Investigation of the antitumor activity of podocarpic acid derivatives

In Silico Screening for Anti-inflammatory Bioactive Molecules from Ayurvedic Decoction, Balaguluchyadi kashayam

BACKGROUND

Balaguluchyadi kashayam, a polyherbal Ayurvedic decoction prepared from Sidacordifolia L., Tinospora cordifolia (Willd.) Miers, and Cedrusdeodara (Roxb. ex D.Don) G.Don, is used in Ayurveda for the treatment of chronic inflammatory conditions. Although this herbal decoction has been used for a long period for treating chronic inflammatory conditions, the mechanism of action of the decoction in reducing inflammatory conditions associated with chronic inflammation has not been clearly understood. Mass spectroscopy-based identification of bioactive molecules present in the decoction and its interaction with enzymes/proteins involved in the pathogenesis of chronic inflammation has been carried and reported in this study.

INTRODUCTION

Polyherbalism is one of the major principles of Ayurveda. Various phytoconstituents with different activities in the polyherbal decoction act on multi targets of a wide range of diseases. Balaguluchyadi kashayam is a polyherbal decoction prescribed for chronic inflammatory etiologies and the present study aims to evaluate the binding potential of the compounds, identified from Balaguluchyadi kashayam to enzymes/proteins involved in the development and progression of chronic inflammation.

METHODS

The bioactive compounds present in the Balaguluchyadi Kashayam fractions were extracted by preparative HPLC and identified using UPLC MS Q-TOF. The physicochemical characteristics and ADMET properties of the compounds were calculated using Mol soft, Swiss ADME and OSIRIS data warrior software. Then the binding interactions between the molecules and the proinflammatory mediators such as 5 Lipoxygenase, Cyclooxygenase 2, Tumor necrosis factoralpha convertase enzyme (TACE) and Caspase 1 were determined using molecular docking software Auto Dock 4.0 (http://autodock.scripps.edu/downloads).

RESULTS

The identified bioactive molecules in the decoction showed a good binding affinity towards the enzymes/proteins involved in the development and progression of chronic inflammation compared to the binding affinity of known inhibitors/drugs to the respective enzymes/proteins.

CONCLUSION

The bioactive molecules identified in Balaguluchyadi Kashayam could be developed as potential therapeutic molecules against enzymes/proteins involved in the development and progression of chronic inflammation.

Total Synthesis of Hamigerans and Analogues Thereof. Photochemical Generation and Diels−Alder Trapping of Hydroxy-o-quinodimethanes

A number of naturally occurring substances, including hamigerans, contain ring systems which are fused to an aromatic nucleus. A general and streamlined method for the construction of such benzannulated bi- and polycyclic carbon frameworks has been developed, and its scope and limitations were explored. On the basis of the photoenolization of substituted benzaldehydes and subsequent Diels-Alder (PEDA) trapping of the generated hydroxy-o-quinodimethanes, this method was optimized to set the stage for the total synthesis of several naturally occurring members of the hamigeran class. Specifically, the developed synthetic technology served as the centerpiece process for the successful asymmetric synthesis of hamigerans A (2), B (3), and E (7). In addition to the PEDA reactions, several other novel reaction processes are described, including a high-yielding decarbonylative ring contraction and an oxidative decarboxylation of a hydroxyl beta-keto ester to afford an alpha-diketone. A number of analogues of these biologically active natural products were also prepared by application of the developed technology.

Inhibition of influenza virus hemagglutinin-mediated membrane fusion by a compound related to podocarpic acid

Entry of influenza virus into the host cell is dependent on the fusion of the viral envelope with the endosomal membrane and is mediated by a low-pH-induced change of the viral hemagglutinin (HA) to a conformation that is fusogenic. A compound related to podocarpic acid (180299) was identified that inhibits multicycle replication of influenza A/Kawasaki/86 (H1N1) virus in culture. Treatment of Madin-Darby canine kidney (MDCK) cells with 180299 at 1 h before infection resulted in the inhibition of viral protein synthesis. Addition of 20 microgram of 180299/ml at 1 h p.i. had no effect, indicating that 180299 affects an early step of the influenza viral replication cycle. Genetic analysis of reassortants between sensitive and resistant viruses demonstrated that hemagglutinin (HA) conferred the 180299-resistant (180299(r)) phenotype. Twelve independent isolates of influenza A/Kawasaki/86 were selected for resistance to 180299, and sequence analysis revealed that each of these viruses contained amino acid substitutions in the HA. These mutations are dispersed throughout the HA primary amino acid sequence and cluster in one of two regions: the interface between HA1 and HA2 and in a region near the fusion domain of HA2. When compared with the parent virus, the pH-of-inactivation of the resistant mutants was increased by 0.3 to 0.6 pH unit, suggesting that the mutant HAs undergo the conformational change at an elevated pH. Fusion of human erythrocytes to MDCK cells infected with parent influenza A/Kawasaki/86 was inhibited by 180299 (0.1-10 microgram/ml) in a concentration-dependent manner, whereas fusion of erythrocytes to MDCK cells infected with 180299(r) mutants was not affected. These results suggest that 180299 interacts with the neutral pH conformation of influenza A HA and prevents the low-pH-induced change of HA to its fusogenic conformation.