hydroxycinnamoyl-CoA Research Articles

Partial purification and characterization of hydroxycinnamoyl CoA: Transferases from apple and date fruits

Partial purification and characterization of hydroxycinnamoyl CoA: Transferases from apple and date fruits

Biosynthesis of phenolic compounds inVitis vinifera cell suspension cultures: Study on hydroxycinnamoyl CoA:ligase

In cell suspensions cultures from grape berry pulp (Vitis vinifera cv. Gamay fréaux)hydroxycinnamoyl CoA ligase (CoAL) displayed maximum activity (100 %) forp-coumaric acid and then, in decreasing order, for ferulic acid (81.3 %) and caffeic acid (60.4 %). No activity was detected with sinapic and cinnamic acids. The changes in CoAL activity during the growth cycle of the culture displayed two peaks : the highest (6 h after subculturing) was linked with a strong increase in protein caused by dilution ; the second was weaker and occurred on the 7th day of culture.Grape cell suspension accumulated mainly peonidin (Pn) and cyanidin (Cy) glucosides (Pn 3-glucoside, Cy 3-glucoside, Pn 3-acetylglucoside, Pn 3-caffeylglucoside, Pn 3-p-coumarylglucoside, and Cy 3-p-coumarylglucoside). Maximum accumulation of anthocyanins was associated with the exponential growth phase of the culture and might be the result of the substantial increase in CoAL activity resulting from the effect of dilution. The second enzyme activity peak was probably oriented towards the acylation of anthocyanins since the percentage of acylated forms increased with time after subculturing.

ヨウサイ (<i>Ipomoea aquatica</i> Forsk.) の低温障害発生に伴うK<sup>+</sup>漏出速度, 遊離アミノ酸含量並びにフェニルプロパノイド代謝の変化

Water convolvulus (Ipomoea aquatica Forsk.) is widely distributed as leafy vegetables in South-East Asia including southern area in Japan. It shows chilling injury manifested as browning of young leaves (2-3 immature leaves located at top part of each vine) and young stems (top part of each vine) when stored at temperatures about below 9°C. In the present study, the changes of K+ leakage, free amino acid contents, phenylpropanoid contents, and some enzyme activities relating to the biosynthesis of phenylpropanoids were inveatigated with reference to the chilling injury. The materials were sealed in polyethylene bags (0.03mm thickness) and stored at 1, 6, 9, 12, 15, 20, and 30°C.A break point of Arrhenius plot for K+leakage in young and mature leaves was found between 10 and 16°C, whereas the matured leaves showed only a little chilling-sensitivity. A marked increase of the rate of K+ leakage occurred in young leaves stored at 1°C, preceding the appearance of browning.As the contents of phenylpropanoids such as t-cinnamic, p-coumaric, caffeic and chlorogenic acids were investigated, they increased before the occurrence of chilling injury and then tended to decline almost simultaneously with the development of chilling injury. They also increased at 15°C, but the rise delayed and the extent was considerably lower than that at 1°C.Among the enzymes relating to the biosynthesis of chlorogenic acid, a main substrate of browning, hydroxycinnamoyl CoA ligase (CL) activity increased in both of 1°C and 15°C storages, then the increase was faster at 1°C reaching to a peak before the occurrence of chilling injury. Hydroxycinnamoyl CoA: quinate hydroxycinnamoyl transferase (CQT) activity showed a markedly higher increase in the 1°C storage.On the results, we present a conclusion of the low temperature induced browning mechanism as follows; exposure to low temperature leads to a rise of phenolic contents through activation of the enzymes such as CL and CQT. The accumulated phenolics induce the browning after its enzymic oxidation.

Purification and properties of hydroxycinnamoyl CoA quinate hydroxycinnamoyl transferase from potatoes

A rapid method for the purification of hydroxycinnamoyl CoA quinate hydroxycinnamoyl transferase (CQT) from potato tubers which had been stored at low temperatures is described. The method involves affinity chromatography on Blue Sepharose with biospecific desorption of CQT with its substrate, CoA. Elution of the Blue Sepharose column with a gradient of CoA leads to the resolution of CQT, a protein with MW of ca 41500, into 3 peaks of activity; the largest peak elutes first. This fraction is purified × 1440 and gives a single band of protein after PAGE which suggests a high degree of purity. The properties of the 3 fractions of CQT, with respect to substrates and to a number of inhibitors, are described. The first and last eluting CQT fractions are specific for quinate and show no activity towards shikimate. The second peak, however, shows a small activity towards shikimate but this is thought to be due to an underlying peak of a shikimate specific enzyme. The major peak of CQT activity found in potatoes stored at 0° is absent from those stored at 10° throughout the period after harvest.

Synthesis of [formula omitted] coenzyme a with a partially purified [formula omitted]:CoA ligase from cell suspension cultures of soybean ( Glycine max)

1. 1. A p- coumarate : CoA ligase has been isolated from cell suspension cultures of soybean. Partial purification of the enzyme achieved by MnCl 2 and (NH 4) 2SO 2 precipitation and by gel chromatography on Sephades G-100. 2. 2. Under the conditions of the hydroxamic acid assay, the enzyme has a pH optimum at about pH 8.5 and a temperature optimum at about 30°C. It requires Mg 2+ and ATP at a molar ratio of 1.1. The molecular weight of the enzyme was estimated from the elution volume after chromatography on a Sephadex G-100 column to be about 55 000. 3. 3. Of the various cinnamic acids tested, p- coumarate was the most effective substrate. 4. 4. The partially purified p- coumarate :CoA ligase was utilized for the enzymatic synthesis of p- coumaroyl CoA. Gel chromatography on Sephadex G-10 proved to be a simple and rapid procedure for the isolation and purification of the product.

Solid Phase Synthesis of 4-Hydroxycinnamic Acid and its Derivatives for Potential Use in Combinatorial Chemistry A Novel Route for the Synthesis of 4-Hydroxycinnamoyl Coenzyme A and NMDA Receptor Antagonists

Synthesis of 4-hydroxycinnamic acid 6 and its N-hydroxysuccinimide ester 8 has been carried out in high yield on solid support. Further development allowed the synthesis of 4-hydroxycinnamoyl CoA 1 in excellent overall yield. The utility of solid phase as a method for the synthesis of 4-hydroxycinnamic acid derivatives was demonstrated by the synthesis of a number of compounds including the NMDA receptor antagonists, N-(phenylalkyl)cinnamides 9 and 10.