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Consumption of a refreshing beverage prepared from the dried leaves and twigs of Athrixia phylicoides, commonly referred to as bush tea, is widespread in South Africa. The tea has an illustrious history of use by the indigenous people of southern Africa and has the potential for commercialisation. Several ethnic groups use decoctions and pastes prepared from the plant to treat a multitude of unrelated conditions. This review is aimed at providing a comprehensive overview of the ethnopharmacology, phytochemistry, biological activities, toxicity and commercial aspects of A. phylicoides. Books, containing botanical and ethnopharmacological information were extensively consulted, and electronic databases were searched to acquire relevant articles, with no specific time frame set. Although the majority of the traditional uses indicate that A. phylicoides has strong antimicrobial properties, this is not well supported by scientific data, suggesting that more research is required involving more pathogens and the investigation of a potential alternative mode of action. The secondary metabolites of the plant have been extensively explored and several sesquiterpenes, coumarins, flavonoids and phenol carboxylic acids have been identified. However, there is a paucity of information regarding the chemical variation within the species. A multidisciplinary metabolomic approach involving sophisticated and information-rich technologies, in combination with multivariate analysis, should be undertaken to record chemotypic variation and to identify potential biomarker compounds for quality control. Some of the ethnobotanical uses have been supported through scientific studies, but a window of opportunity exists to contribute data on the pharmacological activities. Despite efforts to facilitate the commercialisation of bush tea in South Africa in an effort to grow the bio-economy of the region, more fundamental research is required to ensure the sustainability and expansion of such an industry. The commercialisation of rooibos and honeybush tea in South Africa is underpinned by basic and applied research and serves as appropriate models for the development of the bush tea industry.

The volatile constituents of nine liverworts species ( Asterella marginata , Dumortiera hirsuta , Fossombronia swaziensis , Marchantia pappeana , Marchantia polymorpha subsp. ruderalis , Pallavicinia lyellii , Plagiochasma rupestre , Riccia albolimbata and Symphyogyna podophylla ) from South Africa were determined by gas chromatography. Where possible the volatile constituents identified were compared to those reported for the same species from other countries. Among the analysed liverworts, the chemical compositions of A. marginata , F. swaziensis , M. pappeana , and R. albolimbata are reported for the first time. Each of the analysed liverwort species produced its own characteristic components. Thujopsanes, chamigranes and cuparanes were found to be the most characteristic components of M. polymorpha subsp. ruderalis . The presence of dumortane-type sesquiterpenoids in D. hirsuta indicated that this species is similar in chemistry to an Argentinean sample. This is one of only a handful of reports on the presence of this sesquiterpene-type in liverworts. Simple thallose liverworts, S. podophylla and P. lyellii , were characterized by the presence of labdane-type diterpenoids. In addition, the antimicrobial activities of chloroform:methanol (1:1) extracts of the liverworts were evaluated against several important human pathogens using the serial dilution assay. Four of the liverwort species were active against Pseudomonas aeruginosa with MIC values ranging from 0.50 to 1.0 mg/mL. Some activity (MIC value of 1.0 mg/mL) was also recorded for the crude extracts of P. lyellii and M. pappeana against Escherichia coli. The extract of S. podophylla displayed the best activity towards the yeast Cryptococcus neoformans (MIC = 1.0 mg/mL). Although approximately 300 liverwort species occur in southern Africa, a Scopus search confirmed that this is the first report of the volatile profiles and biological properties of species from the region.

The alkaloid compositions of 99 green coffee (Coffea arabica L.) bean samples comprising eight varieties (Harar, Jimma, Kaffa, Wollega, Sidama, Yirgachefe, Benishangul and Finoteselam) from the major production regions of Ethiopia were investigated. High performance liquid chromatography was applied for the simultaneous determination of four coffee alkaloids in the aqueous extracts of the beans. The limits of detection for the method were established as 13 mg kg−1 for trigonelline, 7 mg kg−1 for theobromine, 8.5 mg kg−1 for caffeine and 4 mg kg−1 for theophylline in the dry coffee beans. Theophylline was not detected in any of the samples. The determined concentrations (% w/w dry coffee beans) ranged from 0.98 to 1.32 % for trigonelline, 0.0048 to 0.0094 % for theobromine and 0.87 to 1.38 % for caffeine. The concentrations of the alkaloids varied significantly, depending on the geographical origin of the beans. Theobromine was not detected in coffee beans from the East (Harar coffees), and its absence in samples can be used to ascertain whether the coffee originates from this region. Coffee beans from the Northwest were characterized by higher concentrations of caffeine. Application of linear discriminant analysis provided 75 % correct classification of samples into the respective production regions, with a 74 % prediction success rate. The moderate classification efficiency obtained when using alkaloid data demonstrates the potential of using this class of compounds in discriminant models for determination of the geographical origin of green coffee beans from Ethiopia.

