Kalulu Taba | University Of Kinshasa (original) (raw)

Papers by Kalulu Taba

Chemischer Informationsdienst, May 27, 1980

Comptes Rendus Chimie, Jul 1, 2016

Contribution a l' etude de la d esinfection de l'eau par photosensibilisation avec des extraits d... more Contribution a l' etude de la d esinfection de l'eau par photosensibilisation avec des extraits de plantes Contribution to the study of water disinfection by photosensitization with plant extracts

International journal of chemical science, Nov 1, 2019

A commercially available niobia hydrate, which is an industrial intermediate in the production of... more A commercially available niobia hydrate, which is an industrial intermediate in the production of pure niobia, was prepared, characterized, and tested as a solid acid catalyst. The gas phase esterification of acetic acid with ethanol was used as a simple model reaction for the determination of the acidity and the catalytic activity. The kinetic evaluation of the experiments includes an estimation of mass transport limitation as well as a mechanistic study.

ChemInform, Feb 6, 1990

ChemInform Abstract Diphenylchlorophosphine and diethylchlorophosphite (I) react with acetylaceto... more ChemInform Abstract Diphenylchlorophosphine and diethylchlorophosphite (I) react with acetylacetone (II) to generate intermediate phosphine enolates (III) which are quenched with the O-diethylboryl derivatives (IV) and then oxidized with H2O2 to give the diphenylphosphinates and diethylphosphates (V). This new approach constitutes an efficient one-pot phosphorylation method for hydroxyl compounds.

Chemischer Informationsdienst, Dec 6, 1983

ChemInform Abstract In order to avoid acid catalysts for bifunctional protection, the protection ... more ChemInform Abstract In order to avoid acid catalysts for bifunctional protection, the protection of carbohydrates by O-ethylboranediylation is investigated. Reaction of the sucrose derivative (I) with ethylboron reagents, e.g. (II), gives mixtures of the products (III) and (IV). Yields and product distributions, which depend on the boron reagent, the molar ratios, the solvent and the temp., are tabulated. The mixture(III)/(IV) is converted to the hexaacetate (VI) and the tetraacetate (VIIa). The derivatives (VIIb) and (VIIc) can be obtained from the sucrose (VIII), intermediate in the reaction (IV) → (VIIa). The results show that the method described above avoids degradation of the sucrose molecule.

ChemInform, Aug 21, 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Springer eBooks, Oct 15, 2007

Low soil fertility and crop productivity is a major problem facing all smallholder farmers in Dem... more Low soil fertility and crop productivity is a major problem facing all smallholder farmers in Democratic Republic of Congo. The low soil fertility is caused by continuous cropping without addition of adequate external soil fertility inputs. The use of inorganic fertilizers to alleviate this constraint is limited mainly by its high costs, untimely availability and low producer prices. A pot and a field experiment were initiated from 2001 to 2003 to investigate the effect of combining inorganics and organic with leafy biomass types (Tithonia diversifolia and Ricinus communis) on tomato yields in soil where this crop is sown during the dry and rain seasons using arenosols with soil pH 4.8 to 5.2 and low available P (1.3-2.6 mg P/kg soil)

Chemischer Informationsdienst, Jul 14, 1981

Aus Arsabenzol (I) erhält man bei der Acetylierung nach Friedel‐Crafts die isomeren Acetylverbind... more Aus Arsabenzol (I) erhält man bei der Acetylierung nach Friedel‐Crafts die isomeren Acetylverbindungen (IIa) und (IIIa), bei der Nitrierung die entsprechenden Nitro‐arsabenzole (IIb) und (IIIb), die zu den entsprechenden Aminen (IIc) und (IIIc) reduziert werden.

Chemischer Informationsdienst, Dec 23, 1986

ChemInform, Aug 25, 1987

Chemischer Informationsdienst, Apr 24, 1984

European Journal of Water Quality, 2008

peer reviewedaudience: researcher, professional, studentSolar water disinfection study using plan... more peer reviewedaudience: researcher, professional, studentSolar water disinfection study using plants extracts, in tryptophan media (1%), has revealed a photodynamic activity of Cassia alata, Cassia occidentalis, Carica papaya, Phyllantus niruri and Coleus kilimandschari aqueous extracts. Aqueous extracts of Lantana camara, Cymbopogon citratus and Hibiscus rosa-sinensis produce a bactericidal effect. Water disinfection by alkaloid extracts of Cassia alata, Cassia occidentalis, Carica papaya, Phyllantus niruri and Coleus kilimandschari shows a bactericidal effect. On the other hand, unalkaloid extracts of the same compounds especially present a photodynamic activity. The photodynamic activity of unalkaloid extract is due to the presence of quinones and anthraquinones which generate singlet oxygen.The singlet oxygen generated attacks and damages the microorganisms contained in polluted water. The necessary sunlight time for coliform inactivation and other germs is one hour for 2 ml of extracts/liter of polluted water

