Determination of the Main Nucleosides and Nucleobases in Natural and Cultured Ophiocordyceps xuefengensis.

Ophiocordyceps xuefengensis, a recently described species of Ophiocordycepsthat is associated with the larvae of Phassusnodus (Hepialidae) in the living root or trunk of the medicinal plant Clerodendrumcyrtophyllum, isthe largest known Cordycepsspecies and is recognized as a desirable alternative for natural Ophiocordycepssinensis. This study investigated the main nucleosides and nucleobases in natural and cultured Ophiocordycepsxuefengensis. The contents of the nucleosides and nucleobases in the natural and cultured samples were determined by reverse phase HPLC. The highest concentration of adenosine was found in the natural fruit body and the cultured stroma, with almost no adenosine in the cadaver of Phassusnodus. The contents of adenine, guanosine, uridine and uracil in the cultured mycelium were significantly higher than those in the natural sample. Inosine was only detected in the natural samples. Thymidine and 2-deoxyadenosine were only found in the cadaver of Phassusnodus. Cordycepin was not detected in the five samples examined. These results suggested that the cultured mycelium and cultured stroma of Ophiocordycepsxuefengensis might be a promising substitute for natural O. xuefengensis.

The nucleoside uridine isolated in the gas phase.

Herein we present the first experimental observation of the isolated nucleoside uridine, placed in the gas phase by laser ablation and characterized by Fourier transform (FT) microwave techniques. Free from the bulk effects of their native environments, anti/C2'-endo-g+ conformation has been revealed as the most stable form of uridine. Intramolecular hydrogen bonds involving uracil and ribose moieties have been found to play an important role in the stabilization of the nucleoside.

Novel nikkomycin analogues generated by mutasynthesis in Streptomyces ansochromogenes.

BACKGROUND: Nikkomycins are competitive inhibitors of chitin synthase and inhibit the growth of filamentous fungi, insects, acarids and yeasts. The gene cluster responsible for biosynthesis of nikkomycins has been cloned and the biosynthetic pathway was elucidated at the genetic, enzymatic and regulatory levels. RESULTS: Streptomyces ansochromogenes ΔsanL was constructed by homologous recombination and the mutant strain was fed with benzoic acid, 4-hydroxybenzoic acid, nicotinic acid and isonicotinic acid. Two novel nikkomycin analogues were produced when cultures were supplemented with nicotinic acid. These two compounds were identified as nikkomycin Px and Pz by electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR). Bioassays against Candida albicans and Alternaria longipes showed that nikkomycin Px and Pz exhibited comparatively strong inhibitory activity as nikkomycin X and Z produced by Streptomyces ansochromogenes 7100 (wild-type strain). Moreover, nikkomycin Px and Pz were found to be more stable than nikkomycin X and Z at different pH and temperature conditions. CONCLUSIONS: Two novel nikkomycin analogues (nikkomycin Px and Pz) were generated by mutasynthesis with the sanL inactivated mutant of Streptomyces ansochromogenes 7100. Although antifungal activities of these two compounds are similar to those of nikkomycin X and Z, their stabilities are much better than nikkomycin X and Z under different pHs and temperatures.

[Isolation and structure elucidation of chemical constituents from Pinellia ternata].

OBJECTIVE: To isolate and identify the chemical constituents of ethanol extract of Pinellia ternata. METHODS: The constituents were isolated by silica-gel, Sephadex LH-20 chromatography and HPLC techniques. The structures were identified by spectroscopic analysis including 2D NMR techniques and chemical properties. RESULTS: Nine compounds were obtained and identified as uridine (1), 5'-S-methyl-5'-thioadenosine (2), adenine (3), chrysophanol (4), 5-hydroxymethylfurfural (5), nicotinamide (6), (2S)-1-O-(9Z, 12Z-octadecadienoyl)-3-O-beta-galactopyranosylglycerol (7), daucosterol (8), beta-sitosterol (9). CONCLUSION: Compounds 2, 6, 7 are isolated from this plant for the first time.

