Yukiko Negishi

Biosynthesis of Vanillin via Ferulic Acid in Vanilla planifolia

(14)C-Labeled phenylalanine, 4-coumaric acid, 4-hydroxybenzaldehyde, 4-hydroxybenzyl alcohol, ferulic acid, and methionine were applied to disks of green vanilla pods 3 and 6 months after pollination (immature and mature pods), and the conversion of these compounds to vanillin or glucovanillin was investigated. In mature green vanilla pods, radioactivities of 11, 15, 29, and 24% from (14)C-labeled phenylalanine, 4-coumaric acid, ferulic acid, and methionine, respectively, were incorporated into glucovanillin within 24 h. In the incorporation processes of methionine and phenylalanine into glucovanillin, some of the (14)C labels were also trapped by the unlabeled ferulic acid. However, (14)C-labeled 4-hydroxybenzaldehyde and 4-hydroxybenzyl alcohol were not converted to glucovanillin. On the other hand, in immature green vanilla pods radioactivities of the above six compounds were not incorporated into glucovanillin. Although 4-coumaric acid, ferulic acid, 4-hydroxybenzaldehyde, and 4-hydroxybenzyl alcohol were converted to the respective glucose esters or glucosides and vanillin was converted to glucovanillin, their conversions were believed to be from the detoxication of the aglycones. These results suggest that the biosynthetic pathway for vanillin is 4-coumaric acid --> --> ferulic acid --> --> vanillin --> glucovanillin in mature vanilla pods.

Content of Methylated Inositols in Familiar Edible Plants

Familiar plants contain large amounts of inositols; soybean, white clover, red clover, bush clover, locust tree, wisteria, and kudzu of the legume family contain pinitol (3-O-methyl-chiro-inositol) at approximately 200-600 mg/100 g fresh weight (FW). The contents of pinitol in other plants were 260 mg/100 g FW for sticky mouse-ear, 275 mg/100 g FW for chickweed, and 332 mg/100 g FW for ginkgo. chiro-Inositol of 191 and 156 mg/100 g FW was also found in dandelion and Japanese mallotus, respectively. Ononitol (4-O-methyl-myo-inositol) of 166 mg/100 g FW was found in sticky mouse-ear. Furthermore, young leaves of ginkgo contained sequoyitol (5-O-methyl-myo-inositol) of 287 mg/100 g FW. Hydroxyl radical scavenging activities of the methylated inositols were higher than those of the original inositols. Effective uses of these familiar edible plants are expected to promote good health.

Phenylpropanoid 2,3-dioxygenase involved in the cleavage of the ferulic acid side chain to form vanillin and glyoxylic acid in Vanilla planifolia

Enzyme catalyzing the cleavage of the phenylpropanoid side chain was partially purified by ion exchange and gel filtration column chromatography after (NH4)2SO4 precipitation. Enzyme activities were dependent on the concentration of dithiothreitol (DTT) or glutathione (GSH) and activated by addition of 0.5 mM Fe2+. Enzyme activity for ferulic acid was as high as for 4-coumaric acid in the presence of GSH, suggesting that GSH acts as an endogenous reductant in vanillin biosynthesis. Analyses of the enzymatic reaction products with quantitative NMR (qNMR) indicated that an amount of glyoxylic acid (GA) proportional to vanillin was released from ferulic acid by the enzymatic reaction. These results suggest that phenylpropanoid 2,3-dioxygenase is involved in the cleavage of the ferulic acid side chain to form vanillin and GA in Vanilla planifolia. Phenylpropanoid 2,3-dioxygenase is involved in the cleavage of the ferulic acid side chain to form vanillin and glyoxylic acid in Vanilla planifolia.

In vivo deodorisation with caffeoylquinic acid derivatives

Ku-ding-cha contained a large amount of the caffeoyl quinic acid (CQA) derivatives, di-CQA, 16.7% in dry weight as well as mono-CQA, 9.2%. A mixture of 3,5-DiCQA and 5-CQA with an apple acetone powder (AP), containing polyphenol oxidase, showed high capturing activities towards methanethiol (MeSH), propanethiol (PrSH), and 2-propenethiol (AllSH). Two adducts from 3,5-diCQA and methanethiol (MeSH) were identified. Furthermore, drinking Ku-ding-cha and eating apple or prune reduced the amount of allyl methyl sulfide (AMS) and AllSH gas after garlic ingestion. These results indicate the good effects of CQA derivatives on in vivo deodorisation.

Nutritional and chemical study on newly cultivated mushrooms

エリンギPleurotus eringii, ウスヒラタケpleurotus pulmomrius, アワビタケPleurotus cystidiosus, ヌメリスギタケPholiota adiposa, ササクレヒトヨタケCoPorinus comatusおよびヤナギマツタケAgrocybe cylindraoeaの6種類の市販栽培キノコ類について一般成分, 食物繊維, ミネラル, 糖・糖アルコール, 有機酸および遊離アミノ酸の分析を行った. またトキイロヒラタケPleurotus salmoneostramineusついては糖・糖アルコールおよび有機酸の分析を行った. その結果, エリンギはたんぱく質, カリウムおよび遊離アミノ酸量が少なく, 糖・糖アルコール(特にトレハロース) 量が多かった. ウスヒラタケはたんぱく質, 亜鉛, 有機酸および遊離アミノ酸量が多く, ナトリウムおよび糖・糖アルコール量が少なかった. アワビタケは今回分析したキノコ類の中ではたんぱく質および遊離アミノ酸が比較的少なく, カリウム, カルシウム, 亜鉛および食物繊維量が多かった. ササクレヒトヨタケはたんぱく質, ナトリウム, 糖・糖アルコール (特にトレハロース), 有機酸および遊離アミノ酸量が比較的多く, 食物繊維量は少なかった. ヤナギマッタケとヌメリスギタケは一般成分, 糖. 糖アルコール, 有機酸および遊離アミノ酸量は今回分析した他のキノコ類の中間的な値を示していたが, カリウムおよび食物繊維量はやや多かった. トキイロヒラタケはたんぱく質, リン, 亜鉛および遊離アミノ酸量は多かったが糖・糖アルコールおよび有機酸量は少なかった.

