Levulinic acid production through two-step acidic and thermal treatment of food waste using dilute hydrochloric acid

Kinetics of formation of 2-imino-4-thiazolidone from S-ethoxycarbonylmethylisothiouronium chloride has been studied in aqueous buffers and dilute hydrochloric acid. The reaction is subject to general base catalysis, the β value being 0.65. Its rate limiting step consists in acid-catalyzed splitting off of ethoxide ion from dipolar tetrahedral intermediate. At pH < 2 formation of this intermediate becomes rate-limiting; rate constant of its formation is 2 . 104 s-1.

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Synthesis of the semi-rigid analogues of prothiadene and dithiadene as potential antidepressant and antihistamine agents: 11-[2-(Dimethylaminomethyl)cyclohexylidene]-6,11-dihydrodibenzo[b,e]thiepins and 4-[2-(dimethylaminomethyl)cyclohexylidene]-4,9-dihydrothieno-[2,3-c]-2-benzothiepins

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19851078 ◽

1985 ◽

Vol 50 (5) ◽

pp. 1078-1088 ◽

Cited By ~ 4

Author(s):

Zdeněk Polívka ◽

Jiří Holubek ◽

Emil Svátek ◽

Jan Metyš ◽

Miroslav Protiva

Keyword(s):

Hydrochloric Acid ◽

Ir Spectrum ◽

Title Compound ◽

Dilute Hydrochloric Acid ◽

Amino Alcohols ◽

Geometric Isomers ◽

Pharmacological Testing

Reaction of dibenzo[b,e]thiepin-11(6H)-one with 2-(dimethylaminomethyl)cyclohexylmagnesium chloride gave a mixture of stereoisomeric amino alcohols IX from which four homogeneous bases (IXa to IXd) were separated by chromatography. Dehydration of these compounds with boiling dilute hydrochloric acid afforded mixtures of racemic geometric isomers of the title compound VII, which were separated by crystallization. To the prevailing less polar base VIIa (E)-configuration was assigned on the basis of the IR spectrum. Using a similar procedure, thieno[2,3-c]-2-benzothiepin-4(9H)-one gave mixture of amino alcohols X from which three homogeneous stereoisomers X-A to X-C were isolated. Their dehydration resulted in both expected racemic geometric isomers VIII-A and VIII-B. Pharmacological testing proved the character of an antidepressant for the semi-rigid analogue of dithiadene VIII.

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Impact of storage duration and micro-aerobic conditions on lactic acid production from food waste

Bioresource Technology ◽

10.1016/j.biortech.2020.124618 ◽

2021 ◽

Vol 323 ◽

pp. 124618

Author(s):

Zengshuai Zhang ◽

Panagiotis Tsapekos ◽

Merlin Alvarado-Morales ◽

Irini Angelidaki

Keyword(s):

Lactic Acid ◽

Food Waste ◽

Acid Production ◽

Lactic Acid Production ◽

Storage Duration ◽

Aerobic Conditions

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An alternative method for assaying cerebrospinal fluid protein in the presence of methotrexate.

Clinical Chemistry ◽

10.1093/clinchem/34.10.2091 ◽

1988 ◽

Vol 34 (10) ◽

pp. 2091-2092 ◽

Cited By ~ 1

Author(s):

L M Kasper ◽

W R Moorehead ◽

T O Oei ◽

M Markanich

Keyword(s):

Cerebrospinal Fluid ◽

Hydrochloric Acid ◽

Trichloroacetic Acid ◽

Dilute Hydrochloric Acid ◽

Constant Amount ◽

Manual Method ◽

Turbidimetric Method ◽

Methotrexate Concentration ◽

Cerebrospinal Fluid Protein ◽

Positive Interference

Abstract Therapeutic concentrations of methotrexate can cause significant positive interference in cerebrospinal fluid (CSF) protein values when assayed in the Du Pont aca. Conversely, our modified turbidimetric method, in which trichloroacetic acid (TCA) plus a sample blank containing dilute hydrochloric acid is used in place of TCA, exhibits little or no interference from methotrexate. This was verified by assaying solutions that contained a constant amount of protein (approximately 430 mg/L) and various amounts of methotrexate (0.0-2.3 x 10(-4) mol/L) by both the Du Pont aca and the manual turbidimetric method. As expected, the aca results showed increasing protein values with increasing methotrexate, whereas the manual method gave results approximating the expected protein value irrespective of the methotrexate concentration.

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