# Seasonal Variability and Effect of Sample Storage on Volatile Components in _Calypogeia azurea_
## 2 Results and Discussion
### The Effect of Seasonality on the Content of Volatile Organic Compounds  
The liverworts of the _Calypogeia azurea_ species are characterized by a visible variation in the composition of specialized metabolites resulting from the vegetation period of the plant. Cyclical changes in the VOC composition were observed in spring, summer, and autumn, repeated in 2019-2021. It is most visible in the example of compounds dominating in the composition of the VOC. The observed changes can be divided into compounds with the highest content in summer. These include: \(\delta\)-elemene (**22**), anastreptene (**25**), alloaromadendrene (**40**), selina-5,11-diene (**41**), germacrene D (**47**), bicyclogermacrene (**49**), cuparene (**51**), compound IR = 1637 (**63**), and germacra-4(15),5,10(14)-trien-1-alpha-ol (**77**). The second group consists of compounds with the lowest content in summer. They include: compound IR = 902 (**8**), \(\beta\)-pinene (**12**), limonene (**14**), \(\beta\)-cyclodextrin (**19**), 1,4-dimethyl  
Figure 1: Compare VOC percentages for samples stored refrigerated and frozen for 1 month and 3 months. Compounds: 1: 4-(cyclopent-1-enyl)benzoic acid methyl ester (**74**), 2: bicyclogermacrene (**49**), 3: alloaromadendrene (**40**), 4: germacrene D (**47**), 5: selina-5,11-diene (**41**), and 6: isospathulenol (**67**). Storage: \(\blacksquare\) fresh, \(\blacksquare\) fridge—1 month, \(\blacksquare\) fridge—3 months, \(\blacksquare\) freezer—1 month, \(\blacksquare\) freezer—3 months. azulene (**60**), and 4-(cyclopent-1-enyl)benzoic acid methyl ester (**74**). A small group of compounds showed a continuous increase or decrease in content from spring to autumn; examples include methyl 2-methylazulene-1-carboxylate (**79**), compound IR = 1224 (**18**), and compound IR = 1392 (**28**). Plants secrete a variety of volatile organic compounds that provide protection against mechanical damage, environmental changes, and pathogens. As a result, these tiny plants developed a unique variety of bioactive compounds as part of their survival strategies. Most sesquiterpenoids increase during spring and peak in summer. These compounds are likely to be elevated during the summer to allow liverworks to cope with abiotic stresses such as high temperatures and droughts. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**No. **} & \multirow{2}{*}{**Compounds**} & \multirow{2}{*}{**RI \({}^{*}\)**} & \multicolumn{6}{c}{**Code \({}^{\text{b}}\)**} \\ \cline{4-9}  & & & & **C-1** & **C-2** & **C-3** & **C-4** & **C-5** \\ \hline
1 & 2-methyl-1-propanol & \textless{}700 & - & - & - & - & - \\
2 & pentanal & \textless{}700 & 0.13 (0.02) & 0.10 (0.02) & 0.05 (0.01) & 0.07 (0.03) & 0.03 (0.01) \\
3 & cyclopentanol & 748 & - & - & - & - & - \\
4 & 3-methyl-1-butanol & 768 & 0.04 (0.02) & 0.02 (0.02) & 0.50 (0.08) & 0.26 (0.08) & 0.32 (0.08) \\
5 & hexanal & 834 & 0.05 (0.01) & 0.03 (0.02) & 0.02 (0.01) & 0.02 (0.01) & 0.01 (\({}^{\circ}\)) \\
6 & (\(Z\))-3-hexen-1-ol & 886 & - & - & - & 0.04 (0.01) & 0.11 (0.04) \\
7 & 1-hexanol & 896 & - & - & - & 0.06 (0.02) & 0.11 (0.03) \\
8 & 10(M+[5]8) 91(100)77(13) & 902 & 0.79 (0.06) & 0.59 (0.07) & 0.11 (0.04) & 0.35 (0.11) & 0.02 (0.01) \\
9 & tricyclene & 939 & - & - & - & - & - \\
10 & a-pinene & 952 & 0.06 (0.01) & 0.04 (0.02) & 0.02 (0.01) & 0.03 (0.01) & 0.01 (\({}^{\circ}\)) \\
11 & camphene & 971 & - & - & - & - & - \\
12 & \(\beta\)-pinene & 1004 & 0.66 (0.01) & 0.18 (0.03) & 0.11 (0.04) & 0.07 (0.02) & 0.02 (0.01) \\
13 & 3-octanol & 1018 & - & 0.13 (0.02) & - & - & 0.15 (0.11) & - \\
14 & limonene & 1048 & 0.67 (0.01) & 0.62 (0.02) & 0.26 (0.05) & 0.65 (0.21) & 0.13 (0.04) \\
15 & benzenealdehyde & 1093 & 0.12 (0.02) & 0.33 (0.02) & 0.09 (0.02) & 0.48 (0.12) & 0.01 (\({}^{\circ}\)) \\
16 & 1-octran-3-yl-acetate & 1123 & 0.01 (?) & 0.03 (0.02) & 0.07 (0.02) & 0.02 (0.01) & 0.08 (0.02) \\
17 & benzenehanol & 1156 & 0.01 (?)