Species of the Combretaceae have an impressive history of traditional use for the treatment of microbial infections. Ethnopharmacological studies have shown that both crude extracts and isolated compounds possess antimicrobial properties. While previous reviews were limited to individual species or genera, this study provides data to elucidate patterns, trends, and progress in confirming the antimicrobial activities of the family Combretaceae from 1976 to 2022. This review also explores collaborations and contributions of authors and countries to identify opportunities for further research. Data from the Scopus database were filtered and analyzed using VOSviewer, an open-source network visualization software, to identify publication volumes, research trends, author contributions, and research progress during the review period. Term analysis of the 677 articles retrieved from the database revealed five distinct clusters. The first cluster focused on the antimicrobial activities of crude extracts against a variety of pathogens associated with oral infections, gastrointestinal tract infections, urinary tract infections, and multidrug-resistant pathogens. The second cluster identified compounds with antimicrobial activities. The third cluster focused on biofilm formation and anti-QS, with an emphasis on oral infections. The fourth cluster describes the use of nanoparticle-synthesized extracts. The major antimicrobial constituents in the family are tannins (hydrolysable and condensed) and triterpenoids. However, there are challenges associated with the bio-availability and pharmacokinetics of these molecules in humans. Therefore, research on the external applications of plant extracts and isolated compounds from the Combretaceae family is recommended. Furthermore, the use of several species in different regions for treating infections, and the similarities in their phytochemistry, reflect the efficacy of these species in treating microbial infections. Therefore, species belonging to Combretaceae are worthy of further investigation for their potential against antibiotic-resistant pathogens.

Artemisia afra Jacq. ex Willd. (Asteraceae), referred to as African wormwood, is an aromatic, perennial shrub that can grow up to 2 m in height. The finely divided leaves have a silver-green colour due to the presence of fine hairs. The plant is found in the mountainous regions of Africa, as far north as Ethiopia. In southern Africa, it occurs in Namibia, Zimbabwe, Swaziland (Eswatini), Lesotho and South Africa, where it is widespread and abundant. The plant is mainly used in the form of decoctions, infusions, poultices, or as an inhalant, to treat a range of ailments including coughs, colds, headaches, chills, colic, asthma, malaria, diabetes, influenza, convulsions, fever and rheumatism. In vitro and in vivo studies of the plant have indicated that it has promising antimicrobial, anti-oxidant, anti-inflammatory, antidiabetic and antimycobacterial activities. The essential oil composition has been reported to be highly variable, and several (artemisia ketone, 1,8-cineole, α-thujone, β-thujone, camphor and myrcenone) chemotypes have been described. Chemical profiles of A. afra essential oils, obtained by hydro-distillation were obtained using semi-automated high-performance thin-layer chromatography (HPTLC) and gas chromatography coupled to mass spectroscopy (GC–MS). The HPTLC plate, viewed under white light after derivatisation with anisaldehyde, confirms variation in the composition of the oils. The use of UPLC–MS for non-volatile qualitative analysis enabled the identification of scopolin, rutin, scopoletin, chrysoeriol, 3,5-di-O-caffeoylquinic acid and acacetin in the acetone:methanol extracts. The use of HPTLC indicated considerable variation in the phenolic compound composition of samples from different populations.

Helichrysum petiolare Hilliard & B.L.Burtt (Asteraceae), also known as ‘African incense’, ‘kooigoed’, and ‘imphepho’, is a perennial plant of 0.3–1 m in height, with round aromatic leaves that are tightly matted with hairs. The shrub occurs in the Western and Eastern Cape provinces of South Africa. The plant is burnt as incense to invoke the ancestors during cultural rites. Medicinal uses include the treatment of coughs, colds, catarrh, headache, fever, menstrual disorders and urinary tract infections. The species is used interchangeably with Helichrysum odoratissimum. Although H. petiolare is widely traded and used traditionally, there are no commercial products available. The phytochemistry of the plant remains largely unexplored. This monograph is a summary of the available literature on the plant. Semi-automated high-performance thin-layer chromatography (HPTLC) and ultra-performance liquid chromatography coupled to mass spectrometry (UPLC–MS) were used to obtain the chemical profiles of H. petiolare. Mid-infrared (MIR) spectroscopy analysis was used to establish a characteristic spectrum for the powdered material. A marker compound, which was present in all the H. petiolare samples, was identified as 4,5-dicaffeoylquinic acid and is visible on the HPTLC plates and on the UPLC–MS chromatograms.

