Triterpenoid mastic

Dammar resin was introduced into Europe in the nineteenth century, mainly as a paint varnish It is still used today since it has good optical properties and low acidity. It is derived from various species (the genus Hopea and Shorea of the Dipterocarpaceae family). It is characterised by tetracyclic triterpenoids of the dammarane series and contains minor amounts of pentacyclic triterpenoids of the series of olanane, ursane and hopane. It also contains a polymeric fraction named polycadinene or [S-resene. Dammar resin triterpenoids undergo oxidation with ageing, as described for the components of mastic resin. 

The first two PCs account for 85% of the total variance of the data set. The PCA highlights that the sample is placed in the area of the mastic resin cluster. This confirmed the hypothesis made on the basis of a qualitative examination of the mass spectra, even though the sample is clearly shifted at lower values of PC2 with respect to the centroid of the mastic cluster. This was attributed to the presence of other substances mixed with the resin, and/or to a different quantitative distribution of the triterpenoids present in the censer with respect to the reference raw mastic resin. 

Despite the complexity of the chemical composition of the resinous materials, in a few minutes such techniques provide a mass spectral fingerprint, which highlights the compounds that are the main components in the sample. They avoid any sampling treatment before analysis. They have thus enabled diterpenoid resinous materials from Coniferae, and several triterpenoid materials to be clearly identified. In particular, the DE-MS technique is able to distinguish between different triterpenoid materials such as mastic resin, frankincense resin and birch bark tar. In fact, using PCA on DE-MS mass... 

Two slightly different laser desorption/ionisation methods were developed simultaneously by Karas and Hillenkamp [1] and Tanaka et al. [2]. Whereas Karas and Hillenkamp used small organic matrix molecules to assist and facilitate the desorption and ionisation of analytes (MALDI), Tanaka et al. used ultra-fine metal powders and glycerol. Zumbiihl et al. first analysed natural triterpenoid resins, dammar and mastic, both... 

A study of the photoageing of single triterpenes was undertaken to establish the suitability of the GALDI-MS method [39]. The triterpenes served as a simplified reference system for the more complex natural triterpenoid resins, dammar and mastic. Seven triterpenes were... 

The resin composition was indeed found to influence the ageing processes in mastic, the polymer fraction was shown to reduce the oxidation of triterpenoids (Figure 5.8). This was found for both natural ageing [33, 36] and artificial ageing. Because the polymer, a polymyrcene, contains many double bonds that can easily be oxidised [42], it might act as a radical stabiliser. The mastic samples shown in Figure 5.8 were obtained from three aliquots of the same mastic solution, the polymer part of the first aliquot was removed and added to the third. 

Figure 5.8 GALDI mass spectra of mastic with variable amounts of polymer, artificially aged for 880 h (36] (a) without polymer (b) normal mastic and (c) with added polymer. Oxidation and decomposition is enhanced with lower amounts of polymer, thus the mastic polymer retards oxidation of the triterpenoids...

J. Boon, and G. Van der Doelen, Advances in the Current Understanding of Aged Dammar and Mastic Triterpenoid Varnishes on the Molecular Level, in Postprints of Fimis, Material Aesthetik Geschichte, International Kolloquium, AdR, Braunschweig, 1998, pp. 92 104. 

Figure 7.10 Some triterpenoid compounds found in mastic (Pistacia resin) (a) moronic acid, (b) oleanonic acid, (c) zsomasticadienonic acid, (d) masticadienonic acid.

Some triterpenoid compounds found in mastic (Pistacia resin) 156... 

The assessment of the origin of terpenic resins by GC7MS is generally based on the qualitative recognition of specific molecular biomarkers that are normally specific for the genus [1,2,8,27,81-86]. Figures 36.8-36.10 illustrate the mass spectra of several biomarkers of mastic resin, frankincence resin, and birch bark tar, respectively. The GC/MS analysis of di- and triterpenoids requires the extraction and derivatization of... 

The first online TLC-MS attempt in the field of triterpenoids was done only in 2005 in the study of the photo-oxidation of natural di- and triterpenoid resins used as paint varnishes [10], The resinous samples were applied onto a cellulose-coated TLC plate, which afterward was subjected to direct MALDI-TOF-MS analysis without any development. The plates were only sprayed with a saturated ethanol solution of 2,5-dihydroxybenzoic acid as matrix to assist the ionization of compounds. Triterpenoids were observed as protonated molecules or as sodium clusters. Dammaradienone, dammaradienol, nor-a-amyrone, and dammarenolic, oleanonic, and ursonic acid were detected in dammar resin moronic acid, masticadienonic acid, and 3-0-acetyl-3-epi(iso)masticadienonic acid were found in mastic resin and diterpenoid abietane and pimarane acids were present in colophony. The induced aging process produced oxidized triterpenoids, which were observed in the MS spectra... 

Boon, J. J., van der Doelen, G. (1999). Advances in the current understanding of aged dammar and mastic triterpenoid varnishes on the molecular level. In A. Harmssen (Ed.), Fimis Material, Asthetik, Geschichte Internationales Kolloquium Braunschweig 15-17 June 1998 Papers (pp. 92-104). Herzog Anton Ulrich-Museum. 

---