Journal of applied life sciences international, Apr 24, 2020

The aim of this study was to investigate parameters affecting biogas production from cassava peel... more The aim of this study was to investigate parameters affecting biogas production from cassava peels by using fractional factorial design method. The parameters studied were initial pH, organic loading rate, particle size and co-substrate type. Eight biodigesters (TH1, TH2, TH3, TH4, TH5, TH6, TH7 and TH8) in duplicate were performed to produce biogas from cassava peels. The experimental results showed that organic loading rate (X2), particle size (X3) and co-substrate (X4) have significant effect on the yield of biogas. The full mathematical model developed includes two main Original Research Article

International Research Journal of Pure and Applied Chemistry, 2020

The present study reports the preparation of four solid acids (CS, CPS, CAS and CPAS) from cassav... more The present study reports the preparation of four solid acids (CS, CPS, CAS and CPAS) from cassava peels and investigates their catalytic activities in the esterification of free fatty acid (FFA) in palm Kernel oil (PKO). The activated carbon obtained from carbonization was directly sulfonated with sulfuric acid (CS) or treated first with phosphoric acid before sulfonation (CPS). Another part of activated carbon was pyrolyzed at 800°C and treated as in the two previous cases (CAS and CPAS). The FTIR spectra of CS, CPS, CAS and CPAS showed characteristic absorption peaks of functional groups such as O=S=O (1031 cm-1), OH (3849 and 3405 cm-1), C=C (1555-1574 cm-1), S=O (1042,1031 cm-1) and P=O (754 cm-1), which confirm the presence of sulfonic, carboxylic and phosphoric groups on the surface of the activated carbon acids prepared. The total acid densities of the catalysts range from 2.26 to 3.49 mmol/g whereas the -SO3H densities were from 0.92 to 2.20 mmol/g. Amongthe four catalysts ...

Chemischer Informationsdienst, 1984

ChemInform Abstract Kohlenhydrate (I) werden nachÜberführung mit Triethylboran in Diethylalkoxybo... more ChemInform Abstract Kohlenhydrate (I) werden nachÜberführung mit Triethylboran in Diethylalkoxyborane (II) mit dem Tributylstannylenolat (III) selektiv in die Zinn-Derivate (IV) umgewandelt, die auf direktem Wege nur schlecht zugänglich sind.

The plastics are polluting the environment and affect the humans. 94% of the plastics are thermop... more The plastics are polluting the environment and affect the humans. 94% of the plastics are thermoplastics or recyclable materials such as PET (polyethylene terephthalate) and PVC (Polyvinyl Chloride). The purpose of bioplastic production is an alternative for synthetic plastic. The starch is a natural biopolymer. Cassava starch is used for bioplastic production in many ways.

International journal of engineering & technology, Jun 7, 2022

GSC biological and pharmaceutical sciences, Dec 30, 2022

In the face of the emergence of bacteria resistant to common antibacterials and excessive accumul... more In the face of the emergence of bacteria resistant to common antibacterials and excessive accumulation of free radicals that can cause several diseases, it is important to look for new antibacterials and antioxidants. The goal of this work was to synthesize three chalcones derivatives by the Claisen-Schmidt condensation and then evaluate their antibacterial and antioxidant activities. The structure of these 3 compounds has been determined by NMR (1 H and 13 C) spectroscopy. The in vitro antibacterial activity assessed by Microdilution methods, was tested against Gram positive bacteria (Staphylococcus aureus and Bacillus subtilis) and gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa) at different concentrations ranging from 7.82 to 1000 µg/mL. All three synthesized chalcones showed good antibacterial activity against gram positive and negative bacteria used with a range of MIC ranging from 62.50 to 1000 µg/mL. However, the (E)-3-(3, 4-dimethoxyphenyl)-1-(2-hydroxyphenyl) prop-2-en-1-one showed excellent activity against Bacillus subtilis with Minimum Inhibitory Concentration (MIC) of 62.5 µg/mL which is similar to that of the standard (Ampicillin) against the same bacterial strain. Antioxidant activity evaluated using 2,2-diphenyl2-picryl-hydrazyle (DPPH) revealed that all the synthesized chalcones showed an antioxidant activity with IC50 values of 8.22; 6.89 and 3.39 µg/mL for (E)-1-(2-hydroxyphenyl)-3-(4-hydroxyphenyl) prop-2-en-1-one, (E)-1-(2-hydroxyphenyl)-3-(4methoxyphenyl) prop-2-en-1-one and (E)-3-(3, 4-dimethoxyphenyl)-1-(2-hydroxyphenyl) prop-2-en-1-one, respectively. These values are closer to that of ascorbic acid used as a standard. The results suggest that the synthesized chalcones, especially the (E)-3-(3, 4-dimethoxyphenyl)-1-(2-hydroxyphenyl) prop-2-en-1-one could be used, after in vivo and clinical tests, like antibacterial and antioxidant supplement or even replace current drug therapies.