The Use of Carbon-13 Nuclear Magnetic Resonance Spectroscopy in Natural Products Chemistry. In: Herz W, Grisebach H, Kirby GW, editors. Fortschritte der Chemie Organischer Naturstoffe / Progress in the Chemistry of Organic Natural Products. Vienna: Springer; 1979. pp. 1-229. [DOI: 10.1007/978-3-7091-3265-4_1]

Synthesis and Analgesic Activity of Monoterpenoid Aldehyde-derived Hydro-2H-chromeneols

Background:

Despite a variety of drugs used to stop acute pain, problems related to their insufficient efficacy and undesirable side effects have remained unresolved. Therefore, the search for analgesics of new structural types, which combine high activity with low toxicity, is a topical issue. It is known that a number of compounds with a hydrogenated 2H-chromene skeleton exhibit significant analgesic activity in in vivo tests.

Methods:

New hydro-2H-chromenols containing monoterpenoid moieties were obtained via one-pot synthesis by the interaction between para-menthane alcohols and commercially available monoterpene aldehydes: Citral, hydroxycitronellal, myrtenal, and perillaldehyde. The analgesic activity of these compounds wаs studied in the acetic acid-induced writhing test and hot plate test.

Results:

The target compounds were characterized using NMR and HR-MS. Most of them exhibited pronounced analgesic activity.

Conclusion:

Due to high analgesic activity, (2S,4aR,8R,8aR)-2-((E)-2,6-dimethylhepta-1,5-dien-1- yl)-4,7-dimethyl-3,4,4a,5,8,8a-hexahydro-2H-chromene-4,8-diol is considered as candidate compound to participate in further research.

Triterpenoids from the orchids Agrostophyllum brevipes and Agrostophyllum callosum

Agrostophyllinol and agrostophyllinone, two new triterpenoids, were isolated from the orchid Agrostophyllum brevipes. Agrostophyllinone was also isolated from another orchid Agrostophyllum callosum. The structures of agrostophyllinol and agrostophyllinone were established as 24-methylene-lanosta-9(11)-en-3beta-ol (5a) and 24-methylene-lanosta-9(11)-en-3-one (5c), respectively, from spectral and chemical evidence. The above triterpenoids are of considerable biogenetic importance.