Contamination of soils with the explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX, Research Department Explosive) as a result of military applications is a large-area problem globally. Since coniferous trees dominate the vegetation of large areas of military land in Central Europe, particularly in Germany, the long-term fate of (14)C-RDX in the conifers Scots pine and Dwarf Alberta spruce was studied. Acetic acid was the most effective solvent for the removal of extractable RDX residues from homogenates of RDX-laden tree material (85%, 80-90% and 64-80% for roots, wood and needles, respectively). On average, only a fifth of RDX-derived (14)C was bound in non-extractable residues (NER). Within the main cell wall compartments, lignin was the dominant binding site for NER (needles: 32-62%; roots: 38-42%). Hemicellulose (needles: 11-18%; roots: 6-11%) and cellulose (needles: 12-24%; roots: 1-2%) were less involved in binding and a considerable proportion of NER (needles: 15-24%; roots: 59-51%) was indigestible. After three-year incubation in rot chambers, mineralisation of tree-associated (14)C-RDX to (14)CO2 clearly dominated the mass balance in both tree species with 48-83%. 13-33% of (14)C-RDX-derived radioactivity remained in an unleachable form and the remobilisation by water leaching was negligible (2%).

The chemical profiles of essential oils isolated from nine populations of Helichrysum splendidum were obtained by gas chromatography. Plants were harvested in both summer and winter seasons in two provinces of South Africa. Essential oils originating from Limpopo Province were characterized by high levels of β-phellandrene, 1,8-cineole, δ-cadinene, α-cadinol, τ-cadinol, and β-pinene. These could be clearly distinguished through multivariate analysis from those collected in Mpumalanga Province. The Mpumalanga oils contained germacrene D, spathulenol and bicyclogermacrene as major constituents. Seasonal variations in the volatile compositions and yields were observed. A prediction model obtained through orthogonal projection to latent structures discriminant analysis was used to compare the essential oil profiles to that of a commercial H. splendidum sample, in addition to those reported for Zimbabwean specimens. One of the specimens from Zimbabwe differed substantially from all the others, indicating the existence of more chemotypes. The structures of the oil-bearing trichomes, as observed on the leaf surfaces using scanning electron microscopy, were investigated and are described for the first time. Since this investigation forms part of an ongoing screening of plants to identify natural alternatives to synthetic fungicides, the essential oils were tested in vitro against several economically important pathogens of fruit. Essential oils from Mpumalanga specimens totally inhibited the growth of Alternaria alternata from avocado and Colletotrichum gloeosporioides isolated from mango at a concentration of 500 μL/L in a toxic medium assay. The presence of high concentrations of germacrene D, spathulenol and bicyclogermacrene probably contributed to the antifungal properties of these essential oils.

Infection of mango panicles and young leaf shoots by Fusarium results in significantly lower fruit yields. Some mango cultivars are known to be tolerant to blossom malformation, while others are highly susceptible. Previous researchers linked the ability of certain cultivars to confine Fusarium infection to the production of high levels of mangiferin. This study further elucidates the role of phenolic metabolites contributing to tolerance. Phenolic profiles of mature leaf extracts from cultivars with varying degrees of resistance to Fusarium infection were obtained by ultrahigh performance liquid chromatography–time-of-flight-mass detection. Chemometric models constructed from the data revealed a clear distinction between the profiles of tolerant and susceptible cultivars and permitted the identification of biomarkers associated with susceptibility to infection. The presence of elevated levels of mangiferin, maclurin and maclurin O-galloyl-glucoside in the leaves were associated with a higher degree of tolerance. In contrast, high levels of iriflophenone glucosides were linked to increased susceptibility of the cultivars to infection. These models can serve as an important tool to investigate appropriate cultivars, prior to their introduction to areas prone to the disease.

