Astramalabaricosides A-T, Highly Oxygenated Malabaricane Triterpenoids with Migratory Inhibitory Activity from Astragalus membranaceus var. mongholicus.

Twenty new malabaricane triterpenoids, astramalabaricosides A-T (1-20), were isolated from the roots of Astragalus membranaceus var. mongholicus (Astragali Radix). Their structures were determined by spectroscopic analysis, and the use of the circular dichroism exciton chirality method, quantum chemical calculations, and chemical methods. Malabaricane triterpenoids, an unusual group with the 6-6-5-tricyclic core, are distributed in plants (e.g., Simaroubaceae, Polypodiaceae, and Fabaceae), a marine sponge, and fungi, and their number obtained to date is limited. Compounds 1-20 were characterized as glycosides with a highly oxygenated side chain, and 13-20 were the first cyclic carbonate derivatives among the malabaricane triterpenoids. The stereocluster formed from the continuous hydroxylated chiral carbons in each highly oxygenated side chain and the 6-6-5-tricyclic core system were entirely segregated, and the independent identification of their stereoconfigurations required considerable effort. The migratory inhibitory and antiproliferative activities of 1-20 were evaluated by wound-healing and cell-viability assays, respectively. Most compounds showed significant migratory inhibitory activity, and a preliminary structure-activity relationship was developed. Malabaricane triterpenoids are being reported in the genus Astragalus for the first time.

4-Hydroxy Pyridones from Heterologous Expression and Cultivation of the Native Host.

4-Hydroxy pyridones are a class of fungi-derived polyketide-nonribosomal peptide products featuring a core of 4-hydroxy-2-pyridone which have a wide range of biological activities. Genome mining of in-house strains using polyketide synthase-nonribosomal peptide synthase as a query identified an endophyte Tolypocladium sp. 49Y, which possesses a potential 4-hydroxy pyridone biosynthetic gene cluster. Heterologous expression in Aspergillus oryzae NSAR1 revealed that this gene cluster is functional and able to produce a rare type of 4-hydroxy pyridones called tolypyridones (compounds 3 and 4). Tolypocladium sp. 49Y was grown in a variety of media which led to the isolation of six 4-hydroxy pyridones (5-10) and one pyrrolidone (11) from a rice culture, and compounds 3 and 9 showed antifungal activity. These latter compounds are different from those obtained by heterologous expression. This study shows that both heterologous expression and cultivation of the native host are complementary approaches to discover new natural products.

The Oxidation Cascade of a Rare Multifunctional P450 Enzyme Involved in Asperterpenoid A Biosynthesis.

The cytochrome P450 enzymes (P450s or CYPs) are heme-containing enzymes which catalyze a wide range of oxidation reactions in nature. In our previous study, a rare multifunctional P450 AstB was found, which can dually oxidize two methyl groups (C-19 and C-21) of preasperterpenoid A to asperterpenoid A with 3-carboxyl and 11-hydroxymethyl groups. However, the oxidation order of C-19 and C-21 catalyzed by AstB is unclear. In order to reveal this oxidation order, probable pathways catalyzed by AstB were proposed, and the oxidation order of C-19 and C-21 was obtained by quantum chemistry calculations. The potential intermediates (three new asperterpenoids D-F, 1-3) were obtained through the chemical investigation on the extract of the transformant strain and chemical conversions, which were used as the standards to detect their existences in the extract of the transformant strain with HPLC-MS. Combined with the quantum chemistry calculation and the HPLC-MS analysis, the catalyzed order of AstB in asperterpenoid A biosynthesis was revealed. Furthermore, the mPTPB inhibition of obtained asperterpenoids was evaluated, and the results showed that 3-carboxyl and the oxidation station of C-21 would be the key factors for mPTPB inhibition of asperterpenoids.

[Clinical characteristics and survival of peripheral T-cell lymphoma-not otherwise specified: a report of 57 cases].