Terminalia sericea Burch. ex DC. (Combretaceae), commonly referred to as 'silver cluster-leaf', is a small-to-medium-sized shrub or brush tree of 3–16 m in height, although some trees reach a height of 23 m. The species is naturally distributed in the Limpopo, Mpumalanga, North West, Gauteng, KwaZulu Natal and Northern Cape provinces of South Africa. The bark is grey to pale brown and coarsely fissured, while the leaves are blueish-green in colour, with silvery hairs. The cream-coloured flowers emit an unpleasant odour. The plant is a very popular traditional medicine for the treatment of coughs, skin infections, diabetes, diarrhoea, gonorrhoea, menorrhagia and infertility. This monograph is a record of the ethnobotany, phytochemistry, in vitro and in vivo biological and pharmacological properties of the plant, as well as its toxicity profile. Chemical profiling of the non-volatile constituents was carried out using semi-automated high-performance thin-layer chromatography (HPTLC) and ultra-performance liquid chromatography coupled to mass spectrometry and photodiode array detection (UPLC–MS–PDA). A characteristic mid-infrared spectrum was obtained for the powdered root. Resveratrol-3-O-β-rutinoside, sericic acid and sericoside were identified as the major constituents and marker compounds of the root based on both HPTLC and UPLC–MS analyses.

Helichrysum odoratissimum (L.) Sweet (Asteraceae), also known as ‘African incense’, ‘kooigoed’ and ‘imphepho’ is a perennial herb that reaches 1.75 m in height. The plant has a silver appearance and bears pale golden-yellow flowers. It is abundant throughout southern Africa, where it is one of the most popular traditional remedies. It occurs in six provinces of South Africa, from sea level to altitudes of over 3000 m above sea level. Helichrysum odoratissimum is of great cultural significance in South Africa. The aerial parts are burnt to rebuke evil spirits, or inhaled as a steam to attract good luck. Medicinal uses include the treatment of heart diseases, relief of chest pains, and for calming. Furthermore, H. odoratissimum is used to treat coughs, fever and urinary tract infections, suggesting that it possesses antimicrobial properties. Helichrysum odoratissimum is one of the most frequently harvested and traded plants in South Africa, with potential for commercialisation. The chemical profiles of individual plants harvested from different locations were obtained using semi-automated high-performance thin-layer chromatography (HPTLC) and ultra-performance liquid chromatography coupled to mass spectrometry (UPLC–MS). Mid-infrared (MIR) spectroscopy analysis was performed to obtain a characteristic spectrum. 4,5-Dicaffeoylquinic acid was isolated as a marker compound, and its presence confirmed in samples through HPTLC and UPLC–MS analysis.

There is a growing concern of the ecological effect of the direct discharge of wastewater effluent into the water bodies (stream, lakes, dams, etc). Wastewater effluent consist of various pollutants both chemical and biological that may negatively impact the quality of the receiving body. Majority of the identified pollutants are endocrine disruptors, reported to potentially induce the development of various health issues including feminization, cell mutation and neurological disorder. The aim of this study was to evaluate the toxicity of the effluent discharged into the Blesbokspruit and that of the receiving body using the zebrafish embryo and the calorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazolium reduction, MTT. The wastewater effluent and the river samples demonstrated acute toxicity towards the zebrafish embryo assays with their teratogenicity indicated by yolk sac malformation, pericardial oedema, hatching abnormalities, tail deformation, chorion deformation and craniofacial malformation. The %LC50 range from 8.97 to 25.6. The formation of various malformation is indicative of the endocrine disruption. The exposure of normal (Vero) and cancer (HeLa and MCF-7) cells to the effluent and river water indicated their cytotoxicity. The LC50 range was 16.5 – 49.2% for Vero, 52.8 – 86.5% HeLa and 10.8 – 47.3% MCF-7 with cell viability <50% in all cells. Although the samples were toxic towards the cancer cells, mainly MCF-7, they were toxic towards the normal cell. The direct discharge of the wastewater effluent into the Blesbokspruit negatively impacts its quality, the water from this water demonstrated toxicity towards the zebrafish embryos and the Vero cells.

