## 2 Classes of Secondary Metabolites
### Diterpenes
Dihydrosarsolenone **218** resulting from sarsolenone **223** by terminal double bond \(\Delta^{15}\) reduction followed by the oxidation of C-18 gave methyl dihydrosarsolenoneate **219**. Capnosane diterpenes were first isolated from _S. solidum_ and _S. trocheliphorum_. The only example reported with \(\alpha\), \(\beta\)-unsaturated \(\varepsilon\)-lactone subunit was sarsolilide A **222**, from _S. solidum_, in which, the hydration of the exomethylene group provided carbon-10 epimers, sarsolilides B and C **220** and **221**[80]  
Ethyl acetate extract of _S. trocheliophorum_ yielded twenty-three isolates, of which nineteen were cembranoids with unique capnosane skeleton identified as trocheliophols A-S **224-242** and two analogues, 4-epi-sarcophyll L **243** and sarcophylolide C **182**. The structures were investigated by a full spectral data, and their absolute configurations were established through modified Mosher's assay, CD and X-ray diffraction. Trocheliophols C **226**, E **228**, F **229**, and M **236** all possessed a structure similar to sarcophytolide C **176**, while, trocheliophol Q **240** was identified as the C-8 methoxylated model of trocheliophol F **229**. However, trocheliophol R **241** possessed a similar structure to trocheliophol F **229** but it differed in the presence of the methoxy group [81]. Chemical determination of _S. elegans_ CH\({}_{2}\)Cl\({}_{2}\)/MeOH extract resulted in isolation of four cembranoids identified as sarcophelegans A-D **244-247**. Sarcophelegan A **244** was found to be the 11,12-epoxy derivative of sarcophelegan C **246**. Through X-ray crystallographic examination using anomalous scattering of Cu K\(\alpha\) radiation, sarcophelegan A **244** structure was verified. Moreover, sarcophelegan C **246** was found to be the 7-hydrogenated derivative of sarcophelegan B **245**[18]. Five polyoxygenated cembranoids were identified as polyoxygenated cembranoids, (+)-1,15-epoxy-2 methoxy-12 methoxycarbonyl-11\(E\)-sarcophyll-11\(E\)-sarcophyll-11\(E\)-sarcophyll-11\(E\)-sarcophile **249**, 3\(A\)-epoxyhenberoxide A **250**, ehrenberogl D **251** and ehrenberogl E **252** in _S. ehrenbergi_. The authors proposed that (+)-1,15-epoxy-2-methoxy-12 methoxycarbonyl-11\(E\)-sarcophylloxide **248** was the 1,15 epoxy-2-methoxyal equivalent of lobophynin C **162**. Through investigating the spectral data and X-ray crystallization of (+)-2-epi-12-methoxycarbonyl-11\(E\)-sarcophile **249** it was found that it differed in the alignment of the \(\alpha\),\(\beta\)-unsaturated \(\gamma\)-lactone ring attached to C-2 of the 14-membered ring [63]. 3,4-epoxyhenberoxide A **250**; an analogue to ehrenberoxide A **159** where the epoxide in ehrenberoxide A **159** was substituted by a double bond at C3 and C4 [82]. Eight metabolites were isolated from _S. solidum_, three sarsolenanes, 7-deacetyl-sarsolenone **253**, sarsolenone **223**, and methyl dihydro-sarsolenoene **219** together with, sarsolilide B **220**. All 7-deacetyl-sarsolenone **253**, sarsolenone **223**, sarsolilide B **220**, could be used as a chemotaxonomic marker for this species [83]. Three isolates; trocheliane **254**, tetracyclic biscembrane and two cembranoid diterpenes, sarcotrocheldiols A and B **255** and **256**, were isolated from _S. trocheliophorum_. Their relative configuration and structure of the isolates were investigated by spectral data [84]. From _Sarcophyll_ sp., one cembrane diterpene, 16-hydroxycembra-1,3,7,11-tetraene **257**, besides, 15-hydroxycembra-1,3,7,11-tetraene **258** were reported. Structures were investigated by spectral data [85]. Three cembranoids from _S. trocheliophorum_, sarcophyltols D-F **259-261** highly oxidative compounds, besides, 11,12-epoxy-1(_E_),3(_E_), 7(_E_)-cembratrien-15-ol **262** and sinugibberol **263** were isolated. All structures were investigated by a full spectral data and by comparing with previous stated data [86]. Another six cembranoids, sacrophytrols G-L **264-269** together with cassumol A **270**, were isolated from _S. trocheliorhorn_[87].