Hypoglycemic active principles from the leaves of Bauhinia holophylla: Comprehensive phytochemical characterization and in vivo activity profile

Abstract

Bauhinia holophylla leaves, also known as "pata-de-vaca", are traditionally used in Brazil to treat diabetes. Although the hypoglycemic activity of this medicinal plant has already been described, the active compounds responsible for the hypoglycemic activity have not yet been identified. To rapidly obtain two fractions in large amounts compatible with further in vivo assay, the hydroalcoholic extract of B. holophylla leaves was fractionated by Vacuum Liquid Chromatography and then purified by medium pressure liquid chromatography combined with an in vivo Glucose Tolerance Test in diabetic mice. This approach resulted in the identification of eleven compounds (1–11), including an original non-cyanogenic cyanoglucoside derivative. The structures of the isolated compounds were elucidated by nuclear magnetic resonance and high-resolution mass spectrometry. One of the major compounds of the leaves, lithospermoside (3), exhibited strong hypoglycemic activity in diabetic mice at the doses of 10 and 20 mg/kg b.w. and prevents body weight loss. The proton nuclear magnetic resonance (1H NMR) quantification revealed that the hydroalcoholic leaves extract contained 1.7% of lithospermoside (3) and 3.1% of flavonoids. The NMR analysis also revealed the presence of a high amount of pinitol (4) (9.5%), a known compound possessing in vivo hypoglycemic activity. The hypoglycemic properties of the hydroalcoholic leaves extract and the traditional water infusion extracts of the leaves of B. holophylla seem thus to be the result of the activity of three unrelated classes of compounds. Such results support to some extent the traditional use of Bauhinia holophylla to treat diabetes.

NMR-Based Metabolomics Reveals Effects of Water Stress in the Primary and Specialized Metabolisms of Bauhinia ungulata L. (Fabaceae)

“…Glucose and sucrose are the common sugars present in plants, while D-pinitol is a known inositol ether, also widely distributed in plants, especially Fabaceae [ 35 ]. D-pinitol was previously identified in B. ungulata [ 4 ], B. holophylla [ 36 ], and B. variegata leaves [ 37 , 38 ].…”

“…Diabetic rats treated with Mesembryanthemum crystallinum L. (Aizoaceae) extract, which is rich in D-pinitol, also had effective control of blood glucose levels [ 56 ]. D-pinitol was also found in higher concentrations, and was related to one of the active principles of Bauhinia holophylla (Fabaceae) leaf extracts, for diabetes treatment [ 36 ].…”

Advanced high-resolution chromatographic strategies for efficient isolation of natural products from complex biological matrices: from metabolite profiling to pure chemical entities

“…This method has also been effectively used to introduce samples into flash chromatography (Azzollini et al 2016), MPLC (Challal et al 2015;Saldanha et al 2021), and supercritical fluid chromatography, while maintaining resolution (Miller and Mahoney 2012), even with high sample amounts injected.…”

Natural Products Containing the Nitrile Functional Group and Their Biological Activities

“…Steud. (Fabaceae), a plant used in Brazilian traditional medicine to treat diabetes 71 afforded the new compound (-)-(1 E ,4 R ,5 S ,6 S )-6-(β-D-glucopyranosyloxy)-4,5-dihydroxy-2-cyclohexen-1-ylideneacetonitrile 123 (Figure 13), a stereoisomer of the known compound (-) lithospermoside, itself also isolated, along with its steric isomer aglycone at C-1, ( + )-(1 E ,4 R ,5 S ,6 S )-45,6-trihydroxy-2-cyclohexen-1-ylideneacetonitrile.…”