Table 1.
Published concentrations of eugenol and thymol in selected plants. Concentrations are given in ppm fresh mass when possible. Where references quantified concentrations in percent of essential oil per unit dry mass, concentrations were converted based on other studies that quantified leaf moisture content and/or essential oil yield, as explained in “Notes” column
| Species | Sample type | Concentration | References | Notes |
|---|---|---|---|---|
| A. Plant species high in eugenol | ||||
| Ocimum selloi | Leaves | ~1,200 ppm | Martins et al. (1997) | 0.2% essential oil by fresh mass, 63% eugenol in oil |
| Flowers | ~2,400 ppm | Martins et al. (1997) | 0.4% essential oil by fresh mass, 63% eugenol in oil | |
| Ocimum basilicum | Leaves (broad‐leaf variety) | ~70 ppm | Wogiatzi, Papachatzis, Kalorizou, Chouliara and Chouliaras (2011) | 500 ppm in dried leaves; 86% leaf moisture (Rocha, Lebert, & Marty‐Audouin, 1993). O. basilicum may also contain thymol (Lee et al., 2005) |
| Leaves (narrow‐leaf variety) | ~100 ppm | Wogiatzi et al. (2011) | 700 ppm in dried leaves; 86% moisture (Rocha et al., 1993) | |
| Rosa x hybrida | Stamens | 50 ppm | Bergougnoux et al. (2007) | 13.1% of 380.6 ppm total analytes |
| Cucurbita pepo cv. Tosca | Petals | 0.99–1.2 ppm | Granero, Gonzalez, Sanz, and Vidal (2005) | |
| Nectar | 0.02–0.57 ppm | Granero et al. (2005) | ||
| Dianthus caryophyllus | Floral volatiles | Trace‐84.1% of emissions | Clery, Owen, Chambers and Thornton‐Wood (1999) | |
| Gymnadenia densiflora | Flower headspace | 0.839 ppm | Gupta et al. (2014) | |
| Rosmarinus spp. | Monofloral honey | 0.02–0.03 ppm | Castro‐Vázquez, Pérez‐Coello and Cabezudo (2003) | |
| B. Plant species high in thymol | ||||
| Lippida sidoides | Leaves | ~8,200 | de Medeiros et al. (2011) | 1.06% oil in leaves (Veras et al., 2012), 78% thymol in oil |
| Origanum dictamnus | Leaves | ~1,300 | Daferera et al. (2000) | 1.05% essential oil by mass (Argyropoulou, Papadatou, Grigoriadou, Maloupa, & Skaltsa, 2014), 78% thymol in oil, 84% moisture in leaves (Loghmanieh, Bakhoda, & Issa, 2013). |
| Origanum vulgare | Leaves and flowers | ~990 ppm | De Martino, De Feo, Formisano, Mignola and Senatore (2009) | 2.3% essential oil by dry mass. 63% thymol in oil, 84% moisture in leaves (Loghmanieh, Bakhoda, and Issa, 2013). O. vulgaris may also contain eugenol (De Martino et al., 2009; Milos et al., 2000) |
| Thymus vulgaris | Leaves | ~,3200 ppm | Daferera et al. (2000) | ~0.5% essential oil by fresh mass (Hudaib, Speroni, Di Pietra, & Cavrini, 2002), 64% thymol in oil |
| Thymus vulgaris | Leaves | ~1,370 ppm | Lee et al. (2005) | 8550 ppm in dried leaves; assume 84% moisture in leaves (Loghmanieh et al., 2013). T. vulgaris may also contain eugenol (Lee et al., 2005) |
| Thymus pulegioides L. | Leaves and flowers | ~1,500 ppm | Senatore (1996) | 0.5% essential oil by fresh mass, 30% thymol in oil |
| Satureja montana | Leaves | ~1,000 ppm | Nikolić et al. (2014) | 1.5% essential oil by dry mass (Sefidkon, Jamzad, & Mirza, 2004), 44% thymol in oil, 84% moisture in leaves (Loghmanieh, Bakhoda, and Issa, 2013) |
| Origanum majorana | Leaves | ~1,100 ppm | Daferera et al. (2000) | Assume 0.5% essential oil by fresh mass (Hudaib et al., 2002), 14% thymol in oil. O. majorana may also contain eugenol (Deans & Svoboda, 1990) |
| Thymus vulgaris | Nectar | 5.2–8.2 ppm | Palmer‐Young, Sadd et al. (2016) | |
| Thymus spp. | Honey | 0.27 ppm | Nozal, Bernal, Jiménez, González and Higes (2002) | |