• 약학회지
• /
• 제45권2호
• /
• pp.214-219
• /
• 2001

Nineteen hydrolysable tannins isolated from the Euphorbia helioscopia (Euphorbiaceae) were tested for the inhibitory effect on mushroom tyrosinase activity in vitro. Inhibitory effect of gallotannin group exhibited more potent than that of phenolcarboxylic acid and ellagitannin groups against the enzyme activity. The inhibitory activity by pentagalloyl glucose on mushroom tyrosinase was more potent ($IC_{50}$/, 4.9 $\mu$M) than that of kojic acid ($IC_{50}$/, 8.7 $\mu$M).

• Journal of the Korean Wood Science and Technology
• /
• 제51권6호
• /
• pp.481-492
• /
• 2023

The ecofriendly lifestyle has attracted considerable support for sustainable development. Natural dyes, as sustainable products, have become a research focus and development area for many scientists. Ecofriendly processing also supports circular sustainable development. This study effectively obtained tannins as a natural dye from merbau (Intsia bijuga) sawdust using water as an ecofriendly solvent. Merbau sawdust is an underutilized industrial waste. Temperature and solid-solvent ratio variations were performed to extract tannins from merbau sawdust. Temperature and solid-solvent ratio positively affected solution yield and tannin concentration. The optimal condition was identified using response surface methodology and experimental observations. A yield of 0.2217 g tannins/g merbau was obtained under the conditions of 333.15 K and 0.125 solid-solvent ratio. Extraction was controlled by convective mass transfer at the interface of solid particles.

• Asian-Australasian Journal of Animal Sciences
• /
• 제27권7호
• /
• pp.937-945
• /
• 2014

Green and black tea by-products, obtained from ready-made tea industry, were ensiled at $10^{\circ}C$, $20^{\circ}C$, and $30^{\circ}C$. Green tea by-product silage (GTS) and black tea by-product silage (BTS) were opened at 5, 10, 45 days after ensiling. Fermentation characteristics and nutrient composition, including tannins, were monitored and the silages on day 45 were subjected to in vitro ruminal fermentation to assess anti-nutritive effects of tannins using polyethylene glycol (PEG) as a tannin-binding agent. Results showed that the GTS and BTS silages were stable and fermented slightly when ensiled at $10^{\circ}C$. The GTS stored at $20^{\circ}C$ and $30^{\circ}C$ showed rapid pH decline and high acetic acid concentration. The BTS was fermented gradually with moderate change of pH and acid concentration. Acetic acid was the main acid product of fermentation in both GTS and BTS. The contents of total extractable phenolics and total extractable tannins in both silages were unaffected by storage temperatures, but condensed tannins in GTS were less when stored at high temperature. The GTS showed no PEG response on in vitro gas production, and revealed only a small increase by PEG on $NH_3$-N concentration. Storage temperature of GTS did not affect the extent of PEG response to both gas production and $NH_3$-N concentration. On the other hand, addition of PEG on BTS markedly increased both the gas production and $NH_3$-N concentration at any ensiled temperature. It can be concluded that tannins in both GTS and BTS suppressed rumen fermentation, and tannins in GTS did more weakly than that in BTS. Ensiling temperature for both tea by-products did not affect the tannin's activity in the rumen.

• Applied Biological Chemistry
• /
• 제39권6호
• /
• pp.477-481
• /
• 1996

바나나 과실을 시중에서 구입하여 미숙과실과 황숙과실로 구별하고 이것들을 과육부분과 과피부분으로 나누어서 동결건조 및 열풍건조시켜 실험 시료로서 사용하였다. 탄닌 함량을 분석한 결과 황숙과실 보다도 미숙과실에서 높았으며, 과육보다는 과피에서 열풍건조 보다는 동결건조시킨 시료에서 높은 경향을 나타내었다. 탄닌의 분획은 Sephadex LH-20칼럼을 사용하여 분획하였다. 바나나 과실에 함유하고 있는 탄닌은 prodelphinidin, procyanidin을 구성 단위로 하는 proanthocyanidin류의 축합성 탄닌으로 이러한 탄닌은 소화효소인 trypsin(EC 3. 1. 1. 3), ${\alpha}-amylase$(EC 3. 4. 21. 4), lipase(EC 3. 2. 1. 1)에 대하여 in vitro에 있어서 저해작용을 가지고 있는 것이 확인되었으며 또한 탄닌은 중합도가 높을수록 저해율이 높다는 것이 확인되었다.