[Studies on the chemical constituents from aerial parts of Gynura divaricata].

OBJECTIVE: To study the chemical constituents from aerial parts of Gynura divaricata. METHODS: The constituents were isolated on silica gel column chromatography, preparative TLC and Sephadex LH-20 column chromatography, identified by physicochemical properties and the structures were elucidated by spectral analysis. RESULTS: 10 compounds were isolated and identified as 2-(1', 2', 3', 4'-tetrahydroxybutyl)-6-(2", 3", 4"-trihydroxybutyl)-pyrazine (1), 2-(1', 2', 3', 4'-tetrahydroxybutyl)-5-(2", 3", 4"-trihydroxybutyl) -pyrazine (2), nicotinic acid (3), 5-hydroxy-picolinic acid(4), methyl-5-hydroxy-2- pyridinecarboxylate (5), adenosine (6), uridine (7), stigmasterol-5-O- beta-D-glucoside (8), dibutyl terephthalate (9), methyl chlorogenate (10). CONCLUSION: Compounds 1, 2, 5, 9, 10 are obtained from this genus for the first time, Compounds 3, 4 are obtained from this plant for the first time.

Managing the column equilibration time in hydrophilic interaction chromatography.

For a wide variety of hydrophilic interaction chromatography stationary phases, a repeatable partial equilibration was demonstrated in gradient elution after purging with as little as 12 column volumes of mobile phase. Relative standard deviations of retention time of on average ~0.15% could be obtained after 1 or 2 conditioning (blank) runs. The equilibration period must be kept strictly constant, otherwise selectivity changes occur, but this is not problematic on modern instruments. Partial equilibration was largely independent of stationary phase or gradient slope. Alternatively, full column equilibration is favoured for stationary phases that do not trap extensive water layers, and for materials with a wider pore size that have a lower surface area. Temperatures somewhat above ambient also shorten the equilibration time. Some stationary phases under optimum conditions can achieve full column equilibration using purging with ~12 column volumes, which is useful for rapid set-up of isocratic separations or for conventional gradient analysis.

A new isoflavane-4-ol derivative from Melilotus officinalis (L.) Pall.

A new isoflavane derivative, melilofficinaside together with seven other metabolites including coumarin, uridine, methyl-α-d-fructofuranoside, and flavonoid glucosides were isolated from the aerial parts of Melilotus officinalis (L.) Pall.

Sansanmycins B and C, new components of sansanmycins.

Two new antibiotics, sansanmycins B and C, were isolated from Streptomyces sp. SS. Their structures were elucidated by extensive 1D and 2D NMR and MS spectral analyses. Sansanmycins B and C exhibited inhibitory activity against our test strain of Pseudomonas aeruginosa with MIC values of 8.0 and 16 microg/ml, respectively. Sansanmycin B also exhibited inhibitory activity against Mycobacterium tuberculosis H37Rv and multidrug-resistant Mycobacterium tuberculosis, with the MIC values ranging from 8.0 to 20 microg/ml.

Effects of sample preparation methods on the quantification of nucleosides in natural and cultured Cordyceps.

Sample preparation is the first and very important step, which can greatly influence the repeatability and accuracy of the analysis. To date, several sample preparation methods with different solvents have been used for quantitative determination of nucleosides in Cordyceps, but their data are greatly various. In this study, five nucleosides, including adenosine, guanosine, inosine, uridine and cordycepin, in Cordyceps were determined using three extraction methods i.e. organic solvent pressurized liquid extraction, boiling water extraction and ambient temperature water extraction and high performance liquid chromatography (HPLC)-diode array detection (DAD). The similar results were obtained when organic solvent pressurized liquid extraction and boiling water extraction were applied. However, the amounts of nucleosides in natural C. sinensis and cultured C. militaris extracted with ambient temperature water were greatly increased except those of adenosine in natural C. sinensis and cordycepin in cultured C. militaris. In addition, the amount of investigated nucleosides in cultured C. sinensis had no obvious variation among the three extraction methods. The results suggest that sample preparation has significant effect on the quantification of nucleosides in Cordyceps.