Cyclopia genistoides (L.) R.Br (Fabaceae), commonly referred to as ‘honeybush tea’, is one of 23 Cyclopia species endemic to South Africa. The natural habitat of this small fynbos shrub is restricted to very small areas in the Western Cape Province, spanning from the West Coast to Mossel Bay on the Southern Cape coast. Honeybush tea is mostly enjoyed as a hot beverage of the ‘fermented’ product. ‘Fermentation’ refers to the high-temperature oxidation process essential for the development of the sought-after sweet, floral aroma and flavour, and brown colour. Traditional medicinal uses include use as an expectorant in pulmonary tuberculosis, chronic catarrh, and a restorative with astringent properties. ‘Caspa Cyclopia Tea’ was the first branded product to appear on the market in the 1960s. The development of a formal industry in the 1990s gave rise to different branded honeybush products, and the production of extracts. Several studies investigating the anti-oxidant, anticancer, antidiabetic, anti-obesity, antimicrobial, anti-inflammatory and immunomodulating activities have been documented for different Cyclopia species (fermented and unfermented). Quality control protocols based on the chromatographic profiling of methanol extracts were developed using a semi-automated high-performance thin-layer chromatography (HPTLC) system. The HPTLC profiles of the extracts viewed under 366 nm radiation after derivatisation with vanillin-sulphuric acid reagent revealed the presence of mangiferin, isomangiferin and hesperidin in all samples, compounds ubiquitous to all Cyclopia species. Their presence in the methanol extracts was confirmed by ultra-performance liquid chromatography coupled to mass spectrometry (UPLC–MS).

Carvone and spearmint essential oil vapours are suitable candidates for the control of citrus postharvest pathogens due to their strong antifungal activity. However, the high volatility of essential oils remains a hurdle that needs to be overcome before it can be applied as an alternative fungicide. This work investigates the antifungal activity of 20 and 30 wt-% spearmint essential oil or carvone, incorporated into ethylene–vinyl acetate (EVA) and linear low-density polyethylene (LLDPE) strands postharvest pathogens affecting kumquats. Following the melt-extrusion process, an average yield of 16–29 % and 15–28 % of the total carvone and spearmint essential oil, respectively, was determined in the polymer strands. Morphological studies using scanning electron microscopy (SEM) revealed the presence of microporous structures in the internal structure of the strands. The membrane-like skin that covers the polymer strand was also confirmed by SEM. Variations in the release rates were observed between carvone and spearmint essential oils, which was attributed to the difference in the vapour pressure of the neat essential oils. Furthermore, in this study, the results demonstrated that the diffusion exponent ‘n’ of the Korsmeyer–Peppas, Weibull and Log-logistic models exceeded 1.0. In most cases, the Super Case II mechanism was observed. In the case of the Mapossa model, as k2 was ˃> 1, it implies that the outer skin-like membrane covering the polymer strand fully controlled the carvone release. The application of the essential oil-loaded polymer strands resulted in a significant reduction in deterioration, caused by citrus postharvest pathogens, of kumquats kept at room temperature for 21 days. This study indicates that the incorporation of spearmint essential oil or carvone into LLDPE or EVA polymer strands promoted the preservation of kumquat over a 21-day period.

