Chemical constituents from roots of Arctium lappa / 中草药

Objective: To research the chemical constituents from the roots of Arctium lappa. Methods: The compounds were isolated and purified by column chromatography over normal phase silical gel, reverse phase silical gel, ODS column chromatography and semi-preparative HPLC. Their structures were identified by various spectroscopic analysis, including NMR. Results: Fourteen compounds were isolated from the 55% EtOH extract of the roots of A. lappa. And their structure were identified as 1,5-di-O-caffeoyl-3-O-maloyl quinic acid (1), 3,5-di-O-caffeoyl-1-O-(2-O-caffeoyl-4-maloyl)-quinic acid (2), 3,5-di-O- caffeoyl-1-(2-O-caffeoyl-4-maloyl methyl ester)-quinic acid (3), 3,5-di-O-caffeoyl-1-O-succinyl methyl ester quinic acid (4), 3,4-di-O-caffeoyl-1-O-succinyl methyl ester quinic acid (5), 1,3,5-tri-O-caffeoyl-4-O-succinyl quinic acid (6), 1,5-di-O- caffeoyl-3-O-succinyl quinic acid (7), 1,5-di-O-caffeoyl-4-O-succinyl quinic acid (8), 1,5-di-O-caffeoyl-4-O-succinyl methyl ester quinic acid (9), 1,5-di-O-caffeoyl-3-O-succinyl methyl ester quinic acid (10), 1,3,4-tri-O-caffeoyl quinic acid (11), 1,4,5-tri-O-caffeoyl quinic acid methyl ester (12), 3-O-caffeoyl quinic acid (13), and 4-hydroxy-phenylacetic acid (14). Conclusion: Compounds 3-5, 9, 11, 12 are obtained from Arctium genus for the first time, and compound 14 is isolated from A. lappa for the first time.

Chemical constituents from roots of Pedicularis henryi / 中草药

Objective: To investigate the chemical constituents from the roots of Pedicularis henryi. Methods: The compounds were isolated by the combined separation Sephadex LH-20, RP18, MCI-gel CHP-20P, and semipreparative HPLC column chromatography. The structures were identified on the basis of NMR data and the comparison with literatures. Results: Nine compounds were isolated from the 95% ethanol extract of P. henryi, and identified as syringaresinol mono-β-D-glucoside (1), plantarenaloside (2), phenylacetic acid (3), 2″, 3″-O-acetylmartynoside (4), cis-2″, 3″-O-acetylmartynoside (5), martynoside (6), cis-martynoside (7), leucoseceptoside A (8), and jionoside D (9). Conclusion: Compounds 1-9 are isolated from this species for the first time.

Identification, isolation and optimization of antifungal metabolites from the Streptomyces Malachitofuscus ctf9

An indigenous Streptomyces isolate CTF9, exhibiting promising antifungal activity against Mucor miehei and Candida albicans in pre-screening studies, was investigated by cultivation in a 50-L fermenter and by subsequent isolation, purification, and structure elucidation of the active metabolites. Based on the morphological, biochemical, and physiological characterization, as well as the 16S rRNA gene sequence, the isolate CTF9 was identified as Streptomyces malachitofuscus. Using a series of chromatographic techniques, two pure compounds were isolated from the obtained extracts after the fermentation of the isolate CTF9. The isolated compounds were identified as phenylacetic acid and indolyl-3-lactic acid by mass spectrometry (MS) and NMR analysis. The culture optimization studies revealed that the isolate CTF9 can use a variety of low-cost carbon and nitrogen sources to generate the maximum quantity of industrially important metabolites at an elevated temperature of 35°C and at a pH 7.8.