Effect of different strains and supplements on constituents in fruit, Yamabushitake (Hericium erinaceum) cultivated on sawdust substrate beding body

We analyzed the proximate composition, total dietary fiber, minerals, free amino acids, free sugars, free sugar alcohol, organic acids and nucleotides in the fruiting body, Yamabushitake (Hericium erinaceum) , cultivated on a sawdust substrate bed with differentstrains and supplements in order to make it clear that the cultivation conditions affectthe contents of the fruiting body. The protein, fat, total dietary fiber and nucleotide contentin the fruiting bodies of Hericium erinaceum showed differences according to thedifferent strains and supplements. And also the mineral, free amino acid, free sugar, freesugaralchol and organic acid content indicated remarkable differences among the differentstrains and supplements, but the major components and their ratio showed the sametendencies regardless of strain and supplements.

The Safety of Powdered Soft Drink Containing Galactosylsucrose in Healthy Volunteers

It was reported that some volunteers had watery stools after the ingestion of powderedcoffee containing galactosylsucrose (LS) with milk in a previous paper. The effect o f theingestion of milk on defecation and fecal condition in the same 11 volunteers were studiedand compared to the LS-powdered coffee data that was previously described.The sub-jects were each given 200ml, 400ml and 600ml of milk in 3 days (ingestion phase), and theprepared blank phase when they were not fed any milk for a week between the ingestionphases. The excretion of watery stools was significantly increased by the ingestion ofmilk as compared with the noningestion in the group although a significant effect was notobserved in comparison with the each ingestion phase. When children (50-12 years old) ingested LS-powdered coffee (16g, LS2. 1g), the fecal conditions such as volume, shapeand hardness feeling were also significantly improved. No significant changes were ob-served in either the excretion of watery stools or the ingestion of LS. These results indi-cate that the defecation fo watery stools is caused by the oral ingestion of too much milk, and the Ls-powdered coffee is less likely to cause watery stools when orally ingested inregular doses.

Improving Effects of Powdered Coffee Containing Galactosylsucrose on Defecation in Healthy Volunteers

健常な被験者 (50名) を対象に乳果オリゴ糖 (LS) 入り粉末清涼飲料 (16g, LSとして2.1g) を2週間摂取させ, 排便日数, 糞便菌叢, 便性状など複数の観点から排便状況に及ぼす影響を検討した. 対照には甘味料としてショ糖と麦芽糖のみを使用したプラセボ粉末清涼飲料を用い, プラセボ粉末清涼飲料摂取期 (Cont. 期) とLS入り粉末清涼飲料摂取期 (LSlw期, LS2w期) の間に1週間の非摂取期間 (Blank期) をおいた.対象者全員で比較すると, 1週間当たりの排便日数は非摂取期 (Blank期) に比べてLS入り粉末清涼飲料摂取により有意 (p<0.05) に増加傾向を示した. しかし, プラセボ粉末清涼飲料摂取期 (Blank期) に比べると有意差は認められなかった. また便秘傾向者の場合はその影響が顕著になり, プラセボ粉末清涼飲料を摂取したCont. 期との比較では, LSlw期は有意な増加は認められなかったが, LS2w期は有意 (p<0.05) な排便日数の増加が認められた. 便性状に関しては便の量, 便の形状, 感覚的な便の硬さの3項目で非摂取期に比べて有意 (p<0.05) な改善が見られた. また, プラセボ粉末清涼飲料摂取期との比較でもLS入り粉末清涼飲料摂取により便の形状, 感覚的な便の硬さにおいて有意 (p<0.05) な改善効果を示した.糞便中の総嫌気性菌に対するBifidobacterium占有率はLS入り粉末清涼飲料摂取により非摂取期に比べて有意 (p<0.05) な増加が見られた. また, プラセボ粉末清涼飲料摂取期との比較でも有意 (p<0.05) に増加した. また, LS入り粉末清涼飲料の摂取量を段階的に2倍量 (32g, LSとして4.2g), 3倍量 (48g, LSとして6.3g) まで増加した場合, それぞれ29.4%, 37.9%の割合で泥状便が出現し, 「お腹が痛かった」「お腹がゴロゴロした」「膨満感」「おならが出た」などの腹部症状が発生した. しかしながら, これら泥状便, 腹部症状の発生頻度とLS摂取量の増加との間には相関は確認されず, むしろ多量の牛乳摂取によるものと考えられる.以上の結果より, LS入り粉末清涼飲料の摂取はBifidobacteriumなどの有用菌を増加させ, 排便日数, 排便量, 便の色, 便の形状, 便の硬さなどに対して改善効果を示すことが明らかになった.