[Studies on the chemical constituents of the roots of Anemone altaica].

OBJECTIVE: To investigate the chemical constituents of the roots of Anemone altaica Fisch. ex C. A. May. METHODS: The constituents of n-BuOH-soluble portion were isolated and purified by means of chromatography. Compounds were identified by their physical characteristics and spectral features. RESULTS: Six compounds were isolated and identified as cimigenol-3-O-beta-D-xylopyranoside (1), cimigenol-3-O-beta-D-xylopyranol (1 -->3)-beta-D-xylopyranoside (2), isolariciresinol-9-O-beta-D-glucopyranoside (3), adenosine (4), uridine (5) and methyl-beta-D-glucopyranoside (6). CONCLUSION: All compounds are isolated from this genus for the first time.

[Study on HPLC fingerprint characteristic analysis of Cordyceps sinensis and its similar products].

OBJECTIVE: To study on HPLC fingerprint characteristic analysis of Cordyceps sinensis and its similar products. METHODS: To determinate 13 samples of Cordyceps sinensis and its similar products by HPLC, and analyze the HPLC results with similar appraisal method and graphical methods of multivariate sample in two dimensional plane such as the methods of profile, radar chart and constellation graph. RESULTS: The similar appraisal method might synthesize the similar degree in quantification, while the graphical methods such as profile graph, radar chart and constellation graph could show more details about the classification and the characteristic of varieties directly. CONCLUSIONS: We recommend the combined application of similar appraisal method and the graphical methods due to its advantages on the judgment and characteristic analysis of fingerprint.

Uridine derivatives from the seeds of Lepidium apetalum Willd. and their estrogenic effects.

Ten uridine derivatives (lepidiumuridine B-K) were isolated from the seeds of Lepidium apetalum Willd. Lepidiumuridine B-J were previously undescribed compounds, and were structurally characterized using analysis of their NMR and MS data. Lepidiumuridine C, D, I, and J increased cell proliferation and expression of ERα in the MCF-7 cell line. In addition, blockage of ERα completely abolished cell proliferation and expression of ERα in MCF-7 cells, suggesting that the proliferation effects of lepidiumuridine C, D, I, and J were ERα-mediated. The uridine derivatives might belong to undescribed phytoestrogens.

A new nucleosidyl-peptide antibiotic, sansanmycin.

A new nucleosidyl-peptide antibiotic, sansanmycin, was isolated from an unidentified Streptomyces sp SS. The structure of sansanmycin was elucidated by analyses of its alkaline hydrolysate and spectroscopic analyses. Sansanmycin exhibits antibacterial activity against Mycobacterium tuberculosis H(37)Ra and Pseudomonas aeruginosa with MIC values of 10 and 12.5 mug/ml, respectively.

[Chemical study of nucleosides on Cordyceps militaris].

OBJECTIVE: To investigate the nucleosides of Cordyceps militaris. METHODS: The primary extract technique of nucleosides from Cordyceps militaris was founded, the nucleosides were isolated by chromatography. RESULTS: Four compounds were isolated from the mycelium of Cordyceps militaris. They were identified as uridine (1), adenosine (2), guanosine (3) and p-tyrosine (4), respectively. CONCLUSION: Compounds 1, 2 and 3 are the main nucleosides in Cordyceps militaris.

A new nucleoside derivative, AJP117510, as an inhibitor of integrin alpha2beta1-collagen binding.

A new nucleoside derivative, AJP117510 (1) was isolated from unidentified fungus AJ117510. The structure of 1 was elucidated by spectroscopic analyses. Nucleoside 1 inhibited the binding of integrin alpha2beta1 to collagen in a dose dependent manner with an IC50 value of 5.9 microM.

The isolation from ribonucleic acid of substituted uridines containing alpha-aminobutyrate moieties derived from methionine.

