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The resin of the plant Commiphora wildii Merxm. (omumbiri) is traditionally used by Ovahimba women (Kunene, Namibia) as the main ingredient for their perfume. Although essential oil produced from the resin by steam distillation is sold commercially, its detailed chemical composition and biological properties are not known. Knowledge on the potential antimicrobial and antioxidant activities of C. wildii essential oil is desired by perfume, cosmetics, and detergent manufacturers, in order to add value to their products when using the oil as an ingredient. Furthermore, once the oil has been chemically characterized, the concentrations of the bioactive constituents can be monitored for quality‐control purposes. In this study the chemical characterization of the volatile constituents of the essential oil of C. wildii resin was performed using gas chromatography–mass spectrometry (GC–MS) and GC coupled to a flame ionization detector (GC–FID). Fifty compounds were identified in the oil, most of which were terpenoids. The major compounds were α‐pinene (50.0% w/w), heptane (24.0% w/w), and β‐pinene (11.7% w/w). The antimicrobial activity of the oil was determined against Candida albicans, Escherichia coli, Klebsiella pneumaniaea, and Staphylococcus aureus. The best antimicrobial activity was noted against S. aureus, with a minimum inhibitory concentration (MIC) of 8 mg ml–1. Biofilm reduction was below 40%, but inhibition was between 93% (K. pneumaniaea) and 99% (C. albicans). An 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging assay revealed the antioxidant potential of the oil (with a half‐maximal inhibitory concentration, IC50, of 0.2257 mg ml–1).These results may be used by different industries to guide the formulation of their products and also to assess the safety of this oil when used as an ingredient. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) is a versatile and inexpensive semiconductor with a wide direct band gap that has applicability in several scientific and technological fields. In this work, we report the synthesis of ZnO thin films via two simple and low-cost synthesis routes, i.e., the molecular precursor method (MPM) and the sol–gel method, which were deposited successfully on microscope glass substrates. The films were characterized for their structural and optical properties. X-ray diffraction (XRD) characterization showed that the ZnO films were highly c-axis (0 0 2) oriented, which is of interest for piezoelectric applications. The surface roughness derived from atomic force microscopy (AFM) analysis indicates that films prepared via MPM were relatively rough with an average roughness (Ra) of 2.73 nm compared to those prepared via the sol–gel method (Ra = 1.55 nm). Thin films prepared via MPM were more transparent than those prepared via the sol–gel method. The optical band gap of ZnO thin films obtained via the sol–gel method was 3.25 eV, which falls within the range found by other authors. However, there was a broadening of the optical band gap (3.75 eV) in thin films derived from MPM. [ABSTRACT FROM AUTHOR]