The relevance of indigenous technology in curriculum 2005/RNCS with special reference to the technology learning area

In this article it is argued that indigenous technology with its long history cannot be ignored and should be as signed a more prominent place in the Technology Learning Area (TLA) within Curriculum 2005/RNCS Grades R – 9.2 The argument is based on the findings of a study in which the relevance of indigenous technology in the TLA curriculum was investigated. The findings not only pointed to the long history of indigenous technology, but also evidenced the continued use of such technology among indigenous people, especially in the rural contexts. The findings in the study are suggestive of an enhanced recognition of indigenous technology in the TLA curriculum. Therefore, informed by the findings, the authors pose certain recommendations pertaining to the TLA curriculum.The article has as secondary purpose creation of awareness of, and sensitivity for, the cultural heritage of indigenous people in South Africa and context-specific community needs which can be recognised and addressed in learning areas such as the TLA.South African Journal of Education Vol. 26 (4) 2006: pp. 501-51

2-Aryl-6,8-dibromo-2,3-dihydroquinazolin-4(1H)-ones as substrates for the synthesis of 2,6,8-triarylquinazolin-4-ones

Direct bromination of 2-aminobenzamide was achieved using N-bromosuccinimide in chloroform-carbon tetrachloride mixture at room temperature for 3 h to afford 2-amino-3,5-dibromobenzamide in high yield and purity. 2-Amino-3,5-dibromobenzamide was, in turn, condensed with benzaldehyde derivatives in the presence of boric acid to afford novel 2-aryl-6,8-dibromo-2,3-dihydroquinazolin-4(1H)-ones. Suzuki-Miyaura cross-coupling of the latter with arylboronic acids yielded the corresponding 2,6,8-triaryl-2,3-dihydroquinazolin-4(1H)-ones. These triarylquinazolin-4(1H)-ones were dehydrogenated using iodine (2 equiv.) in ethanol under reflux to yield the potentially tautomeric 2,6,8-triarylquinazolin-4(3H)-ones. KEY WORDS: 2-Amino-3,5-dibromobenzamide, 2-Aryl-6,8-dibromo-2,3-dihydroquinazolin-4(1H)-ones, Suzuki-Miyaura cross-coupling, 2,6,8-Triaryl-2,3-dihydroquinazolin-4(1H)-ones, 2,6,8-Triarylquinazolin-4(3H)-ones Bull. Chem. Soc. Ethiop. 2014, 28(1), 81-90.   DOI: http://dx.doi.org/10.4314/bcse.v28i1.1

Crystal structure of 1-(6-hydroxy-2-phenylbenzofuran-5-yl)ethan-1-one, C16H12O3

C16H12O3, orthorhombic, Pbca (no. 61), a = 10.7095(3) Å, b = 8.1455(2) Å, c = 27.5374(8) Å, V = 2402.20(11) Å3, Z = 8, Rgt(F) = 0.0369, wRref(F2) = 0.0947, T = 173(2) K

Spectroscopic, X-ray Diffraction and Density Functional Theory Study of Intra- and Intermolecular Hydrogen Bonds in Ortho-(4-tolylsulfonamido)benzamides

The conformations of the title compounds were determined in solution (NMR and UV-Vis spectroscopy) and in the solid state (FT-IR and XRD), complemented with density functional theory (DFT) in the gas phase. The nonequivalence of the amide protons of these compounds due to the hindered rotation of the C(O)–NH2 single bond resulted in two distinct resonances of different chemical shift values in the aromatic region of their 1H-NMR spectra. Intramolecular hydrogen bonding interactions between the carbonyl oxygen and the sulfonamide hydrogen atom were observed in the solution phase and solid state. XRD confirmed the ability of the amide moiety of this class of compounds to function as a hydrogen bond acceptor to form a six-membered hydrogen bonded ring and a donor simultaneously to form intermolecular hydrogen bonded complexes of the type N–H···O=S. The distorted tetrahedral geometry of the sulfur atom resulted in a deviation of the sulfonamide moiety from co-planarity of the anthranilamide scaffold, and this geometry enabled oxygen atoms to form hydrogen bonds in higher dimensions

