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

Abstract

In this study, two previously undescribed diterpenoids, (5R,10S,16R)-11,16,19-trihydroxy-12-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-17(15→16),18(4→3)-diabeo-3,8,11,13-abietatetraene-7-one (1) and (5R,10S,16R)-11,16-dihydroxy-12-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-17(15→16),18(4→3)-diabeo-4-carboxy-3,8,11,13-abietatetraene-7-one (2), and one known compound, the C13-nor-isoprenoid glycoside byzantionoside B (3), were isolated from the leaves of Clerodendrum infortunatum 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′-O-caffeoyl-12-glucopyranosyloxyjasmonic acid (4), jionoside C (5), jionoside D (6), brachynoside (7), and incanoside C (8), 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 6 showed the most potent effect against mammalian α-amylase (IC50 3.4 ± 0.2 μM) compared to the reference standard acarbose (IC50 5.9 ± 0.1 μM). As yeast α-glucosidase inhibitors, compounds 1, 2, 5, and 6 displayed moderate inhibitory activities, ranging from 24.6 to 96.0 μM, compared to acarbose (IC50 665 ± 42 μM). All of the tested compounds demonstrated negligible anticholinesterase effects. In an anticancer test, compounds 3 and 5 exhibited moderate antiproliferative properties with IC50 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 (IC50 > 100 μM).

Biologically Active Diterpenoids in the Clerodendrum Genus—A Review

“…Clerodendrum infortunatum aerial parts were used for extraction and isolation of terpenoid compounds [ 76 ]. Among various known compounds, two previously unknown diterpenes were isolated and identified as (5 R ,10 S ,16 R )-11,16,19-trihydroxy-…”

“…12-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-17(15→16),18(4→3)- diabeo -3,8,11,13-abietatetraene-7-one ( 111 ) and (5 R ,10 S ,16 R )-11,16-dihydroxy-12-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-17(15→16),18(4→3)- diabeo -4-carboxy-3,8,11,13-abietatetraene-7-one ( 112 ) [ 76 ]. The extraction method used for the phytochemicals analyses of this plant species is shown in Table 6 .…”

“…Compound 111 ((5 R ,10 S ,16 R )-11,16,19-trihydroxy-12-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-17(15→16),18(4→3)- diabeo -3,8,11,13-abietatetraene-7-one) inhibited these enzymes activity with an IC 50 value of 18.5 and 24.6 µM, respectively. (5R,10S,16R)-11,16-dihydroxy-12-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-17(15→16),18(4→3)- diabeo -4-carboxy-3,8,11,13-abietatetraene-7-one demonstrated weaker activity (IC 50 = 64.6 and 78.3 µM) [ 76 ]. Additionally, the studied compounds were tested for acethyl- and buthyrylcholinesterase (AChE and BChE) inhibition, showing weak activity against AChE with an IC 50 of 191 and 139 µM, respectively [ 76 ].…”

“…(5R,10S,16R)-11,16-dihydroxy-12-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-17(15→16),18(4→3)- diabeo -4-carboxy-3,8,11,13-abietatetraene-7-one demonstrated weaker activity (IC 50 = 64.6 and 78.3 µM) [ 76 ]. Additionally, the studied compounds were tested for acethyl- and buthyrylcholinesterase (AChE and BChE) inhibition, showing weak activity against AChE with an IC 50 of 191 and 139 µM, respectively [ 76 ].…”

Exploring the Phytochemical Profile and Biological Activities of Clerodendrum infortunatum

“…Only a few reports have documented the active components, each demonstrating the cytotoxicity in one or two cell lines. 5,6 The active component responsible for the cytotoxic effect has been reported to vary from glycoproteins 7 to abietane-type diterpenoidglycosides, 6 oleanolic acid, clerodinin A, 8 and so forth in these reports. Hence, a consensus could not be obtained, and none of these reports has been substantiated further, which prompted us to study the leaf and root extract in a systematic way to identify the potential cytotoxicity in a wide panel of human tumor cells with different characters and origins.…”