potent cytotoxicity against the tested cancer cell lines, and almost all of them were found to be more cytotoxic than GLA and oridonin. Of the synthesized derivatives, compound 17 presented the greatest cytotoxicity, with IC50 values of 0.26µM and 1.10µM in HL-60 and CCRF-CEM cells, respectively. Furthermore, this compound induced weak apoptosis of A549 cells but showed great potential in stimulating the apoptosis of HL- 60 cells. Acute toxicity assays indicated that compound 17 is relatively safer. CONCLUSION: The results reported herein indicate that the synthesized GLA derivatives exhibited greater cytotoxicity against leukemia cells than against other types of tumors. In particular, 7,14-diacylation product of GLA was found to be an effective anti-tumor agent. However, the cytotoxicity mechanism of this product in A549 cells is expected to be different than that in other tumor cell lines. Further research is needed to confirm this hypothesis.

[Aerobic Denitrification and Microbial Community Shift in SBR Bioaugmented with Strains YH01 and YH02].

The enhanced aerobic denitrification capability of the mixed strains YH01+YH02 in utilizing potassium nitrate, and the dynamic changes in the microbial community component during the period of operation, were evaluated. The microbial community in different stages of the SBR was analyzed by using high-throughput sequencing technology after inoculation with YH01+YH02. The results showed that the NO3--N, TN, and COD removal efficiencies increased by 12.1%, 9.2%, and 9.4%, respectively. The relative abundances of the microbes in the microbial community increased at the genus level, and the diversity in the microbial community decreased after enhancement. Principal component analysis and UPGMA analysis revealed that the period of SBR operation was roughly divined into four phases. The relative abundances of Delftia and Acidovorax increased during the period of operation, and YH01+YH02 exhibited excellent compatibility with the SBR ecosystem and played an important part in aerobic denitrification.

Monomeric and dimeric ent-kauranoid-type diterpenoids from rabdosia japonica and their cytotoxicity and anti-HBV activities.

Two new ent-kauranoid-type diterpenoids (1 and 2) and one new rare dimer of ent-kauranoids (3) with a cyclobutane ring by a [2+2] cycloaddition, together with nine known diterpenoids (4-12) were obtained from the aerial parts of Rabdosia japonica. Their chemical structures were established by 1D and 2D NMR techniques and mass spectrometry and by comparison with spectroscopic data reported. All ent-kauranoids were test for their cytotoxic effects against A549, HCT116, CCRF-CEM and HL-60 tumor cell lines. Compounds 1, 2, 4, 5, 7, 10 and 12 showed potent and selective cytotoxicity. In addition, some selected ent-kauranoids were test for their anti-HBV activities, and the results showed compound 8 had inhibitory effect on HBsAg with a 59% inhibition ratio at the concentration of 20µg/mL.

Chemical constituents from the rhizome of Polygonum paleaceum and their antifungal activity.

A new compounds neopaleaceolactoside (1), along with nine known compounds phyllocoumarin (2), quercetin (3), quercitrin (4), quercetin-3-methyl ether (5), vincetoxicoside B (6), isoquercitrin (7), kaempferol (8), (-)-epicatechin (9), and chlorogenic acid (10), was isolated from Polygonum paleaceum Wall. Their chemical structures were established based on one-dimensional and two-dimensional nuclear magnetic resonance techniques, mass spectrometry and by comparison with spectroscopic data reported. Some selected compounds were screened for their antifungal activity. Quercetin (3), vincetoxicoside B (6), kaempferol (8), and (-)-epicatechin (9) showed synergistic antifungal activities with the FICI values <0.5. A preliminary structure-activity relationship could be observed that free 3-OH in the structure of flavonoids was important for synergistic antifungal activity.

Constituents from the Roots of Actinidia chinensis and Their Cytochrome P450 Enzyme Inhibitory Activities.