OBJECTIVE: To analyze the clinical characteristics and survival data of 57 patients with peripheral T-cell lymphoma-not otherwise specified (PTCL-NOS). METHODS: The medical records of 57 patients with PTCL-NOS classified according to the revised REAL-WHO criteria, treated from Jan 1993 to Dec 2007 at the First and the Third affiliated Hospitals of Medical School of Xi'an Jiaotong University, were retrospectively evaluated by K-M univariate and COX multivariate analysis. RESULTS: 39 of the patients (68.4%) were males and 18 (31.6%) were females, aged 44 (3 - 88). Nine of the 57 patients (15.8%) were treated with chemo-radiotherapy, 43 (75.4%) with chemotherapy, 3 (5.3%) with radiotherapy, and 2 with supported treatment alone (2.5%). The overall response rate was 87.3%, with a complete remission (CR) rate of 60.0% in 55 evaluable cases. The 1-, 3-, and 5-year overall survival (OS) rates were 67.0%, 48.0% and 24.3%, respectively, with a median follow-up of 30.4 months (ranged 1-100 months). The median survival time (MST) was 36.0 months. Multivariate analysis showed that the prognostic index for T cell lymphoma (PIT) score was an independent prognostic factor for PTCL-NOS (P < 0.05), but bone marrow involvement, performance status, extranodal involvement, stage, B symptom were not independent prognostic factors. CONCLUSION: Although conventional chemotherapy yields a high response rate for PTCL-NOS, the long-term survival is still low and further investigation for optional treatment is needed.

The effects of miR-1207-5p expression in peripheral blood on cisplatin-based chemosensitivity of primary gallbladder carcinoma.

OBJECTIVE: The aim of this study was to investigate the association between miR-1207-5p expression in peripheral blood and the chemosensitivity of primary gallbladder carcinoma (PGBC). METHODS: A total of 85 patients with PGBC undergoing preoperative chemotherapy were divided into effective (n=18) and ineffective (n=67) groups. Another 70 healthy individuals were selected as the control group. An miR-1207-5p mimic (mimic group), an inhibitor (inhibitor group), and a negative control (NC group) sequence were transfected into human gallbladder carcinoma GBC-SD cells. Real-time quantitative polymerase chain reaction was used to determine miR-1207-5p expression. After 48 hours of cisplatin treatment, CCK-8 method was used to detect cell proliferation and flow cytometry were performed to examine cell apoptosis. RESULTS: miR-1207-5p expression in peripheral blood was significantly associated with tumor node metastasis staging of PGBC (P<0.05). Before chemotherapy, miR-1207-5p expression in patients was higher than in healthy individuals (P<0.05). After chemotherapy, the effective group had lower miR-1207-5p expression than the ineffective group (P<0.05). The rates of positive expression of Ki67 protein in the effective group were significantly lower than those in the ineffective group (P<0.05). Receiver operating characteristic curves showed that the area under curve, sensitivity, and specificity of miR-1207-5p used to diagnose PGBC were 0.898, 77.6%, and 97.1% at a cutoff of 1.470, respectively. After 48 hours of cisplatin treatment, compared with the NC group and nontransfected (non-T) group, the mimic group had decreased rates of cell inhibition and apoptosis, but the inhibitor group had increased rates (all P<0.05). The expression levels of caspase3 protein were increased in the mimic group and decreased in the inhibitor group. Cell survival rates in the mimic group at different time points after cisplatin treatment were significantly higher than the corresponding rates in the NC and non-T groups, whereas the cell survival rates in the inhibitor group were significantly lower than the rates in the NC and non-T groups (all P<0.05). The concentration and action time of cisplatin were negatively associated with the cell survival rate in each group (all P<0.05). CONCLUSION: Cisplatin-based chemosensitivity of PGBC increased as expression of miR-1207-5p in peripheral blood declined. Thus, miR-1207-5p appears to be a promising and novel chemosensitizer for the treatment of PGBC.