Records of Natural Products

Plants are rich sources of biologically and/or pharmacologically active phytochemicals. This study aimed to determine the chemical composition, antioxidant, tyrosinase, anti-cholinesterase, and anti-diabetic activities of ethyl acetate (EtOAc), methanol (MeOH), and water extracts obtained from the aerial parts of Onopordum caricum (Hub.-Mor.), which is an endemic plant species to Turkish flora. As a result of spectrophotometric analysis, the MeOH extract was the richest in total phenolics and flavonoids (46.26 mg GAEs/g and 20.97 mg QEs/g, respectively). In quantitative chromatographic analysis, the MeOH extracts contained considerable amounts of chlorogenic acid, eriodictyol, luteolin 7-O-glucoside, vanillic acid, syringic acid, 4-hydroxybenzoic acid, and pinoresinol. Except for the ferrous ion chelating activity assay, MeOH extract showed higher activity than others in all test systems. The activity data exhibited by the MeOH extract in phosphomolybdenum, DPPH and ABTS radical scavenging, CUPRAC, and FRAP tests were 1.46, 1.10, 1.30, 0.87, and 0.76 mg/mL, respectively. The EtOAc extract showed higher activity in all enzyme inhibition assays. The AChE, BChE, α-amylase, α-glucosidase and tyrosinase inhibitory activities of this extract were 0.95, 1.20, 2.37, 1.18 and 1.77 mg/mL, respectively. There was a very high correlation between the extracts' total phenolic and flavonoid contents and their antioxidant activities (phosphomolybdenum, radical scavenging, and reducing power). Since the antioxidant and enzyme inhibitory activity data presented in the current study were found to be higher than the activities of some other Onopordum species in the literature, it was concluded that the plant species in question could be used in the treatment of Alzheimer's, diabetes, hyperpigmentation, and disorders occurred as a result of oxidative stress pressure.

A new alkaloid, named scopariaine A (1), was obtained from the whole plant of Scoparia dulcis L. The new structure was established by various spectroscopic tmethods including 1D (1H-, 13C-NMR), 2D-NMR (HMBC, HSQC) and high resolution electrospray ionization mass spectrometry (HR-ESI-MS). Scopariaine A (1) was tested for its protective effect on attenuating palmitate-induced viability at 5, 10 and 25 μM. The results showed that the cell viability was increased in palmitic acid combined with scopariaine A (1) treated H9C2 cells.

Abstract

In the present work, the flower volatiles and seed fatty acids compositions of three populations (P-I, P-II, P-III) of Rosa iliensis were investigated for the first time. R. iliensis is a rare, endangered, narrow-endemic species growing in floodplains of the Ili and Sharyn rivers of Almaty region. The flower volatiles have been investigated with the tandem of MSD-SPME and GC-MS/FID techniques. The seed lipids were extracted from the ripe fruits with the microextraction technique. The flower volatiles of R. iliensis three populations were characterized by the abundance of oxygenated monoterpenes with benzaldehyde (13.3-38.7 %) and citronellol (2.6-8.8 %) as the major constituents. There were detected significant differences in floral scents between the populations. The flowers of P-I (from Sharyn River) contain sesquiterpene g-elemene (8.8%), the flowers of P-II (upper reaches of the Ili River) were rich in a-gurjunene (12.8%), while flowers of P-III (lower reaches of the Ili River) contained any sesquiterpenes. Seven fatty acids were determined in the seeds and unsaturated acids were found to be dominant for studied populations. Linoleic (43.0-51.0%), a-linolenic (26.5-28.1%) and oleic (12.0-16.1%) acids were detected as the major constituents. The present study shows that R. iliensis species is rich source of valuable volatiles and fatty acids.

Two new 13-oxomilbemycins, 13-oxomilbemycin β3 (1) and 25-ethyl-13-oxomilbemycin β3 (2), were isolated from the broth of a NTG-induced mutation strain of Streptomyces avermitilis AVE-H39. The structures of 1 and 2 were determined based on MS and extensive NMR analysis. Compounds 1 and 2 possessed moderate nematocidal activity.