The RNA of an established line of Chinese hamster cells growing in cell culture contains a small number of uridines substituted at the 3-position with a gamma-linked alpha-aminobutyrate residue. Structure has been ascertained by: (a) examination of incorporation of isotopic labels from precursors; (b) degradation with anhydrous hydrazine and comparison of the products with synthetic material or with hydrazinolysis products of known uridines; and (c) comparison of the unknowns as their hydantoin derivatives with the 5-beta-(bromoethyl)hydantoin alkylation products of uridine and of 1- and 3-methylpseudouridine. In this manner it is shown that 18-S RNA of ribosomes contains a single residue of a nucleoside which we tentatively identify as 1-methyl-3-gamma-(alpha-amino-alpha-carboxypropyl)pseudouridine per molecule. RNA isolated from the supernatant fraction, sedimenting at 4 S and co-electrophoresing with transfer RNA on polyacrylamide gels, contains several similar bases, one of which is identified as 3-gamma-(alpha-amino-alpha-carboxypropyl)uridine. Each of the above nucleosides derives its alpha-aminobutyrate residue from methionine.

Small molecule inhibitors of mucin-type O-linked glycosylation from a uridine-based library.

The polypeptide N-acetyl-alpha-galactosaminyltransferases (ppGalNAcTs, also abbreviated ppGaNTases) initiate mucin-type O-linked glycosylation and therefore play pivotal roles in cell-cell communication and protection of tissues. In order to develop new tools for studying mucin-type O-linked glycosylation, we screened a 1338 member uridine-based library to identify small molecule inhibitors of ppGalNAcTs. Using a high-throughput enzyme-linked lectin assay (ELLA), two inhibitors of murine ppGalNAcT-1 (K(I) approximately 8 microM) were identified that also inhibit several other members of the family. The compounds did not inhibit other mammalian glycosyltransferases or nucleotide sugar utilizing enzymes, suggesting selectivity for the ppGalNAcTs. Treatment of cells with the compounds abrogated mucin-type O-linked glycosylation but not N-linked glycosylation and also induced apoptosis. These uridine analogs represent the first generation of chemical tools to study the functions of mucin-type O-linked glycosylation.

[Studies on chemical constituents in herbs of Acanthus ilicifolius].

OBJECTIVE: To study the chemical constituents of Acanthus ilicifolius. METHOD: Chromatographic methods were used to isolate compounds from A. ilicifolius, and chemical and spectral methods were used to elucidate the structures of the isolated compounds. RESULT: Five compounds, luteolin 7-O-beta-D-glucuronide (1), apigenin-7-O-beta-D-glucuronide (2), methylapigenin-7-O-beta-D-glucuronate (3), uridine (4) and uracil (5) were obtained. CONCLUSION: 1, 4 and 5 were obtained from the genus for the first time.

[Studies on chemical constituents in herb of Lamium maculatum var. kansuense (II)].

OBJECTIVE: To study the chemical constituents from Lamium maculatum var. kansuense. METHOD: The chemical constituents were isolated and repeatedly purified on silica gel column and the structures were elucidated by the NMR spectra and physico-chemical properties. RESULT: Six compounds were obtained and identified as polypodine B (I), 5-OH-8-epiloganin (II), shlanzhiside methyl ester (III), liriodendrin (IV), quercitroside (V), uridine (VI). CONCLUSION: Compound IV was found from genus Lamium for the first time and the rest of the compounds were found from Lamium maculatum var kansuense for the first time.

[Identification of 5 constituents of the aqueous extract of Isatis indigotica by HPLC-MS2].

OBJECTIVE: To identify five constituents in the aqueous extract of Isatis indigotica Fort. METHODS: After separation of the aqueous extract of Isatis indigotica Fort. by HPLC, the eluates of five peaks were collected separatively and analysed by MS2. UV spectra and MS2 were compared with those of reference standards of cytidine, uridine, guanosine xanthine and hypoxanthine. RESULTS: Each HPLC elute of the aqueous extract had same retention time, UV spectra and fragment pattern in the MS2 spectrum as the corresponding standards. CONCLUSION: Five constituents of the aqueous extract of Isatis indigotica Fort. are identified as cytidine, hypoxanthine, uridine, xanthine and guanosine.