New pregnane-type steroidal alkaloids from Sarcococca saligna and their cholinesterase inhibitory activity

Cholinesterase Inhibiting and Antiplasmodial Steroidal Alkaloids from Sarcococca hookeriana

“…The stereochemistry in compound 1 was largely assigned on biogenetic grounds as all known pregnane-type steroidal alkaloids are being biosynthesized from cholesterol via pregenolone. 8,[11][12][13][14][15][16] The assignments were further supported by ROESY experiment and by chemical shift/coupling constant comparison with the reported data. 22) Above mentioned spectroscopic data and comparative literature analysis led us to propose structure 1 to this compound, which was further supported the mass fragmentation pattern Hookerianamide I (2) was obtained as a white amorphous ϩ at m/z 450.…”

“…6) Previous studies on the plants from the genus Sarcococca have reported the isolation as well as chemical and microbial transformation of a number of bioactive steroidal alkaloids. [7][8][9][10][11][12] Although a number of studies have reported the biological properties of steroidal alkaloids isolated from the family Buxaceae such as cholinesterase inhibtion 7,8,[11][12][13][14] as well as antibacterial, 15) antitumour 16) and antiulcer 17) activities, no investigation has been reported, to the best of our knowledge, on their antiplasmodial activity. Malaria, mainly caused by the parasite Plasmodium falciparum, remains one of the most important infectious diseases in the world and constitutes a public health problem in more than 90 countries, inhabited by about 40% of the world's population.…”

Steroidal Alkaloids from Holarrhena antidysenterica (L.) WALL.

“…The attachment of hydroxyl group at amine center was further confirmed by the analysis of mass fragmentation data which showed the peaks at m/z 317 [MϩHϪCH 3 CONOH] ϩ (-C-N-bond cleavage), 289 reported compounds and biogenetic considerations. [9][10][11][12][13][14][15][16][17][18][19][20] Based on critical spectroscopic studies, the structure of compound 1 was established as (20S)-20-acetylhydroxylamino,3b -amino,13b -hydroxymethylenepregn-5-ene and was designated as holadysenterine.…”

“…Two wide multiplets at d 2.92 and 3.53 were assigned to H-3a-and H-20b-, respectively. The b-orientation of H-20 was deduced by comparing the spectral values with published data for steroidal alkaloids [9][10][11][12][13][14][15][16][17][18][19] and biogenetic considerations keeping in view of the fact that all pregnane-type steroidal alkloids are biosynthesized from cholesterol via pregnenolone. 10,20) The H-21 (3H, d, Jϭ 6.6 Hz) and H-19 (3H, s) methyl groups appeared at d 1.38 and 1.09, respectively.…”

New diterpenoid alkaloids fromAconitum heterophyllum Wall: Selective butyrylcholinestrase inhibitors

“…The discovery of natural cholinesterase inhibitors has been a very challenging area of drug development due to the involvement of cholinesterases in Alzheimer's disease and other related dementias. We have previously reported a number of new natural inhibitors of cholinesterases (AChE and BChE) isolated from indigenous medicinal plants [15,16].…”