Synthesis, Evaluation for Cytotoxicity and Molecular Docking Studies of Benzo[c]furan-Chalcones for Potential to Inhibit Tubulin Polymerization and/or EGFR-Tyrosine Kinase Phosphorylation

A series of 2-arylbenzo[c]furan-chalcone hybrids 3a–y have been synthesized and evaluated for antiproliferative effects against the human breast cancer (MCF-7) cell line and for its potential to induce apoptosis and also to inhibit tubulin polymerization and/or epidermal growth factor receptor-tyrosine kinase (EGFR-TK) phosphorylation. Most of these compounds exhibited moderate to significant antigrowth effects in vitro against the MCF-7 cell line when compared to the reference standard actinomycin D. The capabilities of the most cytotoxic benzofuran-chalcone hybrids 3b and 3i, to induce apoptosis, have been evaluated by Annexin V-Cy3 SYTOX staining and caspase-3 activation. The experimental and molecular docking results suggest that the title compounds have the potential to exhibit inhibitory effects against tubulin polymerization and epidermal growth factor receptor tyrosine kinase (EGFR-TK) phosphorylation. The modeled structures of representative compounds displayed hydrophobic interactions as well as hydrogen and/or halogen bonding with the protein residues. These interactions are probably responsible for the observed increased binding affinity for the two receptors and their significant antigrowth effect against the MCF-7 cell line

Synthesis, Conformational Analysis and Evaluation of the 2-aryl-4-(4-bromo-2-hydroxyphenyl)benzo[1,5]thiazepines as Potential α-Glucosidase and/or α-Amylase Inhibitors

The ambident electrophilic character of the 5-bromo-2-hydroxychalcones and the binucleophilic nature of 2-aminothiophenol were exploited to construct the 2-aryl-4-(4-bromo-2-hydroxyphenyl)benzo[1,5]thiazepines. The structures and conformation of these 2-aryl-4-(4-bromo-2-hydroxyphenyl)benzo[1,5]thiazepines were established with the use of spectroscopic techniques complemented with a single crystal X-ray diffraction method. Both 1H-NMR and IR spectroscopic techniques confirmed participation of the hydroxyl group in the intramolecular hydrogen-bonding interaction with a nitrogen atom. SC-XRD confirmed the presence of a six-membered intramolecularly hydrogen-bonded pseudo-aromatic ring, which was corroborated by the DFT method on 2b as a representative example in the gas phase. Compounds 2a (Ar = -C6H5), 2c (Ar = -C6H4(4-Cl)) and 2f (Ar = -C6H4(4-CH(CH3)2) exhibited increased inhibitory activity against α-glucosidase compared to acarbose (IC50 = 7.56 ± 0.42 µM), with IC50 values of 6.70 ± 0.15 µM, 2.69 ± 0.27 µM and 6.54 ± 0.11 µM, respectively. Compound 2f, which exhibited increased activity against α-glucosidase, also exhibited a significant inhibitory effect against α-amylase (IC50 = 9.71 ± 0.50 µM). The results of some computational approaches on aspects such as noncovalent interactions, calculated binding energies for α-glucosidase and α-amylase, ADME (absorption, distribution, metabolism and excretion) and bioavailability properties, gastrointestinal absorption and blood–brain barrier permeability are also presented

Benzofuran–appended 4-aminoquinazoline hybrids as epidermal growth factor receptor tyrosine kinase inhibitors: synthesis, biological evaluation and molecular docking studies

A series of 2-arylbenzo[b]furan–appended 4-aminoquinazoline hybrids were prepared and evaluated for cytotoxicity in vitro against the human lung cancer (A549), colorectal adenocarcinoma (Caco-2), hepatocellular carcinoma (C3A) and cervical cancer (HeLa) cell lines. Compounds 10d and 10j exhibited significant cytotoxicity against the C3A and Caco-2 cell lines and induced apoptosis in these cell lines. Likewise, compounds 10d and 10e exhibited significant inhibitory activity towards epidermal growth factor receptor- tyrosine kinase phosphorylation (IC50 values of 29.3 nM and 31.1 nM, respectively) against Gefitinib (IC50¼33.1 nM). Molecular docking of compounds 10 into EGFR-TK active site suggests that they bind to the region of EGFR like Gefitinib does.http://www.tandfonline.com/loi/ienz20am2019Paraclinical Science