Chemical constituents, total phenolic content, total oxidant status, total antioxidant status, lipid hydroperoxides, total free –SH levels, and antimicrobial activity of essential oil obtained from the Ferulago sandrasica (Umbelliferae) were investigated. The essential oil was obtained by hydrodistillation using a Clevenger-type apparatus. The chemical constituents were analyzed by gas chromatography‐mass spectrometry. The main components of the essential oil were ocimene (30.5%), carene-δ-3 (27.4%), and α-pinene (17.8). The antimicrobial activity was tested by a disc diffusion method against E. coli MC 400, E. coli ATCC 25922, E. coli 0157 H7, E. colaecea ATCC 23355, E. feacalis ATCC 19433, P. aeruginosa NRRL B-2679, S. aureus ATCC 25923, B. nischenoformis NRRL B-1001, S. aureus ATCC 33862, B. cereus NRRL B-3711, B. subtilis NRRL B-209, M. luteus NRRL B-1013, L. monocytogenes ATCC 7644, B. subtulis ATCC 6633.
The marine sponge-derived fungus Auxarthron reticulatum produces the cannabinoid receptor antagonist amauromine (1). Recultivation of the fungus to obtain further amounts for more detailed pharmacological evaluation of 1 additionally yielded the novel triterpene glycoside auxarthonoside (2), bearing, in nature, a rather rare sugar moiety, i.e., N-acetyl-6-methoxy-glucosamine. Amauromine (1), which inhibited cannabinoid CB1 receptors (Ki 0.178 µM) also showed antagonistic activity at the cannabinoid-like orphan receptor GPR18 (IC50 3.74 µM). The diketopiperazine 1 may thus serve as a lead structure for the development of more potent and selective GPR18 antagonists, which are required to study the orphan receptorʼs potential as a new drug target. Despite the execution of many biological assays, to date, no bioactivity could be found for auxarthonoside (2). * Dedicated to Professor Dr. Dr. h. c. mult. Adolf Nahrstedt on the occasion of his 75th birthday.