• Korean journal of food and cookery science
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• v.18 no.5
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• pp.487-494
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• 2002

This study was conducted to investigate the thermal stability of water-soluble and fat-soluble vitamins dissolved in water and milk by various heat treatments. Vitamin samples were prepared by dissolving them in water and milk at various concentrations, and were heat treated for 30 min at 65$\^{C}$, 15 sec at 85$\^{C}$, 5 sec at 100$\^{C}$, 121$\^{C}$ at 15 min, the levels of residual vitamin were measured by using HPLC. Milk samples were fortified with vitamins before and after UHT treatment. As heating over 100$\^{C}$, riboflavin in water were destructed more than 92% but fortified in milk showed less than 20% destruction, suggesting that riboflavin was protected by milk components. Also retinol heated ever 100$\^{C}$ was more stable in milk than in water. L-Ascorbic acid and cholecalciferol(D$_3$) showed a similar destruction rate in water and in fortified milk. L-ascorbic acid was easily destructed by UHT treatment. Destruction of thiamin and tocopherol was increased in fortified milk. Among tour capsulated water-soluble vitamins, L-ascorbic acid was much more stable compared with powder form. Nicotinic acid and folic acid either in capsule or powder form showed a slight destruction by heat treatment. The results suggested that the fortification of unstable vitamins such as L-ascorbic acid, thiamin, tocopherol and cholecalciferol(D$_3$) should be made in milk after heat treatment.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.5
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• pp.431-439
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• 2014

The aim of the present study was to investigate whether ginsenoside-Rb2 (Rb2) can affect the secretion of catecholamines (CA) in the perfused model of the rat adrenal medulla. Rb2 ($3{\sim}30{\mu}M$), perfused into an adrenal vein for 90 min, inhibited ACh (5.32 mM)-evoked CA secretory response in a dose- and time-dependent fashion. Rb2 ($10{\mu}M$) also time-dependently inhibited the CA secretion evoked by DMPP ($100{\mu}M$, a selective neuronal nicotinic receptor agonist) and high $K^+$ (56 mM, a direct membrane depolarizer). Rb2 itself did not affect basal CA secretion (data not shown). Also, in the presence of Rb2 ($50{\mu}g/mL$), the secretory responses of CA evoked by veratridine (a selective $Na^+$ channel activator ($50{\mu}M$), Bay-K-8644 (an L-type dihydropyridine $Ca^{2+}$ channel activator, $10{\mu}M$), and cyclopiazonic acid (a cytoplasmic $Ca^{2+}$-ATPase inhibitor, $10{\mu}M$) were significantly reduced, respectively. Interestingly, in the simultaneous presence of Rb2 ($10{\mu}M$) and L-NAME (an inhibitor of NO synthase, $30{\mu}M$), the inhibitory responses of Rb2 on ACh-evoked CA secretory response was considerably recovered to the extent of the corresponding control secretion compared with the inhibitory effect of Rb2-treatment alone. Practically, the level of NO released from adrenal medulla after the treatment of Rb2 ($10{\mu}M$) was greatly elevated compared to the corresponding basal released level. Collectively, these results demonstrate that Rb2 inhibits the CA secretory responses evoked by nicotinic stimulation as well as by direct membrane-depolarization from the isolated perfused rat adrenal medulla. It seems that this inhibitory effect of Rb2 is mediated by inhibiting both the influx of $Ca^{2+}$ and $Na^+$ into the adrenomedullary chromaffin cells and also by suppressing the release of $Ca^{2+}$ from the cytoplasmic calcium store, at least partly through the increased NO production due to the activation of nitric oxide synthase, which is relevant to neuronal nicotinic receptor blockade.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.4
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• pp.155-164
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• 2008

