Induction of cell cycle arrest by the carbazole alkaloid Clauszoline-I from Clausena vestita D. D. Tao via inhibition of the PKCδ phosphorylation

Sixteen carbazole alkaloids from Clausena vestita D. D. Tao were extracted, and their anti-tumor activities were evaluated. Among the extracts, Clauszoline-I exhibited an obvious growth inhibitory activity against several cancer cell lines through its ability to induce cell cycle arrest in the S and G2/M phases. A dramatic morphologic change with decreased F-actin staining and RhoA activity was found in Clauszoline-I treated HepG2 cells, in which the phosphorylation of PKCδ (Ser643) was inhibited. Our results indicated that induction cell cycle arrest by Clauszoline-I might be achieved by decreasing the RhoA activity via the inhibition of PKCδ phosphorylation.

Characterization of anti-Coxsackie virus B3 constituents of Radix Astragali by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry

To profile the anti-Coxsackie virus B3 constituents of Radix Astragali, an HPLC-DAD-MS(n) analytical method, combined with an in vivo test, has been developed to identify the constituents of the active part, which has been demonstrated to have potency to inhibit the proliferation of virus in cardiac muscle, alleviate infraction in heart and elevate the survival rate of the animal. By comparing their retention time and MS data with those obtained from the authentic compounds and the published data, a total of 19 compounds, including 11 isoflavonoids and eight saponins, were identified, among which one pterocarpane glucoside was reported for the first time. The present study provides an approach to rapidly screening bioactive constituents in traditional Chinese medicines.

Genetic map construction and QTL mapping of resistance to blackleg (Leptosphaeria maculans) disease in Australian canola (Brassica napus L.) cultivars

Genetic map construction and identification of quantitative trait loci (QTLs) for blackleg resistance were performed for four mapping populations derived from five different canola source cultivars. Three of the populations were generated from crosses between single genotypes from the blackleg-resistant cultivars Caiman, Camberra and (AV)Sapphire and the blackleg-susceptible cultivar Westar(10). The fourth population was derived from a cross between genotypes from two blackleg resistant varieties (Rainbow and (AV)Sapphire). Different types of DNA-based markers were designed and characterised from a collection of 20,000 EST sequences generated from multiple Brassica species, including a new set of 445 EST-SSR markers of high value to the international community. Multiple molecular genetic marker systems were used to construct linkage maps with locus numbers varying between 219 and 468, and coverage ranging from 1173 to 1800 cM. The proportion of polymorphic markers assigned to map locations varied from 70 to 89% across the four populations. Publicly available simple sequence repeat markers were used to assign linkage groups to reference nomenclature, and a sub-set of mapped markers were also screened on the Tapidor x Ningyou (T x N) reference population to assist this process. QTL analysis was performed based on percentage survival at low and high disease pressure sites. Multiple QTLs were identified across the four mapping populations, accounting for 13-33% of phenotypic variance (V (p)). QTL-linked marker data are suitable for implementation in breeding for disease resistance in Australian canola cultivars. However, the likelihood of shifts in pathogen race structure across different geographical locations may have implications for the long-term durability of such associations.

Complete NMR spectral assignments of two new iridoid diastereoisomers from the flowers of Plumeria rubra L. cv. acutifolia

Two new iridoid diastereoisomers (1, 2), together with five known compounds, were isolated from the flowers of Plumerian rubra L. cv. acutifolia. Their structures were elucidated by the means of in-depth spectroscopic and mass-spectrometric analyses, particularly 1D and 2D NMR spectroscopy.

