Table 1.
List of perforated pots with their number of perforations, provenance, age and type of analysis performed.
Figure 1.
Perforated funerary pots and their context: (a) location of archaeological sites in Belgium, (b) picture of grave T183 with funerary pots (Liège, Place Saint-Lambert), (c) picture of perforated funerary pots from grave T183 (Liège, Place Saint-Lambert).
Abbreviations: H = Huy, L = Liège, N = Namur, Q = Quaregnon, R = Rebecq.
Figure 2.
GC-MS chromatograms of silylated extracts of (a) modern Boswellia carterii resin, (b) sample R9, (c) sample Q10 and (d) sample Q11.
Insets in (b) and (d) show partial m/z 292 chromatograms. Legend to compound labels: I.S. = internal standard, C16∶0 = palmitic acid, C18∶0 = stearic acid, DHA = dehydroabietic acid, 1 = serratol (free OH), 2 = incensol (free OH), 3 = incensol (OTMS), 4 = des-A-ursa-5(10),12-diene, 5 = des-A-26,27-dinorursa-5,7,9,11,13-pentaene, 6 = 1,9-dimethylchrysene, 7 = 24-noroleana-3,9(11),12-triene, 8 = 24-norursa-3,9(11),12-triene, 9 = 24-noroleana-3,12-diene, 10 = 24-norursa-3,12-diene, 11 = 24,25,26,27-tetranorursa-1,3,5(10),6,8,11,13-heptaene, 12 = epi-β-amyrin, 13 = epi-α-amyrin, 14 = β-amyrenone, 15 = 24-norursa-3,12-dien-11-one, 16 = Δ2-α-boswellic acid, 17 = α-amyrenone, 18 = Δ2-β-boswellic acid, 19 = α-boswellic acid, 20 = β-boswellic acid, 21 = lupeolic acid, 22 = 2,9-dimethylpicene, 23 = β-elemonic acid, 24 = β-elemolic acid, 25 = 11-keto-α-amyrin, 26 = 3-O-acetyl-α-boswellic acid, 27 = 11-keto- Δ2-β-boswellic acid, 28 = 3-O-acetyl-β-boswellic acid, 29 = 3-O-acetyl-lupeolic acid, 30 = 11-keto-β-boswellic acid, 31 = 3-O-acetyl-11-keto-β-boswellic acid.
Table 2.
Relative abundances (%) of di- and triterpenoids identified in commercial specimens of Boswellia resins.
Figure 3.
Mass spectral deconvolution of incensol and serratol in an underivatized extract of Boswellia carterii.
Abbreviations: TIC = total ion count chromatogram, ECC = extracted compound chromatogram, m/z = mass to charge ratio. Deconvoluted mass spectra are identified as (#1) incensol and (#2) serratol (see text).
Figure 4.
Deconvoluted mass spectra of Δ2-boswellic acids as recorded in sample Q11: (a) Δ2-α-boswellic acid = oleana-2,12-dien-24-oic acid, (b) Δ2-β-boswellic acid = ursa-2,12-dien-24-oic acid, (c) Δ2,9(11)-β-boswellic acid = ursa-2,9(11),12-dien-24-oic acid and (d) 11-keto-Δ2-β-boswellic acid = 11-keto-ursa-2,12-dien-24-oic acid.
Abbreviations: m/z = mass to charge ratio, TMS = trimethylsilyl, rDA = retro-Diels-Alder, M = molecular ion.
Figure 5.
Detail of the total ion count (TIC) and extracted ion chromatograms of sample Q11, showing the presence of mono- and polyaromatic triterpenoids.
Selected ions are specific for 24,25-dinorursa-1,3,5(10),12-tetraene (m/z 361+376), 24,25-dinorursa-1,3,5(10),9(11),12-pentaene (m/z 359+374), 24,25,26,27-tetranorursa-1,3,5(10),6,8,10,13-heptaene (m/z 357+342) and corresponding oleanane compounds and 2,9-dimethylpicene (m/z 289+306).
Figure 6.
GC-MS chromatogram of silylated extracts of sample N13.
Abbreviations (n = carbon number, m = number of double bonds): internal standard (I.S.), ω-(alkylphenyl)-alkanoic acid (APAA, n:m), fatty acids (filled rhombi, n:m), 9,10-dihydroxyalkanoic acid (filled circle, n:m), n-alkanols (open triangles, n) and mid-chain ketones (filled squares, n). Synthetic contaminants are marked with an asterisk.
Figure 7.
Mass spectral deconvolution of the mid-chain ketones detected in sample N13.
Based on the profile of mid-chain ketones and the distribution of their carbonyl position, the fatty acyl profile can be reconstituted (see text). Ketones are abbreviated by their carbon number (CN) and fatty acyl chains are abbreviated by n:m (n = carbon number, m = number of double bonds).
Table 3.
Identification and abundance (in %) of charcoal fragments found in the perforated pots.
Figure 8.
Summary of triterpenoid degradation reactions, demonstrated for ursane-type compounds.
*Hydroxy-amyrins were not identified as such but are putative intermediates in the formation of dehydrated amyrins.
Table 4.
Summary of major resin markers identified in samples R2, R9, Q10, Q11, Q12, L14 and L15. A full list of all individual compounds can be found in Table S1.