A newly discovered triterpenoid, (2α,3ß)-2,3,23-trihydroxyurs-13(18)-en-28-oic acid (1), along with twelve known compounds (2 - 13), were isolated from the roots of Actinidia chinensis Planch (Actinidiaceae). Their chemical structures were determined by 1D- and 2D-NMR spectra and mass spectrometry (MS). The crude extracts and six main constituents (8 - 13) were tested for cytochrome P450 (CYPs) enzyme inhibitory activity. The results showed that, except for compound 8, compounds 9 - 13 had different inhibitory effects on the cytochrome P450 (CYPs) enzyme, and compound 9 significantly inhibited the catalytic activities of CYP3A4 to < 10% of its control activities.

A Schisandra-Derived Compound Schizandronic Acid Inhibits Entry of Pan-HCV Genotypes into Human Hepatocytes.

Despite recent progress in the development of hepatitis C virus (HCV) inhibitors, cost-effective antiviral drugs, especially among the patients receiving liver transplantations, are still awaited. Schisandra is a traditional medicinal herb used to treat a range of liver disorders including hepatitis for thousands of years in China. To isolate the bioactive compounds of schisandra for the treatment of HCV infection, we screened a schisandra-extracts library and identified a tetracyclic triterpenoid, schizandronic acid (SZA), as a novel HCV entry inhibitor. Our findings suggested that SZA potently inhibited pan-HCV genotype entry into hepatoma cells and primary human hepatocytes without interfering virus binding on cell surface or internalization. However, virion-cell fusion process was impaired in the presence of SZA, along with the increased host membrane fluidity. We also found that SZA inhibited the spread of HCV to the neighboring cells, and combinations of SZA with interferon or telaprevir resulted in additive synergistic effect against HCV. Additionally, SZA diminished the establishment of HCV infection in vivo. The SZA target is different from conventional direct-acting antiviral agents, therefore, SZA is a potential therapeutic compound for the development of effective HCV entry inhibitors, especially for patients who need to prevent HCV reinfection during the course of liver transplantations.

Trachelogenin, a novel inhibitor of hepatitis C virus entry through CD81.

Although much progress has been made in antiviral agents against hepatitis C virus (HCV) in recent years, novel HCV inhibitors with improved efficacy, optimized treatment duration and more affordable prices are still urgently needed. Here, we report the identification of a natural plant-derived lignan, trachelogenin (TGN), as a potent entry inhibitor of HCV without genotype specificity, and with low cytotoxicity. TGN was extracted and purified from Caulis trachelospermi, a traditional Chinese herb with anti-inflammatory and analgesic effects. A crucial function of TGN was the inhibition of HCV entry during a post-binding step without affecting virus replication, translation, assembly and release. TGN blocked virus infection by interfering with the normal interactions between HCV glycoprotein E2 and the host entry factor CD81, which are key processes for valid virus entry. In addition, TGN diminished HCV cell-to-cell spread and exhibited additional synergistic effects when combined with IFN or telaprevir. In conclusion, this study highlights the effect of a novel HCV entry inhibitor, TGN, which has a target that differs from those of the current antiviral agents. Therefore, TGN is a potential candidate for future cocktail therapies to treat HCV-infected patients.

[Chemical Constituents from Polygonum paleaceum].

Objective: To isolate and identify the chemical constituents from Polygonum paleaceum. Methods: Chemical constituents were isolated and purified by column chromatography on silica gel,Sephadex HL-20 and macroporous resin etc. The chemical structures were identified by MS,NMR and spectral analysis. Results: Ten compounds were isolated and their structures were elucidated as ethyl chlorogenate( 1),methyl chlorogenate( 2), kaempferol-3-O-α-L-rhamnopyranoside( 3), (-)-epicatechin( 4), paleaceolactoside( 5), protocatechuic acid( 6), kaempferol( 7), gallic acid( 8), chlorogenic acid( 9) and isoquercitrin( 10). Conclusion: Compounds 1,3,6,7 and 10 are isolated from this plant for the first time.

Cytotoxic dibenzocyclooctadiene lignans from Kadsura coccinea.

Three new dibenzocyclooctadiene lignans, kadusurain A-C (1-3), together with two known compounds kadsuphilin A (4) and B (5), were isolated from an EtOAc fraction of the 80 % acetone extract of Kadsura coccinea (Lem.) A. C. Smith. Their structures were established by 1D and 2D NMR techniques, and mass spectroscopy. Anti-proliferative effect of isolated compounds was evaluated against four human tumor cell lines (A549, HCT116, HL-60, and HepG2), and it was found that compound 1 exhibited significant antiproliferative effects with IC50 values ranging from 1.05 to 12.56 µg/ml.