Together with Penicillium moulds, Geotrichum citri-aurantii (sour rot) is a major cause of citrus fruit decay. Fifty-nine commercially available essential oils and some of their major components were screened to determine their effects on the mycelial growth of G. citri-aurantii using toxic medium assays. Nine of these essential oils totally inhibited the mycelial growth of the pathogen at 1000 μl/l. Gas chromatographic analysis revealed the compositions of the most effective oils. Exposure to the vapours of selected essential oils (Thymus vulgaris, Citrus aurantium var. amara, Cymbopogon citratus, Cymbopogon martinii, Origanum vulgare, Geranium graveolens roseum Bourbon) proved fungistatic, rather than fungicidal, towards the pathogen. ‘Valencia’ oranges, inoculated with G. citri-aurantii, were treated with the most promising botanicals. Essential oils (1000 μl/l) of C. citratus, C. martinii, O. vulgare and G. graveolens roseum Bourbon, incorporated into coating or applied as a curative dip, resulted in a drastic reduction in decay when compared to the negative control. No physiological breakdown of the fruit was evident at this concentration. C. citratus (lemongrass) was selected as the most cost-effective option for control of G. citri-aurantii. Previous commercial trials indicated the protective properties of Mentha spicata essential oil against Penicillium digitatum. To develop an effective multi-target protection product against G. citri-aurantii, P. digitatum and Penicillium italicum, essential oil of C. citratus was combined with that of M. spicata. A toxic medium, containing both essential oils, each at 750 μl/l, totally controlled all three pathogens. Although individual essential oil-amended coatings have previously been applied for postharvest control, this study proposes a mixture of these essential oils for control of two serious citrus pathogens (G. citri-aurantii, P. digitatum), in addition to P. italicum.

Lippia species are widely used as traditional remedies by many South African communities. The identification of Lippia spp. indigenous to South Africa is currently based on the morphology and geographical origin of the specimen. However, morphological similarities are evident and due to sympatric distributions, different species may co-occur in the same natural environment, thereby presenting difficulties in the taxonomic delimitation of these taxa. In this paper, gas chromatography–mass spectrometry (GC–MS) and vibrational spectroscopic analyses were used to investigate the chemotaxonomic differentiation of four Lippia species ( L. javanica , L. scaberrima , L. rehmannii and L. wilmsii ), based on the essential oil composition. The results demonstrate that multivariate classification of chromatographic data enabled separation of Lippia oils into three distinct clusters representing L. scaberrima , L. rehmannii and L. javanica . With the aid of chemometric algorithms, it was also possible to use both mid infrared (MIR) and near infrared (NIR) spectroscopy for a clear distinction of the Lippia spp., with results comparable to those obtained by GC–MS. Orthogonal projections to latent structures (OPLS) presented a better classification algorithm than principal component analysis (PCA), in both GC–MS and spectroscopy analyses. Chemical variations within the Lippia spp. complex were evident, particularly for L. javanica and L. scaberrima , which exhibited significant intra-species variation.

The development of natural crop protective products as alternatives to synthetic fungicides is currently in the spotlight. In vitro experiments are valuable precursors to more costly in vivo trials, allowing the identification of effective essential oils and establishing the concentrations required for inhibition of a specific, or spectrum of decay pathogens. In this study, the antifungal properties of eighteen essential oils were evaluated in vitro by addition to the fungal growth medium of five pathogens ( Lasiodiplodia theobromae , Colletotrichum gloeosporioides , Alternaria citrii , Botrytis cinerea and Penicillium digitatum ) isolated from mango, avocado, citrus, grapes and cactus pear. The inhibitory properties of some of the major compounds of the oils, identified and quantified by gas chromatography–mass spectroscopy and gas chromatography–flame ionization detection were also determined. Most of the oils were selected on the basis of commercial availability and for containing a predominant compound. Visual inspection of fungal growth was done and the lowest concentration where fungal growth was completely inhibited on all replicates was recorded. Thyme oil proved to be the most effective inhibitor, totally inhibiting all of the pathogens tested at concentrations of 1000 μl/l and lower, with the exception of a resistant Penicillium strain. Cinnamon oil, rich in eugenol (81.2%), demonstrated good fungicide potential, while the carvone-rich oils displayed promising activity against the citrus pathogens. Oils characterized by high concentrations of S-carvone were less effective than those containing the R-enantiomer. Essential oil of Lippia citriodora was active against all of the pathogens, excluding L. theobromae from avocado. These essential oils, applied alone or in combination, are good candidates for further in vivo testing and for investigations concerning their modes of action.

