Chemical constituents from Schefflera leucantha R.Vig. (Araliaceae)

Manniosides G-J, New Ursane- and Lupane-Type Saponins from Schefflera mannii (Hook.f.) Harms

Four previously unreported triterpenoid saponins named 3β-hydroxy-23-oxours-12-en-28-oic acid 28-O-β-D-glucopyranosyl ester (mannioside G) (1), 23-O-acetyl-3β-hydroxyurs-12-en-28-oic acid 28-O-β-D-glucopyranosyl ester (mannioside H) (2), ursolic acid 28-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl] ester (mannioside I) (3), and 3β-hydroxy-23-oxolup-20(29)-en-28-oic acid 28-O-β-D-glucopyranosyl ester (mannioside J) (4) were isolated as minor constituents from the EtOAc soluble fraction of the MeOH extract of the leaves of Schefflera mannii along with the known compounds 23-hydroxyursolic acid 28-O-β-D-glucopyranosyl ester (5), ursolic acid 28-O-β-D-glucopyranosyl ester (6), pulsatimmoside B (7) betulinic acid 28-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl] ester (8), 23-hydroxy-3-oxo-urs-12-en-28-oic acid (9), hederagenin (10), ursolic acid (11), betulinic acid (12), and lupeol (13). Their structures were elucidated by a combination of 1D and 2D NMR analysis and mass spectrometry. The MeOH extract, the EtOAc and n-BuOH fractions, and some of the isolated compounds were evaluated for their antibacterial activity against four bacteria: Staphylococcus aureus ATCC1026, Staphylococcus epidermidis ATCC 35984, Escherichia coli ATCC10536, and Klepsiella pnemoniae ATCC13882. They were also screened for their antioxidant properties, but no significant results were obtained.

Heptaellipside A, a rare new 2,28-bidesmosidic lupane-type saponin from the leaves of Heptapleurum ellipticum

For the first time, phytochemical constituents of the leaves of Heptapleurum ellipticum were investigated. One rare new 2,28-bidesmosidic lupane-type saponin, named heptaellipside A (1), along with four other lupane-type analogs (2-5) were purified by combining differently chromatographic methods. All of the separated compounds (1-5) were communicated for the first time from H. ellipticum. The structures of them were definitely illustrated following extensive and comprehensive UV/VIS, FTIR, HRMS/ESI, and NMR techniques. Further, all isolated compounds were evaluated for their α-glucosidase and α-amylase inhibition. As the results, compound 3 respectively exhibited stronger in both inhibitory activities against α-glucosidase and α-amylase (IC50 values of 15.53 and 26.93 μM), than the acarbose standard (IC50 values of 214.50 and 143.48 μM).

Urinary Tract Infections Caused by Uropathogenic Escherichia coli: Mechanisms of Infection and Treatment Options

Urinary tract infections (UTIs) are common bacterial infections that represent a severe public health problem. They are often caused by Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumonia), Proteus mirabilis (P. mirabilis), Enterococcus faecalis (E. faecalis), and Staphylococcus saprophyticus (S. saprophyticus). Among these, uropathogenic E. coli (UPEC) are the most common causative agent in both uncomplicated and complicated UTIs. The adaptive evolution of UPEC has been observed in several ways, including changes in colonization, attachment, invasion, and intracellular replication to invade the urothelium and survive intracellularly. While antibiotic therapy has historically been very successful in controlling UTIs, high recurrence rates and increasing antimicrobial resistance among uropathogens threaten to greatly reduce the efficacy of these treatments. Furthermore, the gradual global emergence of multidrug-resistant UPEC has highlighted the need to further explore its pathogenesis and seek alternative therapeutic and preventative strategies. Therefore, a thorough understanding of the clinical status and pathogenesis of UTIs and the advantages and disadvantages of antibiotics as a conventional treatment option could spark a surge in the search for alternative treatment options, especially vaccines and medicinal plants. Such options targeting multiple pathogenic mechanisms of UPEC are expected to be a focus of UTI management in the future to help combat antibiotic resistance.

Total Asymmetric Synthesis and Stereochemical Confirmation of (+)- and (-)-Lyoniresinol and Its Deuterated Analogues

Lyoniresinol and its derivatives are lignans which have been isolated from a plethora of plant species. In addition to exhibiting a range of interesting biological activities including anticancer, anti-inflammatory, antimicrobial, and others, these compounds have also been discovered in wines and spirits and shown to have gustatory effects in these alcoholic matrices. (+)-Lyoniresinol 1 is reported to impart a strong bitter taste while its enantiomer (-)-lyoniresnol 2 is tasteless. The first total asymmetric synthesis of both natural enantiomers (+)-1 and (-)-2 and their deuterated analogues (D₄)-(+)-3 and (D₄)-(-)-4 has been achieved, confirming the structure and stereochemistry of the natural products. The synthesized compounds can be utilized as internal standards in stable isotope dilution analysis for improving and optimizing the existing lyoniresinol quantitation methods in the future.

The genus Schefflera: A review of traditional uses, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Schefflera is the largest genus in the family Araliaceae, which contains 602 known species indigenous to Asia, Africa, and the southwest Pacific region, several of which are used in traditional medicine.

AIM OF THE REVIEW

The review discusses current knowledge of the traditional uses, phytochemistry, and biological activities of Schefflera species, to assess the medicinal potential of this genus.

MATERIALS AND METHODS

The literature were explored using the keyword "Schefflera" in SciFinder®, Google Scholar®, and PubMed® databases. The taxonomy of all reported plants was authenticated using "The Plant List". Additional data on traditional uses was obtained from secondary references including books and online resources.

RESULTS

Fourteen species were documented as traditional medicines in China, India, Vietnam, Thailand, and Indonesia, specifically to manage rheumatism, pain, and trauma. Other species are used in the treatment of liver disorders, skin conditions, respiratory infections, cancer, diarrhea, malaria, paralysis, and many other conditions. The main phytochemical constituents identified were triterpenoids and saponins, with sesquiterpenes, phenylpropanoids, and lignans. Pharmacological properties of extracts and pure isolated compounds included analgesic, anti-inflammatory, anticancer, hypoglycemic, antimicrobial, hepatoprotective, neuroprotective, antimalarial, and antiallergic effects.

CONCLUSION

The reported biological activities of Schefflera species support their traditional uses, although the available data, even for medicinal species, was limited. Reports of chemical constituents or biological activities could be found for only about 20 species, but suggest that further investigation of efficacy and safety of the largely unexplored genus Schefflera is necessary.