Phenolics from Bidens bipinnata and their amylase inhibitory properties.

A new chlorinated flavonoid, 3, 6, 8-trichloro-5, 7, 3', 4'-tetrahydroxyflavone (1), a new biscoumaric acid derivative, 4-O-(2″, 3″-O-diacetyl-6″-O-p-coumaroyl-ß-D-glucopyranosyl)-p-coumaric acid (2), and 8, 3', 4'-trihydroxyflavone-7-O-ß-D-glucopyranoside (3) together with twenty-four known compounds (4-27) were isolated from the whole plant of Bidens bipinnata. All chemical structures were established on the basis of UV-, MS- and NMR (¹H, ¹³C, ¹H-¹H COSY, HMQC and HMBC) spectroscopic data. Some of the isolated compounds were tested for the inhibition of α-amylase. The result showed that isookanin (6) was a potent inhibitor of α-amylase (IC50=0.447 mg/ml).

A new furostanol saponin from Asparagus cochinchinensis.

A new furostanol saponin, (25S)-26-O-ß-D-glucopyranosyl-5ß-furost-20(22)-en-3ß, 15ß,26-triol-3-O-[α-L-rhamnopyranosyl-(1-4)]-ß-D: -glucopyranoside, namely, aspacochioside D (1) were isolated from Asparagus cochinchinensis (Lour.) Merr, along with three known saponins, aspacochioside C (2), (25S)-5ß-spirostan-3ß-yl-O-[O-α-L-rhamnopyranosyl-(1-4)]-ß-D-glucopyranoside (3), and pseudoprotoneodioscin (4). The structure of 1 was elucidated on the basis of chemical reactions and spectral analysis (IR, GC, ESI-MS, (1)H-NMR, (13)C-NMR, DEPT, HMBC, HMQC and NOESY). The antiproliferative effects of 1-4 were evaluated in a cytotoxicity assay against the human tumor cell line, A549. Compound 2 (Aspacochioside C) exhibited moderate cytotoxicity against A-549, with an IC(50) value of 3.87 µg/mL.

Two new triterpenoid acids from Kadsura coccinea.

An investigation of EtOAc extracts of Kadsura coccinea (Lem.) A. C. Smith, has led to the isolation of two new compounds characterized as 3-hydroxy-12-hydroxyl coccinic acid (1) and 3-hydroxy-neokadsuranic acid A (2). Their structures were established by 1D and 2D NMR techniques and mass spectroscopy. Antiproliferative effects of the isolated compounds were evaluated against four human tumor cell lines (A549, HCT116, HL-60 and HepG2), and it was found that compound 1 exhibited antiproliferative effects with IC(50) values ranging from 3.01 to 18.08 µg/mL.

Chemical constituents of Trachelospermum jasminoides.

Ten compounds, comprising a new C(8) normonoterpenoid glycoside, trachelinoside (1), structurally as 4-(2-O-beta-D-glucopyranosyl)-hydroxyethyl-5,5-dimethyldihydrofuran-2(3H)-one, together with nine known compounds, were isolated from the 85% ethanol extract of the vines and leaves of Trachelospermum jasminoides (Lindl.) Lem.

[Study on the flavonoids constituents of Trachelospermum jasminoides].

OBJECTIVE: To study the flavonoids constituents of Trachelospemum jasminoides. METHODS: The compounds were separated and purified by column chromatography with silica gel, and identified by IR, MS, NMR and 2D-NMR. RESULTS: Six flavonoids were identified as apigenin (I), apigenin 7-O-beta-glucoside (II), apigenin 7-O-beta-neospheroside (III), luteoloside (IV), narngin (V) 6,8-di-C-glucopyanosylapigenin (VI), respectively. CONCLUSION: Compounds V and VI are isolated from this plant for the first time.

Two new triterpenoids from the roots of Actinidia chinensis.