Proliferation of fungal pathogens, such as Mycogone perniciosa , can severely affect the yields of cultivated mushrooms, including that of the button mushroom, Agaricus bisporus. A reduction in the number of fungicidal products approved for commercial application is currently providing new challenges to the mushroom industry . Forty essential oils, seven pure terpenoids and one phenylpropanoid were screened in vitro to determine the abilities of these substances to inhibit the growth of M. perniciosa . The fungal growth medium of both A. bisporus and M. perniciosa was supplemented with each test substance at a concentration of 50 μL/L. Ten essential oils were further investigated at lower concentrations ranging from 5 to 40 μL/L. The main components of these oils were determined by GC–FID and GC–MS. Lemon verbena ( Lippia citriodora ), lemongrass ( Cymbopogon citratus ) and thyme ( Thymus vulgaris ) oils were found to substantially inhibit the growth of the pathogen, while demonstrating lower toxicity towards A. bisporus than any of the other oils tested. A preliminary in vivo trial using M. perniciosa -inoculated casings revealed that the preventative use of lemon verbena or thyme oils was able to control the development of the disease. A commercial trial using these oils, as well as two of their main components (nerol and thymol), at a concentration of 40 μL/L, revealed that none of these treatments were detrimental to the growth of the A. bisporus and an overall yield similar to that following application of a commercial fungicide (Chronos 450 SC) was obtained. These results suggest that essential oils or mixtures of selected pure components of essential oils may in future find application in button mushroom production, either as a substitute for synthetic fungicides or as an additional protective measure.

Mycobiocides are attracting research interest worldwide as possible postharvest pathogen control measures to replace synthetic fungicides. In this study, the application of two essential oils as fungicides was evaluated. Initially, the in vitro antifungal effects of Lippia scaberrima essential oil and three of the major oil components, ( d )-limonene, R-(−)-carvone, and 1,8-cineole, as well as that of S-(+)-carvone, were investigated against Colletotrichum gloeosporioides , Lasiodiplodia theobromae , and an Alternaria isolate. The oil and terpenoids caused significant inhibition of the mycelial growth of all the pathogens when applied at a concentration of 2000 μL L −1 . The most potent volatile component of L . scaberrima essential oil, able to inhibit all the pathogens tested, proved to be R -(−)-carvone. The efficacy of the essential oil (1000 and 2000 μL L −1 ) incorporated into the commercial coating was confirmed on fruit inoculated with two of the pathogens. A simulated export trial was done using Lippia essential oil, in addition to Mentha spicata (spearmint) essential oil, as supplements for fruit coatings. Results indicate that essential oils rich in R-(−)-carvone could be valuable alternatives to synthetic fungicides for the postharvest management of avocado fruit. The combination of essential oils with a commercial coating, acceptable to the organic market, offers additional protection to this vulnerable commodity.

The mango gall fly (Procontarinia) is a growing concern in many countries that import mango trees. Mangoes flush (produce opening buds) twice a year: once in spring, and the main flush, which occurs in early autumn flush and corresponds to the photoperiod necessary for the gall fly to emerge. Gall flies attack only very young mango flush leaves. Three cultivars displaying varying susceptibility were used in this study: Heidi, which typically is heavily infected; Keitt, which displays antixenosis properties; and Sensation, which is resistant to gall fly attack. Headspace profiles of the three cultivars were obtained over two full growing seasons. It was found that flush leaves emit higher levels of volatile organic compounds than mature leaves. Volatile emissions peaked during the main flush, after which they declined as the tree went into the winter dormant period. The levels of α- and β-pinene increased in gall fly-susceptible cultivars as the season progressed, while very low levels of these terpenes were emitted by resistant cultivars. The changes in the profiles of these emissions suggest that α- and β-pinene may be linked to gall fly susceptibility. In addition, chemometric analysis confirmed the correlation between volatile emissions and gall fly susceptibility. Copyright © 2010 John Wiley & Sons, Ltd.

Lippia rehmannii H.Pearson (Verbenaceae) is an aromatic bush, indigenous to the northern parts of South Africa. As far as could be ascertained, the essential oil composition has not been previously reported and forms the subject of this investigation. Aerial parts of the shrub were collected from two localities in Gauteng, South Africa, and the isolated essential oils were analysed by gas chromatography. Citral, a mixture of the E- and Z-isomers, was found to be the main constituent of the oils, while borneol, camphor, neryl acetate, isocaryophyllene, p -cymene, β-caryophyllene and β-caryophyllene oxide were other major compounds present. Oil compositions, within and between the two localities, did not differ significantly. The in vitro antifungal activity of L. rehmannii essential oil was compared to that of Cympopogon citratus (lemongrass) and pure citral, against a number of pre- and postharvest fungal food pathogens. At a concentration of 3000 µL/L, lemongrass oil and pure citral caused complete growth inhibition of all the pathogens tested. Lippia rehmannii , containing less citral than lemongrass oil, was effective at this concentration against the majority of pathogens, but only partially restricted the growth of Lasiodiplodia theobromae and Botrytis cinerea. This finding suggests that citral may be largely responsible for the observed antifungal activities. Essential oil from L. rehmannii appears to be a good candidate for the in vitro control of Fusarium oxysporum and Rhizoctonia solani and application of these oils in the field should be investigated.