Hypoxis hemerocallidea Fisch., C.A.Mey. & Avé-Lall. (Hypoxidaceae) is known as African potato. It is described as an herbaceous perennial plant, with a scythe-like appearance and bright yellow star-shaped flowers. It occurs in tropical and southern Africa, growing abundantly throughout the summer rainfall areas of South Africa. The rootstock is traditionally used for the treatment of a wide range of conditions, including urinary tract infections, common cold, influenza, nausea, heart weakness, infertility, depression and anxiety, but is best known for the treatment of benign prostate hypertrophy and HIV. A range of products including creams, capsules, tinctures and tonics prepared from H. hemerocallidea are available commercially. In vitro and in vivo investigations have proven anti-oxidant, anti-inflammatory, antidiabetic, anticonvulsant, antibacterial and CD4-count reduction potential for African potato and/or its metabolites. Semi-automated high-performance thin-layer chromatography (HPTLC) and ultra-performance liquid chromatography hyphenated with mass spectrometry (UPLC–MS) have been used to determine the chemical profiles of H. hemerocallidea. The chemical marker compound hypoxoside (Rf 0.32) was identified by HPTLC and UPLC–MS. In addition, hemerocalloside (Rt = 3.50 min; m/z 519) and geraniol glycoside (Rt = 7.60 min; m/z 447) were also identified as marker compounds in the methanol extract of H. hemerocallidea.

Lippia javanica (Burm.f.) Spreng (Verbenaceae), commonly known as 'fever tea', is an erect, highly aromatic, woody shrub that grows up to 2 m in height, with hairy leaves that are thinly veined. The plant is native to central, eastern and southern Africa, and occurs in Botswana, Malawi, Swaziland (Eswatini), Mozambique, Tanzania, Zambia and Kenya. It is traditionally used as a decoction or infusion to treat respiratory and gastro-intestinal conditions, as well as skin infections, and has spiritual significance. Commercially, essential oil of the plant is used as a mosquito repellent and in household fragrances, and dried aerial parts are sold as herbal tea. The in vitro and in vivo pharmacological activities (anti-oxidant, antimalarial and antimicrobial) of the plant extracts and essential oils have been studied extensively, and some of the results confirm the traditional use. The essential oil composition is highly variable and several chemotypes, characterised by carvone, piperitenone, ipsenone and myrcenone, have been identified. Phytochemicals present in the non-volatile fraction of the plant include iridoid glycosides, triterpenoids, flavones and various phenolic compounds. Chromatographic techniques, namely semi-automated high-performance thin-layer chromatography (HPTLC), ultra-performance liquid chromatography, coupled to mass spectrometry (UPLC–MS), and gas chromatography, coupled to mass spectrometry (GC–MS), were used to establish chemical profiles of the solvent extracts and essential oils of L. javanica. The analysis of the oils, using HPTLC and GC–MS/FID, confirmed different chemotypes, whilst HPTLC enabled the identification of theveside and verbascoside. Isoverbascoside, diosmetin and apigenin were further detected using UPLC analysis.

High performance thin layer chromatography (HPTLC) has been widely implemented for the rapid chemical fingerprinting of medicinal plant extracts for identification and authentication purposes. Despite herbal teas of rooibos (Aspalathus linearis) and honeybush (Cyclopia spp.) being important local and export products of South Africa, characteristic and well-defined HPTLC chemical profiles for the species that could assist in identification and authentication, have not been established and reported. ‘Fermentation’, an oxidation processing step for flavour and colour development, is known to alter the chemical composition of these plant materials, with consequences for their therapeutic properties. In this study, HPTLC fingerprints were established that characterise these herbal teas in terms of phenolic constituents linked to their health benefits. Selected flavonoids present in rooibos were clearly distinguished from the extract matrix, and the marked depletion of aspalathin in the fermented samples was demonstrated. The analytical method developed for honeybush achieved partial separation of the major xanthone constituents, mangiferin and isomangiferin. Lower relative concentrations of the regio-isomers were evident in the fermented samples of C. genistoides compared to their unfermented counterparts. The chemical profile of fermented C. subternata was markedly different to those of C. genistoides and C. intermedia in that mangiferin/isomangiferin was detected in only one of the five samples of C. subternata. Cost-effective HPTLC methods are herein described that can be used for the rapid analysis of multiple samples in industrial environments, as a tool for quality control, in particular for the identification of these herbal teas of South African origin.

