title: A new dammarane saponin and other triterpenoids from Siolmatra brasiliensis and evaluation of the antidiabetic activity of its extract.
abstract: Context Siolmatra brasiliensis (Cogn.) Baill (Cucurbitaceae) is a climbing plant widely used for the treatment of diabetes mellitus symptoms. Objective This work evaluates the antidiabetic activity of an extract of S. brasiliensis in streptozotocin-diabetic rats and promotes the phytochemical investigation to isolate the major compounds of the same extract. Materials and methods Male Wistar rats were divided into normal (N) and diabetic rats (DC) treated with water; diabetic rats treated with 3U insulin (DI) or with 250 (DSb250) or 500 mg/kg (DSb500) of hydroalcoholic extract of the stalks of S. brasiliensis, via oral gavage, for 21 days. Physiological and biochemical parameters classically altered in diabetes were monitored. The triterpenoids were isolated from the ethyl acetate fraction under silica gel column chromatography and Sephadex-LH20 methods and their structures were determined by NMR, HR-ESI-MS and DC analysis. Results When compared with DC, DSb250 rats showed a reduction in the hyperglycemia (DC: 26.46 ± 0.69 versus DSb250: 19.67 ± 1.06 mmol/L) and glycosuria (DC: 43.02 ± 3.19 versus DSb250: 28.46 ± 2.14 mmol/24 h) and increase in hepatic glycogen (DC: 14.44 ± 1.26 versus DSb250: 22.08 ± 4.26 mg/g). Three known cucurbitacins were isolated from a hydroalcoholic extract of S. brasiliensis, i.e., cayaponosides A1, B4, D, and a new dammarane saponin 3-O-β-d-gentiobiosyl-26-O-β-d-glucopyranosyl-20-hydroxydammar-24-ene. The structures of these compounds were elucidated by spectral data analysis of the natural products and their acetyl derivatives. Discussion and conclusion The known cucurbitacins and/or the new identified saponin may be related with the antidiabetic activity of S. brasiliensis.
authors.affiliation: a Programa De Pós-Graduação Em Química, Departamento De Química , Instituto De Ciências Exatas, Universidade Federal Rural Do Rio De Janeiro , Seropédica , RJ , Brazil ;
authors.forename: Carlos Henrique Corrêa
authors.initials: CH
authors.lastname: Dos Santos
authors.affiliation: b Departamento De Química , Instituto De Ciências Exatas E Da Terra, Universidade Federal De Mato Grosso , Cuiabá , MT , Brazil ;
authors.forename: Izabeau Pontes
authors.initials: IP
authors.lastname: Borges
authors.affiliation: b Departamento De Química , Instituto De Ciências Exatas E Da Terra, Universidade Federal De Mato Grosso , Cuiabá , MT , Brazil ;
authors.forename: Virgínia Claudia
authors.initials: VC
authors.lastname: da Silva
authors.affiliation: b Departamento De Química , Instituto De Ciências Exatas E Da Terra, Universidade Federal De Mato Grosso , Cuiabá , MT , Brazil ;
authors.forename: Paulo Teixeira
authors.initials: PT
authors.lastname: de Sousa
authors.affiliation: b Departamento De Química , Instituto De Ciências Exatas E Da Terra, Universidade Federal De Mato Grosso , Cuiabá , MT , Brazil ;
authors.forename: Nair Honda
authors.initials: NH
authors.lastname: Kawashita
authors.affiliation: c Departamento De Análises Clínicas , Faculdade De Ciências Farmacêuticas, Universidade Estadual Paulista , Araraquara , SP , Brazil.
authors.forename: Amanda Martins
authors.initials: AM
authors.lastname: Baviera
authors.affiliation: a Programa De Pós-Graduação Em Química, Departamento De Química , Instituto De Ciências Exatas, Universidade Federal Rural Do Rio De Janeiro , Seropédica , RJ , Brazil ;
authors.forename: Mario Geraldo de
authors.initials: MG
authors.lastname: Carvalho
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D002942:Circular Dichroism; D019662:Cucurbitaceae / Q000737:chemistry; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000139:chemically induced / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D006003:Glycogen / Q000378:metabolism; D006029:Glycosuria / Q000139:chemically induced / Q000517:prevention & control; D007004:Hypoglycemic Agents / Q000302:isolation & purification / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D015394:Molecular Structure; D008517:Phytotherapy; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D018547:Plant Stems; D010946:Plants, Medicinal; D066244:Proton Magnetic Resonance Spectroscopy; D017208:Rats, Wistar; D012503:Saponins / Q000302:isolation & purification / Q000494:pharmacology*; D021241:Spectrometry, Mass, Electrospray Ionization; D013311:Streptozocin; D013997:Time Factors; D014315:Triterpenes / Q000302:isolation & purification / Q000494:pharmacology*; D000097669:Dammaranes
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D006003:Glycogen; D007004:Hypoglycemic Agents; D007328:Insulin; D010936:Plant Extracts; D012503:Saponins; D013311:Streptozocin; D014315:Triterpenes; D000097669:Dammaranes
keywords: Antihyperglycemic effect; Cucurbitaceae; cucurbitacins; diabetes mellitus