• 생약학회지
• /
• 제26권1호
• /
• pp.27-30
• /
• 1995

Tannins were isolated from the stems of Rubus coreanum and identified as (-)-epicatechin, (+)-catechin, procyanidin B-4 and sanguiin H-4 by spectral analysis.

• 한국산업안전학회:학술대회논문집
• /
• 한국안전학회 1998년도 추계 학술논문발표회 논문집
• /
• pp.89-92
• /
• 1998

Tannins are complex polyphenolic substances present in plants. They may be classified as either hydrolysable or condensed tannins, and extracts of the latter type have displayed carcinogenic properties in animal studies (Hausen, 1981). The International Agency for Research on Cancer has determined that exposure to airborne wood dust, especially hardwood dust during furniture manufacture, is a cause of sino-nasal cancer, notably nasal adenocarcinoma. (omitted)

• Asian-Australasian Journal of Animal Sciences
• /
• 제20권2호
• /
• pp.220-228
• /
• 2007

The nutritive value and the effect of tannins on the utilization of foliage from three commonly used legumes, Acacia nilotica, Albizia procera, and Sesbania acculeata, were determined. Three mature rumen-fistulated bullocks were used to study in sacco degradability and twelve adult sheep were randomly allocated on the basis of live weight to 4 groups of 3 in each to study the in vivo digestibility of the foliages. In all foliages, the contents of crude protein (17 to 24% of DM) were high. Fibre was especially high in Albizia (NDF 58.8% of DM vs. 21% in Sesbania and 15.4% in Acacia). Contents of both hydrolysable (4.4 to 0.05%) and condensed tannins (1.2 to 0.04%) varied from medium to low in the foliages. Acacia contained the highest level of total phenolics (20.1%), protein precipitable phenolics (13.2%) and had the highest capacity to precipitate protein (14.7%). Drying in shade reduced the tannin content in Acacia and Albizia by 48.6 and 69.3% respectively. The foliages ranked similarly for each of the different methods used to estimate tannin content and activity. Acacia and Sesbania foliage was highly degradable (85-87% potential degradability of DM in sacco), compared to Albizia (52%), indicating a minimal effect of tannins in Acacia and Sesbania. Yet, in vitro, the tannins in the Acacia inhibited microbial activity more than those in Albizia and Sesbania. Following the addition of polyethylene glycol to neutralise the tannins, gas production and microbial growth increased by 59% and 0.09 mg RNA equiv./dg microbial yield respectively in the Acacia, compared to 16-17% and 0.06 mg RNA equiv./dg microbial yield in the other foliages. There was a trend for low in vivo apparent digestibility of N in the Acacia (43.2%) and Albizia (44.2%) compared to the Sesbania (54.5%) supplemented groups. This was likely to be due to presence of tannins. Consistent with this was the low N retention (0.22 and 0.19 g N/g NI) in sheep supplemented with Acacia and Albizia compared to that for the Sesbania (0.32). Similarly, a trend for poor microbial N yield was observed in sheep fed these foliages. Across the foliages tested, an increase in tannin content was associated with a reduction in ruminal fermentation, N digestibility and N retention. For overall nutritive value, Sesbania proved to be the superior forage of the three tested.

