Records of Natural Products

OA new alkaloid, isocyanogramide (1) together with six known compounds, including cyanogramide (2), marinacarboline F (3), marinacarboline H (4), caerulomycinamide (5), cerulomyconitrile (6), and 5ʹ-deoxyuridine (7) were isolated from the agar culture of the marine-derived actinomycete Actinoalloteichus cyanogriseus G631. Compounds 1-7 were evaluated for antimicrobial activity against Gram (+) bacteria, Enterococcus faecalis, Staphylococcus aureus, and Bacillus cereus, Gram-(–) bacteria, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, and the yeast, Candida albicans. All compounds significantly exhibited antibacterial effects on three tested Gram-(+) bacteria and the yeast C. albicans with the MIC values ranging from 64 to 256 µg/mL. Compounds 4, 5, and 7 significantly inhibited B. cereus bacteria with MIC values of 16, 128, and 128 µg/mL, respectively.

One new norsesquiterpene and four known bisabolanes were obtained from the organic extract of Trichoderma atroviride TD-8 isolated from ocean sediments. Their structures were assigned by detailed interpretation of 1D/2D NMR and HRESIMS data, and they were determined to be nor-bisabolan-1,11-diol (1), (3R,6R,7R)-1,10-bisaboladien-3-ol (2), (3R,6R,7S)-1,10-bisaboladien-3,6-diol (3), (3R,6S,7R,10R)-1-bisabolen-3,10,11-triol (4), (3R,6R,7S,10R)-1-bisabolen-3,10,11-triol (5). Nor-bisabolan-1,11-diol (1) exhibited moderate cytotoxicity against HeLa and HCT-8 cell lines with IC50 values of 28.6 and 30.3 μM, respectively.

Herein, the chemical analysis of petroleum ether extract of Eupatorium adenophorum was conducted which led to the identification of a previously unreported sesquiterpenoid, named eupatorione A (1). The structure of eupatorione A (1) was elucidated through comprehensive spectroscopic analysis, including 1D, 2D-NMR techniques, as well as HRMS. Additionally, X-ray diffraction was employed to further confirm the structure.  The anti-inflammatory activity of compound 1 was assessed by measuring its inhibitory effects on the production of nitric oxide (NO), induced by lipopolysaccharide (LPS) in RAW264.7 LPS-activated macrophages.

Platycodon grandiflorum (Jacq.) A.DC is a perennial single-species herb in the Campanulaceae family, and its dried roots have been widely used for a long time to diffuse the lung, soothe the throat, dispel phlegm, and expel pus as a Chinese traditional medicine. In addition, P. grandiflorum compounds are homologous to those in medicines and foods approved by the Ministry of Health of China, and many related foods have been marketed. It has been reported that the glycosides in pentacyclic triterpenoids, also known as saponins, are the main biologically active constituents of P. grandiflorum. This article offers a systematic review of recently reported saponins isolated from P. grandiflorum over the past decade covering the literature from the beginning of 2017 through the end of 2022 and describes their structural diversity and pharmacological studies. To the best of our knowledge, a total of 74 natural saponins have been isolated to date. For this review, 131 references on saponins were obtained, and the information from these articles is compiled herein. This review may be of interest to pharmacognosists and natural-product chemists. This review provides new ideas for the development and utilization of natural saponins for clinical applications in the future.