## 2 Results
### Volatile Compounds Analysis  
Gas chromatography-mass spectrometry (GC-MS) results of the volatile compounds obtained from _Helichrysum_ crude extracts are shown in Table 2. In this study, a total of 71 volatile compounds were tentatively identified across both extraction solvents. These compounds were classified into 16 chemical classes. Based on the result obtained, the contribution of individual chemical classes from the 70% acetone and 95% ethanol extracts of _H. odoratissimum_ differed quantitatively (_p_\(\leq\) 0.05). Acetone extract of _H.__odoratissimum_ contained the most abundant volatiles with sesquiterpenoids (40.2%) > alkanes (10.6%) > aromatic hydrocarbons (10.2%) > sesquiterpenes (8.7%) > monoterpencids (4.3%) > monoterpenes (1.8%) > terpene (1.2%) > epoxide (0.8%) > phenylproene and terpenoid (0.3%) > bromodiphenyl ethers (0.2%). On the other hand, the most abundant classes volatile compounds in ethanolic extracts of _H.__odoratissimum_ were in the following order: sesquiterpenoids (37.8%) > sesquiterpenes (18.6%) > oxanes (14%) > alkane hydrocarbons (12.4%) > terpene (3.3%) > monoterpenes (1.9%) > terpenoid (1.6%) > epoxide, phenylprope, and bromodiphenyl ethers (0.7%) > monoterpencids (0.6%) > aliphatic compounds (0.3%). A similar pattern was obtained for _H.__pathum_ for each given solvent with lesser quantities of mostly commonly identified compounds. Sesquietrepenoids are modified class of terpen with different functional groups and oxidized methyl groups moved or removed at various positions with three carbon isoprene units. These terpene derivatives are equipped with high pharmacological properties [14]. Thus, their presence in plant extracts signals its potential therapeutic effects. Viridiflorol, a sesquiterpenoid, was the major compound across all _Helichrysum_ spp. and both extraction solvent tested. This study showed the relative percentage/concentration of viridiflorol (26.2 \(\pm\) 1.24% and 16.8 \(\pm\) 0.31%) for acetone and ethanol extracts of _H.__odoratissimum_; the relative percentage/concentration of viridiflorol (17.9 \(\pm\) 2.15%) for acetone and (17.0 \(\pm\) 0.01%) ethanol extracts of _H.__pathum_ extracts were significantly (_p_ < 0.05) lower than the acetone extracts of _H.__odoratissimum_. Relatively, higher concentrations of alkane hydrocarbons such as tetradecane and hexadecane were identified for _H.__odoratissimum_ extracts regardless of extraction solvents compared to _H.__pathum_. Furthermore, compounds such as xylene, para-xylene, and \(\alpha\)-pinene oxide were only identified under acetone extracts of _H.__odoratissimum_, whereas a monoterpene: 1,8-Cineole (percentage: 13.6 \(\pm\) 0.52%) was only recorded in the ethanol extract of _H.__odoratissimum_. Relative percentage of sesquiterpenes: \(\alpha\)-gurjunene (1.2 \(\pm\) 0.19% and 1.4 \(\pm\) 0.08%), \(\beta\)-caryophyllene (1.2 \(\pm\) 0.16% and 1.3 \(\pm\) 0.03%), \(\beta\)-selineen (2.2 \(\pm\) 0.20% and 3.2 \(\pm\) 0.01%), and \(\gamma\)-gurjunene (3.2 \(\pm\) 0.57% and 3.3 \(\pm\) 0.08%), were only identified in _H.__pathum_ for both acetone and ethanol solvents, respectively. Similarly, a significantly higher (_p_ < 0.05) concentration of a fatty acid methyl ester methyl cinnamate (cinnamic acid, methyl ester), which is a sesquiterpene, was only identified in the acetone and ethanol extracts of _H.___patulum_ (20.6 \(\pm\) 0.03% and 19.7 \(\pm\) 0.05%, respectively). On the contrary, _8_-cadinene was identified as the second major compounds under the sesquiterpenoid category, however, significantly high concentrations of _8_-cadinene (20.4 \(\pm\) 1.30% and 16.1 \(\pm\) 0.49%) were quantified in the acetone and ethanol extracts of _H. patulum_ extracts than those of _H. odoratissimum_ (5.5 \(\pm\) 0.46% and 2.1 \(\pm\) 0.20%). \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Classification**} & \multirow{2}{*}{**Compounds**} & \multirow{2}{*}{**RT**} & \multirow{2}{*}{**RI (Exp. )**} & \multirow{2}{*}{**RI (Lib.