Artoindonesianins Q-T,four isoprenylated flavones from Artocarpus champeden Spreng. (Moraceae)

Four isoprenylated flavones, artoindonesianins Q-T, were isolated from the heartwood of Artocarpus champeden Roxb. The structures of these compounds were elucidated on the basis of their spectroscopic data.     

Cytotoxic properties of oligostilbenoids from the tree barks of Hopea dryobalanoides

A new modified stilbene dimer, diptoindonesin D (1), was isolated from the acetone extract of the tree bark of Hopea dryobalanoides, together with seven known compounds, parviflorol (2), (-)-balanocarpol (3), heimiol A (4), hopeafuran (5), (+)-alpha-viniferin (6), vaticanol B (7) and (-)-hopeaphenol (8). Cytotoxic properties of compounds 1-8 were evaluated against murine leukemia P-388 cells. Compound 8 was found to be the most active with IC50 of 5.7 microM.     

Cytotoxic chalcones and flavanones from the tree bark of Cryptocarya costata

A new flavanone, 7-hydroxy-5,6-dimethoxyflavanone (1), together with three other flavonoids, didymocarpin (2), 2',4'-dihydroxy-5',6'-dimethoxychalcone (3), and isodidymocarpin (4), had been isolated from the methanol extract of the tree bark of Cryptocarya costata. The structures of these compounds were determined based on spectral evidence, including UV, IR, 1-D and 2-D NMR, and mass spectra. Cytotoxic properties of compounds 1-4 were evaluated against murine leukemia P-388 cells. The chalcones 3 and 4 were found to have substantial cytotoxicity with IC50 of 5.7 and 11.1 microM, respectively.     

Pegasys: software for executing and integrating analyses of biological sequences

Background  

We present Pegasys – a flexible, modular and customizable software system that facilitates the execution and data integration from heterogeneous biological sequence analysis tools.     

First report of Phytopythium vexans causing the “Avocado sadness” in Michoacan,Mexico

Mexico is the main producer, consumer and exporter of avocado in the world, being Michoacan the main producer state contributing more than 80% of the national production. There are phytopathogens that decimate the production causing the death of the tree. Root samples were collected in avocado trees that showed the characteristic symptomatology of the disease known as avocado sadness, the sampling was carried out in four of the main avocado producing towns, in the state of Michoacan, Mexico. The isolation consisted in sowing root tissue in Petri dishes with V8^®-PARPH culture medium, subsequently they were identified morphologically and for species level it was determined by molecular biology, with the PCR-ITS technique. Pathogenicity tests were performed in triplicate with avocado seedlings with more than six leaves. After 24 hours, the inoculated plants expressed decay in the apical part, after 120 hours the leaves showed yellowing and after 15 days there was a generalized wilt on the stem and leaves, re-isolating the phytopathogen Phytopythium vexans. This study confirms the first report of the oomycete P. vexans affecting avocado trees in the most important producing region of the Mexican Republic.     

Novel complex Re-Arrangement of ARG1 commonly shared by unrelated patients with Hyperargininemia

Background

Hyperargininemia is a very rare progressive neurometabolic disorder caused by deficiency of hepatic cytosolic arginase I, resulting from mutations in the ARG1 gene. Until now, some mutations were reported worldwide and none of them were of Southeast Asian origins. Furthermore, most reported mutations were point mutations and a few others deletions or insertions.

Objective

This study aims at identifying the disease-causing mutation in the ARG1 gene of Malaysian patients with hyperargininemia.

Methodology

We employed a series of PCR amplifications and direct sequencing in order to identify the mutation. We subsequently used quantitative real-time PCR to determine the copy number of the exons flanking the mutation. We blasted our sequencing data with that of the reference sequence in the NCBI in order to obtain positional insights of the mutation.

Results

We found a novel complex re-arrangement involving insertion, inversion and gross deletion of ARG1 (designated g.insIVS1 + 1899GTTTTATCAT;g.invIVS1 + 1933_ + 1953;g.delIVS1 + 1954_IVS2 + 914;c.del116_188;p.Pro20SerfsX4) commonly shared by 5 patients with hyperargininemia, each originating from different family. None of the affected families share known relationship with each other, although four of the five patients were known to have first-cousin consanguineous parents.

Conclusion

This is the first report of complex re-arrangement in the ARG1. Further analyses showing that the patients have shared the same geographic origin within the northeastern part of Malaysia prompted us to suggest a simple molecular screening of hyperargininemia within related ethnicities using a long-range PCR.     

Novel mutations in <Emphasis Type="Italic">katG</Emphasis> gene of a clinical isolate of isoniazid-resistant <Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis>

Most of isoniazid-resistant Mycobacterium tuberculosis evolved due to mutation in the katG gene encoding catalase-peroxidase. A set of new mutations, namely T1310C, G1388T, G1481A, T1553C, and A1660G, which correspond to amino acid substitutions of L437P, R463L, G494D, I518T, and K554E, in the katG gene of the L10 clinical isolate M. tuberculosis was identified. The wild-type and mutant KatG proteins were expressed in Escherichia coli BL21(DE3) as a protein of 80 kDa based on sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis. The mutant KatG protein exhibited catalase and peroxidase activities of 4.6% and 24.8% toward its wild type, respectively, and retained 19.4% isoniazid oxidation activity. The structure modelling study revealed that these C-terminal mutations might have induced formation of a new turn, perturbing the active site environment and also generated new intramolecular interactions, which could be unfavourable for the enzyme activities.     

Phenolic constituents from the wood of Morus australis with cytotoxic activity

A new methylated flavonol, 5,7,2',4'-tetrahydroxy-3-methoxyflavone (1), had been isolated from the methanol extract of the wood of Morus australis, along with nine known compounds, kuwanon C (2), morusin (3), morachalcone A (4), oxyresveratrol (5), 4'-(2-methyl-2-buten-4-yl)oxyresveratrol (6), moracins M (7) and C (8), alboctalol (9), and macrourin B (10). The structures of these compounds were determined based on spectral evidence, including UV, IR, NMR, and mass spectra. Cytotoxic properties of compounds 1-10 were evaluated against murine leukemia P-388 cells. The prenylated stilbene 6 and 2-arylbenzofuran 8, and morusin (3) were found to have strong cytotoxic effects with IC50 values of 6.9, 8.7, and 10.1 microM, respectively.     

Artoindonesianins X and Y, two isoprenylated 2-arylbenzofurans, from Artocarpus fretessi (Moraceae)

Two isoprenylated 2-arylbenzofurans, artoindonesianins X and Y (1-2), together with seven known flavonoids, have been isolated from the roots and tree bark of Artocarpus fretessi. Their structures were established on the basis of spectral analysis. Compounds 1 and 2 showed moderate activity against the brine shrimp Artemia salina.