Secondary Metabolites from Two Species of Pulicaria and Their Cytotoxic Activity

Abstract

Two new compounds, the sesquiterpene (1E,5E)-8β-acetoxy-4α-hydroxy-7βH-germacra-1(10),5-dien-14-oic acid (2), and a nor-sesquiterpene, (5E)-8β-acetoxy-4α-hydroxy-7βH-germacr-5-en-10-one (3), were isolated from Pulicaria canariensis ssp. lanata, along with ten known compounds, including the flavonoid 5,3'-dihydroxy-3,7,4'-trimethoxyflavone (4). From Pulicaria burchardii, we isolated seven known compounds; the physical and spectroscopic data of the triterpenoid 3β-hydroxytaraxaster-20-en-30-al (1) are reported. The structures of compounds 1-3 were determined on the basis of HR-MS, and 1D- and 2D-NMR studies. The structure of 2 was corroborated by X-ray crystal diffraction. Cell viability experiments revealed that the semisynthetic flavonoid 4b was the most cytotoxic compound against human leukemia cells, and the cytotoxicity was caused by induction of apoptosis, as determined by microscopy of nuclear changes.

Innovative perspectives on Pulicaria dysenterica extracts: phyto‐pharmaceutical properties, chemical characterization and multivariate analysis

“…Peak 21 was characterized as ferulic acid. These compounds were extracted only by SE and previously detected in different Pulicaria species …”

Natural sesquiterpenoids

“…The new germacrane derivatives 240 and 241 have been found in an extract of Pulicaria canariensis, 237 whilst the rearranged germacrane inulasalene 242 has been obtained from the aerial parts of Inula salsoloides. 238 Bioassay-guided chromatography of an extract from Neolitsea daibuensis 147 afforded the new sesquiterpenes daibulactone A 243 and daibulactone B 244, whilst myrrhterpenoids B-D 245-247 and myrrhterpenoid F 248 have been discovered in the resinous exudates of Commiphora myrrha.…”

Polyphenols of the Inuleae-Inulinae and Their Biological Activities: A Review

“…They were found in Blumea spp., Carpesium spp., Chiliadenus spp., Dittrichia spp., Duhaldea spp., Inula spp., Pentanema spp., Pulicaria spp., and Rhanterium spp. The most frequently isolated compound from this group was scopoletin [69,114,176,235,250,[349][350][351]. Other coumarins were mostly detected in the plant extracts by different analytical methods.…”

“…Zhang et al [176], from the whole plants of I. hookeri isolated a derivative of esculetin, ayapin (6,7-methylenedioxycoumarin). Scopoletin (6-methoxyesculetin; gelsemic acid; 6-methoxy-7-hydroxycoumarin) was obtained from the plants of the genera Carpesium (C. lipskyi, C. macrocephalum) [349,350] Chiliadenus (C. candicans) [250], Duhaldea (D. cappa, D. wissmanniana) [69,114], Inula (I. hookeri) [176], Pulicaria (P. burchardii) [235] and was identified (by GC-MS) in the extract from R. epapposum [351]. The compound (from C. macrocephalum) turned out to be devoid of antibacterial activity [349].…”