Structural investigation of a polysaccharide (Fr. I) isolated from the aqueous extract of an edible mushroom, Volvariella diplasia

A water-soluble polysaccharide, (Fr. I) isolated from the aqueous extract of an edible mushroom, Volvariella diplasia, is composed of D-glucose, D-mannose, and D-galactose in a molar ratio 3:1:1. Compositional analysis, methylation analysis, periodate oxidation study, Smith degradation, and NMR studies (1H, 13C, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC) revealed the presence of the following repeating unit in the polysaccharide: [FORMULA: SEE TEXT].     

NMR and MALDI-TOFMS analysis of a heteroglycan isolated from hot water extract of edible mushroom, Volvariella bombycina

A water-soluble polysaccharide, isolated from the hot aqueous extract of an edible mushroom, Volvariella bombycina, consists of d-glucose, d-mannose, and d-galactose in a molar ratio 2:1:1. On the basis of total hydrolysis, methylation analysis, periodate oxidation, and NMR studies ((1)H, (13)C, TOCSY, DQF-COSY, NOESY, ROESY, HMQC, and HMBC), and MALDI-TOFMS analysis, the repeating unit of the polysaccharide is established as.     

Cellulase production by the edible mushroom Volvariella diplasia

Volvariella diplasia produced cellulolytic enzymes (550 U CM-cellulase and 69 U filter-paper cellulase/l) when grown in shake culture at pH 5.4 and 28°C with 0.5% cellulose powder as carbon source. Alkali-treated as well as untreated cellulosic substrates were hydrolysed by both enzymes (sp. act. 2.75 U/mg protein), with cellobiose and glucose as the end products.The author is with NCIM, Division of Biochemical Sciences, National Chemical Laboratory, Pune 411 008, Maharashtra, IndiaNCL Communication No. 6168.     

Structural investigation of a water-soluble glucan from an edible mushroom, Astraeus hygrometricus

A water-soluble glucan, Fraction I, was isolated from the aqueous extract of the fruit bodies of the mushroom Astraeus hygrometricus. On the basis of total hydrolysis, methylation analysis, periodate oxidation, and NMR studies ((1)H, (13)C, 2D-COSY, TOCSY, NOESY, and HSQC), the structure of the repeating unit of the glucan is determined as:This glucan shows strong splenocyte activation.     

A water-soluble glucan isolated from an edible mushroom Termitomyces microcarpus

A water-soluble glucan was isolated from an edible mushroom, Termitomyces microcarpus. On the basis of total acid hydrolysis, methylation analysis, periodate oxidation and NMR studies ((1)H, (13)C, TOCSY, DQF-COSY, NOESY and HSQC), the repeating unit of the polysaccharide is established as -->4)-alpha--Glcp-(1-->3)-beta--Glcp-(1-->     

Structural analysis of a water-soluble glucan (Fr.I) of an edible mushroom, Pleurotus sajor-caju

A water-soluble glucan was obtained from the fruit bodies of an edible mushroom, Pleurotus sajor-caju, by hot water extraction, ethanol precipitation, dialysis, and Sepharose 6B gel filtration. On the basis of total hydrolysis, methylation analysis, periodate oxidation, and NMR studies ((1)H, (13)C, DQF-COSY, TOCSY, NOESY, and HSQC), the structure of the repeating unit of the glucan is determined as [carbohydrate structure: see text].     

Chemical analysis of a new fucoglucan isolated from an edible mushroom, Termitomyces robustus

A water-soluble fucoglucan, isolated from alkali-treated edible mushroom, Termitomyces robustus, consists of L-fucose and D-glucose in a molar proportion of 1:4. Structural investigation of the polysaccharide was carried out by using total hydrolysis, methylation analysis, and periodate oxidation followed by GLC-MS, and the final structure was determined using NMR experiments (1H, 13C, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC). On the basis of the above experiments it is concluded that the following repeating unit is present in the polysaccharide: [FORMULA: SEE TEXT].     

The structure of a polysaccharide from Fraction-II of an edible mushroom, Pleurotus florida

A water-soluble polysaccharide was isolated from Fraction-II of the aqueous extract of the fruit bodies of the mushroom, Pleurotus florida. Compositional analysis, methylation analysis, periodate oxidation study, Smith degradation, and NMR studies (1H, 13C, DQF-COSY, TOCSY, NOESY, HSQC, and HMBC) revealed the presence of the following repeating unit in the polysaccharide: [structure: see text].     

