A novel iridoid fromTorricellia angulatavarintermedia

Abstract

A new iridoid, named torricellate, was isolated from root bark of Torricellia angulata var intermedia, a Chinese folk medicinal plant used to treat bone fracture, tonsillitis and asthma. Its structure was elucidated by NMR, MS, IR and UV, and confirmed by X-ray diffraction studies.

Cyclopenta[c]pyrans

“…The most recently discovered iridoid with a cyclopenta[ c ]pyran skeleton, torricellate 21 (Chart ), was isolated from the fresh root bark of Torricella angulata var intermedia (Torricelliaceae), a plant used in Chinese traditional medicine to treat bone fracture, tonsillitis and asthma [34].…”

“…The parent compound 1 (Chart ) has a lemon‐yellow color in solution, and generally, both, naturally occurring and non‐natural cyclopenta[ c ]pyrans were isolated as yellow to intense red solids or oils. Consequently, in the UV‐vis spectra, the absorption maxima at longest wavelengths were found to vary between 367 and 493 nm [3, 4, 11, 16, 20, 26, 29, 31, 32, 34, 41–43, 47]. Although there are no systematic investigations as to the influence of substituents on the position of the longest wavelength absorption, one may observe that the presence of an electron‐withdrawing substituent results in a bathochromic shift, though it may be very small, and also in an increase of the molecular extinction coefficient.…”

“…Important information on the structure of cyclopenta[ c ]pyrans in the solid state is provided by single crystal X‐ray diffraction. Heretofore, eight compounds [4, 33, 34, 46, 50, 54, 56] were investigated by this method. Three of them are of natural origin, namely cerbinal 12 [56], fulvoipolamiide 20 [33] and torricellate 21 [34].…”

“…Heretofore, eight compounds [4, 33, 34, 46, 50, 54, 56] were investigated by this method. Three of them are of natural origin, namely cerbinal 12 [56], fulvoipolamiide 20 [33] and torricellate 21 [34]. Most of these cyclopenta[ c ]pyrans crystallize in monoclinic or orthorhombic crystal systems, whereas a triclinic space group was found for compound 56 [46].…”