Two new saponins from Thalictrum fortunei

Two new cycloartane glycosides were isolated from the aerial parts of Thalictrum fortunei (Ranunculaceae). The chemical structures of these compounds were elucidated as 3-O-β-D-glucopyranosyl (1 → 4)-β-d-fucopyranosyl-(22S,24Z)-cycloart-24-en-3β,22,26,30-tetraol 26-O-β-D-glucopyranoside and 3-O-β-D-glucopyranosyl (1 → 4)-β-D-fucopyranosyl-(22S,24Z)-cycloart-24-en-3β,22,26,29-tetraol 26-O-β-D-glucopyranoside by extensive 1D and 2D NMR methods, HR-ESI-MS, and hydrolysis. Their cytotoxic activities toward human hepatoma Bel-7402 cells, human colon carcinoma LoVo cells, and human non-small-cell lung cancer NCIH-460 cells were evaluated by MTT assay, respectively.

Flavone C-glycosides from the leaves of Lophatherum gracile and their in vitro antiviral activity

Four new flavone C-glycosides, luteolin 6-C-α-L-arabinopyranosyl-7-O-β-D-glucopyranoside, apigenin 6-C-β-D-galactopyranosiduronic acid (1 → 2)-α-L-arabinopyranoside, luteolin 6-C-β-D-galactopyranosiduronic acid (1 → 2)-α-L-arabinopyranoside, and luteolin 6-C-β-D-glucopyranosiduronic acid (1 → 2)-α-L-arabinofuranoside, along with three known ones, were isolated from the leaves of Lophatherum gracile. The structures of the new compounds were elucidated by extensive spectroscopic methods as well as acid hydrolysis. All the flavone glycosides isolated from this plant were screened for their in vitro antiviral activity against respiratory syncytial virus (RSV) with cytopathic effect (CPE) reduction assay, and several flavone 6-C-monoglycosides showed potent in vitro anti-RSV effect.

Variations in fuel use in the flight muscles of wing-dimorphic Gryllus firmus and implications for morph-specific dispersal

Although a considerable amount of information is available on tradeoffs in wing-polymorphic insects, only limited data are available on the relationship between flight and biochemical variation within species. In the current study, we compared the biochemical basis in the dorsolongitudinal flight muscle of the wing-dimorphic sand cricket, Gryllus firmus Scudder, with respect to tradeoffs in energy resources related to morph-specific flight, including glycogen, trehalose, and triglycerides. Our results show that levels of glycogen and trehalose in long-winged adults (LW[f]) were significantly higher before dispersal, on days 5 and 7. Considering that this is the period during which long-winged adults are flight-capable, these results suggest that both glycogen and trehalose are important to flight. However, levels of triglycerides in short-winged crickets (SW) were higher than in long-winged crickets, suggesting that triglycerides are not directly related to initial flight. In SW adults, triglyceride content on days 5 and 7 was significantly higher just before lights off than at the same time on day 1 or at any other time after lights on all other days. This suggests that triglycerides are probably related to reproductive behaviors, such as mating and oviposition, in the SW morph. In addition, flight muscle water content was significantly lower in the LW(f) morph than in the SW morph.

[Effects of wheat planted adjacent to rape on the major pests and their natural enemies in wheat field]

Based on the dynamic analysis of insect community structure characteristics, an investigation was conducted on the composition, abundance, and stability of wheat aphids and their major natural enemies in the wheat field adjacent to rape field in Handan City, Hebei Province in 2008-2009. The wheat and rape fields had the similar composition of insect communities. The main pests were aphids, their predatory natural enemies included ladybirds, green lacewings, spiders, and hover flies, and their parasitic natural enemies were wasps. In 2008-2009, the composition of insect communities in the wheat and rape fields had definite changes, but the common features were the lowest abundance of aphids and the highest abundance of predatory and parasitic natural enemies in wheat field adjacent to rape field. The insect community, aphid sub-community, and predatory natural enemy' s sub-community had a high stability in the wheat field adjacent to rape field and a low stability far from the rape field, suggesting that planting wheat adjacent to rape could effectively protect and make use of the natural enemies and promote their control ability on wheat aphids in wheat field.

