## 2 Natural Products from Gorgonian Corals Belonging to the Genus _Junccella_
### Junceella juncea  
Five new steroidal glycosides, 4\({}^{\prime}\)-\(O\)-acetyl-3-\(O\)-[\(\beta\)-D-arabino-pyranosyl-oxy]-cholest-5-ene-3\(\beta\),19-diol (**39**) [34] and junceellosides A-D (**40-43**) [35], and a new glycerol, 1,2-\(O\)-[2\({}^{\prime}\)-hydroxyoctadecyl]-glycerol (**44**) [34] (Table 4) along with various known metabolites, including four sterols, 24\(\alpha\)-methylcholest-7, 22-dien-3\(\beta\),5\(\alpha\),6\(\beta\)-triol, 24\(\alpha\)-methylcholest-3\(\beta\),5\(\alpha\),6\(\beta\)-triol-25-monoacetate, 24\(\alpha\)-methylcholest-3\(\beta\),5\(\alpha\), 6\(\beta\)-triol, and 24\(\alpha\)-methylcholest-5,23-dien-3\(\beta\)-ol; six amines, 1-\(O\)-\(\beta\)-D-gluco-pyranosyl-(2\(S\),3\(S\),4\(R\), 8\(Z\))-2-\(N\)-(2\({}^{\prime}\)-hydroxypalmitoyl)-octadecashinga-8-ene, (2\(S\),3\(R\))-2-\(N\)-palmitoyl-octadecashinga, (2\(S\),3\(R\),4\(E\))-2-\(N\)-palmitoyloctadecashinga-4-ene, thymine, uracil, and adenosine; and butyl alcohol, were isolated from the gorgonian coral _J. juncea_, collected off the South China Sea in 2004-2005 [34,35]. In addition, 14 new briarane derivatives, juncins O-Q (**45-47**) [36], R-ZI (**48-57**) [37], and ZII (**58**) [38] (Table 5), along with eight known briaranes, praelolide, junceellin, gemmacolides A-C and F, junceellolide D [34,38], and (+)-11\(\beta\),20\(\beta\)-epoxyjunceellolide D [30,38], were also isolated from _J. juncea_. \begin{table}
\begin{tabular}{c c c c} \hline
**Structure** & **No. ** & **Name** & **Ref. ** \\ \hline \(\begin{array}{c}\text{HO}\\ \text{ \begin{table}
\begin{tabular}{c c c c c} \hline
**Structure** & **No.** & **Name** & **Biological Activity** & **Ref.** \\ \hline
**AcO** & **45** & Juncin O & juncins O–Q showed medium antifeedant & [36,38] \\  & & (R = OC(O) & activity (90.7, 69.0, 46.5\%) toward the & \\  & & CH\({}_{2}\)CH(CH\({}_{3}\))\({}_{2}\)) & second-instr larvae of _Spodoptera litura_ at & \\  & & & a concentration of 500 \(\mu\)g/mL & \\  & & & juncins O–Q and ZII were not active in & \\  & & & cytotoxicity testing with K562, A549, Hela & \\  & & & and Hep2 cells \({}^{a}\) & \\  & & & medium cytotoxicity (cell mortality: & \\  & & & 8.7\% in 24 h and 11.9\% in 48 h) toward & \\  & & & the second-instr larvae of _S. litura_ at a & \\  & & & concentration of 100 \(\mu\)g/mL & \\  & & & & concentration of 100 \(\mu\)g/mL & \\ \hline \end{tabular}
\end{table} 
Table 5: The new natural products from _Junceella juncea_-V. \begin{table}
\begin{tabular}{l l l} \hline \hline \(R_{4}\) & Juncin R & juncins R–ZII (**48–58**) exhibited [37] \\  & (R\({}_{1}\) = R\({}_{2}\) = R\({}_{3}\) = OAc, & antifouling activity toward the \\  & R\({}_{4}\) = OC(O)CH\({}_{2}\)CH(CH\({}_{3}\))\({}_{2}\), & barnacle _Balanus amphitrite_ \\  & R\({}_{5}\) = CI) & larvae (EC\({}_{50}\) = 0.004, 0.3, 2.7, \\  & 49 & Juncin S \\  & (R\({}_{1}\) = R\({}_{3}\) = R\({}_{4}\) = OAc, & and 0.004 \(\mu\)g/mL) \\  & R\({}_{2}\) = OC(O)CH\({}_{2}\)CH(CH\({}_{3}\))\({}_{2}\), & \\  & R\({}_{5}\) = CI) & \\
**50** & [PERSON] & \\  & (R\({}_{1}\) = OC(O)CH\({}_{2}\)OC(O) & \\  & (CH\({}_{2}\))\({}_{2}\)CH(CH\({}_{3}\))\({}_{2}\), & \\  & R\({}_{2}\) = R\({}_{3}\) = R\({}_{4}\) = OAc, & \\  & R\({}_{5}\) = OH) & \\
**51** & [PERSON] & \\  & (R\({}_{1}\) = R\({}_{2}\) = R\({}_{4}\) = OAc, & \\  & R\({}_{3}\) = OC(O)CH\({}_{2}\)CH(CH\({}_{3}\))\({}_{2}\), & \\  & R\({}_{5}\) = OCH\({}_{3}\)) & \\
**52** & Juncin V & \\  & (R\({}_{1}\) = R\({}_{3}\) = OAc, & \\  & R\({}_{2}\) = R\({}_{4}\) = OH, & \\  & R\({}_{5}\) = OCH\({}_{3}\)) & \\
**53** & Juncin W & \\  & (R\({}_{1}\) = R\({}_{3}\) = R\({}_{5}\) = OAc, & \\  & R\({}_{2}\) = R\({}_{4}\) = OH) & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: _Cont._In biological activity testing, juncins R-ZII (**48**-**58**) showed potent antifouling activities against the larval settlement of barnacle _Balanus amphitrite_ at a nontoxic concentration (Table 5), and the structure-activity relationships have been discussed [37,38].