Stereostructure of Plagiochiline A and Conversion of Plagiochiline A and Stearoylvelutinal into Hot-Tasting Compounds by Human Saliva.

Pungent and Bitter, Cytotoxic and Antiviral Terpenoids from Some Bryophytes and Inedible Fungi

“…In fact, treatment of plagiochiline A (16) with either human saliva or with amylase in phosphate buffer, as shown in Fig. 1, resulted in the formation of two 2,3secoaromadendrane aldehydes, plagiochilal B (20), which has been isolated from P. fruticosa, and furanoplagiochilal (21), reported for P. yokogurensis and three other Plagiochila species [24]. The former dialdehyde (20) possesses a strong hot taste, which implies that the intense pungency is not due to plagiochiline itself, but to plagiochilal B (20), the partial structure of which resembles that of the pungent polygodial (13) and sacculatal (14).…”

“…The stem-leafy liverwort Chiloscyphus polyanthos produces pungent substances which are due to a mixture of eudesmanolides, ent-diplophyllolide (23) and its double bond isomer, entdiplophyllin 24, ent-3-oxodiplophyllin (25), and 7-hydroxy-entdiplophyllolide (26) [26]. Diplophyllum albicans also shows pungency, which is due to the same eudesmanolides (23,24) found in C. polyanthos [26]. Porella acutifolia subsp.…”

Biological activity of natural sesquiterpenoids containing a gem-dimethylcyclopropane unit

“…Plagiochiline A (196) is an ent-secoaromadendrane-type sesquiterpene hemiacetal which was isolated from Plagiochila species [71][72][73] that showed cytotoxic activity against P-388 murine leukemia tumor cells, 74 KB cells 75 and which exhibited strong antifeedant activity against the African army worm Spodoptera exempta. 76 Plagiochiline C (198) showed signicant antiplatelet effects on the arachidonate and collagen induced aggregations of washed rabbit platelets.…”

Recent Advances of Biologically Active Substances from the Marchantiophyta

“…It is suggested that 6 might be converted into pungent unsaturated dialdehydes by human saliva. Enzymatic treatment of 6 with either amylase in phosphate buffer or with human saliva produces two strong pungent 2,3secoaromadendrane-type aldehydes, plagiochilal B (43), whose partial structure is similar to that of the pungent drimane-type sesquiterpene dialdehyde, polygodial (34), and furanoplagiochilal (44) ( Figure 5) [41]. The New Zealand liverwort, Hymenophyton flavellatum, produces different pungent tasting substances from the other aforementioned liverworts.…”