Chemical Constituents of the Fruiting Bodies of Clitocybe nebularis and Their Antifungal Activity

During a continuing search for antimicrobial substances from Korean native wild mushroom extracts, we found that the methanolic extract of the fruiting body of Clitocybe nebularis exhibited mild antifungal activity against pathogenic fungi. Therefore we evaluated the antifungal substances and other chemical components of the fruiting body of Clitocybe nebularis, which led to the isolation of nebularine, phenylacetic acid, purine, uridine, adenine, uracil, benzoic acid, and mannitol. Nebularine showed mild antifungal activity against Magnaphorthe grisea and Trichophyton mentagrophytes, and phenylacetic acid potently inhibited the growth of Pythium ultiumand displayed moderate antifungal activity against Magnaphorthe grisea, Botrytis cinerea, and Trichophyton mentagrophytes. The other isolated compounds showed no antimicrobial activity.

Bio-synthesis and hydrolysis of ethyl phenylacetate and ethyl 2-phenylpropionate in organic solvent by lyophilized mycelia

To select the best biocatalysts for ethanol acylations with phenylacetic and 2-phenylpropionic acids, lyophilized mycelia of Aspergillus oryzae CBS 10207, A. oryzae MIM, Rhizopus oryzae CBS 11207, R. oryzae CBS 39134, R. oryzae CBS 26028 and R. oryzae CBS 32847 were tested in this study. The carboxylesterase activities of A. oryzae MIM and R. oryzae 11207, which revealed to be the best biocatalysts, were investigated either in 0.1 M phosphate buffer or in n-heptane to catalyze the hydrolysis or the synthesis of ethyl esters of these acids, respectively. A. oryzae proved more effective than R. oryzae, probably due to more favorable microenvironment conditions and thermodynamic scenario. The results in terms of product formation and substrate consumption versus time were used to estimate the maximum conversion yields, the equilibrium constants and the times needed to reach half maximum conversion, thus providing sufficient information about these equilibria.

Micélios liofilizados de Aspergillus oryzae CBS 10207, A. oryzae MIM, Rhizopus oryzae CBS 11207, R. oryzae CBS 39134, R. oryzae CBS 26028 e R. oryzae CBS 32847 foram testados neste estudo com vista à seleção do melhor biocatalisador para efetuar a acilação de etanol com ácidos fenilacético e 2-fenilpropiônico. As atividades carboxilesterásicas de A. oryzae MIM e R. oryzae 11207, que resultaram ser os melhores biocatalisadores, foram investigadas tanto em tampão fosfato 0,1 M como em n-heptano para catalisar a hidrólise ou a síntese dos ésteres etílicos destes ácidos. A. oryzae pareceu ser mais eficaz que R. oryzae, provavelmente devido a condições micro-ambientais e a um cenário termodinâmico mais favoráveis. Os resultados obtidos em termos de formação do produto e consumo dos substratos em função do tempo foram usados para a estimativa dos rendimentos de conversão máximos, as constantes de equilíbrio e os tempos necessários para alcançar metade da conversão máxima, fornecendo desta forma suficientes informações sobre esses equilíbrios.

Molecular Cloning and Characterization of a Glutathione S-transferase Gene Repressed by Phenylacetic Acid From Penicillium chrysogenum / 生物化学与生物物理进展

Glutathione S-transferase (GST) gene, PcgstA was cloned from the penicillin producing strain Penicillium chrysogenum,which is important for understanding the industrial fermentation process. PcgstA gene has an open-reading-frame of 840 bp in length,which is interrupted by two introns. The deduced amino acid sequence shows about 50% identity to several characterized filamentous fungi GSTs. The recombinant PcGSTA in Escherichia coli were overexpressed and purified. Enzymatic assays showed that the recombinant PcGSTA had a specific activity with 1-chloro-2, 4-dinitrobenzene of (0.159±0.031) μmol/(min· mg). It was found that the expression level of PcgstA in the penicillin producing medium supplemented with phenylacetic acid, the side chain precursor of penicillin G, was significant down regulated than that in medium without phenylacetic acid. This result suggested that PcGST may be related to phenylacetic acid metabolism in the penicillin producing strain.