UHPLC-ESI-QTOF-MS/MS-Based Molecular Networking Guided Isolation and Dereplication of Antibacterial and Antifungal Constituents of Ventilago denticulata

Muhaiminatul Azizah; Patcharee Pripdeevech; Tawatchai Thongkongkaew; Chulabhorn Mahidol; Somsak Ruchirawat; Prasat Kittakoop

doi:10.3390/antibiotics9090606

UHPLC-ESI-QTOF-MS/MS-Based Molecular Networking Guided Isolation and Dereplication of Antibacterial and Antifungal Constituents of Ventilago denticulata

Antibiotics (Basel). 2020 Sep 15;9(9):606. doi: 10.3390/antibiotics9090606.

Authors

Muhaiminatul Azizah¹, Patcharee Pripdeevech^{2

3}, Tawatchai Thongkongkaew¹, Chulabhorn Mahidol^{1

4}, Somsak Ruchirawat^{1

4

5}, Prasat Kittakoop^{1

4

5}

Affiliations

¹ Chulabhorn Graduate Institute, Chemical Biology Program, Chulabhorn Royal Academy, Laksi, Bangkok 10210, Thailand.
² School of Science, Mae Fah Luang University, Muang, Chiang Rai 57100, Thailand.
³ Center of Chemical Innovation for Sustainability (CIS), Mae Fah Luang University, Muang, Chiang Rai 57100, Thailand.
⁴ Chulabhorn Research Institute, Kamphaeng Phet 6 Road, Laksi, Bangkok 10210, Thailand.
⁵ Center of Excellence on Environmental Health and Toxicology (EHT), CHE, Ministry of Education, Bangkok 10210, Thailand.

Abstract

Ventilago denticulata is an herbal medicine for the treatment of wound infection; therefore this plant may rich in antibacterial agents. UHPLC-ESI-QTOF-MS/MS-Based molecular networking guided isolation and dereplication led to the identification of antibacterial and antifungal agents in V. denticulata. Nine antimicrobial agents in V. denticulata were isolated and characterized; they are divided into four groups including (I) flavonoid glycosides, rhamnazin 3-rhamninoside (7), catharticin or rhamnocitrin 3-rhamninoside (8), xanthorhamnin B or rhamnetin 3-rhamninoside (9), kaempferol 3-rhamninoside (10) and flavovilloside or quercetin 3-rhamninoside (11), (II) benzisochromanquinone, ventilatones B (12) and A (15), (III) a naphthopyrone ventilatone C (16) and (IV) a triterpene lupeol (13). Among the isolated compounds, ventilatone C (16) was a new compound. Moreover, kaempferol, chrysoeriol, isopimpinellin, rhamnetin, luteolin, emodin, rhamnocitrin, ventilagodenin A, rhamnazin and mukurozidiol, were tentatively identified as antimicrobial compounds in extracts of V. denticulata by a dereplication method. MS fragmentation of rhamnose-containing compounds gave an oxonium ion, C₆H₉O₃⁺ at m/z 129, while that of galactose-containing glycosides provided the fragment ion at m/z 163 of C₆H₁₁O₅⁺. These fragment ions may be used to confirm the presence of rhamnose or galactose in mass spectrometry-based analysis of natural glycosides or oligosaccharide attached to biomolecules, that is, glycoproteins.

Keywords: MS fragmentation of sugar; Ventilago denticulata; antibacterial activity; antifungal activity; dereplication; flavonoid glycosides; mass spectrometry; molecular networking; natural products.