• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.867-872
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• 2002

This study was performed to investigate the optimum process conditions for manufacturing yeast extract from waste brewer's yeast using various enzymes. Contents of IMP, GMP, free amino acids, and crude protein of yeast extracts were measured by enzymes treatment. Crude protein contents of yeast extracts subjected to cell wall digestion enzyme treatment were 21.1, 33.6, and 28.0% for the control grouup, glucanase (0.5%, 12 h), and tunicase (1%, 18 h), respectively. Crude protein contents of yeast extracts subjected to protease treatment were 22.0, 30.8, and 29.8% for control group, bromelin (1%, 3 h), and protamex (1%, 3 h), respectively. Crude protein content of yeast extract subjected to glucanase and protamex mixed treatment was 34.4%. The total contents of IMP and GMP of yeast extracts subjected to G+P+A (glucanase+phosphodiesterase+adenyldeminase) and G+Pro+P+A (glucanase+protamex+phosphodiesterase+adenyldeaminase) treatments were 1,066 and 1,047 mg/100 g, respectively. The content of free amino acids of yeast extract was the highest (2,302 mg/100 g) in G+Pro+P+A treatment. Optimum concentration and process condition of enzyme treatment to obtain yeast extract with high IMP, GMP, and free amino acid content were in the order of glucanase (0.5%, 12 h), protamex (1%, 3h), phosphodiesterase (0.1%, 3 h) and adenyldeaminase (1%, 1.5 h) treatments.

• Applied Biological Chemistry
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• v.22 no.4
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• pp.210-216
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• 1979

RNA degrading bacteria were isolated from soil of Korea. One strain (no. JSC-114), having strong 5'-phosphodiesterase activity, was identified as belonging to the genus Streptomyces on the basis of taxonomic characteristics. The optimum conditions of 5'-phophosdiesterase production were found at $30^{\circ}C$ for 4 day in a medium containing 4.5% of soluble starch, 0.15% of peptone, 0.6% of yeast extract, 0.1% of $MgSO_4{\cdot}7H_2O$, 0.01% of $CaCl_2{\cdot}2H_2O$, 0.25% of $KNO_3$, and 0.5% of $KH_2PO_4$(pH 7.0). The maximum production rate of 5'-nucleotides from yeast RNA was 95% at $40-45^{\circ}C$ for 4hrs, and the products were identified as 5'-IMP, 5'-GMP, 5'-CMP and 5'-UMP(5.5 : 5.0 : 4.9 : 5.0).

• 대한약리학회:학술대회논문집
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• 2006.10a
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• pp.92.1-92.1
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• 2006

• Proceedings of the Korean Society of Applied Pharmacology
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• 2002.07a
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• pp.211-211
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• 2002

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.135.2-136
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• 2001

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.105.2-105.2
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• 2001

• Proceedings of the PSK Conference
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• 2002.04a
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• pp.219.2-219.2
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• 2002

• Korean Journal of Clinical Pharmacy
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• v.30 no.1
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• pp.59-64
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• 2020

The emergence of phosphodiesterase (PDE) 5 inhibitors gave rise to the solution for erectile dysfunction, starting with the development of sildenafil. Although their efficacy in treating erectile dysfunction has been shown, the side effects of PDE5 inhibitors, especially sildenafil, must be taken into consideration. A 64-year-old man received 100 mg of sildenafil and experienced blue vision in both eyes; however, after a day or so, his symptoms improved. The symptoms disappeared when he stopped administering sildenafil, but reappeared when the medication was re-administered. Therefore, he discontinued sildenafil treatment and was prescribed udenafil instead. After that, visual adverse events no longer occurred. Causality assessment showed that in this case, sildenafil-induced cyanopsia was "certain" under the World Health Organization-Uppsala Monitoring Center (WHO-UMC) criteria and Korean causality assessment algorithm (Ver.2), and was "probable" according to the Naranjo scale. In addition, sildenafil also led to abnormal visual reactions in other cases. Sildenafil can also inhibit PDE6, which is present in retinal cells, unlike other PDE5 inhibitors. Thus, visual adverse reactions, such as blue vision, are the unique results of sildenafil, and other PDE5 inhibitors may be used to prevent them.

• YAKHAK HOEJI
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• v.51 no.4
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• pp.235-238
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• 2007

To determine the regulatory roles of phosphodiesterase (PDE) inhibitors on $PGE_2$-induced osteoclastogenesis, we investigated the effect of PDE inhibitors on osteoclast formation in the presence of $PGE_2$. Among PDE isozyme specific inhibitors, milrinone, a selective PDE3 inhibitor, and rolipram, a specific PDE4 inhibitor, increased $PGE_2$-induced osteoclast formation in cocultures of mouse bone marrow cells and osteoblasts. To verify that whether the PDE3 and PDE4 inhibitors act indirectly on osteoblasts, we measured the concentration of intracellular cAMP in osteoblasts. Treatment of milrinone or rolipram increased $PGE_2$-stimulated cAMP levels in osteoblasts. Furthermore, northern blot analysis revealed that the PDE3 and PDE4 inhibitors works synergistically with $PGE_2$ to increase the expression of TRANCE mRNA in osteoblasts. On the contrary, the PDE3 and PDE4 inhibitors did not augment the number of osteoclasts differentiated from bone marrow cells by $PGE_2$. In conclusion, the stimulation of $PGE_2$-induced osteoclast formation by the PDE3 and PDE4 inhibitors are attributable to their indirect effect on osteoblasts, not to their direct effect on bone marrow-derived osteoclast precursors.

• Journal of the Korean Chemical Society
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• v.42 no.1
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• pp.64-68
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• 1998

Three anthraquinones, chrysophanol, physcion and 1-o-methyl-2-methoxychrysophanol which have $Na^+,K^+-ATPase$ and cyclic AMP phosphodiesterase lowering activities related to cardiotonic action were isolated from the Korean marine echiura, Urechis unicintus. Spectroscopic methods, including HMQC, HMBC and NOE studies, were used to establish the structures.