Comparative study on saponin fractions from Panax notoginseng inhibiting inflammation-induced endothelial adhesion molecule expression and monocyte adhesion

BACKGROUND

Panax notoginseng is commonly used for the treatment of cardiovascular diseases in China. The present study investigates the effects of three different saponin fractions (ie total saponins, PNS; protopanaxadiol-type saponin, PDS; and protopanaxatriol-type saponin, PTS) and two major individual ingredients (ie ginsenoside Rg1 and Rb1) from P. notoginseng on the endothelial inflammatory response in vitro and in vivo.

METHODS

Recombinant human tumor necrosis factor-α (TNF-α) was added to the culture medium of human coronary artery endothelial cells (HCAECs) to induce an inflammatory response. A cell adhesion assay was used to determine the effect of the P. notoginseng saponin fractions on endothelial-monocyte interaction. The cell adhesion molecule (CAMs) expression, including ICAM-1 and VCAM-1, in the protein level on the surface of endothelial cells were measured by cellular ELISA. CAMs expression in mRNA level was also assayed by qRT-PCR in the HCAECs and the aorta of rat fed with high cholesterol diet (HCD). Western blotting was used to detect effect of the saponin fractions on CAMs protein expression in HCAECs. In addition, nuclear translocation of p65, a surrogate marker for NF-κB activation, was measured by immunostaining.

RESULTS

Three saponin fractions and two individual ginsenosides exhibited the inhibitory effects on monocyte adhesion on TNF-α-activated HCAECs and expression of ICAM-1 and VCAM-1 at both mRNA and protein levels in vitro. The saponin fractions exhibited a similar trend of the inhibitory effects on the mRNA expression of CAMs in the aorta of HCD-fed rat in vivo. These inhibitory effect of saponin fractions maybe attribute partially to the suppression of the TNF-α-induced NF-κB activation.

CONCLUSION

Our data demonstrate that saponin fractions (ie PNS, PDS and PTS) and major individual ginsenosides (ie Rg1 and Rb1) have potential anti-atherogenic effects. Among the tested saponin fractions, PDS is the most potent saponin fraction against TNF-α-induced monocyte adhesion as well as the expression of adhesion molecules in vitro and in vivo.

[Nitrogen uptake rate and use efficiency by rice under different levels of the controlled-release N fertilizers (CRF) in the Nansi Lake basin]

The nitrogen (N) fertilizers overused or misused are the main contributors for water eutrophication of the Nansi Lake in eastern China. A field experiment with different application levels of controlled-release N fertilizer (CRF) was carried out at a rice field in the Nansi lake basin to provide information on the nitrogen uptake rate and use efficiency by rice with CRF application at different growth stages of rice. The fertilization levels for the controlled fertilizer in this study were 0, 300, 337.5 and 375 kg/hm2, respectively, and 375 kg/hm2 for conventional urea (CU). We estimated the N uptake rate in different growing season and apparent recovery of fertilizer in root, stover and grain of rice. The result showed that grain yield increased by higher N rate. However, the N uptake rate did not increase linearly with the nitrogen application amount. The highest N uptake rate was 22.48 mg/(plant x d) under the fertilization amount of 337.5 kg/hm2 during the young panicle differentiation stage. Apparent N recovery efficiency for CU with traditional application amount of 375 kg/hm2 was 21.86%. Apparent N recovery efficiency for CRF with application amount of 337.5 kg/hm2 was highest with 37.17%. Based on the statistical data, with CU of traditional urea application amount of 375 kg/hm2, nitrogen loss and soil N residue at one growing season are 130.07 x 10(3) t for Jining city and 11.4 x 10(3) t for Yutai county of the Nansi Lake basin. If using CRF with the optimized application amount of 337.5 kg/hm2, nitrogen loss and soil residual at one growing season is 10.46 x 10(4) t for Jining city. It could reduce losses of 2.55 x 10(4) t N for Jining city and 2 235.26 t N for Yutai county per year. Because of releasing patterns more closely matched to crop N uptake patterns, controlled release N fertilizer could be a good way to prevent water eutrophication due to nitrogen fertilizer overused or misused in the Nansi Lake.

