Triterpenoid Saponins from the Seeds of Pharbitis nil

Abstract

Pharbitis nil CHOISY [ϭIpomoea nil (L.) ROTH] is found throughout Southeast Asia. The seeds and the resin extracted from the plant are medicinal. The main use is as a purgative.1) The Japanese morning glory has been domesticated as an ornamental plant in Japan. There have been several reports on the isolation of resin glycosides, 2-4) a diterpenoid, pharbitic acid, 5) flavonoids, caffeic acid, and chlorogenic acid derivatives, 6) and anthocyanins 7-10) from the seeds and flowers of this plant but there has been no report on the chemical investigation of the saponins in the seeds. In continuation of our studies on phytochemical studies on naturally occurring bioactive glycosides, [11][12][13][14] we became interested in the saponin content of the seeds of the plant. This paper describes the structural determination of the two new saponins isolated from the MeOH extract of the seeds.The powdered seeds of P. nil were sonicated with MeOH and partitioned as described in the Experimental. b-Sitosterol and its glucoside and caffeic acid and its methyl ester were isolated by successive chromatography using silica gel and reverse-phase C 18 from the hexane and EtOAc fractions, respectively. The BuOH-soluble fraction after repeated chromatographic purification over MCI gel and reverse-phase C 18 afforded two compounds designated pharbitosides A (1) and B (2).Pharbitoside A (1) was obtained as colorless crystalline needles. High-resolution (HR) FAB-MS gave the composition C 48 H 78 O 18 . An inspection of the 1 H-and 13 C-NMR spectra of the compound readily indicated the presence of three monosaccharide units through easily identifiable signals for anomeric protons and carbons. Acid hydrolysis of 1 afforded glucose (Glc) and rhamnose (Rha) as the sugar components identified on TLC analysis by comparison with authentic samples. The absolute configurations of sugars were determined to be the L-form for Rha and D-form for Glc, respectively, which were identified by GLC analysis of the thiazolidine derivatives.15) The negative-ion mode FAB mass spectrum of 1 exhibited an [MϪH] Ϫ ion at m/z 941, which is consistent with a trisaccharide glycoside carrying two Glc, one Rha, and an aglycon with a molecular mass of 472. Ϫ showed the presence of a linear sugar chain, and the sugar sequence appeared to be that of Glc-Glc-Rha.16) The spectroscopic data of the aglycon moiety of 1 were closely related to those of oleanolic acid 17) ; however, the molecular formula of the aglycon moiety was higher by one oxygen atom than that of oleanolic acid, implying the presence of one more hydroxyl group in addition to the C-3 hydroxyl group. The oxygenated methylene protons at

Active Compound of Pharbitis Semen (Pharbitis nil Seeds) Suppressed KRAS-Driven Colorectal Cancer and Restored Muscle Cell Function during Cancer Progression

“…Seeds of Pharbitis nil contains several bioactive compounds such as polysaccharides [ 16 ], pharbitin (resin glycosides) [ 25 ], anthocyanins, diterpenoids [ 26 ], triterpene saponins [ 27 ], pharbilignan C [ 17 ], neolignane, and monoterpene glycosides [ 28 ]. Pharbilignan C has been reported to induce human breast cancer cell apoptosis via the mitochondria-medicated intrinsic pathway [ 17 ], and lignans exhibited anti-inflammatory and anti-cancer activities [ 29 ].…”

Metabolite Profile, Ruminal Methane Reduction, and Microbiome Modulating Potential of Seeds of Pharbitis nil

“…Pharbitis nil (Convolvulaceae) is an annual climbing herb widely distributed throughout Korea, Japan, and China, and PA is used as a purgative agent and in treating digestive disorders ( Kim et al, 2020 ). Previous phytochemical investigations have reported the isolation of bioactive chemical constituents such as resin glycosides ( Ono, 2017 ), monoterpenoids ( Lee et al, 2017 ), diterpenoids ( Ki et al, 2009 ; Woo et al, 2017 ), triterpenoid saponins ( Jung et al, 2008 ), flavonoids, chlorogenic acid derivatives ( Saito et al, 1994 ), and phenolic compounds ( Kim et al, 2011 ) from different parts of P. nil . Similarly, we reported the enrichment of PUFAs in PA using gas chromatography-mass spectroscopy (GC-MS) without derivatization ( Bharanidharan et al, 2021a ).…”

Identification and Evaluation of Apoptosis-Inducing Activity of Ipomone from Ipomoea nil: A Novel, Unusual Bicyclo-[3.2.1] Octanone Containing Gibberic Acid Diterpenoid

“…An array of diverse chemical constituents have been isolated from the Ipomoea nil seeds viz. gibberellins and their glycosides (from the immature seeds), allogibberic acid, monoterpene glycosides, phenylethanoid glycosides, and phenylpropanoids, ent -kaurane diterpenoids and their glycosides, ent -gibbane diterpene glycoside, resin glycosides, phenolic amides, lignans, , neolignans, triterpenoid saponins, fatty acid derivatives, and spermidine alkaloid . The plant has been reported to have diverse pharmacological activities including antibacterial, antifungal, anti-inflammatory, , antioxidant, cytotoxic, ,,, α-glucosidase inhibitory, hepatoprotective, and multidrug-resistance reversal activities…”