Zum stoffwechsel von aromaten, II. über die muconsäurespaltung von einfachen o-diphenolen / on the metabolism of aromatic compounds, ii * the muconic acid scission of simple o-diphenols

1973 ◽  
Vol 28 (11-12) ◽  
pp. 662-674 ◽  
Author(s):  
Günther Schulz ◽  
Erich Hecker

Abstract The preparation of substituted cis,cis-muconic acids by oxidative ring scission of simple o-di-phenols with peracetic acid is investigated. Scission of pyrocatechol (1) to cis,cis-muconic acid (2) gives optimal yields, if acetic acid or ethyl acetate is used as solvent and if the solution is 15-20% with respect to sulfuric acid free peracetic acid comprising a one molar excess of oxidant. Under similar conditions, 3-tosylamino-pyrocatechol yields with peracetic acid the hitherto unknown α-tosylamino-cis,cis-muconic caid (18). 18 may be converted to α-tosylamino-traras,trans-muconic acid (19) by means of iodine, UV light or heating. From protocatechuic acid (4) under similar conditions not β-carboxy-cis,cis-muconic acid (5) is obtained, but rather β-carboxy-mucono-lactone (6 b, γ-carboxymethyl-β-carboxy-Δα-butenolide). As yet, this lactone has been accessible only from an isomer of β-carboxy-cis,cis-muconic acid, the latter being obtainable by enzymatic scission of protocatechuic acid (4). Steric effects are responsible for both, the formation of the free cis,cis-muconic acids 2 and 18 from pyrocatechol (1) and α-tosylamino-pyrocatechol, and the formation of the γ-lactone 6 b instead of β -carboxy-cis,cis-muconic acid by scission of protocatechuic acid (4). The time course of the reactions shows that - compared to pyrocatechol (1) - a 3-tosylamino-group enhances the peracetic acid scission, whereas a 4-carboxygroup as in 4 slows it down


Author(s):  
Rajni Singh Khureja ◽  
Dinesh Kumar

Chromatography is a powerful analytical method suitable for the separation and quantitative determination of a considerable number of compounds, even from complicated matrix. Thin Layer Chromatography (TLC) has some advantages such as rapidity, sensitivity, easiness, cheapness and this method does not require complex instrumental equipment. In present study, Quercetin 3 -O -α- d- glucuro pyranoside (miquelianin; QG), quercetin 3-O-α-d glucopyranoside (isoquercitrin), quercetin 3-O-α-d-galactopyranoside (hyperoside) and rutin in ethyl acetate fractions from aerial parts of selected Potentilla species on a HPTLC plates using a mixture consisting of ethyl acetate/methyl ethyl ketone/diisopropyl ether/formic acid (3:10:4:1, v/v/v/v). Rutinosides and quercetin were also eluted using methanol-water-acetic acid (50/44/6, v/v/v) and benzene: pyridine: formic acid (36:9:5). The spot visualization was evaluated under UV light at 254 nm and Ferric chloride reagent.



1973 ◽  
Vol 28 (11-12) ◽  
pp. 675-684 ◽  
Author(s):  
G Walter ◽  
E Hecker

Abstract By cleavage of the aromatic ring of 6,7-dihydroxy-tetraline (1) with peracetic acid 1,2-bis-carboxymethylene- cyclohexane (3 a) is obtained. The addition of one mole of water to 3 a leads to 1-hydroxy-1-carboxymethyl-2-carboxymethylene-cyclohexane (4), which is readily converted to the lactone 1-hydroxy-2-carboxymethylene-cyclohexane-γ-lactone-aceticacid-(1) (5). By melting of compound 4 or 5 1,2-dihydroxy-cyclohexane-diaceticacid-1 (1,2) -di-γ-lactone (6) is obtained. 1,2-bis-carboxymethylene-cyclohexane (3 a) shows a molecular asymmetry which is of a type similar as found in atropisomeric compounds. On the basis of conformational considerations it is demonstrated that in the dilactone 6 the cyclohexane ring is stabilized in the boat form. Cleavage of the aromatic A-ring of 2-hydroxy-estradiol- (17β) -acetate (7) with peracetic acid occurs in a manner analogous to that of compound 1, giving rise to 2,3-seco-Δ10(1)-estrenediol- (5ξ, 17β)-diacid-(2,3)-lactone-(2 → 5) -17-acetate (8 a). 8 a is converted to the methylester 9 and further to the corresponding estrone derivative 11 a. Estrone-[16-14C] was incubated with the 15 000 × g supernatant from rat liver homogenate in order to investigate the possibility if scission of the aromatic ring A of estrogens is a step in their katabolism. Substance 11 a was used as a carrier in these studies