Leaching behavior of nitrogen in a long-term experiment on rice under different N management systems

The leaching behavior of nitrogen was studied in single rice paddy production ecosystems in Tsukuba, Japan after 75 years of consistent fertilization regimes (no fertilizer, ammonium sulfate, a combination of composted rice straw with soybean cake, and fresh clover). During the 75-year period, management was unchanged with respect to rice planting density, irrigation, and net N fertilization for each field to which an N-source was added. Percolation water was collected, from May 2001 to April 2002, using porous suction cups installed in the fields at depths of 15, 40, and 60 cm. All water samples were taken to the laboratory for the measurement of both NH(4) ( + )-N and NO(3) ( - )-N concentrations using a continuous-flow nitrogen analyzer. The result indicated that there were significant differences in N leaching losses between treatments during the rice growing season. Total N leaching was significantly lower with the application of composted rice straw plus soybean cake (0.58 kg N ha( - 1)) than with ammonium sulfate (2.41 kg N ha( - 1)), which resulted in N leaching at a similar level to that with the fresh clover treatment (no significant difference). The majority of this N leaching was not due to NO(3) ( - )-N loss, but to that of NH(4) ( + )-N. The mean N leaching for all fertilizer treatments during the entire rice growing season was 1.58 kg N ha( - 1). Composted rice straw plus soybean cake produced leaching losses which were 65-75% lower than those with the application of fresh clover and ammonium sulfate. N accumulation resulting from nitrification in the fallow season could be a key source of nitrate-N leaching when fields become re-flooded before rice transplanting in the following year; particular attention should be paid to this phenomenon.

[Studies on the flavonoids from the flowers of Hylocereus undatus]

OBJECTIVE

To study the chemical constituents of the flowers of Hylocereus undatus.

METHODS

The constituents were isolated and purified by various modern chromatographic techniques. The structures of the compounds were elucidated based on their physicochemical properties and spectral analyses.

RESULTS

Thirteen compounds were isolated from the flowers of H. undatus. Their structures were elucidated as kaempferol (1), quercetin (2), isorhamnetin (3), kaempferol 3-O-alpha-L-arabinfuranoside (4), kaempferol 3-O-beta-D-glucopyranoside (5), quercetin 3-O-beta-D-glucopyranoside (6), isorhamnetin 3-O-beta-D-glucopyranoside (7), kaempferol 3-O-beta-D-galactopyranoside (8), quercetin 3-O-beta-D-galactopyranoside (9), kaempferol 3-O-beta-D-rutinoside (10), isorhamnetin 3-O-beta-D-rutinoside (11), kaempferol 3-O-alpha-L-rhamopyranosyl-(1 --> 6)-beta-D-galactopyranoside (12), and isorhamnetin 3-O-alpha-L-rhamopyranosyl-(1 --> 6)-beta-D-galactopyranoside (13).

CONCLUSION

All the compounds are isolated from this plant for the first time.

Five new C21 steroidal glycosides from Periploca sepium

Five new C(21) steroidal glycosides, named periseosides A-E (1-5), along with six known analogues, were isolated from the root barks of Periploca sepium. Their structures were elucidated on the basis of spectroscopic analysis and chemical evidence. All compounds were evaluated for their immunosuppressive activities.

