Two New Sesquiterpene Alcohols Isolated from Senecio hadiensis Forssk. Grown in Saudi Arabia.

Phytochemical investigation on the aerial parts of Senecio hadiensis Forssk. led to the isolation of two new sesquiterpenoids, presilphiperfolan-2α,5α,8α-triol (1) and presilphiperfolan-2α,5α,8α,10α-tetraol (2) featuring the rare presilphiperfolane-type frameworks. The structures of 1 and 2 were elucidated on the basis of extensive spectroscopic (1D- and 2D-NMR, HR-ESI-MS) methods and by comparison with the literature data. The isolates 1 and 2 were evaluated in-vitro for antiinflammatory, cytotoxic, and peroxisome proliferator activated receptor alpha and gamma (PPARα and PPARγ) agonistic activities.

Inter-species comparative antioxidant assay and HPTLC analysis of sakuranetin in the chloroform and ethanol extracts of aerial parts of Rhus retinorrhoea and Rhus tripartita.

CONTEXT: Extensive research on Rhus (Anacardiaceae) shows their antioxidant potential, which warrants further evaluation of its other species. OBJECTIVE: To perform a comparative antioxidant assay on extracts of R. retinorrhoea and R. tripartita, including sakuranetin quantification by a validated HPTLC method. MATERIALS AND METHODS: In vitro antioxidant assay was performed on chloroform and ethanol extracts of R. retinorrhoea Steud. ex Oliv. (RRCE and RREE) and R. tripartita (Ucria) Grande (RTCE and RTEE) by DPPH radical scavenging (at 31.25, 62.5, 125, 250 and 500 µg/mL concentrations) and ß-carotene-linoleic acid bleaching methods at 500 µg/mL concentration. Densitometric HPTLC method was developed and validated using toluene: ethyl acetate: methanol (8:2:0.2; v/v/v) as mobile phase, executed on glass-backed silica gel F254 plate and scanned at 292 nm. RESULTS: Antioxidant activity of Rhus extracts tested by the two methods (DPPH/BCB) was found in order of RTEE > RREE > RTCE > RRCE with IC50 118.67/256.26, 315.75/82.35, 827.92/380.0 and 443.69/292.75, respectively. Scanning of the HPTLC plate provided an intense peak of sakuranetin at Rf = 0.59. The estimated sakuranetin content in the dry weight of the extracts was highest in RREE (27.95 µg/mg) followed by RRCE (25.22 µg/mg), RTEE (0.487 µg/mg) and RTCE (0.0 µg/mg). Presence of sakuranetin in RREE, RRCE and RTEE supported the highest antioxidant property of the two Rhus species. Nonetheless, low sakuratenin in R. tripartita indicated the presence of other bioactive constituents responsible for synergistic antioxidant activity. CONCLUSION: The developed HPTLC method therefore guarantees its application in quality control of commercialized herbal drugs and formulations containing sakuranetin.

Scropolioside-D2 and harpagoside-B: two new iridoid glycosides from Scrophularia deserti and their antidiabetic and antiinflammatory activity.

Five iridoid glycosides, including the two new compounds scropolioside-D(2) (1) and harpagoside-B (2), were isolated from the aerial parts of Scrophularia deserti DEL (Scrophulariaceae). Their structures were elucidated on the basis of spectral data to be 6-O-[2",4"-di-O-acetyl-3"-O-trans-cinnamoyl)-alpha-L-rhamnopyranosyl]-8 alpha-hydroxymethyl-1 alpha,5 beta,6 alpha,7 alpha,9 beta-pentahydro-7(8)-epoxy-2-oxaind-3-ene-1-O-beta-D-glucopyranoside-6'-O-acetate (1) and 5-O-beta-hydroxy-8-O-beta-trans-cinnamoyl-8 alpha-methyl-1,6,7,9-tetrahydro-2-oxaind-3-ene-1-O-beta-D-glucopyranoside (2), respectively. In addition, three more iridoid glycosides, scropolioside-D (3), koelzioside (4), and 8-O-acetyl-harpagide (5), were also isolated and characterized from this source. The biological activity and the structure activity relationship of the compounds were also studied, and scropolioside-D (3) and harpagoside-B (2) were found to possess significant antidiabetic and antiinflammatory activity, respectively.