## 3 Results
### Whitening Ability
1A had the highest total chlorogenic acid and chlorogenic acid contents and the third highest neochlorogenic acid content. No. 1D had the third highest total chlorogenic acid and chlorogenic acid contents, as well as the second highest neochlorogenic acid content and the third highest cryptochlorogenic acid content. At low concentration (0.2 mg/mL), the tyrosinase inhibitory activity of No. 1B was lower than that of No. 2D and similar to that of No. 2A (Figure 2). However, at higher concentrations (0.4-1.0 mg/mL), tyrosinase inhibitory activities were significantly higher than those of both No. 2D and No. 2A. The results of total and individual chlorogenic acid contents showed that the total chlorogenic acid content of No. 1B (53.38 mg/g, sixth highest) is much lower than that of No. 2D (6445.59 mg/g, second highest) and No. 2A (3059.37 mg/g, fourth highest). The total chlorogenic acid content of No. 1B (53.38 mg/g, sixth highest) was much lower than that of No. 2D (6445.59 mg/g, second highest) and No. 2A (3059.37 mg/g, fourth highest). For No. 1B, only chlorogenic acid was detected, while for both No. 2D and No. 2A four different chlorogenic acids were detected. No. 1C, No. 2B, and No. 2C were \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & **No. 1A** & **No. 2A** & **No. 1B** & **No. 2B** & **No. 1C** & **No. 2C** & **No. 1D** & **No. 2D** \\ \hline Neochlorogenic acid [2] & 538.89 & 277.96 & ND 1  & 3.12 & ND 1  & ND 1 & 1090.31 & 1378.25 \\ Chlorogenic acid [2] & 6056.57 & 2244.90 & 53.38 & 102.19 & ND 1  & 4205.76 & 4892.28 \\ Cryptochlorogenic acid [2] & ND 1  & ND 1 & 0.38 & ND 1  & ND 1 & 52.62 & 171.13 \\ Isochlorogenic acid [2] & ND 1  & 138.89 & ND 1  & ND 1 & ND 1  & ND 1 & 3.93 \\ Total chlorogenic acid [2] & 6595.46 & 3059.37 & 53.38 & 106.69 & ND 1 & ND 1  & 5348.69 & 6445.59 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: The total and individual chlorogenic acid contents of the four solvent extracts of two varieties of Hang Ju. \begin{table}
\begin{tabular}{c c} \hline \hline  & **Tyrosinase Inhibition Activities** \\ \hline Neochlorogenic acid & 0.6427 \\ Chlorogenic acid & 0.6623 \\ Cryptochlorogenic acid & 0.1492 \\ Isochlorogenic acid & \(-\)0.0086 \\ Total chlorogenic acid & 0.6502 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: The Pearson correlation coefficients (r) between the total and individual chlorogenic acid contents and the tyrosinase inhibition activities. ranked among the bottom three on the basis of tyrosinase inhibitory activities. Their total chlorogenic acid contents were undetectable, 106.69 ug/g (fifth highest), and undetectable, respectively. From the above results, there are strong positive correlations for the tyrosinase inhibitory activity of each extract and total chlorogenic acids (\(r\) = 0.6502), the chlorogenic acid (\(r\) = 0.6623), and the neochlorogenic acid (\(r\) = 0.6427) but weak positive correlation for the cryptochlorogenic acid (\(r\) = 0.1492) and negative correlation for the isochlorogenic acid (\(r\) = -0.0086) (Table 5). The tyrosinase inhibitory activity did not depend entirely on the total chlorogenic acid content, chlorogenic acid content, or neochlorogenic acid content. For example, No. 1B had the third highest tyrosinase-inhibitory activity, but its total chlorogenic acid content was much lower than that of No. 2D and No. 2A, which had lower levels of tyrosinase-inhibitory activity. It was also lower than that of No. 2B, which had less than half of the tyrosinase-inhibitory activity at the same concentration. This indicated that No. 1B contains strong tyrosinase-inhibitory substance(s) that are not chlorogenic acids. Other components like adenosines, triterpenoids, or proteins should be analyzed in the future.