Introduction . Penicillium digitatum is a commercially important postharvest pathogen of citrus that is responsible for significant annual global losses. Strains of the fungus, which exhibit strong resistance to widely used synthetic fungicides, are of major concern to the industry. The aim of the study was to investigate the antifungal activities of polar extracts and compounds from Lippia species, indigenous to South Africa, against a Guazatine® -resistant strain of P. digitatum. Materials and methods . In vitro tests were done by incorporating the compounds and plant extracts into Malt Extract Agar at concentrations ranging from (0.2 to 1.0) mg·mL–1 . An in vivo (curative) assay was conducted using the checkerboard technique on ‘Valencia’ oranges. Results and discussion . A strong correlation between the in vitro and in vivo results was observed. All the compounds and extracts were able to inhibit fungal growth at concentrations above 0.6 mg·mL–1 . Verbascoside was the most active compound, while extracts of Lippia javanica and Lippia rehmannii caused significant inhibition of mycelial growth. The observed activity was largely ascribed to the presence of verbascoside in the plant extracts. Conclusion . Polar extracts of Lippia species have potential as environmentally friendly alternatives for the control of P. digitatum on citrus.

SummaryDiscolouration of mango lenticels intensifies progressively from a slight red halo during the initial development of the condition, to a blackened area surrounding each lenticel. Initial aqueous methanol extracts of discoloured tissue were further fractionated into phenolic groups and analysed by means of reversed-phase high performance liquid chromatography. Discernable shifts in phenolic profiles correlated with the colour changes in affected lenticels. After staining with Vanillin-HCl, fluorescence microscopy of fixed material revealed the locations of, and changes in the different forms of phenolics associated with various degrees of discolouration. The results confirmed that the compounds responsible for the discolouration of lenticels were simpler flavonones rather than more complex anthocyanidins. The chromatographic results correlated with previous observations using transmission electron microscopy, which indicated that the accumulation of cell wall-bound phenolics did not result from vacu...

Lippia scaberrima , an aromatic shrub with medicinal properties, is indigenous to southern Africa. Essential oil obtained from aerial plant parts was assessed in vitro and in vivo for antifungal activity against Botryosphaeria parva and Colletotrichum gloeosporioides isolated from mango fruit. Exposure to oil vapour for 2 and 4 days caused inhibition of mycelial growth of both isolates. Three major terpenoids identified in the oil, limonene, R -(−)-carvone, and 1,8-cineole, as well as S -(+)-carvone, were individually evaluated in vitro . The two enantiomers of carvone, along with L. scaberrima oil, were found to have the highest fungistatic activity. Oil and carvone enantiomer fungicidal activities were less pronounced. The use of commercial wax coatings enriched with essential oils led to reduced fungal infection by both pathogens. Results of the in vitro and preliminary in vivo studies suggest that employing L. scaberrima oil to control postharvest pathogens is worthy of further investigation.

Lippia scaberrima (Verbenaceae) is an aromatic, medicinal shrub which is indigenous to southern Africa. Quantitative and qualitative analyses of the essential oil were conducted using gas chromatog...

Hypoxis species (Hypoxidaceae) are amongst the most widely used medicinal plants in southern Africa. Although the phytochemistry of Hypoxis hemerocallidea has been extensively investigated, little is known regarding the secondary metabolites of the other indigenous species, including Hypoxis colchicifolia and Hypoxis galpinii. Two new phenolic glycosides, 3-hydroxy-4-O-β-d-glucopyranosylbenzaldehyde and 1,5-bis(3,4-dihydroxyphenyl)-1,2-dihydroxy-4-pentyne-2-p-coumaroyl-β-d-glucopyranoside were isolated from corms of H. colchicifolia and H. galpinii, respectively. The norlignan glycosides (hypoxoside, dehydroxy hypoxoside and bis-dehydroxy hypoxoside) were isolated from H. colchicifolia for the first time, using high performance countercurrent chromatography and elucidated by 1D and 2D NMR as well as high resolution MS. In addition, geraniol glycoside and β-sitosterol, previously described in Hypoxidaceae, were isolated from the same species. The presence of hypoxoside in all three species investigated indicated that the interchangeable use of Hypoxis species by communities has some merit. Establishing the biological properties of the new constituents will provide more insight into the medicinal value of the genus.