Two new triterpenoids (1, 2), together with one flavonoid glycoside and thirteen known triterpenoids were isolated from the roots of Actinidia chinensis Planch (Actinidiaceae). The structures of the new constituents were elucidated as 12α-chloro-2α, 3ß, 13ß, 23-tetrahydroxyolean-28-oic acid-13-lactone (1), 2α, 3α, 19α, 23, 24-pentahydroxyurs-12-en-28-oic acid (2). Structure elucidation was accomplished by 1D, 2D NMR spectra (HMQC, HMBC, (1)H-(1)H COSY, TOCSY, and NOESY) and mass spectrometry (ESIMS). Moreover, two known triterpenoids showed positive cytotoxic activity against LOVO and HepG2 cell lines.

Three new compounds from Arnebia euchroma.

A new naphthoquinone dimer, arnebiabinone (1), a new phenolic compound, ethyl 9-(2',5'-dihydroxyphenyl) nonanoate (2), and a new natural product, octyl ferulate (3), were isolated from the EtOH extract of dried roots of Arnebia euchroma (Royle) Johnst. Their structures were elucidated on the basis of chemical reaction and spectral analysis.

A new indole alkaloid from Ervatamia yunnanensis.

The stems of Ervatamia yunnanensis have afforded a new indole alkaloid, ervataine (1), whose structure was determined by spectroscopic analysis. Five known compounds, ibogaine (2) coronaridine (3), heyneanine (4), voacangine hydroxyindolenine (5) and coronaridine hydroxyindolenine (6), were also isolated.

Validation of VKORC1 and CYP2C9 genotypes on interindividual warfarin maintenance dose: a prospective study in Chinese patients.

OBJECTIVES: To develop a warfarin-dosing algorithm that could be combined with pharmacogenomic and demographic factors, and to evaluate its effectiveness in a randomized prospective controlled clinical trial. METHODS: A pharmacogenetics-based dosing model was derived using retrospective data from 266 Chinese patients and multiple linear regression analysis. To prospectively validate this model, 156 patients with an operation of heart valve replacement were enrolled and randomly assigned to the group of pharmacogenetics-guided or traditional dosing for warfarin therapy. All patients were followed up for 50 days after initiation of warfarin therapy. The log-rank test was compared with the time-to-event (Kaplan-Meier) curves. Cox proportional hazards-regression model was used to assess the hazard ratio of the time to reach stable dose. RESULTS: The linear regression model derived from the pharmacogenomic model correlated with 54.1% of warfarin dosing variance. The final multiple linear regression model included age, body surface area, VKORC1, and CYP2C9 genotype. The study showed that the hazard ratio for the time to reach stable dose was 1.932 for the traditional dosing group versus the model-based group and a close and highly significant relationship was observed to exist between the predicted and the actual warfarin dose (R=0.454). CONCLUSION: A pharmacogenetics-based dosing algorithm has been developed for improvement in the time to reach the stable dosing of warfarin. This model may be useful in helping the clinicians to prescribe warfarin with greater safety and efficiency.

Alkaloids from Corydalis saxicola and their anti-hepatitis B virus activity.

Eight protoberberine-type alkaloids and two indole alkaloids were isolated from the MeOH extracts of the herb Corydalis saxicola Bunting (Papaveraceae). Their structures were identified as dehydrocavidine (1), dehydroapocavidine (2), dehydroisoapocavidine (3), berberine (4), dehydroisocorypalmine (5), coptisine (6), tetradehydroscoulerine (7), berbinium (8), 1-formyl-5-methoxy-6-methylindoline (9), and 1-formyl-2-hydroxy-5-methoxy-6-methylindoline (10). Compounds 3, 9, and 10 are new alkaloids. All compounds were tested for anti-HBV activity against the 2.2.15 cell line in vitro. Dehydrocavidine (1), dehydroapocavidine (2), and dehydroisoapocavidine (3) exhibited inhibitory activity against HBsAg and HBeAg, but no cytotoxicity against the 2.2.15 cell line.

A new quinazolinedione alkaloid from the fruits of Evodia officinalis.

A new quinazolinedione alkaloid, wuchuyuamide IV (1) was isolated from the fruits of Evodia officinalis.1 showed moderate cytotoxicity against Hela and HT1080 cell lines.