Table 3.
Tentative identification of the phenolic components of the extracts obtained by different ethanol or acetone concentration, after 70 min of extraction, at 22 °C, solid-to-liquid ratio 1:20, and non-specific particle size.
| Coding | Identified Compounds | r.t. | Recovery of Compounds (mg/gdw) in | Reference | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| (min) | Acetone in Water Extracts | Water Extract | Ethanol in Water Extracts | For UV and r.t. Data | |||||||
| 100% | 80% | 60% | 40% | 60% | 80% | 96% | |||||
| 1 | nepitrin 1,a | 35.2 | 0 | 2.20 | 3.01 | 2.66 | 2.05 | 3.01 | 2.25 | 0 | [41,49,50,51] |
| rosmarinic acid b | 38.0 | 0.66 | 10.02 | 13.49 | 14.20 | 15.13 | 10.11 | 8.24 | 2.16 | - | |
| 2 | isoscutellarein 1,a | 40.1 | 0 | 2.58 | 5.97 | 4.43 | 3.97 | 4.90 | 3.23 | 0 | [31,33] |
| x | salvianolic acid A 2,a | 41.8 | 0 | 3.51 | 6.23 | 5.11 | tr | 3.79 | 3.25 | 0 | [52,53] |
| a | hispidulin 1,a | 48.0 | 1.24 | 1.69 | 1.58 | 1.17 | 0 | 1.62 | 1.54 | 1.23 | [40,41,42,43] |
| b | ladanein 1,a | 49.0 | 0.93 | 1.14 | 1.20 | 1.45 | 0 | 1.04 | 1.11 | 0.96 | [44] |
| c | genkwanin 1,a | 50.8 | 1.30 | 1.56 | 1.48 | 1.19 | 0 | 1.33 | 1.41 | 1.34 | [31,33,34,40,46,47] |
| d | salvigenin 1,a | 52.2 | 1.38 | 1.47 | 1.37 | 1.34 | 0 | 1.31 | 1.35 | 1.30 | [44,45] |
| carnosol 3,b | 53.5 | 7.55 | 13.83 | 14.69 | 5.57 | 0 | 7.38 | 10.48 | 10.19 | - | |
| e | 4′-methoxytectochrysin 1,a | 54.8 | 1.23 | 0.99 | 1.37 | 0.82 | 0 | 1.06 | 1.16 | 1.33 | [31,33,36,48] |
| carnosic acid b | 58.0 | 26.54 | 23.84 | 19.37 | 10.79 | 0 | 10.18 | 24.43 | 22.28 | - | |
1 expressed as quercetin equivalents; 2 expressed as rosmarinic acid equivalents; 3 expressed as carnosic acid equivalents; a Assginment is based on comparison with UV- and retention time data from literature and hence tentative; b Identified by direct comparison of retention time and UV spectrum with authentic reference samples.