New sesquiterpenes from Asteriscus graveolens

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

Polyphenols are ubiquitous plant metabolites that demonstrate biological activities essential to plant-environment interactions. They are of interest to plant food consumers, as well as to the food, pharmaceutical and cosmetic industry. The class of the plant metabolites comprises both widespread (chlorogenic acids, luteolin, quercetin) and unique compounds of diverse chemical structures but of the common biosynthetic origin. Polyphenols next to sesquiterpenoids are regarded as the major class of the Inuleae-Inulinae metabolites responsible for the pharmacological activity of medicinal plants from the subtribe (Blumea spp., Dittrichia spp., Inula spp., Pulicaria spp. and others). Recent decades have brought a rapid development of molecular and analytical techniques which resulted in better understanding of the taxonomic relationships within the Inuleae tribe and in a plethora of data concerning the chemical constituents of the Inuleae-Inulinae. The current taxonomical classification has introduced changes in the well-established botanical names and rearranged the genera based on molecular plant genetic studies. The newly created chemical data together with the earlier phytochemical studies may provide some complementary information on biochemical relationships within the subtribe. Moreover, they may at least partly explain pharmacological activities of the plant preparations traditionally used in therapy. The current review aimed to systematize the knowledge on the polyphenols of the Inulae-Inulinae.

Research Progress on Sesquiterpene Compounds from Artabotrys Plants of Annonaceae

Artabotrys, a pivotal genus within the Annonaceae family, is renowned for its extensive biological significance and medicinal potential. The genus's sesquiterpene compounds have attracted considerable interest from the scientific community due to their structural complexity and diverse biological activities. These compounds exhibit a range of biological activities, including antimalarial, antibacterial, anti-inflammatory analgesic, and anti-tumor properties, positioning them as promising candidates for medical applications. This review aims to summarize the current knowledge on the variety, species, and structural characteristics of sesquiterpene compounds isolated from Artabotrys plants. Furthermore, it delves into their pharmacological activities and underlying mechanisms, offering a comprehensive foundation for future research.

Antioxidant and Antimicrobial Potencies of Chemically-Profiled Essential Oil from Asteriscus graveolens against Clinically-Important Pathogenic Microbial Strains

Recently, the antimicrobial potential of essential oils extracted from plants has gained extensive research interest, primarily for the development of novel antimicrobial treatments to combat emerging microbial resistance. The current study aims at investigating the antimicrobial activity and chemical composition of essential oil derived from gold coin daisy, which is known as Asteriscus graveolens (EOAG). In this context, a gas chromatography-tandem mass spectrometry (GC-MS) analysis of EOAG was conducted to identify its phytoconstituents. The in vitro antioxidant capacity of EOAG was determined by the use of three tests, namely: 1,1-diphenyl-2-picrylhydrzyl (DPPH), ferric reducing activity power (FRAP), and total antioxidant capacity (TAC). The antimicrobial activity of EOAG against clinically important bacterial (Escherichia coli, K12; Staphylococcus aureus, ATCC 6633; Bacillus subtilis, DSM 6333; and Pseudomonas aeruginosa, CIP A22) and fungal (Candida albicans, ATCC 10231; Aspergillus niger, MTCC 282; Aspergillus flavus, MTCC 9606; and Fusarium oxysporum, MTCC 9913) strains was assessed. Antimicrobial efficacy was determined on solid (inhibition diameter) and liquid media to calculate the minimum inhibitory concentration (MIC). GC/MS profiling of EOAG revealed that 18 compounds were identified, with a dominance of α-Thujone (17.92%) followed by carvacrol (14.14%), with a total identification of about 99. 92%. The antioxidant activity of EOAG was determined to have IC₅₀ values of 34.81 ± 1.12 µg/mL (DPPH), 89.37 ± 5.02 µg/mL (FRAP), and 1048.38 ± 10.23 µg EAA/mg (TAC). The antibacterial activity in a solid medium revealed that the largest diameter was recorded in P. aeruginosa (28.47 ± 1.44 mm) followed by S. aureus (27.41 ± 1.54 mm), and the MIC in S. aureus was 12.18 ± 0.98 µg / mL. For the antifungal activity of EOAG, the largest inhibition diameter was found in F. oxysporum (33.62 ± 2.14 mm) followed by C. albicans (26.41 ± 1.90 mm), and the smallest MIC was found in F. oxysporum (18.29 ± 1.21 µg/mL) followed by C. albicans (19.39 ± 1.0 µg/mL). In conclusion, EOAG can be useful as a natural antimicrobial and antioxidant agent and an alternative to synthetic antibiotics. Hence, they might be utilized to treat a variety of infectious disorders caused by pathogenic microorganisms, particularly those that have gained resistance to standard antibiotics.

Antibacterial and Antifungal Sesquiterpenoids from Aerial Parts of Anvillea garcinii

Two new sesquiterpenoids belonging to the guaiane, 4α,9α,10α-trihydroxyguaia-11(13)en-12,6α-olide (1), and germacrane, 9β-hydroxyparthenolide-9-O-β-D-glucopyranoside (2), classes have been isolated from the leaves of the Saudi medicinal plant Anvillea garcinii along with seven known compounds (3–9). The structures of the new metabolites were elucidated by spectroscopic analysis, including one-dimensional (1D) and two-dimensional (2D) Nuclear Magnetic Resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HR-ESIMS). The antimicrobial properties of 1–9 were screened against seven different pathogenic microbes, and compounds 1–3 showed a potent antifungal activity.