Chemical Constituents from the Aerial Parts of Cyrtopodium paniculatum

Abstract

Abstract:We report the first phytochemical study of the neotropical orchid Cyrtopodium paniculatum. Eight new compounds, including one phenanthrene 1, one 9,10-dihydro-phenanthrene 2, one hydroxybenzylphenanthrene 3, two biphenanthrenes 4-5, and three 9,10 dihydrophenanthrofurans 6-8, together with 28 known phenolic compounds, mostly stilbenoids, were isolated from the CH 2 Cl 2 extract of its leaves and pseudobulbs. The structures of the new compounds were established on the basis of extensive spectroscopic methods.

Phenanthrenes: A Promising Group of Plant Secondary Metabolites

“…Hydroxybenzyl-substituted monophenantheres were isolated from genera of the Orchidaceae family, including Bletilla (e.g., 108 – 110 ), Cremastra (e.g., 64 , 111 , 112 ), Cyrtopodium ( 118 ), Monomeria ( 119 ), and Pholidota ( 162 ) and Dioscoreaceae species ( D. bulbifera ; diobulbinone A, 66 ) …”

“…Phenanthrofurans and phenanthropyrans form another group of monophenanthrenes. These rings are usually attached to the phenanthrene core at C-1 and C-2 ( 147 , 148 , 150 – 154 , 158 – 160 ), ,,,,,, C-2 and C-3 ( 149 , 155 – 157 ), , or C-4 and C-5 ( 162 ) . Interestingly, all of the novel furan-condensated derivatives are saturated between C-9 and C-10, and among the phenanthropyrans, only loddigesiinol B ( 160 ) has an unsaturated phenanthrene skeleton, while the others are dihydrophenanthrenes.…”

“…Most of the dimers isolated from the family Orchidaceae are considered to be formed by the coupling of the commonly occurring monomers of Orchidaceae species, e.g., lusianthridin ( 172 , 175 , 176 , 179 , 181 , 190 , 196 – 199 ), ,,,,,, lusianthrin ( 198 , 199 , 212 ), coelonin ( 171 , 172 , 178 , 189 , 191 , 193 – 195 ), ,,, 6-methoxycoelonin ( 186 , 188 ), , flavanthrinin ( 191 , 192 , 206 – 208 ), ,, orchinol ( 182 ), nudol ( 186 , 196 , 197 , 205 , 209 , 210 ), ,,, and 2-hydroxy-4,7-dimethoxyphenathrene ( 187 – 190 , 193 – 195 , 209 , 211 ). ,, Monbarbatains B ( 198 ) and C ( 199 ) are both derived by the coupling of lusianthridin with lusianthrin and differ only in the positions of their linkages . In the case of compound 207 , the recently isolated aerosanthrene ( 89 ) serves as a monomer. , Symmetrical dimers can also be found among the isolated compounds of Orchidaceae species, for example, in a diphenanthrene ( 170 ) obtained from Bletilla yunnanensis , in which two O -methylorchinol monomers are linked at C-1 and C-1′ .…”

“…87 The 9,10-dihydrophenanthrene skeleton of monbarbatain E (67) is also linked to a dihydrostilbene moiety (stilbostemin E), but in this case through an O atom, in contrast with the above-mentioned phenanthrenes, where the two parts of the compounds are connected via C−C coupling. 88 Hydroxybenzyl-substituted monophenantheres were isolated from genera of the Orchidaceae family, including Bletilla (e.g., 108−110), 89 Cremastra (e.g., 64,111,112), 90 Cyrtopodium (118), 91 Monomeria (119), 6 and Pholidota (162) 18 and Dioscoreaceae species (D. bulbifera; diobulbinone A, 66). 92 Symmetrical naturally occurring phenanthrene derivatives are rather uncommon, but recently a symmetrical tetracyclic molecule, juncutol (74), was obtained from Juncus acutus.…”

Three Novel Biphenanthrene Derivatives and a New Phenylpropanoid Ester from Aerides multiflora and Their α-Glucosidase Inhibitory Activity

“…The family Orchidaceae is divided into 5 subfamilies, i.e., Epidendroideae, Orchidoideae, Vanilloideae, Cypripedioideae, and Apostasioideae [ 44 ]. So far, dimeric phenanthrenes have been reported from only two subfamilies, i.e., Epidendroideae (the genera Stanhopea, Bletilla, Pholidota, Pleione, Otochilus, Arundina, Bulbophyllum, Dendrobium, Monomeria, Cremastra, Agrostophyllum, Liparis, Cyrtopodium , Eria , Eulophia , Cirrhopetalum , Calanthe, Lusia, and Prosthechea ) and Orchidoideae (the genera Spiranthes and Gymnadenia ) [ 34 , 39 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 ]. No biphenanthrenes have been found outside these two subfamilies.…”