According to the World Health Organisation, “A Pharmacopoeiaʼs core mission is to protect public health by making available standards to help ensure the quality of medicines” [1]. There are several known documents containing herbal remedies, such as those that date back to ancient Egypt more than 3000 years ago. However, De Materia Medica dating from the 1st century CE in Greece and Rome is arguably perhaps the first example of a “Pharmacopoeia”. Despite the tremendous botanical diversity and widespread use of African Traditional Medicines in South Africa, a compilation of herbal monographs in the form of a Pharmacopoeia acutely focused on the South African flora is lacking. To address this void, we have aimed to collate existing, and generate new data to compile 25 species monographs for botanicals that are currently commercialised or earmarked for commercialisation. In this paper, we discuss the complex workflow required to gain a better understanding of the safety, quality and efficacy of medicinal plants, since these aspects are crucial in monograph development. Several examples will be discussed to illustrate the integration of classic and modern techniques to develop detailed monographs. Ongoing research to document pharmacological activity in an evidence-based ethnopharmacology approach will be presented. Through this project, we aim to provide valuable information for academic research institutions, industrial manufacturers of herbal products, as well as national and international policymakers and regulators, to ensure that products of a desired quality reach the consumer.

Cannabigerol (CBG) is one of the major phytocannabinoids present in Cannabis sativa L. but is presumed to be an artefact or degradation product of cannabigerolic acid (CBGA), the principal precursor of several cannabinoids. The growing interest in CBG has been attributed to its non-psychotropic properties, low cannabinoid receptor potency and relative abundance in some commercial Cannabis varieties. A broad pharmacological profile has been described, where CBG is reported to exhibit anti-inflammatory, anticancer, anti-oxidant, antimicrobial, neuroprotective and appetite-enhancing properties, among others. Previous reviews on CBG have been limited to either the pharmacological potential of the molecule, with little detail on the chemistry, or to advances in the analytical tools used to explore CBG content in a wide range of biological samples. The current review seeks to highlight the chemistry, biosynthesis, pharmacology and safety aspects of the molecule. Additionally, we provide new insights into, and critical evaluation of, the pharmacological interactions of CBG via different receptor sites based on in silico predictions, using retrieved 3D structures of alpha-2 adrenergic receptors from the Protein Data Bank (PDB). For the first time, a bibliometric overview of the literature was performed, and with the aid of scientometric tools it was possible to present a visual overview of the research trends over the years, assess research performance of countries, and delineate the research output trajectory, hotspots and voids. In-depth analysis of the published literature revealed that clinical trials establishing the efficacy, safety and side-effects of CBG therapy in specific disease conditions are limited, as well as industry-friendly quality control procedures for CBG-enriched cannabis extracts.

Introduction Many species within Combretaceae are traditionally used for the treatment of bacterial infections. The similarity in chemistry and antimicrobial activities within the family pose a challenge in selecting suitable species for herbal drug development. Objective This study aimed at rapidly identifying antimicrobial compounds using bioautography-guided high-performance thin-layer chromatography coupled with mass spectrometry (HPTLC-MS). Methods Hierarchical cluster analysis of ultra-performance liquid chromatography-mass spectrometry data from the methanol extracts of 77 samples, representing four genera within Combretaceae, was carried out. Based on groupings on the dendrogram, 15 samples were selected for bioautography analysis against four pathogens (Staphylococcus aureus, Bacillus cereus, Escherichia coli and Salmonella typhimurium). Active compounds were identified using HPTLC-MS analysis of bands corresponding to the inhibition zones. Results Bioautography revealed 15 inhibition zones against the four pathogens, with the most prominent present for Combretum imberbe. Analysis of the active bands, using HPTLC-MS indicated that flavonoids, triterpenoids and combretastatin B5 contributed to the antibacterial activity. The compounds corresponding to molecular ions m/z 471 (Combretum imberbe) and 499 (Combretum elaeagnoides) inhibited all four pathogens, and were identified as imberbic acid and jessic acid, respectively. Chemotaxonomic analysis indicated that arjunic acid, ursolic acid and an unidentified triterpenoid (m/z 471) were ubiquitous in the Combretaceae species and could be responsible for their antibacterial activities. Conclusion Application of HPTLC-MS enabled the rapid screening of extracts to identify active compounds within taxonomically related species. This approach allows for greater efficiency in the natural product research workflow to identify bioactive compounds in crude extracts.

