## 2 Results and Discussion
### Identification of Pharmacologically Active Volatiles of Houttuynia cordata Thunb by GC/SAW
2-Undecanone also known as methyl nonyl ketone is contributed as an insect repellent for strong odor. Also, unpleasant and fishy odors of _H. cordata_ Thunb is caused by decanoyl acetaldehyde and lauraldehyde [32]. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Peak**} & \multirow{2}{*}{**Compound**} & \multicolumn{4}{c}{_Huntuynia cordata_ Thunb} \\ \cline{3-8}  & & \multicolumn{2}{c}{**Leaves**} & \multicolumn{2}{c}{**Aerial Stems**} & \multicolumn{2}{c}{**Underground Stems**} \\ \cline{3-8}  & & **GC/SAW** & **HS-SPME** & **GC/SAW** & **HS-SPME** & **GC/SAW** & **HS-SPME** \\ \hline
23 & 5-Methyl-3-(1-methyl-ethenyl)cyclohex & - & 0.2(20.98) & - & 0.1(19.01) & - & 0.3(13.77) \\
24 & 1-Methyl-3-(1-methyl-ethenyl)cyclohex & - & 0.1(16.37) & - & 0.1(25.93) & - & 0.2(15.79) \\
25 & \(\alpha\)-Terpinenyl acetate & - & - & - & 0.1(23.01) & - & 0.4(19.04) \\
26 & Neryl acetate & - & t & - & 0.1(20.01) & - & 0.2(15.90) \\ n & Geranyl acetate & - & 2.5(34.74) & 10.4(2.45) & 1.6(23.63) & 3.1(7.94) & 1.1(29.07) \\
27 & \(\beta\)-Elemene & - & 0.1(27.35) & - & 0.1(26.17) & - & 0.1(21.45) \\ o & **Lauraldehyde** & 3.5(7.69) & 4.4(50.59) & - & 0.4(35.12) & - & 0.1(43.17) \\ p & \(\beta\)-Caryophyllene & 7.8(8.73) & 5.5(34.50) & 9.7(9.31) & 6.6(40.31) & 5.6(11.87) & 5.1(30.01) \\
28 & Aromadendrene & - & t & - & - & - & - \\
29 & \(\beta\)-Farmesene & - & 0.2(48.56) & - & 0.2(37.81) & - & 0.1(40.48) \\
30 & \(\alpha\)-Humulene & - & 0.3(37.04) & - & 0.3(40.89) & - & 0.3(33.67) \\
31 & Azulene & - & - & - & 0.1(26.38) & - & 0.4(22.93) \\
32 & Germacrene-D & - & 0.2(55.55) & - & 0.1(43.10) & - & t \\
33 & \(\alpha\)-Farmesene & - & 0.2(54.50) & - & - & - & - \\
34 & Aromadendrene & - & 0.1(41.41) & - & 0.1(47.17) & - & 2.2(38.38) \\
35 & _allo_-Aromadendrene & - & 0.2(46.97) & - & 0.1(39.05) & - & - \\
36 & Bicyclogermacrene & - & 0.9(56.26) & - & - & - & - \\
37 & \(\alpha\)-Selinene & - & - & - & 0.7(41.42) & - & 0.7(42.59) \\
38 & \(\delta\)-Cadinene & - & t & - & - & - & - \\
39 & Caryophyllene oxide & - & - & - & - & 0.1(27.67) \\ \hline \hline \end{tabular} (-) Not detected; t, \(<\)0.05%. % Figures are their relative proportions as percent of total area, %(RSD), \(n=3\). The characteristic compounds are indicated in bold. _H. cordata_ Thunb which are from Anmyeon Island, South Korea was used. Column: DB-624 (6% cyanopropyl phenyl polydimethylsiloxane, 1 m \(\times\) 0.25 mm \(\times\) 0.25 \(\upmu\)m) fused silica capillary column was used by GC/SAW. Ultra 2 (5% phenyl polydimethylsiloxane, 25 m \(\times\) 0.25 mm \(\times\) 0.33 \(\upmu\)m) fused silica capillary column was used by HS-SPME-GC-MS. Sampling time: The headspace vapor of sample was swept into the trap inside the system at 25 \({}^{\circ}\)C for 1 s by GC/SAW. The SPME fiber was exposed to the headspace above the sample vial at 25 \({}^{\circ}\)C for 1 h by HS-SPME-GC-MS.  
\end{table} 
Table 1: _Cont._Monoterpenes (\(\beta\)-myrcene, _cis_-ocimene, and limonene), decanal, geranyl acetate, and bornyl acetate have pharmacological properties such as antimicrobial, anti-fungal, anti-bacterial. In addition, limonene has an anti-cancer effect. Lauraldehyde and 2-undecanone have anti-virus properties [2,33]. In aerial stems for _H. cordata_ Thunb, \(\beta\)-myrcene, _cis_-ocimene and decanal, which comprise 50.1% of the total amounts, are also the dominant volatile components. 2-Undecanone and lauraldehyde were not found. The concentration of bornyl acetate (17.4%) is considerably higher than that of leaves (1.7%) and geranyl acetate (10.4%) was found, as indicated in Table 1. The total amounts of pharmacologically active volatiles of aerial stems for _H. cordata_ Thunb are four times lower than those of leaves or underground stems. In underground stems for _H. cordata_ Thunb, monoterpenes involving \(\beta\)-myrcene, _cis_-ocimene, camphene, sabinene, \(\beta\)-pinene, limonene, and \(\alpha\)-terpinolene which comprise 74.6% of the total amounts, are also the dominant volatile components.