Kinmoonosides A−C, Three New Cytotoxic Saponins from the Fruits of Acacia concinna, a Medicinal Plant Collected in Myanmar

Abstract

Three genuine saponins, named kinmoonosides A-C (1-3), have been isolated, together with a new monoterpenoid (4), from a methanolic extract of the fruits of Acacia concinna. The structures of kinmoonosides A-C were elucidated on the basis of spectral analysis as 3-O-¿alpha-L-arabinopyranosyl(1-->6)-[beta-D-glucopyranosyl(1-->2) ]-b eta-D-glucopyranosyl¿-21-O-¿(6R, 2E)-2-hydroxymethyl-6-methyl-6-O-[4-O-(2'E)-6'-hydroxyl-2'-hydroxymet hyl-6'-methyl-2',7'-octadienoyl-beta-D-quinovopyranosyl]-2, 7-octadienoyl¿acacic acid 28-O-alpha-L-arabinofuranosyl(1-->4)-[beta-D-glucopyranosyl(1-->3)]-a lpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl ester (1); 3-O-¿alpha-L-arabinopyranosyl(1-->6)-[beta-D-glucopyranosyl(1-->2) ]-b eta-D-glucopyranosyl¿-21-O-¿(6S, 2E)-2-hydroxymethyl-6-methyl-6-O-[4-O-(2'E)-6'-hydroxyl-2'-hydroxymet hyl-6'-methyl-2',7'-octadienoyl-beta-D-quinobopyranosyl]-2, 7-octadienoyl¿acacic acid 28-O-alpha-L-arabinofuranosyl(1-->4)-[beta-D-glucopyranosyl(1-->3)]-a lpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl ester (2); and 3-O-¿alpha-L-arabinopyranosyl(1-->6)-[beta-D-glucopyranosyl(1-->2) ]-b eta-D-glucopyranosyl¿-21-O-[(2E)-6-hydroxyl-2-hydroxymethyl-6-methyl- 2,7-octadienoyl]acacic acid 28-O-alpha-L-arabinofuranosyl(1-->4)-[beta-D-glucopyranosyl(1-->3)]-a lpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl ester (3), respectively. The new monoterpenoid 4 was determined as 4-O-[(2E)-6-hydroxyl-2-hydroxymethyl-6-methyl-2, 7-octadienoyl]-D-quinovopyranose. Compounds 1-3 showed significant cytotoxicity against human HT-1080 fibrosarcoma cells.

A review of acacic acid-type saponins from Leguminosae-Mimosoideae as potent cytotoxic and apoptosis inducing agents

“…Compounds 1-3 showed significant cytotoxic activity against human HT-1080 fibrosarcoma cels, with ED 50 values of 0.70, 0.91, and 2.83 lM, respectively (Tezuka et al 2000). Their cytotoxicity was greater than that of 5-fluorouracil (ED 50 , 8.0 lM).…”

“…The pod has been used as a skin tonic, a shampoo, an expectorant, a purgative and an emetic agent (Khory and Katrak 1999). The MeOH extract of the fruits of A. concinna was shown to exhibit significant cytotoxicity against human HT-1080 fribrosarcoma cells (Tezuka et al 2000). Then, the authors examined the constituents which were responsible of this activity and identified three genuine saponins named kinmoonosides A-C (1-3) (Fig.…”

“…It was reported that the monoterpene-quinovopyranosyl moiety at C-21 and the oligosaccharide ester at C-28 of the acacic acid-type aglycon are crucial substituents required for the cytotoxicity of Julibroside III (22) and its prosapogenins against KB cells and their hydroxyl group at C-16 may also be important for the cytotoxicity (Ikeda et al 1997). It was also reported that the trisaccharide unit at C-3 of kinmoonosides A-C (1-3) was not crucial for their cytotoxicity, but oligosaccharides at position-3 of the aglycone may intensify the cytotoxicity of acacic acid derivatives (Tezuka et al 2000). The only difference between adianthifoliosides A (8) and B (9) is due to the presence of one N-acetamido group at C-2 of the glucose unit directly attached at C-3 of acacic acid, instead of glucose at the same position in 9 (Fig.…”

Antiproliferative Activity of Diarylheptanoids from the Seeds of Alpinia blepharocalyx

“…The seeds of the plant are used in Chinese traditional medicines for the treatment of stomach disorders. 1) In the course of our studies on antiproliferative natural products, 2) we found that the 95% EtOH extract of the seeds of A. blepharocalyx showed potent antiproliferative activity against human HT-1080 fibrosarcoma cells 3) (ED 50 , 7.3 mg/ml) and highly liver metastatic murine colon 26-L5 carcinoma cells 4) (ED 50 , 33.2 mg/ml). Thus, the extract was separated into hexane, ether and residual fractions, and the latter two fractions were found to show more potent antiproliferative activity than the former fraction; ED 50 values against HT-1080 fibrosarcoma and colon 26-L5 carcinoma cells: hexane fraction, 7.1 and 62.8 mg/ml; ether fraction, 9.0 and 5.0 mg/ml; residual fraction, 12.3 and 6.8 mg/ml, respectively.…”

Naturally Occurring Triterpenoid Saponins

“…5-Fluorouracil used as positive control had an ED 50 value of 8.0 mm. Possibly the ester group at C(21) of the aglycone in these saponins might intensify the cytotoxicity [225].…”