Bioprospecting for active compounds: impact of milling, extract fractions and freeze-drying on targeted terpene compounds of Helichrysum odoratissimum (L.) Sweet

This study investigated the effect of processing and freeze-drying on targeted volatile compounds (terpenes) of Helichrysum odoratissimum (L.) Sweet. Air-dried plant material was processed to obtain: (i) roughly ground leaves and stems (RGMHO); (ii) finely ground leaves and stems (FGMHO); and (iii) wool-like fraction (WLMHO). Terpene content of the air-dried samples, crude ethanol extract (CE, filtrate), sediments and freeze-dried (FDE) powders from the different processed fractions were analysed using gas chromatography-mass spectrometry (GC-MS). Results showed that the highest a-pinene (91.3 mu g l(-1)) was obtained in the CE compared to the freeze-dried (approximate to 3.0 mu g l(-1)) extracts ( p <= 0.05). Eucalyptol was significantly higher in the air-dried leaves (27.3 mu g l(-1)) than were CE and FDE (4.0 and 0.9 mu g l(-1) respectively), while beta-caryophyllene, pulegone and humulene contents were significantly higher in the FDE samples (p <= 0.05). These results demonstrated that processing had significant impact on the concentration of targeted terpenes in H. odoratissimum. This study is the first report on the identification and quantification targeted terpenes in H. odoratissimum (L.) Sweet.

Automated summary

This study investigated the effect of processing and freeze-drying on the concentration of targeted terpenes in Helichrysum odoratissimum. The results showed that processing had a significant impact on the concentration of terpenes in H. odoratissimum.