Ptychantins from the Liverwort Ptychanthus Striatus

Abstract

Five new ptychantins, J-N, along with two known ones, G and I, were isolated from the liverwort Ptychanthus striatus. Their structures were established by NMR spectroscopic analyses.

Biotransformation of ent -13- epi -manoyl oxides difunctionalized at C-3 and C-12 by filamentous fungi

“…The hydroxylations at non-activated positions of the carbocyclic system of this type of compounds are difficult to achieve by classical chemical means, this being tenable by microbial transformation, selecting the microorganism and the functional groups of the diterpene molecule. Some of the isolated metabolites have similar structures to several remarkable compounds, such as forskolin (Bhat et al, 1977), hamachilobenes (Toyota et al, 1988), natural ptychantins (Hashimoto et al, 1994;Wu et al, 2001), etc., but with a skeleton of the enantio series.…”

Highly Oxygenated Labdane-Type Diterpenoids, Ptychantins from Cultured Cells of thePtychantus striatusLiverwort

“…[1][2][3] The intact plants of this liverwort elaborated both sesquiterpenoids [4][5][6] and diterpenoids, [7][8][9] as well as macrocyclic bisbenzyls. 10) Highly oxygenated diterpenes of the labdane type such as ptychantin A (5) and B (6) were isolated from intact plants of Japanese, Taiwanese and Chinese species.…”

“…Compounds 1 (ptychantin G, 2.8 mg) and 3 (ptychantin F, 1.0 mg) were identified by comparing their spectral data with those reported in the literature. [7][8][9] The IR spectrum of novel diterpene 2 (ptychantin O, 1.0 mg) indicated the presence of hydroxyl (3450 cm À1 ) and acetoxy (1730 cm À1 ) groups. The 1 H and 13 C data (see Table 1 9) while those of the carbon atoms (C-1 to C-5) in ring A of 2 resonated at positions similar to those of compounds 1 and 3.…”

“…[7][8][9] The IR spectrum of novel diterpene 2 (ptychantin O, 1.0 mg) indicated the presence of hydroxyl (3450 cm À1 ) and acetoxy (1730 cm À1 ) groups. The 1 H and 13 C data (see Table 1 9) while those of the carbon atoms (C-1 to C-5) in ring A of 2 resonated at positions similar to those of compounds 1 and 3. The basic structure of 2 was thus assigned as that of deacetoxyptycanthin F. The structure of 2 was finally established by NMR spectroscopy, including COSY, HSQC and HMBC experiments.…”