• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.3
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• pp.210-212
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• 2003

Recombinant $\beta$-glucosidase from Thermus caldophilus GK24 was easily purified partially by a heat treatment procedure, resulting in 8-fold and recovery yield of 80% from crude enzyme. When the $\beta$-glucosidase was incubated with a 80% glucose solution (w/w), gentiobiose ($\beta$1,6-glucobiose) was the major product in the reaction mixture. The optimal conditions for producing gentiobiose (11% yields of total sugar) were pH 8-9 and 7$0^{\circ}C$ for 72 h.

• Natural Product Sciences
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• v.6 no.2
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• pp.102-105
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• 2000

Chemical investigation of the hot hexane extract of the stem bark of Gordonia dassanayakei afforded a new oleanane triterpenoid, $11{\alpha},13{\beta}-dihydroxyolean-3,12-dione$ (1) and two other oleanane triterpenoids, $3{\beta}-acetoxy-11{\alpha},13{\beta}-dihydroxyolean-12-one\;(2)\;and\;3{\beta},11{\alpha}-diacetoxy-13{\beta}-hydroxyolean-12-one\;(3)\;and\;a\;hopane\;6{\alpha},22-diol$ (4), which are new to the plant.

• Natural Product Sciences
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• v.20 no.2
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• pp.76-79
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• 2014

In our ongoing search for structurally interesting and biologically active metabolites from Korean wild mushrooms, bioassay-guided fractionation and a chemical investigation of the MeOH extracts of the fruiting bodies of the mushroom Naematoloma fasciculare resulted in the isolation of three ergosterol derivatives, (22E,24R)-ergosta-7,22-diene-$3{\beta}$,$5{\alpha}$,$6{\beta}$,$9{\alpha}$-tetrol (1), (22E,24R)-$5{\alpha}$,$8{\alpha}$-epidioxyergosta-6,22-diene-$3{\beta}$-ol 3-O-${\beta}$-$\small{D}$-glucopyranoside (2), and (22E,24R)-$5{\alpha}$,$8{\alpha}$-epidioxyergosta-6,9,22-triene-$3{\beta}$-ol 3-O-${\beta}$-$\small{D}$-glucopyranoside (3). The structures of 1 - 3 were determined by comparison of their spectroscopic and physical data with reported values. The isolated steroid derivatives 1 and 3 were reported for the first time from this mushroom. Compounds 1 - 3 were tested for their cytotoxic activities against four human cancer cell lines (A549, SK-OV-3, SK-MEL-2, and HCT-15).

• Archives of Pharmacal Research
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• v.23 no.2
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• pp.172-173
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• 2000

The relationship between the metabolites of glycyrrhizin (18$\beta$-glycyrrhetinic acid-3-O--D-glu-curonopyranosyl-($1{\rightarrow}2$)-$\beta$-D-glucuronide, CL) and their biological activities was investigated. By human intestinal microflora, CL was metabolized to 18$\beta$-glycyrrhetinic acid (GA) as a main product and to 18$\beta$-glycyrrhetinic acid-3-O-$\beta$-D-glucuronide (GAMG) as a minor product. The former reaction was catalyzed by Eubacterium L-8 and the latter was by Streptococcus LJ-22. Among GL and its metabolites, GA and GAMG had more potent in vitro anti-platelet aggregation activity than GL. GA also showed the most potent cytotoxicity against tumor cell lines and the potent inhibitory activity on rotavirus infection as well as growth of Helicobacter pylori. GAMG, the minor metabolite of GL, was the sweetest.

• Communications for Statistical Applications and Methods
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• v.1 no.1
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• pp.81-86
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• 1994

A Chi-square approximation to the distribution of product of independent Beta variates denoted by U is developed. The distribution is commonly used as a test criterion for the general linear hypothesis about the multivariate linear models. The approximation is obtained by fitting a logarithmic function of U to a Chi-square variate in terms of the first three moments. It is compared with the well known approximations due to Box(1949), Rao(1948), and Mudholkar and Trivedi(1980). It is found that the Chi-square approximation compares favorably with the other three approximations.

• Natural Product Sciences
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• v.4 no.3
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• pp.153-157
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• 1998

The aqueous ethanolic leaf extract of Ailanthus altissima was found to contain the new natural product, $luteolin\;7-O-{\beta}-(6"-galloylglucopyranoside)$, 13, along with fourteen known phenolic metabolites (1-12, 14 and 15). Structures of all compounds (1-15) were established by conventional methods of analysis and confirmed by FAB-MS, $^1H-\;and\;^{13}C-NMR$ spectral analysis.

• YAKHAK HOEJI
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• v.42 no.2
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• pp.140-143
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• 1998

From the methanol extract of the whole part of Sagittaria trifolia ergosterol peroxide, icariside D2. Thalictoside and 4-nitrophenyl $\{beta}$-D-glucopyranoside wer e isolated and their structures were identified by the physico-chemical and spectral data. This is the first report of these compounds from S. trifolia.

• Korean Journal of Mathematics
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• v.31 no.4
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• pp.485-494
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• 2023

The degree of hesitancy of a vertex in a hesitancy fuzzy graph depends on the degree of membership and non-membership of the vertex. We define a new class of hesitancy fuzzy graph, the intuitionistic hesitancy fuzzy graph in which the degree of hesitancy of a vertex is independent of the degree of its membership and non-membership. We introduce the idea of β-product of a pair of hesitancy fuzzy graphs and intuitionistic hesitancy fuzzy graphs and prove certain results based on this product.

• Applied Biological Chemistry
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• v.41 no.7
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• pp.500-504
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• 1998

The enzymatic transgalactosylation of L-ascorbic acid was investigated to synthesize a chemically stable form of L-ascorbic acid by using commercially available ${\beta}-galactosidases$. Among various enzymes examined, Aspergillus oryzae ${\beta}-galactosidase$ was found to be formed the derivative of ascorbic acid in a high yield from ascorbic acid and lactose. The reaction product was isolated by ion exchange chromatography on a $Dowex\;1\;{\times}\;8$ (Cl - form) resin and Toyopearl HW-40S gel chromatography. The product was identified as $6-O-{\beta}-_D-galactopyranosyl-_L-ascorbic\;acid$ on the basis of various experimental results, viz., UV, IR, $^1H-NMR,\;^{13}C-NMR$ and mass spectral data.

• Natural Product Sciences
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• v.4 no.3
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• pp.143-147
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• 1998

Examination of the chemical constituents of the dried leaves of Isodon eriocalyx (Dunn.) Hara led to the isolation of four new diterpenoids, named maoecrystal Q-T (1-4). Their structures were elucidated as $16(R)-methoxymethyl-6{\beta},\;7{\beta}-dihydroxy-7{\alpha},20-epoxy-ent-kaur-2,3-ethenylene-1$, 15-dione(1), $1{\beta},18-diacetoxy-6{\beta},7{\beta}-dihydroxy-7{\alpha},20-epoxy-ent-kaur-16-en-15-one\;(2),\;6{\beta},\;7{\beta}-dihydroxy-15{\beta}-acetoxy-7{\alpha},20-epoxy-ent-kaur-16-en-1-one$ (3) and $7{\beta}-hydroxy-6{\beta},15{\beta}-diacetoxy-1{\alpha},11{\beta}-acetonide-7{\alpha},20-epoxy-ent-kaur-16-ene$ (4), respectively, on the basis of spectroscopic methods. Meanwhile, five known diterpeonids eriocalyxin B (5), maoecrystal B-D (6-8) and trichokaurin (9) were also obtained.