Bisdemethoxycurcumin protects endothelial cells against t-BHP-induced cell damage by regulating the phosphorylation level of ERK1/2 and Akt

Curcuminoids are the major active components extracted from Curcuma longa and are well known for their antioxidant effects. Previous studies have reported that the antioxidant properties of curcuminoids are mainly attributed to their free radical scavenging abilities. However, whether there are other mechanisms besides the non-enzymatic process and how they are involved, still remains unknown. In the present study, we explored the protective effects of bisdemethoxycurcumin (Cur3) against tert-butyl hydroperoxide (t-BHP)-induced cytotoxicity in human umbilical vein endothelial cells (HUVECs), focusing on the effect of Cur3 on the regulation of the phosphatidylinositol 3-kinase (PI3K)/Akt and the mitogen-activated protein kinase (MAPK) pathways. The pre-treatment with Cur3 inhibited t-BHP-induced cell damage dose-dependently, which was evident by the increased cell viability and the corresponding decrease in lactate dehydrogenase release. The pre-treatment with Cur3 also attenuated t-BHP-induced cell morphological changes and apoptosis. MAPKs, including p38, c-Jun N-terminal kinase (JNK), extracellular signal-regulated protein kinase 1/2 (ERK1/2), as well as PI3K/Akt have been reported to be involved in proliferation, apoptosis and differentiation under various stress stimulations. The pre-treatment with Cur3 decreased t-BHP-induced ERK1/2 phosphorylation and increased t-BHP-induced Akt phosporylation but did not affect the phosphorylation of p38 or JNK. In addition, the Cur3-induced increase in cell viability was attenuated by the treatment with wortmannin or LY294002, the upstream inhibitors of Akt, and was enhanced by the treatment with 2-[2'-amino-3'-methoxyphenyl]-oxanaphthalen-4-one (PD98059), an upstream inhibitor of ERK1/2. These results suggest that the ERK1/2 and PI3K/Akt signaling pathways could be involved in the protective effects of Cur3 against t-BHP-induced damage in HUVECs.

5,6-Didehydroginsenosides from the roots of Panax notoginseng

Two minor novel dammarane-type saponins - 5,6-didehydroginsenoside Rd (1) and 5,6-didehydroginsenoside Rb1 (2) - were isolated from the dried roots of Panax notoginseng along with sixteen known saponins. The structures of the new compounds were elucidated on the basis of spectroscopic and chemical methods.

Different strategies for preparation of non-tagged rV270 protein and its efficacy against Yersinia pestis challenge

OBJECTIVE

LcrV is an important component for the development of a subunit vaccine against plague. To reduce immunosuppressive activity of LcrV, a recombinant LcrV variant lacking amino acids 271 to 326 (rV270) was prepared by different methods in this study.

METHODS

A new strategy that produced non-tagged or authentic rV270 protein was designed by insertion of rV270-thrombin-hexahistidine fusion gene into the vector pET24a, or by insertion of hexahistidine-enterokinase-rV270 or hexahistitine-factor Xa-rV270 fusion gene into the vector pET32a. After Co(2+) affinity chromatography, a purification strategy was developed by cleavage of His tag on column, following Sephacryl S-200HR column filtration chromatography.

RESULTS

Removal of His tag by thrombin, enterokinase and factor Xa displayed a yield of 99.5%, 32.4% and 15.3%, respectively. Following Sephacryl S-200HR column filtration chromatography, above 97% purity of rV270 protein was obtained. Purified rV270 that was adsorbed to 25% (v/v) Al(OH)₃ adjuvant in phosphate-buffered saline (PBS) induced very high titers of antibody to rV270 in BALB/c mice and protected them (100% survival) against subcutaneous challenge with 10⁶ CFU of Y. pestis virulent strain 141.

CONCLUSION

The completely authentic rV270 protein can be prepared by using enterokinase or factor Xa, but they exhibited extremely low cleavage activity to the corresponding recognition site. Thrombin cleavage is an efficient strategy to prepare non-tagged rV270 protein and can be easily operated in a large scale due to its relatively low cost and high cleavage efficacy. The recombinant rV270 can be used as a key component to develop a subunit vaccine of plague.

