Table 2. Relative abundances (%) of di- and triterpenoids identified in commercial specimens of Boswellia resins.
| Compound classes | CommonName | SystematicName | Type | Boswellia carterii | Boswellia sacra | Boswellia serrata | Boswellia papyrifera |
| Diterpenoids | cembrene A | C | 1.0 | 2.1 | 1.7 | 1.8 | |
| cembrene isomer (?) | C | 0.2 | 1.4 | 0.8 | - | ||
| serratol isomer (?) | C | 0.2 | 1.8 | 0.9 | - | ||
| cembrene C | C | 0.3 | 1.7 | 0.5 | 0.2 | ||
| verticilla-4(20),7,11-triene | - | - | - | 6.6 | |||
| unknown (?) | 2.3 | 1.0 | 0.7 | 0.2 | |||
| incensol | C | 17.7 | tr | tr | 6.9 | ||
| serratol | C | 7.0 | 13.7 | 14.3 | - | ||
| incensol acetate | C | - | - | - | 11.8 | ||
| incensol oxide acetate | C | - | - | - | 0.1 | ||
| Triterpenoids | epi-β-amyrin | olean-12-en-3α-ol | O | 3.6 | 2.9 | 0.9 | 0.1 |
| epi-α-amyrin | urs-12-en-3α-ol | U | 10.2 | 5.0 | 3.0 | 0.3 | |
| epi-lupeol | lup-20(29)-en-3α-ol | L | 3.8 | 4.5 | 0.7 | 0.3 | |
| tirucallol | tirucalla-8,24-dien-3-ol | T | 0.2 | 0.4 | 0.6 | 0.4 | |
| β-amyrenone | olean-12-en-3-one | O | 0.5 | 3.8 | 0.5 | ce | |
| β-amyrin | olean-12-en-3β-ol | O | ce | ce | ce | ce | |
| α-amyrenone | urs-12-en-3-one | U | 1.0 | 10.8 | 1.1 | 0.5 | |
| α-amyrin | urs-12-en-3β-ol | U | 2.6 | 3.0 | 1.8 | 0.6 | |
| lupeol | lup-20(29)-en-3β-ol | L | 0.4 | 1.0 | ce | ce | |
| α-boswellic acid | 3α-hydroxy-olean-12-en-24-oic acid | O | 7.6 | 4.6 | 9.3 | 4.8 | |
| β-boswellic acid | 3α-hydroxy-urs-12-en-24-oic acid | U | 13.5 | 14.8 | 23.2 | 11.3 | |
| lupeolic acid | 3α-hydroxy-lup-20(29)-en-24-oicacid | L | 1.1 | 1.5 | 0.3 | 0.1 | |
| 11-hydroxy-β-boswellic acid | 3α,11α-dihydroxy-urs-12-en-24-oicacid | U | 0.7 | - | 0.4 | 0.9 | |
| β-elemonic acid | 3-oxo-tirucalla-8,24-dien-21-oicacid | T | 2.9 | tr | 6.0 | 13.9 | |
| β-elemolic acid | 3-hydroxy-tirucalla-8,24-dien-21-oicacid | T | 1.5 | tr | 0.3 | 2.2 | |
| 3-O-acetyl-β-elemolic acid | 3-acetoxy-tirucalla-8,24-dien-21-oicacid | T | 0.4 | tr | 5.9 | 5.5 | |
| 3-O-acetyl-α-boswellic acid | 3α-acetoxy-olean-12-en-24-oic acid | O | 3.9 | 6.3 | 5.5 | 7.1 | |
| 3-O-acetyl-β-boswellic acid | 3α-acetoxy-urs-12-en-24-oic acid | U | 9.3 | 14.5 | 18.3 | 11.2 | |
| 3-O-acetyl-lupeolic acid | 3α-acetoxy-lup-20(29)-en-24-oicacid | L | 1.0 | 2.1 | 0.1 | 0.5 | |
| 3-O-acetyl-11-hydroxy-β-boswellic acid | 3α-acetoxy-11α-hydroxy-urs-12-en-24-oic acid | U | 0.6 | tr | 0.2 | 2.2 | |
| 11-keto-β-boswellic acid | 3α-hydroxy-11-oxo-urs-12-en-24-oicacid | U | 0.8 | 0.4 | 1.5 | 2.0 | |
| 3-O-acetyl-11-keto-β-boswellic acid | 3α-acetoxy-11-oxo-urs-12-en-24-oicacid | U | 5.6 | 2.7 | 1.6 | 8.3 | |
| Total amyrins: epi -amyrins (3α-OH), amyrenones (3-oxo) and amyrins (3β-OH) | 17.9 | 25.4 | 7.3 | 1.5 | |||
| Total boswellic acids: boswellic acids, hydroxy/keto boswellic acids and their acetates | 42.0 | 43.3 | 60.0 | 47.8 | |||
| Total lupanes (L): epi-lupeol, lupeol, lupeolic acid and its acetate | 6.3 | 9.1 | 1.1 | 0.9 | |||
| Total tirucallanes (T): β-elemonic acid, β- elemolic acid and its acetate | 5.0 | 0.4 | 12.7 | 22.1 | |||
| Ratio of ursanes (U) to oleananes (O) a | 2.2 | 2.5 | 2.8 | 1.9 | |||
| Ratio of 3- O -acetyl-11-keto-β-boswellic acid to 11-keto-β-boswellic acid | 6.9 | 6.4 | 1.1 | 4.2 | |||
Legend: - = not detected, ce = co-eluting compound which could not be resolved with mass spectral deconvolution, tr = trace, italic numbers are deconvoluted compounds. Structure types: C = cembrane, O = oleanane, U = ursane, L = lupane, T = tirucallane. Major diterpenoid and triterpenoid structures are depicted in figure S1.
a
Calculated using epi-amyrins, boswellic acids and 3-O-acetyl-boswellic acids.