Related Experiment Video
Updated: Jul 1, 2025

Biosynthesis of a Flavonol from a Flavanone by Establishing a One-pot Bienzymatic Cascade
Published on: August 14, 2019
New flavonoids with multiple bronchodilator activity pathways from Tephrosia purpurea L. (Pers.) growing in Saudi
Maged S Abdel-Kader1,2, Abdulaziz S Saeedan3, Najeeb U Rehman3
1Department of Pharmacognosy, College of Pharmacy, Prince Sattam bin Abdulaziz University, Al-Kharj 11942, Kingdom of Saudi Arabia.
Abstract:
Total extract of Tephrosia purpurea (T. purpurea) expressed potent ex-vivo bronchodilator effect in isolated Guinea pigs' tracheal muscles. Fractionation of T. purpurea total extract (TPTE) using liquid-liquid technique followed by ex-vivo bronchodilator testing indicated that the activity was trapped to the chloroform (CHCl3) soluble fraction. Phytochemical study of the CHCl3 fraction guided by ex-vivo bronchodilator activity led to the isolation of 7 active flavones of which compounds 1 (epi-Tephroapollin G), 3 (Acetyltephroapollin C), 4 (4''-Dehydroxytephroapollin E), and 5 (epi-Tephroapollin F) were new. Structures were identified using relevant spectroscopic tools including optical rotations and CD data. Compounds 1, 3, 4 and lanceolatin A (6) behaved like papaverine by inhibiting carbachol (CCh) as well as high potassium (K+)-mediated contractions at equivalent concentrations with varied potencies whereas (-)-Tephroapollin G (2) selectively inhibited CCh-mediated contractions but was not found active against high K+. epi-Tephroapollin F (5) and (-)-Pseudosemiglabrin (7) in contrast were significantly more potent to abolish CCh induced contraction when compared with high K+ similar to dicyclomine. Papaverine like dual phosphodiesterase enzyme Ca++ ion inhibitory activities of 1, 3, 4 and 6 were confirmed indirectly by the bolster of the isoprenaline curves against CCh to the left whereas Ca++ inhibitory effect of 1 and 3-7 was confirmed by the rightward deflection of Ca++ concentration-response curves (CRCs) towards right with quashing of the maximum response in same fashion like verapamil. Moreover, compounds 2, 5 and 7 at lower concentrations showed selective blockade of muscarinic receptor similar to atropine. Oral administration of the TPTE, CHCl3 and 7 to guinea pigs significantly protected against bronchospasm induced by 0.2 % histamine aerosol in vivo.
More Related Videos
13:18Network Pharmacology Prediction and Experimental Validation of Trichosanthes-Fritillaria thunbergii Action Mechanism Against Lung Adenocarcinoma
Published on: March 3, 2023
11:06Network Pharmacology Prediction and Metabolomics Validation of the Mechanism of Fructus Phyllanthi against Hyperlipidemia
Published on: April 7, 2023
Related Concept Videos
Antiasthma Drugs: Methylxanthines
Theophylline is thought to inhibit phosphodiesterase enzymes, increasing intracellular levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). This rise in cAMP and cGMP concentrations stimulates cardiac function,...
Structure-Activity Relationships and Drug Design
SAR studies the intricate relationship between a drug's chemical structure and biological activity. It focuses on understanding how modifications to a drug's structure can influence...
Adrenergic Agonists: Mixed-Action Agents
Ephedrine and pseudoephedrine lack a catecholamine group, making them less susceptible to degradation by metabolic enzymes. They have increased oral bioavailability and lipophilicity, resulting in a longer duration of action. Their response is reduced by...
Drug Discovery: Overview
Antiasthma Drugs: β2-Adrenoceptor Agonists
One class of bronchodilators includes β2-adrenoceptor agonists. These agents target the β2-adrenoceptors located on bronchial smooth muscle cells. By stimulating these receptors, β2-agonists induce...
Treatment for Pulmonary Arterial Hypertension: Receptor Tyrosine Kinase Inhibitors and Calcium Channel Blockers
TKIs, such as imatinib (Gleevec), are particularly effective in tackling the growth and mitogenic factors that become upregulated in PAH patients. These factors contribute to the...