2013 ◽  
Vol 781-784 ◽  
pp. 983-987
Author(s):  
De Li Shen ◽  
Xin He ◽  
Wei Guan ◽  
Yu Ping Liu ◽  
Bao Guo Sun

1-(3,3-dimethylcyclohexyl) ethyl acetate was synthesized by the reaction of dihydromycene with acetic acid in the presence of sulfuric acid. The effecting factors including the amount of catalyst, the reaction temperature, the molar ratio of raw materials and the reaction time were investigated. The experimental results showed that the molar raio of the dihydromyrcene to acetic acid to sulfuric acid was 1:3:0.2, the reaction temperature is 60 °C and the reaction time was 6.5 h. The yield reached 45.3%. The structure of product was characterized by gas chromatography, mass spectrometry, infrared spectroscopy and nuclear magnetic resonance. The odor evaluation result indicated that the product had a sweet, woody, floral odor.



OENO One ◽  
2020 ◽  
Vol 54 (2) ◽  
Author(s):  
Debra Inglis ◽  
Jennifer Kelly ◽  
Stephanie Van Dyk ◽  
Lisa Dowling ◽  
Gary Pickering ◽  
...  

Aim: A Saccharomyces uvarum isolate was assessed for its ability to metabolize acetic acid present in juice and during the fermentation of partially dehydrated grapes. The impact on other yeast metabolites was also compared using an S. uvarum isolate and an S. cerevisiae wine yeast. The upper limit of fruit concentration that allowed the S. uvarum isolate to ferment wines to < 5 g/L residual sugar was defined.Methods and results: Cabernet franc grapes were partially dehydrated to three different post-harvest sugar targets (24.5 °Brix, 26.0 °Brix, and 27.5 °Brix) along with non-dehydrated grapes (21.5 °Brix control). Musts from all treatments were vinified with either the S. uvarum isolate CN1, formerly identified as S. bayanus, or S. cerevisiae EC1118. All wines were successfully vinified to less than 5 g/L residual sugar. Fermentation kinetics between the two yeasts were similar for all wines other than 27.5 °Brix, where CN1 took three days longer. During fermentation with CN1, acetic acid peaked on day two, then decreased in concentration, resulting in final wine acetic acid lower than that measured on day two. Wines fermented with EC1118 showed an increase in acetic acid over the time-course of fermentation. Significantly lower wine oxidative compounds (acetic acid, acetaldehyde and ethyl acetate) and higher glycerol resulted in wine produced with CN1 in comparison to EC1118. Both yeasts produced comparable ethanol at each Brix level tested. Further studies showed that CN1 lowered acetic acid seven-fold from 0.48 g/L in juice to 0.07 g/L in wine whereas EC1118 reduced acetic acid to 0.18 g/L.Conclusions: The autochthonous S. uvarum yeast isolate successfully fermented partially dehydrated grapes to < 5 g/L sugar up to 27.5 ºBrix. The consumption rate of acetic acid was faster than its production during fermentation, resulting in low acetic acid, acetaldehyde and ethyl acetate in wine in comparison to a commercial S. cerevisiae yeast while consistently producing higher glycerol.Significance and impact of the study: The S. uvarum yeast isolate can metabolize acetic acid during fermentation to significantly lower acetic acid, ethyl acetate and acetaldehyde in wine. It can also reduce acetic acid by seven-fold from the starting juice to the finished wine, which could have potential application for managing sour rot arising in the vineyard or during the dehydration process in making appassimento-style wines.



2019 ◽  
Vol 10 (4) ◽  
pp. 3626-3635
Author(s):  
Mustafa Q. Alderawy ◽  
Leaqaa A. Alrubaie ◽  
Falah Hassan Sheri ◽  
Basim Jasim Hameed

This work implicates the synthesis of Ibuprofen Acyl Hydrazones and then Converted into the new 1,3,4-Oxadiazoline derivatives that characterized by proton-NMR, FT.IR and elemental microanalysis (CHN) techniques. The intermediates and final compounds were investigated for their physicochemical properties, including the melting point,  color, the yield percent, and thin-layer chromatography performed by using TLC silica gel (60) F254, Merck (Germany), to identify the purity of the products and to know the reaction endpoint. Compounds were monitored by UV light irradiation and the elution by using the following systems:: ethyl acetate: hexane ( 3:7), ethyl acetate, ethanol:dioxan (1:1) and methanol: chloroform (1:9). The study was performed using Swiss albino mice (25-30 g) for the pharmacological activity assessment. Hind edema template of carrageenan used for anti-inflammatory activity assessment and the analgesic activity evaluated using ( writhing induced by acetic acid ) and hot plate method, the results show that all the final compounds present with good anti-inflammatory plus analgesic activities exhibited in the animal model of our experimental work  , we observed that the standard compound and the synthesized derivatives substantially reduced carrageenan-induced edema at all-times (2,4,6,24) hours, all chemically synthesized new compounds actually significantly reduced the number of acetic acid writhings induced in mice and finally in hot plate method there is high increase in the reaction time to painful stimulation  



