Records of Natural Products

Two new isoflavones, caraganin E (1) and caraganin F (2), were purified from 75% ethanolic extract of Caragana jubata roots, in company with ten known compounds. The chemical structures of two novel isoflavones were elucidated by NMR, HR-ESIMS and circular dichroism (CD). GLUT4 translocation activity was tested in L6 cells for all isolated compounds. Among them, compound 5 exhibited the best activity, increasing the fluorescence intensity by 3.25 folds. The results of the exploration may help us understand the chemotaxonomic variety of natural products in Caragana jubata and enhance the diversity of flavonoids.

Chemical investigations on the culture of Penicillium oxalicum 2021CDF-3, a marine red alga-sourced endophytic fungus, revealed a new steroid, namely peniciloxatone A (1). With the aid of high-resolution electrospray ionization mass spectrometry (HRESIMS) and nuclear magnetic resonance (NMR) analyses, the structure of peniciloxatone A (1) was determined to be a polyoxygenated ergostane steroid. Cytotoxic activities of 1 were tested against A549, FADU, and HepG2 cells, and 1 was active against the FADU and HepG2 cells, with IC50 values of 9.5 ± 0.1 and 18.1 ± 0.3 μM, respectively.

The Trixis genus (Asteraceae) is involved in traditional medicine from Latinoamerica. In Mexico, Trixis michuacana Lex. var. michoacana and T. michuacana var. longifolia are used in the P'urhépecha ethnomedicine. The analysis of their volatile compounds by gas chromatography/mass spectrometry (GC-MS) is described herein. The sesquiterpene compounds were the main constituents. β-Caryophyllene (10.80%), germacrene D (7.93%), β-elemene (7.42%), and γ-elemene (7.37%) highlighted from var. michuacana, while β-elemene (10.02%), α-copaene (9.91%), β-caryophyllene (8.97%), germacrene D (7.40%), and γ-elemene (6.89%) were the major constituents from var. longifolia. A systematic analysis of the chemical components provided an approach to the biosynthetic pathway for volatile metabolite production. Antimicrobial assays provided scientific support for the traditional use of the plants. In-vitro assays using Escherichia coli (ATCC 25922), E. coli (82MR), Klebsiella pneumoniae (ATCC 13883), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 29213), S. aureus (23MR), S. epidermidis (ATCC 12228), S. epidermidis, Candida albicans (17MR), C. glabrata, and C. tropicalis were achieved. These assays revealed MIC values >2 mg/mL when observed bacterial inhibition for both Trixis species, except for var. michuacana against S. epidermidis ATCC 12228, which was 0.5 mg/mL. These results could partially justify the use of the studied plants in ethnomedicine.

Achillea millefolium, A. crithmifolia and A. nobilis are distinct species that share morphological similarities, making their differentiation challenging. This study utilized gas chromatography-mass spectrometry (GC/MS) combined with headspace-solid phase microextraction (HS-SPME) to analyze the volatile components of these species and employed chemometric methods for species differentiation. A total of 109 volatile compounds from the three studied species were identified. Of these compounds, 71 were identified in A. millefolium, 75 in A. crithmifolia, and 58 in A. nobilis. The primary volatile compounds of A. millefolium were germacrene D, 1,8-cineole, sabinene, and β-pinene; in A. crithmifolia, the main compounds were caryophyllene, 1,8-cineole, camphor, ascaridole, and ο-cymene, while in the essential oil of A. nobilis, camphor, lavandulyl acetate, camphene, and isobornyl acetate were determined as the main volatile compounds. The study demonstrated that the HS-SPME-GC/MS techniques, combined with chemometric methods such as discriminant analysis (DA) and principal component analysis (PCA), effectively distinguished the samples of A. millefolium, A. crithmifolia, and A. nobilis based on the differences in the chemical composition of their essential oils.