Resveratrol has been known to possess various potent cardiovascular effects in animal, but there is little information on its functional effect on the secretion of catecholamines (CA) from the perfused model of the adrenal medulla. Therefore, the aim of the present study was to determine the effect of resveratrol on the CA secretion from the isolated perfused model of the normotensive rat adrenal gland, and to elucidate its mechanism of action. Resveratrol (10${\sim}100{\mu}$M) during perfusion into an adrenal vein for 90 min inhibited the CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (a direct membrane-depolarizer, 56 mM), DMPP (a selective neuronal nicotinic $N_n$ receptor agonist, 100${\mu}$M) and McN-A-343 (a selective muscarinic $M_1$ receptor agonist, 100${\mu}$M) in both a time- and dose- dependent fashion. Also, in the presence of resveratrol (30${\mu}$M), the secretory responses of CA evoked by veratridine 8644 (an activator of voltage-dependent$Na^+$ channels, 100${\mu}$M), Bay-K-8644 (a L-type dihydropyridine $Ca^{2+}$ channel activator, 10${\mu}$M), and cyc1opiazonic acid (a cytoplasmic $Ca^{2+}$-ATPase inhibitor, 10${\mu}$M) were significantly reduced. In the simultaneous presence of resveratrol (30${\mu}$M) and L-NAME (an inhibitor of NO synthase, 30${\mu}$M), the CA secretory evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644 and cyc1opiazonic acid were recovered to a considerable extent of the corresponding control secretion compared with the inhibitory effect of resveratrol alone. Interestingly, the amount of nitric oxide (NO) released from the adrenal medulla was greatly increased in comparison to its basal release. Taken together, these experimental results demonstrate that resveratrol can inhibit the CA secretory responses evoked by stimulation of cholinergic nicotinic receptors, as well as by direct membrane-depolarization in the isolated perfused model of the rat adrenal gland. It seems that this inhibitory effect of resveratrol is exerted by inhibiting an influx of both ions through $Na^+$ and $Ca^{2+}$ channels into the adrenomedullary cells as well as by blocking the release of $Ca^{2+}$ from the cytoplasmic calcium store, which are mediated at least partly by the increased NO production due to the activation of NO synthase.

• Journal of Ginseng Research
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• v.35 no.2
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• pp.176-190
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• 2011

There seems to be some controversy about the effect of total ginseng saponin (TGS) on the secretion of catecholamines (CA) from the adrenal gland. Therefore, the present study aimed to determine whether TGS can affect the CA release in the perfused model of the adrenal medulla isolated from spontaneously hypertensive rats (SHRs). TGS (15-150 ${\mu}g/mL$), perfused into an adrenal vein for 90 min, inhibited the CA secretory responses evoked by acetylcholine (ACh, 5.32 mM) and high $K^+$ (56 mM, a direct membrane depolarizer) in a dose- and time-dependent fashion. TGS (50 ${\mu}g/mL$) also time-dependently inhibited the CA secretion evoked by 1.1-dimethyl-4 -phenyl piperazinium iodide (DMPP; 100 ${\mu}M$, a selective neuronal nicotinic receptor agonist) and McN-A-343 (100 ${\mu}M$, a selective muscarinic M1 receptor agonist). TGS itself did not affect basal CA secretion (data not shown). Also, in the presence of TGS (50 ${\mu}g/mL$), the secretory responses of CA evoked by veratridine (a selective $Na^+$ channel activator (50 ${\mu}M$), Bay-K-8644 (an L-type dihydropyridine $Ca^{2+}$ channel activator, 10 ${\mu}M$), and cyclopiazonic acid (a cytoplasmic $Ca^{2+}$-ATPase inhibitor, 10 ${\mu}M$) were significantly reduced, respectively. Interestingly, in the simultaneous presence of TGS (50 ${\mu}g/mL$) and N${\omega}$-nitro-L-arginine methyl ester hydrochloride [an inhibitor of nitric oxide (NO) synthase, 30 ${\mu}M$], the inhibitory responses of TGS on the CA secretion evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644, cyclopiazonic acid, and veratridine were considerably recovered to the extent of the corresponding control secretion compared with the inhibitory effect of TGS-treatment alone. Practically, the level of NO released from adrenal medulla after the treatment of TGS (150 ${\mu}g/mL$) was greatly elevated compared to the corresponding basal released level. Taken together, these results demonstrate that TGS inhibits the CA secretory responses evoked by stimulation of cholinergic (both muscarinic and nicotinic) receptors as well as by direct membrane-depolarization from the isolated perfused adrenal medulla of the SHRs. It seems that this inhibitory effect of TGS is mediated by inhibiting both the influx of $Ca^{2+}$ and Na+ into the adrenomedullary chromaffin cells and also by suppressing the release of $Ca^{2+}$ from the cytoplasmic calcium store, at least partly through the increased NO production due to the activation of nitric oxide synthase, which is relevant to neuronal nicotinic receptor blockade, without the enhancement effect on the CA release. Based on these effects, it is also thought that there are some species differences in the adrenomedullary CA secretion between the rabbit and SHR.

• Nuclear Engineering and Technology
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• v.2 no.2
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• pp.73-84
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• 1970

The metabolism of sterol precurosor in leaves of Salanum andigena grafted between photoinduced and noninduced plant was investigated with the use of (2-$^{14}$ C) mevalonic acid. By the technique of the preparative gas-liquid chromatography, radioactive compounds of squalene, 4,4’-dimethylsterols and 4-demethylsterol were isolated and determined quantitatively. When labeled mevalonic acid n as applied to leaves radioactivity was extensively incorporated into non-saponifiable materials of lipid fraction and aqueous fraction (ethanol-water fraction). Radioactivity of 14C derived from (2-$^{14}$ C) mevalonic acid was transmissible from photoinduced plant to non-induced plant across the graft union, as tuberization hormone was, and incorporated into the sterols of the non-induced plant. Inhibitors of sterol biosynthesis, SK & F 7997 and nicotinic acid, are effective suppressors of tuber growing, if applied to leaves during photoinduction period. The experimental results suggest that certain substance containing isoprene unit, or sterol-like compound may participate in tuber growing.

