Structural Diversity, Natural Sources and Pharmacological Potential of Naturally Occurring A-Seco-Triterpenoids

Synthesis, Cyclization, and Cytotoxic Activity of 2,3-Secolupane Triterpenoids With an Ethylketone Fragment

“…Native and semisynthetic derivatives of betulinic acid with a fragmented, expanded, or contracted A ring are of interest as either structurally original biological active compounds or as synthetic platforms for their preparation. [1][2][3] In nature, triterpenic biosynthetic pathways with a 5-membered A ring formation most often are based on cyclizations of the corresponding A-secotriterpenic precursors. 1 The same approach is successfully used in synthetic organic chemistry to obtain A-pentacyclic triterpenoids, including analogs of natural biologically active products.…”

Highly oxygenated isoprenoid lipids derived from terrestrial and aquatic sources: Origin, structures and biological activities

“…Compound (27) showed anticancer activity, and kadsuphilactone B (28) exhibited in vitro anti-HBV activity with IC50 values of 6 μg/mL by HBsAg enzyme immunoassay. [38,39] The sedative triterpenes (30)(31)(32) were found in leaves and roots of the Galphimia glauca. [40] Longipedlactone J (33) showed the cytopathic effect (EC50 3.8 g/mL) of HIV-1 in C8166 cells, and cycloartane triterpenoid angustific acid A (34) from Kadsura angustifolia reaches EC50 values of 6 g/mL.…”

“…[40] Longipedlactone J (33) showed the cytopathic effect (EC50 3.8 g/mL) of HIV-1 in C8166 cells, and cycloartane triterpenoid angustific acid A (34) from Kadsura angustifolia reaches EC50 values of 6 g/mL. [38,41,42] Buxaminol G (35) has been isolated from the alcoholic extract of the leaves of Buxus papilosa, [43] and the crude methanolic extract of Buxus hyrcana, collected from Iran, resulted in the isolation steroidal alkaloid named (+)-O-6-buxafurandiene (36). [44] Both compounds exhibited acetylcholinesterase enzyme inhibitory activity.…”

“…[5,17,[46][47][48][49][50] Steroidal alkaloids were first isolated from the skin glands of Salamandra in the mid-30s of the 20th century, [51] although they have been known since 1866. [52] Samanine (38) and samandarin (39) were isolated from the skin glands of Salamandra. [51,53] More recently, the two major alkaloids, samandarine (39) and samandarone (41), were identified in the skin secretion of individual specimens from two populations of the European fire salamander (Salamandra salamandra terrestris).…”

“…The two subspecies of S. maculosa have significant differences in the composition of the alkaloid mixture. [55] Other these unique steroidal alkaloids (38)(39)(40)(41)(42)(43)(44)(45)(46) were excreted from various kinds of salamanders and their structure was determined to have been described in an excellent overview. [55] HOIL DERIVED FROM MARINE SOURCES HOIL are widely produced by marine organisms, [9,56] but we have a small series (47-67) of these lipids, many of which show different biological activities.…”