2006 ◽  
Vol 3 (12) ◽  
pp. 940-942 ◽  
Author(s):  
Shahnaz Perveen ◽  
Tahira Sarfaraz ◽  
Khalid Khan ◽  
Wolfgang Voelter


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shabnam Javed ◽  
Zaid Mahmood ◽  
Khalid Mohammed Khan ◽  
Satyajit D. Sarker ◽  
Arshad Javaid ◽  
...  

AbstractAntifungal activity of Monothecabuxifolia methanolic extract and its various fractions were assessed against Macrophominaphaseolina, a soil-borne fungal pathogen of more than 500 vegetal species as well as rare and emerging opportunistic human pathogen. Different concentrations of methanolic extract (3.125 to 200 mg mL−1) inhibited fungal biomass by 39–45%. Isolated n-hexane, chloroform and ethyl acetate fractions suppressed fungal biomass by 32–52%, 29–50% and 29–35%, respectively. Triterpenes lupeol and lupeol acetate (1, 2) were isolated from n-hexane while betulin, β-sitosterol, β-amyrin, oleanolic acid (3–6) were isolated from chloroform fraction. Vanillic acid, protocatechuic acid, kaempferol and quercetin (7–10) were isolated from the ethyl acetate fraction and identified using various spectroscopic techniques namely mass spectroscopy and NMR. Antifungal activity of different concentrations (0.0312 to 2 mg mL−1) of the isolated compounds was evaluated and compared with the activity of a broad spectrum fungicide mancozeb. Different concentrations of mencozeb reduced fungal biomass by 83–85%. Among the isolated compounds lupeol acetate (2) was found the highest antifungal against M.phaseolina followed by betulin (3), vanillic acid (7), protocatechuic acid (8), β-amyrin (5) and oleanolic acid (6) resulting in 79–81%, 77–79%, 74–79%, 67–72%, 68–71% and 68–71%, respectively. Rest of the compounds also showed considerable antifungal activity and reduced M.phaseolina biomass by 41–64%.



1978 ◽  
Vol 24 (12) ◽  
pp. 2135-2138 ◽  
Author(s):  
K W Jackson

Abstract Each of 65 laboratories analyzed 10 whole-blood samples for erythrocyte protoporphyrin by one or more of several analytical procedures. These procedures were of two types: (a) extraction of protoporphyrin from the erythrocytes into ethyl acetate/acetic acid, re-extraction into hydrochloric acid, and fluorometric measurement; or (b) direct reading in a portable fluorometer (hematofluorometer), with no pretreatment of the blood sample. Interlaboratory correlation was generally poor, especially between laboratories using extraction procedures. Hematofluorometric results intercorrelated better, but they had a low bias as compared to the extraction approach. Nationwide standardization of the test is required to assure satisfactory interlaboratory performance and to identify laboratories whose results are sufficiently accurate to be used for interpretations according to guidelines set forth by the Center for Disease Control for erythrocyte protoporphyrin testing.



1999 ◽  
Vol 23 (8) ◽  
pp. 470-471
Author(s):  
Motoo Tori ◽  
Masakazu Sono ◽  
Keiko Takikawa ◽  
Reiko Matsuda ◽  
Masao Toyota ◽  
...  

On treatment with m-chloroperbenzoic acid, dihydroeugenol methyl ether and marchantin A trimethyl ether afford muconic acid ester derivatives by oxidation of the aromatic ring as well as hydroxylated derivatives; the m-chlorobenzoate of the dihydroeugenol derivative is also observed for the former.



Author(s):  
Xue Yang ◽  
Yongling Liu ◽  
Tao Chen ◽  
Nana Wang ◽  
Hongmei Li ◽  
...  

Abstract Separation of natural compounds directly from the crude extract is a challenging work for traditional column chromatography. In the present study, an efficient method for separation of three main compounds from the crude extract of Dracocephalum tanguticum has been successfully established by high-speed counter-current chromatography (HSCCC). The crude extract was directly introduced into HSCCC by using dimethyl sulfoxide as cosolvent. Ethyl acetate/n-butyl alcohol/0.3% glacial acetic acid (4: 1: 5, v/v) system was used and three target compounds with purity higher than 80% were obtained. Preparative HPLC was used for further purification and three target compounds with purity higher than 98% were obtained. The compounds were identified as chlorogenic acid, pedaliin and pedaliin-6″-acetate.



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