Salvia africana-lutea L., S. lanceolata L., and S. chamelaeagnea L. are used in South Africa as traditional medicines to treat infections. This paper describes an in-depth investigation into their antibacterial activities to identify bioactive compounds. Methanol extracts from 81 samples were screened against seven bacterial pathogens, using the microdilution assay. Biochemometric models were constructed using data derived from minimum inhibitory concentration (MIC) and ultra-performance liquid chromatography-mass spectrometry data. Active molecules in selected extracts were tentatively identified using high-performance thin layer chromatography (HPTLC), combined with bioautography, and finally, by analysis of active zone eluates by mass spectrometry (MS) via a dedicated interface. Salvia chamelaeagnea displayed notable activity towards all seven pathogens, and the activity, reflected by MICs, was superior to that of the other two species, as confirmed through ANOVA. Biochemometric models highlighted potentially bioactive compounds, including rosmanol methyl ether, epiisorosmanol methyl ether and carnosic acid. Bioautography assays revealed inhibition zones against A. baumannii, an increasingly multidrug-resistant pathogen. Mass spectral data of the eluted zones correlated to those revealed through biochemometric analysis. The study demonstrates the application of a biochemometric approach, bioautography, and direct MS analysis as useful tools for the rapid identification of bioactive constituents in plant extracts.

The antimicrobial activities of spearmint essential oil and six of its constituents were evaluated in vitro and in vivo analysis using direct contact and vapor exposure assays. Qualitative analysis of spearmint essential oil revealed that the main constituents of the essential oil are carvone (62.0%) and limonene (24.6%). Limonene (45%) was found to be the major constituent of the essential oil vapor phase, when sampled using direct headspace and Tenax TA tubes. Spearmint essential oil, carvone, and 1,8-cineole exhibited the highest antifungal activity against Penicillium digitatum and Geotrichum citri-aurantii (Ferraris), with the vapor phase application resulting in more than 50% growth inhibition at 1429 mg/L for 1,8-cineole and complete inhibition occurring at 714 mg/L for carvone and spearmint. The treatment of kumquats with spearmint essential oil and carvone vapors resulted in an average reduction in weight loss and decay rate of approximately 30% and 40%, respectively, when the fruits were stored at 25 degrees C.

This paper describes an investigation into the accumulation and distribution of Cu and Pb in Helichrysum splendidum, to assess the potential use of the plant in the phytoremediation of Cu- and Pb-contaminated soils. Plants of the same age were exposed to soils artificially contaminated with 10, 50, 100, 500 and 1000 mg/L Cu(II) and Pb(II). Although plant growth was not affected by the presence of Cu, high concentrations of Pb (> 500 mg/L) stunted the plants. Chlorophyll production was slightly reduced when plants were exposed to high concentrations of Cu (> 500 mg/L), whereas all the plants growing in Pb-contaminated soils indicated low levels of chlorophyll. Significant amounts of Cu and Pb were accumulated in the roots, with corresponding bioconcentration factors of > 1. Translocation of Cu to the shoots was restricted for plants growing in > 500 mg/L Cu-treated soils, whereas Pb was translocated to the shoots for all treatments, with translocation factors > 1. The Cu and Pb tolerance mechanism was ascribed to chelation and free radical scavenging, through the production of phenolic compounds. Helichrysum splendidum is able to adapt to and ameliorate soils contaminated with low to high levels of Cu(II) and Pb(II) and has potential for application in phytoextraction and phytostabilization of contaminated soils.

