Bioactive Abietane-Type Diterpenoid Glycosides from Leaves of (Lamiaceae).

In this study, two previously undescribed diterpenoids, (5,10,16)-11,16,19-trihydroxy-12--β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-17(15→16),18(4→3)--3,8,11,13-abietatetraene-7-one () and (5,10,16)-11,16-dihydroxy-12--β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-17(15→16),18(4→3)--4-carboxy-3,8,11,13-abietatetraene-7-one (), and one known compound, the C-nor-isoprenoid glycoside byzantionoside B (), were isolated from the leaves of L. (Lamiaceae). Structures were established based on spectroscopic and spectrometric data and by comparison with literature data. The three terpenoids, along with five phenylpropanoids: 6'--caffeoyl-12-glucopyranosyloxyjasmonic acid (), jionoside C (), jionoside D (), brachynoside (), and incanoside C (), previously isolated from the same source, were tested for their in vitro antidiabetic (α-amylase and α-glucosidase), anticancer (Hs578T and MDA-MB-231), and anticholinesterase activities. In an in vitro test against carbohydrate digestion enzymes, compound showed the most potent effect against mammalian α-amylase (IC 3.4 ± 0.2 μM) compared to the reference standard acarbose (IC 5.9 ± 0.1 μM). As yeast α-glucosidase inhibitors, compounds , , , and displayed moderate inhibitory activities, ranging from 24.6 to 96.0 μM, compared to acarbose (IC 665 ± 42 μM). All of the tested compounds demonstrated negligible anticholinesterase effects. In an anticancer test, compounds and exhibited moderate antiproliferative properties with IC of 94.7 ± 1.3 and 85.3 ± 2.4 μM, respectively, against Hs578T cell, while the rest of the compounds did not show significant activity (IC > 100 μM).