The leaves of Leucosidea sericea (Rosaceae) are used medicinally by some indigenous South African people as a vermifuge and astringent. No information on the biological activity and phytochemistry of the plant could be found in the literature. Bioassay-guided fractionation was used to identify the active compound. Partial purification of the petroleum ether extract of the leaves and flowers was followed by fractionation using chromatographic methods. This process yielded the Phloroglucinol derivatives, aspidinol and desaspidinol, which were previously reported to be present in a Dryopteris species. Aspidinol was further isolated and structurally elucidated. This is the first report of the presence of these compounds in Leucosidea sericea. The disk diffusion method used in our study, indicated that the plant has antimicrobial activity against Staphylococcus aureus , Bacillus subtilis and Candida albicans .

†Background and Aims Lippia scaberrima, an aromatic indigenous South African plant, with medicinal application, potentially has economic value. The production of essential oil from this plant has not been optimized, and this study of the chemico-morphological characteristics was aimed at determining the location of oil production within the plant. Furthermore, the locality of other secondary metabolites important in medicinal applications needed to be ascertained. This information would be useful in deciding the protocol required for isolation of such compounds. †Methods The morphology of the glandular trichomes was investigated using a combination of scanning electron and light microscopy. Concurrently, the chemical content was studied by applying various chemical reagents and fluorescence microscopy. †Key Results Three types of trichomes were distinguished on the material investigated. Large, bulbous peltate glands containing compounds of terpenoid nature are probably the main site of essential oil accumulation. Small glands were found to be both peltate and capitate and fluorescent stain indicated the possible presence of phenolic compounds. The third type was a slender tapered seta with an ornamented surface and uniseriate base, and evidently secretory in nature. †Conclusions This study linking the chemical content and morphology of the glandular trichomes of L. scaberrima has contributed to the knowledge and understanding of secretory structures of Lippia spp. in general.

Lippia javanica and Lippia scaberrima are used as herbal remedies and are commercially traded as health teas in southern Africa under the brands “Mosukujane” and “Musukudu”, respectively. This study evaluates the relationship between the presence of phenolic compounds and the antioxidant activities of infusions prepared from four Lippia species ( L. javanica , L. scaberrima , L. rehmannii and L. wilmsii ) indigenous to South Africa. The antioxidant activities of the infusions, determined by the 2,2-diphenylpycrylhydrazyl (DPPH) method, were also compared to those of popular black, green and herbal tea brands. Of the four indigenous species, infusions of L. javanica and L. wilmsii exhibited the highest antioxidant activities (EC 50 : 358 and 525 µg/ml, respectively) and contained the most phenolic compounds (14.8 and 14.5 mg/ml of dry weight gallic acid equivalent, respectively). Antibacterial activities of methanolic extracts of the four Lippia species were determined against four human pathogens ( Staphylococcus aureus , Enterococcus faecalis , Escherichia coli and Pseudomonas aeruginosa ). The extract of L. javanica was the most active against all the pathogens tested. Those Lippia species ( L. javanica and L. wilmsii ) previously reported to produce higher levels of the pharmacologically active phenylethanoid glycosides verbascoside and isoverbascoside, portrayed stronger antioxidant and antibacterial activities. This study gives credence to the use of infusions of these Lippia species for their general health benefits.

Lippia javanica (N.L.Burm.) Spreng. is an aromatic, multipurpose medicinal plant from which a number of volatile compounds have been identified, together with toxic triterpenoids and iridoid glycosides. Two additional phenylethanoid glycosides, verbascoside and isoverbascoside, were isolated from L. javanica and characterized. High performance liquid chromatography analyses of polar extracts of three other Lippia species (L. scaberrima, L. rehmannii and L. wilmsii), indigenous to South Africa, revealed the presence of both isomers. When compared to the other indigenous Lippia species, the leaves of L. javanica were found to contain the highest concentrations of both isomers. In addition, the intraspecies variation of the verbascoside/isoverbascoside content of L. javanica, harvested from the same and different localities, was investigated. The concentrations of the two phenylethanoids remained fairly consistent within and between different populations, even when geographically separated. While these compounds are produced by many genera, they may now be added to the list of iridoid glucosides employed as chemotaxonomic markers for Lippia species.