Helichrysum petiolare and Helichrysum odoratissimum, collectively known as 'Imphepho', are popular medicinal herbs that are indigenous to South Africa. The species are used interchangeably to relieve gastrointestinal and respiratory conditions, fever and urinary tract infections, implying that they produce antibacterial compounds. Although these herbs are sold in informal markets, they have not been commercialized. The aim of this study was to compare the chemical profiles and the antimicrobial activities of solvent extracts of the two species. The profiles of the smoke condensates were also compared, since the smoke from both species is inhaled during cultural rituals to induce central nervous system effects. After optimizing the extractant, the chemical profiles of aqueous methanol extracts of the aerial parts of twelve H. odoratissimum and fifteen H. petiolare samples, collected from several different localities, were obtained using ultra performance liquid chromatography-mass spectrometry (UPLC-MS). Three isomeric compounds were found to be present in both species. The construction of chemometric models from the data indicated a large degree of inter-population variation within H. odoratissimum, with the samples loosely clustering into two main groups. In contrast, the chemistry of H. petiolare was highly conserved. Discriminant analysis identified four distinguishing marker compounds for each species. One of the isomers common to both species, was isolated from H. odoratissimum and identified as 4,5-dicaffeoylquinic acid using nuclear magnetic resonance (NMR) spectroscopy, and is herein reported for the first time from the two species. Following validation of a developed UPLC-photodiode array (PDA) detection method, it was determined that the concentrations of the compound ranged from 3.89 - 31.1 mu g/g in H. odoratissimum and from 2.3 to 13.4 mu g/g in H. petiolare. High performance thin layer chromatography (HPTLC) fingerprints also indicated a greater degree of chemical variation within H. odoratissimum than in H. petiolare. This was confirmed through multivariate analysis of densitograms obtained from images of the fingerprints through the application of rTLC software, effectively mirroring the UPLC-MS results. The antibacterial activity of extracts of all the samples was determined using the minimum inhibitory concentration (MIC) serial dilution assay against selected Gram-positive (Staphylococcus saprophyticus, Enterococcus faecalis, Streptococcus agalactiae) and Gram-negative (Proteus mirabilis, Escherichia coli, Moraxella catarrhalis) pathogens that affect the urinary, respiratory and gastro-intestinal tracts. The MICs obtained for H. odoratissimum extracts indicated that these were more effective towards a larger range of bacteria than extracts of H. petiolare. The methanol extracts yielded average MICs denoting noteworthy or moderate activity towards three pathogens (E. coli, M. catarrhalis and S. agalactiae), while the chloroform: methanol extracts displayed noteworthy or moderate activity towards the same three pathogens, but also towards E. faecalis. These results justify to some degree the traditional use of H. odoratissimum to treat conditions of the gastro-intestinal, respiratory and urinary tracts. The UPLC-PDA profiles of smoke condensates of the two species, obtained under controlled conditions, revealed five major compounds that were common to both species. Although the similarity of the smoke profiles rationalises their interchangeable use for inhalation, the solvent extracts displayed little congruence regarding their chemical profiles or antibacterial activities. (C) 2020 SAAB. Published by Elsevier B.V. All rights reserved.

The knowledge of the levels of polyphenols present in green coffee beans from different geographical origins is important to identify beans that can provide better coffee quality. The aim of this study was to determine the concentrations of both soluble and cell wall-bound polyphenols in green coffee beans (Coffea arbica L.) from different cultivation regions of Ethiopia. A total of 100 samples were collected from four geographical regions (East, West, South, Northwest) and comprised eight commercial types of coffee (Harar, Jimma, Kaffa, Wollega, Sidama, Yirgacheffe, Finoteselam and Benishangul). The total concentrations of soluble and cell wall-bound polyphenols and flavonoids in the sample extracts were determined using the Folin-Ciocalteu and aluminum chloride reagent methods, respectively. Qualitative analysis was also performed by using high performance thin layer chromatography (HPTLC). Results revealed that chlorogenic acids as the predominant constituents of the phenolic fraction of the green coffee beans. The total soluble polyphenol, cell wall-bound polyphenol and flavonoid contents of the green coffee beans were in the range of 21.8–43.6 milligrams of gallic acid equivalents per gram (mg GAE g−1), 8.6–15.3 mg GAE g−1 and 3.3–6.2 milligrams of (+)-catechin equivalents per gram (mg CE g−1) of dry mass, respectively. Cell wall-bound polyphenols were found to contribute significantly (21.0–32.5%) to the total polyphenol contents (TPC) of the green coffee beans. The polyphenol contents of green coffee beans have been found to vary with geographical origins. Harar coffee contained significantly (p < 0.05) lower amounts of both total soluble and cell wall-bound polyphenols than the other regional coffee types. Furthermore, the contribution of cell wall-bound phenolic to the TPC should not be overlooked.