Structural characterization of a water-soluble beta-(1-->6)-linked D-glucan isolated from the hot water extract of an edible mushroom, Agaricus bitorquis

A water-soluble polysaccharide, isolated from the hot aqueous extract of an edible mushroom, Agaricus bitorquis, was found to consist of d-glucose only. On the basis of total hydrolysis, methylation analysis, and NMR studies (¹H, ¹³C, TOCSY, DQF-COSY, NOESY, ROESY, HMQC, and HMBC), the structure of the repeating unit was established as→6)-β-d-Glcp-(1→     

Isolation and structural elucidation of a water-soluble polysaccharide (PS-I) of a wild edible mushroom, Termitomyces striatus

A heteropolysaccharide (PS-I), isolated from the hot aqueous extract of an edible mushroom, Termitomyces striatus, is composed of d-glucose, d-galactose, d-mannose and l-fucose in a molar ratio 2:1:1:1. Structural investigation of the native as well as the Smith-degraded polysaccharide was carried out using methylation analysis, periodate oxidation studies and 1D and 2D NMR spectroscopy, and the repeating unit of the polysaccharide is established as follows: [carbohydrate structure: see text]     

Structural studies of water-soluble polysaccharides of an edible mushroom, Termitomyces eurhizus. A reinvestigation

The structure of two polysaccharides isolated from the hot aqueous extract of fruiting bodies of the mushroom, Termitomyces eurhizus, have been reinvestigated. These consist of two homogeneous fractions PS-I and PS-II. PS-I contains only D-glucose as the monosaccharide constituent. From methylation analysis and periodate oxidation studies, followed by GLC-MS analysis the linkages, the sugar units in PS-I were identified as (1-->3)-D-Glcp and (1-->6)-D-Glcp. PS-II contains D-glucose, and the mode of linkage of d-glucose was identified as (1-->6)-D-Glcp. Finally, the following possible structures of the polysaccharides were assigned using 1H, 2D-COSY, TOCSY, NOESY and 13C NMR spectral analysis: [carbohydrate structure: see text].     

Chemical analysis of a new (1-->3)-, (1-->6)-branched glucan from an edible mushroom, Pleurotus florida

A glucan that was soluble in aqueous sodium chloride was isolated from the aqueous extract of the fruiting bodies of Pleurotus florida. On the basis of total hydrolysis, methylation analysis, periodate oxidation, Smith degradation, and NMR studies (1H, 13C, TOCSY, DQF-COSY, NOESY, and HSQC), the structure of the repeating unit of the polysaccharide is established as: This glucan stimulates the phagocytic activity of macrophages.     

Isolation and characterization of an immunoenhancing glucan from alkaline extract of an edible mushroom, Lentinus squarrosulus (Mont.) Singer

A water-soluble glucan, isolated from the alkaline extract of the fruit bodies of an edible mushroom, Lentinus squarrosulus (Mont.) Singer was found to consist of (1→3,6)-linked, (1→3)-linked, (1→6)-linked, and terminal β-d-glucopyranosyl moieties in a relative proportion of approximately 1:2:1:1. This polysaccharide showed optimum activation of macrophages as well as splenocytes and thymocytes at 10 μg/mL. Structural investigation was carried out using sugar analysis, methylation analysis, periodate oxidation study, and NMR experiments (¹H, ¹³C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC). On the basis of above-mentioned experiments, the structure of the repeating unit of the polysaccharide was established as:     

A (1→6)-β-glucan from a somatic hybrid of Pleurotus florida and Volvariella volvacea: isolation, characterization, and study of immunoenhancing properties

A water-soluble immunoenhancing polysaccharide was isolated from the aqueous extract of fruit bodies of somatic hybrid (Pflo Vv5 FB), obtained through protoplast fusion between Pleurotus florida and Volvariella volvacea strains. On the basis of acid hydrolysis, the polysaccharide was found to contain glucose only. Methylation analysis, periodate oxidation along with ¹H, DEPT-135, and ¹³C NMR spectroscopy, including two-dimensional TOCSY, DQF-COSY, NOESY, ROESY, 1H,13C-HMQC, and HMBC experiments showed that the polysaccharide was a (1→6)-β-d-glucan, which was not a constituent of any of the parent mushrooms previously reported.This glucan stimulated the macrophages, splenocytes, and thymocytes.     

Isolation, characterization and structural determination of a unique type of arabinogalactan from an immunostimulatory extract of Chlorella pyrenoidosa

An arabinogalactan was isolated from a hot water extract of freeze-dried cells of the green microalga, Chlorella pyrenoidosa. This hot water extract is a proprietary immunomodulator, with the trademark Respondintrade mark (ONC-107). The arabinogalactan was recovered from the ethanol-soluble fraction of the supernatant resulting from a process that involved controlled ethanol precipitation followed by size exclusion chromatography on Sephadex G-100, then Cetavlon precipitation. Sugar analyses, GC-MS data for (S)-2-octyl glycosides, and 1D and 2D NMR experiments established unambiguously that the repeating unit was -->2)-alpha-L-Araf-(1-->3)-[alpha-L-Araf-(1-->4)]-beta-D-Galp-(1-->. This structure does not fit into any of the known classes of arabinogalactans. SEC/MALS experiments gave a molecular mass for the arabinogalactan isolated as 47 +/- 4 kDa but the original structure was probably larger.     

草菇聚酮合酶编码基因vv-alb的克隆及其表达的初步分析

聚酮化合物（polyketides）是一类庞大的次级代谢家族,聚酮合酶（polyketide synthase,PKS）是介导聚酮化合物生物合成的关键酶。通过巢氏简并PCR与染色体步行的方法,获得了草菇中的编码PKS的基因vv-alb的全长序列,并通过荧光实时定量RT-PCR方法对vv-alb基因在草菇不同生长阶段与不同部位的表达情况进行了初步分析,为进一步研究PKS在草菇和其他食用真菌生物代谢过程中的作用奠定了一定的基础。