• Natural Product Sciences
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• v.24 no.3
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• pp.189-193
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• 2018

Chemical investigation of the ethyl acetate extract of Gibberella moniliformis JS1055 endophytic fungus derived from a halophyte, Vitex rotundifolia, led to the isolation of nine compounds including 7-butyl-6,8-dihydroxy-3(R)-pent-11-enylisochroman-1-one (1), 7-butyl-6,8-dihydroxy-3(R)-pentylisochroman-1-one (2), 7-butyl6,8-dihydroxy-3(R)-pentylisochroman-1-one (3), $5{\alpha},8{\alpha}$-epidioxyergosta-6,9(11),22-trien-3-ol (4), ergosterol peroxide (5), tetradecanoic acid (6), 8-O-methylfusarubin (7), nicotinic acid (8) and adenosine (9). They were identified by extensive spectroscopic data analysis including 1D, 2D ($^1H-^1H$ COSY, HSQC, HMBC) NMR, and ESIMS. All the isolates (1-9) are reported for the first time from this endophytic fungus.

• Archives of Pharmacal Research
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• v.21 no.3
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• pp.273-277
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• 1998

In order to determine the structure-activity relationships for antioxidative effects of gagaminine, a steroidal alkaloid isolated from the roots of Cynanchum wilfordi (Asclepiadaceae), two derivatives identified as sarcostin and penupogenin were prepared from gagaminine by hydrolysis and reduction. These compounds were evaluated for the inhibitory effects on the aidehyde oxidase activity and on lipid perbxidation in vitro. Furthermore, their effects were compared with those of gagaminine and the related compounds, cinnamic acid and nicotinic acid. The results of this study prove that the cinnamoyl group in the structure of gagaminine is critical in inhibition of the aldehyde oxidase activity while the nicotinoyl group may be necessary for anti-lipid peroxidation of the compound.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.71-71
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• 2003

The quinolinic acid(QA) phosphoribosyltransferase (PRTase) (EC 2.4.2.19), is a key enzyme involved in NAD$\^$+/ biosynthesis in prokaryotes and eukaryotes, The QAPRTase produces nicotinic acid mononucleotide (NAMN) from QA and 5-phosphoribosyl-1-pyrophosphate (PRPP). For this reaction, the QA is decarboxylated (Fig.1). Produced NAMN is used to a synthesis of nicotinate adenine dinucleotide(NAD$\^$+/).

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.4
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• pp.251-261
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• 1987

This study was attempted to increase the production of L-Threonine by Brevibacterium Flavum ATCC 14067, To select the strain which produce the highest threonine, mutants ere induced by N-methyl-N'-nitro-N-nitrosoguanidine treatment. The composition of media and cultural condition for its overproduction of threonine were also studied. In a threonine producer, strain B-13(Met-) was the strain producing the highest amount of threonige among methionine, lysine and isoleucine auxotrophs. The following results were obtained. 1. The wild strain and B-13(Met-) produced threonine 1.4mg/ml and 4.86mg/ml , respectively. 2. The optimum composition of medium for producing threonine by Brevibacterium Flavum B-13 was glucose 10%, ammonium sulfate 4%, potassium phosphate monobasic 0.2%, magnesium sulfate 0.05%, biotin $200{\mu}l$, thiamine $300{\mu}l$. Addition of nicotinic acid also led to increase L-threonine production. 3. In addition of organic nutrients to the fermentation medium, peptone n'ere effective and addition of methionine $100{\mu}g/ml$ produced the highest amount of L-Threonine. Aspartic acid and homoserine were also effective when these amino acid were added to the fermentstion medium. 4. Cultural conditon on threonine production by B-16 were investigated. The optimum pH was 7.0-8.0. The highest amount of threnine was produced after 4 days of cultural period.

• Korean Journal of Food Science and Technology
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• v.26 no.1
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• pp.18-22
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• 1994

This study was designed to investigate the method of the simultaneous determination of water-soluble vitamins (thiamine, ascorbic acid, riboflavin, folic acid, cyanocobalamine, pyridoxin, nicotinic acid) by free soloution capillary electrophoresis. Factors affecting on the separation were pH of the buffer, applied voltage and temperature. On-column detection at 254 nm allowed accurate and reproducible determination of these compounds. All these compounds were separated within ca. 8 min with fused silica capillary at 20 kV.