Seven new resin glycosides from the seeds of Quamoclit × multifida

Abstract

Seven new resin glycosides, multifidins III (1)-IX (7), were isolated from the seeds of Quamoclit × multifida (syn. Q. sloteri House) (Convolvulaceae), along with five known glycosides, quamoclinic acid B methyl ester (8), operculin XIII (9), quamoclin I (10), QM-10 (11), and QM-12 (12). Their structures were determined on the basis of spectroscopic data and chemical evidence. These compounds were of two different types, i.e., those with macrolactone structures and those with non-macrolactone structures. Additionally, cytotoxic activity towards HL-60 human leukemia cells of 1, 2, 5, 8, 9, 11, and 12 was evaluated. Among them, macrolactone-type resin glycosides (jalapins), 1, 2, and 9, specifically demonstrated clear cytotoxic activity with IC values of 3.46, 14.7, and 10.9 μM, respectively.

Chemistry and biological activity of resin glycosides from Convolvulaceae species

“…Quamoclinic acid B ( 3 , 7 S ‐hydroxydecanoic acid 7‐ O ‐ β ‐ d ‐quinovopyranoside) was obtained from alkaline hydrolysis of the ether‐insoluble resin glycoside fraction from the seed of Quamoclit pennata and Q. multifida 29,46 . It was shown to be the side chains of the intact resin glycosides in the following studies 47,48 …”

“…Multifdins IV ( 80 ) and VI ( 81 ) were isolated from the seeds of Q. multifda , and both possessed multifidinic acid A as the aglycone 48 . The macrolactone site of multifdin IV ( 80 ) was located at the C‐2 position of the Rha unit, and an additional Dodeca group was linked at the C‐2 position of the Rha′ unit.…”

“…Five quamoclinic acid A derivatives were isolated from the seeds of Q. multifda and Q. pennata 48,83 . Multifdin V ( 123 ) and quamoclin VII ( 124 ) was characterized as non‐macrolactone derivative of quamoclinic acid A methyl ester 48,83 . They were both acylated by one Mba group at the C‐4 position of the Rha″ unit, and multifdin V ( 123 ) has a more Dodeca residue linked at the C‐2 position of the Rha′ unit.…”

“…Multifidinic acid F ( 208 ) was considered to be a derivative of maltifidinic acid C ( 206 ), in which the hydroxyl group at C‐3 of aglycone was glycosylated with a β ‐ d ‐glucopyranose 93 . Multifdin VII ( 209 ), an acylated maltifidinic acids C ( 206 ) methyl ester was also isolated from Q. multifida , with an Mba residue linked at the C‐2 position of the Rha unit and an Tga group at the C‐4 position of the Fuc unit 48 …”

“…The quamoclinic acids methyl esters were also isolated from Q. pennata and Q. multifida , including QM‐10‐13 ( 240 – 243 ) derived from quamoclinic acid C ( 236 ), 100,101 QM‐14 ( 244 ) derived from quamoclinic acid G ( 238 ), 101 and multifdin VIII ( 245 ) and multifdin IX ( 246 ) derived from quamoclinic acid D ( 237 ) 48 . They all had a quamoclinic acid B ( 3 ) acylated at the C‐2 of Rha unit, except an Mba group for 245 .…”