• Archives of Pharmacal Research
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• 제17권1호
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• pp.54-55
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• 1994

• Archives of Pharmacal Research
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• 제17권1호
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• pp.48-50
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• 1994

Three p-coumaroylamino acids (p-CAAs) were isolated from the yeast-elicited Ephedra distachya cultures by consecutive purification using XAD_2, silicagel and RP-HPLC. Retention times on HPLC as well as their UV, IR, NMR and MS spectral data indicated that the yeast-induced p-CAAs wre p-coumaroyl--D-valine, p-coumaroyl-D-serine and p-coumarouyl-D-threonine, respectively. The structures of p-CAAs were confirmed by the comparison of their physico-chemical properties 3with those of synthetic ones. They were isolated and identified for the first time from natural products and supposed to be accumulated as phytoalexins of Ephedra.

• Archives of Pharmacal Research
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• 제19권3호
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• pp.219-222
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• 1996

Ephedra olistachya cultures have been known to accumulate $rho-coumaroylamino$ acids by elicitor treatment. Based on their chemical structures, the biosynthetic pathway of$rho-coumaroylamino$acids was postulated and phenylalanine ammonia-lyase (PAL), cinnamic acid 4-hydroxylase (4-CH) and p-coumaroyl CoA: D-Ala p-coumaroyltransferase ($rho-CT$) were supposed to be involved in the pathway. The time course inductions of these enzymes were investigated after treatment of yeast extract, yeast-derived mannan glycopeptide and D-Ala. They were detectable at only 4 hours and reached to their maximum level at 9 hours after onset of elicitor treatment. The activities of PAL and 4-CH were almost disappeared within 24 hours, however, that of $rho-CT$was remained up to 48 hours irrespective of the kind of elicitors. $rho-CT$ showed substrate specificity to D-Ala at crude enzyme extract level.

• Archives of Pharmacal Research
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• 제18권5호
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• pp.336-339
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• 1995

Ephedra distachya cultures have been known to accumulate two major $\rho-coumaroylamino$ acids (p-coumaroylgicine and $\rho-coumaroylamino$ -D-alanine) by D-Ala treament. When D-Ala was added together with serial concentrations of yeast-derived elicitor, the accumulation of $\rho-coumaroylamino$ -D-Ala $(\rho-CDA)$ was geatly increased in an additive manner. In feeding experiments, $[1-^14C]$-D-Ala was incorporated into $\rho-CDA$at a rate of 2.2% or 2.3% of added radioactivity, indicating that exogenous D-Ala served as a precursor of the conjugate. $[1-^14C]$-L-Ala wasalso incorporated into p-CDA (0.23%) in the elicitor treated cultures. This fact suggested that at least a part of $(\rho-CDA)$ was produced from active conversion of L-Ala by the elecitation. In order to investigate a possible role of D-Ala as an elicitor of $\rpo-coumaroylamino$ acids $(\rpo-CAA)$, cold D-Ala was added together with labeled L-Ala. Although L-Ala seemed to be incorporated into $\rho-CDA$ by this treatment, the incorporation ratio was too small (0.054%) to draw a clear conclusion. However, the amount of $\rpo-coumaroylglycine$, which did not use D-Ala as a substrate, was also sightly increased by D-Ala treatment irrespective of the presence of elicitor, suggesting that exogenous D-Ala might act as an elicitor of$\rpo-CAA$ as well as a precusor substrate of $\rho-CDA$.

• Archives of Pharmacal Research
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• 제17권1호
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• pp.26-30
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• 1994

Some ammonium oxalate soluble pectic fragments prepared from cultured cell wall of Ephycla distrahya elicited the accumulation of p-coumarocylamino acids (p-CAA) in E. distachya cultures while water soluble and alkali soluble fractions had no activity. Partial purification of the pectic fragments fraction using DEAE-cellulose chromatography afforded two active fractions (PS-I and PS-II) which were composed of mainly uronic acids (98-99 w/w %). They elicited the accumulation of p-CAA in an amount of 52-60 nmol per gram fresh weight of cultures. The acidic sugar compositions of PS-I and PS-II were found to be galacturonic acid and glucuronic acid by TLC analysis. They were supposed to act as endogenous elicitors of p-CAA accumulation. In order to investigate the effect of ethylene on p-CAA accumulation, Ethrel, which is known as ethylene generator, and ACC(1-aminocyclopropane-1-carboxylic acid), a direct precusor of ethylene biosynthesis, were added to the culture. However, they did not glycopeptide elicitor [(Con A-II)], either. Consequently, no relationships between ethylene and p-CAA accumulation were recognized. Several tentative elicitors were teted for their activity. Commercial yeast glucan, $CuCl_2$, laminarin and laminariheptaose had slight activity whereas ${\alpha}$-methylmannopyranoside and commercial yeast mannan had no elicitor activity. ${\alpha}$-methylmannopyranoside which has been known as a tentative inhibitor of glucan elicitor in Glycine max did not affect on the elicitor activity of Con A-II.