Bioassay-Guided Isolation and Structural Modification of the Anti-TB Resorcinols fromArdisia gigantifolia

Systematic identification of reference genes for qRT-PCR of Ardisia kteniophylla A. DC under different experimental conditions and for anthocyanin-related genes studies

Ardisia kteniophylla A. DC, widely known as folk medicinal herb and ornamental plant, has been extensively investigated due to its unique leaf color, anti-cancer and other pharmacological activities. The quantitative real-time PCR (qRT-PCR) was an excellent tool for the analysis of gene expression with its high sensitivity and quantitative properties. Normalizing gene expression with stable reference genes was essential for qRT-PCR accuracy. In addition, no studies have yet been performed on the selection, verification and stability of internal reference genes suitable for A. kteniophylla, which has greatly hindered the biomolecular researches of this species. In this study, 29 candidate genes were successfully screened according to stable expression patterns of large-scale RNA seq data that from a variety of tissues and the roots of different growth stages in A. kteniophylla. The candidates were then further determined via qRT-PCR in various experimental samples, including MeJA, ABA, SA, NaCl, CuSO4, AgNO3, MnSO4, CoCl2, drought, low temperature, heat, waterlogging, wounding and oxidative stress. To assess the stability of the candidates, five commonly used strategies were employed: delta-CT, geNorm, BestKeeper, NormFinder, and the comprehensive tool RefFinder. In summary, UBC2 and UBA1 were found to be effective in accurately normalizing target gene expression in A. kteniophella regardless of experimental conditions, while PP2A-2 had the lowest stability. Additionally, to verify the reliability of the recommended reference genes under different colored leaf samples, we examined the expression patterns of six genes associated with anthocyanin synthesis and regulation. Our findings suggested that PAP1 and ANS3 may be involved in leaf color change in A. kteniphella. This study successfully identified the ideal reference gene for qRT-PCR analysis in A. kteniphella, providing a foundation for future research on gene function, particularly in the biosynthesis of anthocyanins.

Traditional Medicinal Plants as a Source of Antituberculosis Drugs: A System Review

Medicinal plants are the chief components in the different oriental formulations in different traditional medical systems worldwide. As a thriving source of medicine, the medicinal plants with antituberculosis (TB) properties inspire the pharmacists to develop new drugs based on their active components or semimetabolites. In the present review, the anti-TB medicinal plants were screened from the scientific literatures, based on the botanical classification and the anti-TB activity. The obtained anti-TB medicinal plants were categorized into three different categories, viz., 159 plants critically examined with a total 335 isolated compounds, 131 plants with their crude extracts showing anti-TB activity, and 27 plants in literature with the prescribed formula by the traditional healers. Our systemic analysis on the medicinal plants can assist the discovery of novel and more efficacious anti-TB drugs.

Natural Products of Marine Macroalgae from South Eastern Australia, with Emphasis on the Port Phillip Bay and Heads Regions of Victoria

Marine macroalgae occurring in the south eastern region of Victoria, Australia, consisting of Port Phillip Bay and the heads entering the bay, is the focus of this review. This area is home to approximately 200 different species of macroalgae, representing the three major phyla of the green algae (Chlorophyta), brown algae (Ochrophyta) and the red algae (Rhodophyta), respectively. Over almost 50 years, the species of macroalgae associated and occurring within this area have resulted in the identification of a number of different types of secondary metabolites including terpenoids, sterols/steroids, phenolic acids, phenols, lipids/polyenes, pheromones, xanthophylls and phloroglucinols. Many of these compounds have subsequently displayed a variety of bioactivities. A systematic description of the compound classes and their associated bioactivities from marine macroalgae found within this region is presented.

Chemical constituents and biological activities of the fruits of Knema pachycarpa de Wilde

The n-hexane extract of Knema pachycarpa fruits (Myristicaceae family), exhibiting strong anti-acetylcholinesterase activity, was investigated by gas chromatography/mass spectrometry and then purified by column chromatography. Guided by GC/MS profiling and bioassay, chromatographic separations led to the isolation of five new compounds: two anacardic acid derivatives 1-2, two cardanol derivatives 3-4 and a cardol derivative 5, along with mixtures of known phenolic lipids 6-9. The chemical structures were determined by various spectroscopic methods. New isolated compounds 1-5 were evaluated for their cytotoxicity and anti-acetylcholinesterase activity. Cardanol 3 and cardol 5 were the most active compounds in the acetylcholinesterase inhibitory assay with IC₅₀ values of 2.60 ± 0.24 µM and 2.46 ± 0.23 µM, respectively. Cardanol 4 and cardol 5 showed moderate cytotoxicity against Hela and MCF-7 cancer cell lines with IC₅₀ values ranging from 31.36 ± 0.41 µM to 41.30 ± 2.49 µM.

Phenolic Compounds as Promising Drug Candidates in Tuberculosis Therapy

Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB) remains one of the deadliest, infectious diseases worldwide. The detrimental effects caused by the existing anti-TB drugs to TB patients and the emergence of resistance strains of M. tuberculosis has driven efforts from natural products researchers around the globe in discovering novel anti-TB drugs that are more efficacious and with less side effects. There were eleven main review publications that focused on natural products with anti-TB potentials. However, none of them specifically emphasized antimycobacterial phenolic compounds. Thus, the current review’s main objective is to highlight and summarize phenolic compounds found active against mycobacteria from 2000 to 2017. Based on the past studies in the electronic databases, the present review also focuses on several test organisms used in TB researches and their different distinct properties, a few types of in vitro TB bioassay and comparison between their strengths and drawbacks, different methods of extraction, fractionation and isolation, ways of characterizing and identifying isolated compounds and the mechanism of actions of anti-TB phenolic compounds as reported in the literature.

Ionic liquid brush as an efficient and reusable heterogeneous catalytic assembly for the tosylation of phenols and alcohols in neat water

An efficient and reusable heterogeneous catalytic assembly-ionic liquid brush was developed for tosylation of phenols and alcohols in neat water.

Discovery of Bioactive Compounds by the UIC-ICBG Drug Discovery Program in the 18 Years Since 1998

The International Cooperative Biodiversity Groups (ICBG) Program based at the University of Illinois at Chicago (UIC) is a program aimed to address the interdependent issues of inventory and conservation of biodiversity, drug discovery and sustained economic growth in both developing and developed countries. It is an interdisciplinary program involving the extensive synergies and collaborative efforts of botanists, chemists and biologists in the countries of Vietnam, Laos and the USA. The UIC-ICBG drug discovery efforts over the past 18 years have resulted in the collection of a cumulative total of more than 5500 plant samples (representing more than 2000 species), that were evaluated for their potential biological effects against cancer, HIV, bird flu, tuberculosis and malaria. The bioassay-guided fractionation and separation of the bioactive plant leads resulted in the isolation of approximately 300 compounds of varying degrees of structural complexity and/or biological activity. The present paper summarizes the significant drug discovery achievements made by the UIC-ICBG team of multidisciplinary collaborators in the project over the period of 1998-2012 and the projects carried on in the subsequent years by involving the researchers in Hong Kong.