Barbeya oleoides Leaves Extracts: In Vitro Carbohydrate Digestive Enzymes Inhibition and Phytochemical Characterization

This study investigated the in vitro inhibitory potential of different solvent extracts of leaves of Barbeya oleoides on key enzymes related to type 2 diabetes mellitus (α-glucosidase and α-amylase) in combination with an aggregation assay (using 0.01% Triton X-100 detergent) to assess the specificity of action. The methanol extract was the most active in inhibiting α-glucosidase and α-amylase, with IC₅₀ values of 6.67 ± 0.30 and 25.62 ± 4.12 µg/mL, respectively. However, these activities were significantly attenuated in the presence of 0.01% Triton X-100. The chemical analysis of the methanol extract was conducted utilizing a dereplication approach combing LC-ESI-MS/MS and database searching. The chemical analysis detected 27 major peaks in the negative ion mode, and 24 phenolic compounds, predominantly tannins and flavonol glycosides derivatives, were tentatively identified. Our data indicate that the enzyme inhibitory activity was probably due to aggregation-based inhibition, perhaps linked to polyphenols.     

Structure determination of salvadorin, a novel dimeric dihydroisocoumarin from Salvadora oleoides, by NMR spectroscopy

Salvadorin, a new dimeric dihydroisocoumarin (1), was isolated from the chloroform fraction of Salvadora oleoides. Its chemical structure was established as 8-benzyl-6-[6-(6-ethyl-7-methyl-5,8-dihydro-2-naphthalenyl)-1-oxo-3,4-dihydro-1H-isochromen-8yl]-3, 4-dihyro-1H-isochromen-1-one, through spectroscopic techniques and chemical analysis.     

Phytochemistry of Daphne oleoides

Genus Daphne belongs to the Thymelaeaceae family and consists of 70 species. Its various species exist in Europe, Philippine Islands, temperate and subtropical Asia, North Africa, Australia and Pacific. In Pakistan, Daphne is represented by three species. Our focused Daphne oleoides is widely found in diverse climatic conditions from northern cold to central hot regions which creates a rich diversity and novelty in biosynthetic levels of its chemical constituents and hence is a great opportunity. Daphne oeloides is a proven rich source of a variety of unique and interesting nature-made skeletons with a wide range of therapeutic properties. D. oleoides possesses effective therapeutic properties, therefore, has been used in herbal medicines and is still being used to treat various diseases. The modern research by various groups, including ourselves, has resulted in the isolation of a number of natural molecules including some novel tris- and bis- coumarins, daphnane diterpenoids and lignoids. Therefore, due to novelty and richness of the nature-made molecules, and their therapeutic potential combined with our significant work on D. oleoides, this report covers chemical constituents isolated from D. oleoides. The pharmacological activities of the isolated compounds and use of this species in folk medicine have also been reviewed.     

Phytochemical profiles,antioxidant and anti-acetylcholinesterasic activities of the leaf extracts of Rhamnus lycioides subsp. oleoides (L.) Jahand. & Maire in different solvents

In this work, the extracts obtained with different solvents from the leaves of Rhamnus lycioides subsp. oleoides (L.) Jahand. & Maire were studied for their phytochemical profile and then for their antioxidant and acetylcholinesterase inhibitory activities. The phytochemical profiles of the extracts in n-hexane, dichloromethane, ethyl acetate, methanol, anthraquinone rich and water, showed the presence of different compounds belonging to several classes of natural products such as flavonoids, anthraquinones, saccharides and fatty acids. For what concerns the biological tests, the ethyl acetate, methanol and anthraquinone rich extracts showed the highest activities in both assays due to the high amount of compounds possessing those properties such as flavonoids and anthraquinones. By consequence, these specific extracts of the species may be considered to be potential sources of natural antioxidant and anti-acetylcholinesterasic compounds.     

Dapholidins A – C,New Isomeric Biisoflavonoids From Daphne oleoides

Three new isomeric biisoflavonoids, dapholidins A–C ( 1 – 3 , resp.), have been isolated from the AcOEt‐soluble fraction of the MeOH‐soluble extract of the roots of Daphne oleoides, along with the known compounds daphwazirin ( 4 ), daphnetin 8‐O‐β‐D ‐glucopyranoside ( 5 ), daphnin ( 6 ), daphneticin 4″‐O‐β‐D ‐glucopyranoside ( 7 ), and 6,7‐dihydroxy‐3‐methoxy‐8‐[2‐oxo‐2H‐1‐benzopyran‐7‐(O‐β‐D ‐glucopyranosyl)‐8‐yl]‐2H‐1‐benzopyran‐2‐one ( 8 ). The structures of the new compounds were determined by spectroscopic analyses, including 1D‐ and 2D‐NMR.