Sulfonic Acid-Containing Flavonoids from the Roots of Phyllanthus acidus Thuc-Huy Duong, †,‡ Mehdi A. Beniddir, § Van-Kieu Nguyen, ‡ Thammarat Aree, ‡ Jean-Franç ois Gallard, ⊥ Dinh-Hung Mac, ▽ Huu-Hung Nguyen, ∥ Xuan-Hao Bui, † Joë l Boustie, # Kim-Phi-Phung Nguyen, □ Warinthorn Chavasiri,* ,‡ and Pierre Le Pogam* ,§ † Department of Chemistry, Ho Chi Minh City University of Education, 280 An Duong Vuong Street, District 5, Ho Chi Minh City 748342, Vietnam ‡ Center of Excellence in Natural Products Chemistry, Department of Chemistry, Faculty of Science, Chulalongkorn University, Pathumwan, Bangkok 10330, Thailand § E ́ quipe “Pharmacognosie-Chimie des Substances Naturelles”, BioCIS, Université Paris-Sud, CNRS, Université Paris-Saclay, 5 Rue J.-B. Clé ment, 92290 Châ tenay-Malabry, France ⊥ Institut de Chimie des Substances Naturelles, CNRS, ICSN UPR 2301, Université Paris-Saclay, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette, France ▽ Department of Organic Chemistry, University of Science, Ha Noi National University, 19 Le Thanh Tong Street, District Hoan Kiem, Ha Noi City 748355, Vietnam ∥ Faculty of Biotechnology and Environment, Nguyen Tat Thanh University, 300A Nguyen Tat Thanh, District 4, Ho Chi Minh City 748355, Vietnam # Université Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)−UMR 6226, F-35000 Rennes, France □ Department of Organic Chemistry, University of Science, National University−Ho Chi Minh City, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City 748355, Vietnam *S Supporting Information ABSTRACT: Six new sulfonic acid-containing flavonoids, acidoflavanone (1), acidoauronol (2), 5-O-methylacidoauronol (3), acidoaurone (4), acidoisoflavone (5), and acidoflavonol (6), were isolated from the EtOH extract of the roots of Phyllanthus acidus. Their structures were unambiguously established by interpretation of their HRESIMS and 1D and 2D NMR data, single- crystal X-ray diffraction analysis, and comparison to the literature data. These new structures represent the first examples of sulfonic acid-containing flavanones, auronols, aurones, and isoflavones. T he genus Phyllanthus (Phyllanthaceae) includes more than 900 plant species found in tropical and subtropical regions. 1 Many of these species are widely used in folk medicine. 2 Phyllanthus acidus is a deciduous tree that grows 5 to 8 m tall with slender branches terminated by clustered leaves at their upper ends. The sour edible fruits are pale yellow, fleshy drupes. 3 Various ethnobotanical claims are associated with different parts of P. acidus. The fruit is used in folk medicine to treat bronchitis, vomiting, urinary concretions, piles, and hepatopathies in the Ayurvedic system of medicine, while leaves are used to alleviate fevers, piles, smallpox, itching, and gum infection. 4 These traditional uses have been partly corroborated by in vitro data that demonstrated the antibacterial, 5 antiviral, 6,7 analgesic, anti-inflammatory, 8,9 neu- roprotective, 10,11 hepatoprotective, 4,12 antifibrotic, 13 cyto- Received: April 23, 2018 Article pubs.acs.org/jnp Cite This: J. Nat. Prod. XXXX, XXX, XXX-XXX © XXXX American Chemical Society and American Society of Pharmacognosy A DOI: 10.1021/acs.jnatprod.8b00322 J. Nat. Prod. XXXX, XXX, XXX−XXX Downloaded via KAOHSIUNG MEDICAL UNIV on September 12, 2018 at 18:23:14 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.