• 한국자원식물학회지
• /
• 제27권4호
• /
• pp.279-285
• /
• 2014

참나무류 종실에 대한 수종별 성분함량 특성을 비교하기 위하여 동일 환경조건에서 생산된 채종원산 상수리나무, 졸참나무, 굴참나무 및 신갈나무 종실의 전체 페놀, 탄닌류, 아미노산, 무기원소, 식이섬유소, 베타카로틴 등의 함량을 분석하였다. 탄닌의 함량은 수종간에 유의적 차이(p<0.05)가 있었다. 졸참나무에서 79 mg/g으로 가장 높았고, 이외 수종은 62 mg/g 전후로 유사한 함량을 나타냈다. 수용성 탄닌 함량은 졸참나무가 71 mg/g을, 이외의 수종은 45 mg/g 전후로 나타났다. 반면 비수용성 탄닌 함량은 졸참나무가 8.2 mg/g으로 가장 낮았고, 굴참나무 23.5 mg/g으로 가장 높게 함유하고 있는 것으로 나타났다. 전체 식이섬유소 함량은 신갈나무 종실이 42%로 가장 높았고 졸참나무 38%, 상수리 및 굴참나무가 26% 전후로, 특히 졸참나무와 상수리나무의 클론간의 식이섬유소 함량을 비교한 결과 두 수종간에 유의적 차이(p<0.01)가 있었다. 무기성분 및 아미노산 함량은 신갈나무 종실이 다른 수종에 비해 높게 함유하는 경향이었다. 반면 베타카로틴은 신갈나무가 $10{\mu}g/100g$으로 가장 낮았고 굴참나무가 $520{\mu}g/100g$으로 가장 높은 경향이었다. 이상의 결과로 참나무 수종에 따른 도토리의 페놀성 화합물이나 영양성분의 함량은 수종 간에 차이가 있어 참나무 도토리의 종류에 따라 맛이나 영양학적으로 차이가 있을 것으로 추정된다.

• Journal of Nutrition and Health
• /
• 제29권8호
• /
• pp.861-866
• /
• 1996

Tannins in plant foods and beverages may produce antinutritional or toxic effects although some proteins with high affinity for tannins seem to function as defense mechanism to tannin toxicity. Our objectives were to investigate of tea tannins, iron and protein and to evaluate the role of proteins in tannin effects on iron solubility. Iron solubility in vitro was measured using tea with and without proteins. Mixtures of tea, protein in varying concentrations(either gelatin or bovine serum albumin), and iron(eithe 10 or 50ug/mL) were prepared. Controls contained water in place of tea. Iron bioavailability was assessed by measuring iron solubility in the simulated gastric condition with pepsin digestion. Bound iron was removed by centrifugation and soluble in tea alone. When iron concentratin was 10ug/mL, addition of small amounts of protein to tea dramatically reduced iron solubility, but solubility of iron increased in the tea mixturea as the concentration of protein was increased. The percnetage of iron that precipitated was much greater at 10ug Fe/mL than the values at 50ug Fe/mL suggesting that the iron binding sites on the tea-protein complex was saturated. These results suggest that interactions of iron with tea tannins are influenced by the concentratins of protein and iron.

• Asian-Australasian Journal of Animal Sciences
• /
• 제21권1호
• /
• pp.59-65
• /
• 2008

Six total mixed rations (TMR) containing 0, 4, 6, 8, 10, 12% tannin (TMR I-VI), using Accacia nilotica pods as a source of tannin, were used to study the effect of Acacia tannin on in vitro nutrient digestibility and gas production in goats. This study also investigated the degraded products of Acacia nilotica tannin in goat rumen liquor. Degraded products of tannins were identified using high performance liquid chromatography (HPLC) at different hours of incubation. In vitro digestibility of dry matter (IVDMD) and organic matter (IVOMD) were similar in TMR II, and I, but declined (p<0.05) thereafter to a stable pattern until the concentration of tannin was raised to 10%. In vitro crude protein digestibility (IVCPD) decreased (p<0.05) with increased levels of tannins in the total mixed rations. Crude protein digestibility was much more affected than digestibility of dry matter and organic matter. In vitro gas production (IVGP) was also reduced (p<0.05) with increased levels of tannins in the TMR during the first 24 h of incubation and tended to increase (p>0.05) during 24-48 h of incubation. Gallic acid, phloroglucinol, resorcinol and catechin were identified at different hours of incubation. Phloroglucinol and catechin were the major end products of tannin degradation while gallate and resorcinol were produced in traces. It is inferred that in vitro nutrient digestibility was reduced by metabolites of Acacia nilotica tannins and ruminal microbes of goat were capable of withstanding up to 4% tannin of Acacia nilotica pods in the TMR without affecting in vitro nutrient digestibility.