Preparative isolation and purification of six volatile compounds from essential oil of Curcuma wenyujin using high-performance centrifugal partition chromatography

Six volatile compounds, curdione (1), curcumol (2), germacrone (3), curzerene (4), 1,8-cineole (5) and beta-elemene (6), were successfully isolated from the essential oil of Curcuma wenyujin by high-performance centrifugal partition chromatography using a nonaqueous two-phase solvent system consisting of petroleum ether-acetonitrile-acetone (4:3:1 v/v/v). A total of 8 mg of curdione (1), 4 mg of curcumol (2), 10 mg of germacrone (3), 18 mg of curzerene (4), 9 mg of 1,8-cineole (5) and 17 mg of beta-elemene (6) were isolated from the essential oil (300 mg) in 500 min. Their structures were determined by comparison of their retention times and MS data with those of the authentic samples as well as NMR spectroscopic analysis.

[Alkaloids from the leaves of Nauclea officinalis]

To study chemical constituents of the leaves of Nauclea officinalis, eight alkaloids were isolated from 95% ethanol extract by various chromatographic methods. The structures were elucidated on the basis of spectroscopic data (IR, UV, ESI-MS, 1D and 2D NMR) and identified as naucleactonin C (1), strictosamide (2), vincosamide (3), pumiloside (4), angustoline (5), angustine (6), 18, 19-dihydroangustine (7) and naucleofficine D (8). Compound 1 is a new indole alkaloid. Compounds 6 and 7 were isolated from this plant for the first time.

Isolation and identification of two new polyynes from a North American ethnic medicinal plant--Oplopanax horridus (Smith) Miq

Two new polyynes, named oplopantriol A (5) and oplopantriol B (6), were isolated from the root bark of Oplopanax horridus (Smith) Miq, an ethnic medicinal plant of North America, along with four known polyynes: (3S,8S)-falcarindiol (1), oplopandiol (2), (11S,16S,9Z)-9,17-octadecadiene-12,14-diyne-1,11,16-triol, 1-acetate (3) and oplopandiol acetate (4). The structures of the new compounds were elucidated by detailed spectroscopic analyses, including 1D and 2D NMR techniques and chemical methods. The absolute configurations of the new compounds 5 and 6 were determined by comparing their optical rotation values with the hydrolysis products of the known compounds 3 and 4, respectively, derived from the same plant. On the basis of an analysis of their physical and chemical properties we show that the alkaline hydrolysis of 3 and 4 afforded the new compounds 5 and 6, respectively.

[Composition of phenolic allelochemicals in Eupatorium adenophorum root zone soils and its effects on soil-borne pathogens]

The allelochemicals released by Eupatorium adenophorum roots is an important factor inducing the changes of the weed soil environment, which provides favorable conditions for the successful invasion of the weed. By using GC/MS technique, the components and their relative contents of phenolic allelochemicals in aphid-infested and non-infested E. adenophorum root zone soils were analyzed, with unplanted soil as the control. Less difference was observed in the components of phenolic allelochemicals among the test soils, but their relative contents differed significantly. The relative contents of benzoic acid and 4-hydroxybenzoic acid in aphid-infested E. adenophorum root zone soil were significantly higher than the control; whereas that of 4-hydroxylcinnamic acid was in reverse. In the test three soils, the proportions of benzoic acid, 4-hydroxybenzoic acid, and 4-hydroxylcinnamic acid were different. The bacteriostatic test with the three acids and their combinations based on their proportions in test soils showed that at lower concentrations (50-150 mg x L(-1)), the three acids had significant inhibitory effects on five kinds of soil-borne pathogens, but their combinations had different inhibitory effects on the five pathogens, with the effects being significantly higher for the combinations with the proportions in non-infested E. adenophorum root zone soil and the control.