Cytotoxic triterpenoid saponins acylated with monoterpenic acids from fruits of Gleditsia caspica Desf

• Published in: Phytochemistry (Oxford) Vol. 71; no. 16; pp. 1908 - 1916
• Main Authors: Miyase, Toshio, Melek, F.R., Warashina, Tsutomu, Selim, M.A., El Fiki, N.M., Kassem, I.A.A.
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 01.11.2010; Elsevier
• Subjects: anticarcinogenic activity; Antineoplastic Agents, Phytogenic - chemistry; Antineoplastic Agents, Phytogenic - isolation & purification; Antineoplastic Agents, Phytogenic - pharmacology; application rate; Biochemistry & Molecular Biology; Biological and medical sciences; Caspicaosides; Chemical constitution; chemical structure; cytotoxicity; Drug Screening Assays, Antitumor; Echinocystic acid; Egypt; Fruit - chemistry; fruits (plant anatomy); Fundamental and applied biological sciences. Psychology; Gleditsia; Gleditsia - chemistry; Gleditsia caspica; human cell lines; Humans; in vitro studies; Inhibitory Concentration 50; Leguminosae; Life Sciences & Biomedicine; medicinal plants; medicinal properties; Molecular Structure; monoterpenoids; neoplasms; nuclear magnetic resonance spectroscopy; Nuclear Magnetic Resonance, Biomolecular; Plant physiology and development; Plant Sciences; Saponins - chemistry; Saponins - isolation & purification; Saponins - pharmacology; Science & Technology; Stereoisomerism; Structure-Activity Relationship; structure-activity relationships; Triterpenes - chemistry; Triterpenes - isolation & purification; Triterpenes - pharmacology; Triterpenoid saponins; Egypt; Echinocystic acid; Caspicaosides; Leguminosae; Gleditsia caspica; Triterpenoid saponins; JAPONICA MIQUEL; LEGUME SAPONINS; PRINCIPLES; Terpenoid; Fruit; Chemical structure; Cytotoxicity; Saponin; Dicotyledones; Angiospermae; Plant origin; Triterpene; Spermatophyta
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2010.08.001

Four acylated triterpenoid saponins named caspicaosides A–D, were isolated from the fruits of Gleditsia caspica Desf. Their structures were determined by NMR spectroscopy including HOHAHA, 1H– 1H COSY, ROE, HMQC, HMBC experiments and FAB-MS as well as acid hydrolysis. Four bisdesmosidic triterpenoid saponins named caspicaosides A–D, were isolated from the fruits of Gleditsia caspica Desf. Their structures were determined by NMR spectroscopy including HOHAHA, 1H– 1H COSY, ROE, HMQC, HMBC experiments and HRFAB-MS as well as acid hydrolysis. The four 3,28- O-bisdesmosidic triterpenoid saponins comprised echinocystic acid as the aglycone and common oligosaccharide moieties at C3 and C28. The saccharide moiety at C-3 was identified as β- d-xylopyranosyl-(1 → 2)-α- l-arabinopyranosyl-(1 → 6)-β- d-glucopyranosyl while that at C-28 was determined as β- d-xylopyranosyl-(1 → 3)-β- d-xylopyranosyl-(1 → 4)-α- l-rhamnopyranosyl-(1 → 2)-[α- l-rhamnopyranosyl-(1 → 6)-]β- d-glucopyranosyl. The pentasaccharide moiety linked to C-28 was acylated with monoterpenic acid and or monoterpene-arabinoside moieties at C-2 or C-2 and C-3 of the terminal rhamnose unit. The isolated saponins were assayed for their in vitro cytotoxicities against the three human tumor cell lines HepG2, A549 and HT29 using MTT method. The results showed that caspicaosides B and C bearing two and three monoterpene units, respectively, exhibited significant cytotoxic activities against the used cell lines with IC 50 values 1.5–6.5 μM. Caspicaosides A and D with one monoterpene unit exhibited significant cytotoxic activities on HepG2 cell line with IC 50 values equal to 4.5 and 5.4 μM, respectively, and IC 50 values >10 μM against the other two cell lines. The number of monoterpene units seems to play a main role in determining the activity.