Genetic and QTL analyses of seed dormancy and preharvest sprouting resistance in the wheat germplasm CN10955

The inheritance and genetic linkage analysis for seed dormancy and preharvest sprouting (PHS) resistance were carried out in an F8 recombinant inbred lines (RILs) derived from the cross between "CN19055" (white-grained, PHS-resistant) with locally adapted Australian cultivar "Annuello" (white-grained, PHS-susceptible). Seed dormancy was assessed as germination index (GI7) while assessment for preharvest sprouting resistance was based on whole head assay (sprouting index, SI) and visibly sprouted seeds (VI). Segregation analysis of the F2, F3 data from the glasshouse and the RIL population in 2004 and 2005 field data sets indicated that seed dormancy and PHS resistance in CN19055 is controlled by at least two genes. Heritabilities for GI7 and VI were high and moderate for SI. The most accurate method for assessing PHS resistance was achieved using VI and GI7 while SI exhibited large genotype by environment interaction. Two quantitative trait loci (QTLs) QPhs.dpivic.4A.1 and QPhs.dpivic.4A.2 were identified. On pooled data across four environments, the major QTL, QPhs.dpivic.4A.2, explained 45% of phenotypic variation for GI7, 43% for VI and 20% for SI, respectively. On the other hand, QPhs.dpivic.4A.1 which accounted for 31% of the phenotypic variation in GI7 in 2004 Horsham field trial, was not stable across environments. Physical mapping of two SSR markers, Xgwm937 and Xgwm894 linked to the major QTL for PHS resistance, using Chinese Spring deletions lines for chromosome 4AS and 4AL revealed that the markers were located in the deletion bins 4AL-12 and 4AL-13. The newly identified SSR markers (Xgwm937/Xgwm894) showed strong association with seed dormancy and PHS resistance in a range of wheat lines reputed to possess PHS resistance. The results suggest that Xgwm937/Xgwm894 could be used in marker-assisted selection (MAS) for incorporating preharvest sprouting resistance into elite wheat cultivars susceptible to PHS.

Antibacterial phenolic components from Eriocaulon buergerianum

Five phenolic components, 1,3,6-trihydroxy-2,5,7-trimethoxyxanthone (1), 7,3'-dihydroxy-5,4',5'-trimethoxyisoflavone (2), toralactone-9-O-beta-D-glucopyranoside (3), patuletin-3-O-[2-O-E-feruloyl-beta-d-glucopyranosyl-(1-->6)-beta-d-glucopyranoside] (4), patuletin-3-O-[beta-d-glucopyranosyl-(1-->3)-2-O-E-caffeoyl-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside] (5), along with 19 known compounds were isolated from Eriocaulon buergerianum (Eriocaulaceae). Their structures were determined by spectroscopic and chemical methods. All 24 isolated compounds were tested against the pathogenic bacteria Staphylococcus aureus (ATCC 25923); as a result, 10 compounds were found to exhibit antibacterial activity with MICs ranging from 32 to 256 microg/ml.

Cytotoxic diterpenoids and sesquiterpenoids from Pteris multifida

Three new ent-kaurane diterpenoids, named pterokaurane M 1-M 3 ( 1- 3) and three new C 14 pterosin-sesquiterpenoids, named multifidoside A-C ( 4- 6), along with 18 known compounds, were isolated from the whole plants of Pteris multifida . The structures of 1- 6 were established using spectroscopic methods, including extensive 2D NMR and CD analyses. Compounds 4 and 5 showed cytotoxicity against the HepG2 tumor cell line with IC 50 values of less than 10 microM.

Identification and determination of four metabolites of mangiferin in rat urine

Four metabolites of mangiferin were firstly isolated and identified from rat urine. The structures of the four metabolites were determined to be 1,3,7-trihydroxyxanthone (M-1), 1,3,6,7-tetrahydroxyxanthone (M-2), 1,3,6-trihydroxy-7-methoxyxanthone (M-3) and 1,7-dihydroxyxanthone (M-4), respectively. A simple and specific analytical method for determination of the four metabolites in rat urine was developed by high performance liquid chromatography (HPLC). Quercetin was employed as an internal standard. The correlation coefficients of the calibration curves were higher than 0.997, both intra- and inter-day precision of four metabolites were determined and their R.S.D. did not exceed 10%. The accuracy and linear range had been investigated in detail. The cumulative urinary excretions of the four metabolites were measured and the possible metabolic pathway of the metabolites was discussed.