Production, isolation and structure determination of a novel .BETA.-glucosidase inhibitor, cyclophellitol, from Phellinus sp.

Abstract

In the course of our screening of /?-glucosidase inhibitor, a culture filtrate of a mushroom, Phellinus sp. strongly inhibited the enzymeactivity. The active substance wasisolated through charcoal separation, column chromatography and crystallization. Spectroscopic and crystallographic analysis revealed that it had a novel cyclitol structure, (15f,2i?,35f,4/?,57?,6i?)-5-hydroxymethyl-7oxabicyclo[4, l ,0]heptane-2,3,4-triol, and we named it cyclophellitol. It inhibited almond-derived /?-glucosidase with an IC50 of 0.8 ug/ml. 49 /?-Glucosidase inhibitors such as castanospermine and 1-deoxynojirimycin have been reported to inhibit syncytium formation and infection of human immunodeficiency virus (HIV), possibly by perturbing gpl20-linked glycan structurelf2). Castanospermine is also known to suppress experimental metastasis possibly by changing the saccharide structure on tumour cell surface3*. Therefore, glucosidase inhibitors may inhibit HIV infection and metastasis. Consequently we screened culture filtrates of microorganisms for inhibitory activity against^-glucosidase. Amonga thousand strains of bacteria, Actinomycetes and mushrooms,we found that a culture filtrate of a mushroomstrain, Phellinus sp., showedinhibitory activity against almond^-glucosidase. Isolation and structure determination of the active principle, established that it was a novel compound. Wehave namedit cyclophellitol. Materials and Methods General /7-Nitrophenyl-^-D-glucopyranoside and almond /?-glucosidase were purchased from Sigma. NMR spectra were recorded on a Jeol JNM-GX400. The MSspectra were taken by a Hitachi M-80H spectrometer. The mp was measured by the micro mp apparatus, MP-S3(Yanagimoto). The UVand IR spectra were measured by a Hitachi 220S and a 260-10 spectrophotometer, respectively. Optical rotations were taken by a Perkin-Elmer 241 polarimeter using micro-cell (light path 10 cm). #-Glucosidase Assay The enzyme activity was assayed by the method described by Saul et al.4\ with slight modifications.

Screening of Brazilian basidiomycetes for antimicrobial activity

“…Phellinsin A was able to inhibit the growth of fungi such as Colleotrichum lagenarium, Pyricularia oryzae, Rhizoctonia solani, Aspergillus fumigatus and Trichophyton mentagrophytes (Hwang et al 2000). Several studies have showed that Phellinus species can produce substances with cytotoxic (Atsumi et al 1990, 1993, Withers & Umezawa 1991, Han et al 1999, immunomodulatory (Song et al 1995, Kim et al 1996, antiviral (Walder et al 1995), antioxidant, antihepatotoxic (Ajith & Janardhnan 2002) activities.…”

Microarray Analyses of Gene Expression during Chondrocyte Differentiation Identifies Novel Regulators of Hypertrophy

“…These in vivo data thus confirm the expression patterns observed in microarray analyses of micromass cultures. We stably transfected an HA-tagged human RGS2 expression vector into the chondrogenic cell line ATDC5 (Atsumi et al, 1990) and differentiated them for 18 d to further investigate the role of RGS2 expression in chondrocyte differentiation. Overexpression of RGS2 was confirmed by 1) RT-PCR using primers designed against the N-terminal HA-tag and the RGS2 coding region, and 2) Western blotting using an anti-HA antibody.…”

Recent Advances in the Conversion of Carbohydrate Furanosides and Pyranosides into Carbocycles

“…[1,2] They may be divided into two categories, those containing six-and those containing five-membered carbon rings. Among the most prominent of the six-membered representatives are cyclohexane hexitols, such as inositol derivatives, [1b] and pseudosugars, [1f, 2, 3] such as cyclophellitol [4] and valienamine. [5] Structural analogues of the latter are constituents of compounds of key pharmacological interest, for example acarbose, [6] adiposin, [7] trestatin, [8] and amylostatin.…”