Crocus cancellatus subsp. damascenus stigmas: chemical profile, and inhibition of α-amylase, α-glucosidase and lipase, key enzymes related to type 2 diabetes and obesity

Spices are appreciated for their medicinal properties besides their use as food adjuncts to enhance the sensory quality of food. In this study, Crocus cancellatus subsp. damascenus was investigated for its antioxidant activities employing different in vitro systems. Stigma extract demonstrated a radical scavenging activity against both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radicals with IC50 values of 34.6 and 21.6 µg/mL and a good ferric reducing ability (53.9 µM Fe(II)/g). In order to clarify the potential functional properties of this spice, the carbohydrate-hydrolysing enzymes and pancreatic lipase inhibitory properties were investigated. Crocus cancellatus subsp. damascenus extract inhibited α-amylase and α-glucosidase with IC50 values of 57.1 and 68.6 µg/mL, respectively. The bioactivity was discussed in terms of phytochemicals content. The obtained results may be of interest from a functional point of view or as food additive and to promote the revalorization of this species

Tyrosinase, Acetyl- and Butyryl-Cholinesterase Inhibitory Activity of Stachys lavandulifolia Vahl (Lamiaceae) and Its Major Constituents

The n-hexane (HE), dichloromethane (DC), methanol (ME), ethanol 70% (ET), and methanol with Soxlhet apparatus (MS) extracts of Stachys lavandulifolia aerial parts were screened for their potential tyrosinase, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity. ET and MS inhibited tyrosinase with IC 50 values of 33.4 and 42.8 m g/mL, respectively. The phytochemical investigation of these extracts resulted in the isolation of the known compounds monomelittoside (1), melittoside (2), 5-allosyloxy-aucubin (3), acteoside (4) and arbutin (5). The HE extract, characterized by germacrene D, b -pinene, b -myrcene, and trans-caryophyllene as main constituents, showed the highest AChE inhibitory activity with an IC 50 value of 13.7 m g/mL while DC extract was the most active against BChE (IC 50 value of 143.9 m g/mL). The diterpene stachysolone (6) was isolated from this extract. The antioxidant properties were also investigated by four in vitro methods (DPPH, ABTS, FRAP and b -carotene bleaching tests)

Bisabololoxide derivatives from Artemisia persica, and determination of their absolute configurations by ECD

Five antiplasmodial bisabololoxide sesquiterpene diesters were isolated from an EtOAc extract of the aerial parts of Artemisia persica following an HPLC-time-based activity profiling of the extract. Structure elucidation was achieved by 1D and 2D NMR experiments. Relative configurations of cyclohexenone/cyclohexene and tetrahydropyran moieties of 1-5 were established on the basis of (3)J(H-H) coupling constants and NOE difference spectra. Stereochemical correlation of the two rings, and assignment of absolute configuration of 1-5 were achieved by comparison of experimental ECD spectra with simulated ECD data for possible stereoisomers, by using time dependent density function theory (TDDFT). Bisaboloids 1-4 exhibited in vitro antimalarial activity against Plasmodium falciparum, with IC(50) values ranging from 2.8 to 20.1μM, and selectivity indices (SI) in L-6 cells of 3.7-11.9