Warmingiins A and B, Two New Dimeric Naphthoquinone Derivatives from Sinningia warmingii (Gesneriaceae)

Abstract

Chemical investigation of Sinningia warmingii (Gesneriaceae) tubers lead to the isolation of two new dimeric naphthoquinone derivatives, named warmingiins A and B, besides six known compounds, aggregatin E, aggregatin F, tectoquinone, halleridone, cleroindicin B, and cornoside. All compounds were identified by spectroscopic analysis, mainly nuclear magnetic resonance (NMR) and mass spectrometry (MS), and comparison with the literature. The structure of the warmingiin A, which is an artifact of warmingiin B, was confirmed by X-ray diffraction analysis. Antimicrobial activity of the ethanolic extract and fractions of S. warmingii was evaluated against Staphylococcus aureus, S. epidermidis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, C. dubliniensis, C. glabrata and C. parapsilosis. All samples were inactive.

CHEMICAL CONSTITUENTS OF Sinningia mauroana AND SCREENING OF ITS EXTRACTS FOR ANTIMICROBIAL, ANTIOXIDANT AND CYTOTOXIC ACTIVITIES

“…34 Similar results have been found for other Sinningia species, as S. hatschbachii and S. warmingii. 7,10 The antioxidant capacity, measured by ORAC method, was expressed as mmol of trolox equivalent (TE) by gram of dried extract (mmol TE g -1 ). Active extracts should exhibit TE ≥ 800 µmol g -1 .…”

“…2 Since then, new phytochemical studies were carried on S. aggregata 3 and S. allagophylla, 4 and five species were studied for the first time: S. canescens, 5,6 S. hatschbachii, 7 S. leucotricha, 6,8 S. reitzii, 9 e S. warmingii. 10 The chemical profile that arises from these studies shows that the genus is very chemically diverse, producing anthraquinones, naphthoquinones and derivatives, naphthochromenes, terpenoids, flavonoids, cyclohexylethanoids, and phenylethanoid glycosides. [2][3][4][5][6][7][8][9][10] Some compounds isolated from Sinningia spp exhibit biological activity.…”

“…10 The chemical profile that arises from these studies shows that the genus is very chemically diverse, producing anthraquinones, naphthoquinones and derivatives, naphthochromenes, terpenoids, flavonoids, cyclohexylethanoids, and phenylethanoid glycosides. [2][3][4][5][6][7][8][9][10] Some compounds isolated from Sinningia spp exhibit biological activity. The naphthoquinone dunniol, obtained from S. allagophylla, showed strong cytotoxic activity against glioma (U251), breast (MCF-7), ovarian (OVCAR-3), and ovarian resistant (NCI-ADR/ RES) human tumor cell lines.…”

Antitumoral photoinduced effects of crude extract, fractions, and naphthoquinones from Sinningia magnifica (Otto & A. Dietr.) Wiehler (Gesneriaceae) in a bioguided study

“…[8][9][10][11][12] The species of Gesneriaceae are traditionally used for respiratory problems, wounds, fever, inflammation, pain, snake bites, and infectious diseases. 10,12,13,14,15,16 Phytochemical research on Sinninigia species has mainly reported the identification of terpenes, phenolic glycosides, and compounds from the quinone class, some with documented biological activities such as antioxidant, anti-inflammatory properties, and cytotoxic activity for cancer cell lines. 10,12,14,15,16,17,18,19,20,21,22 Sinningia magnifica (Otto & A.…”

“…10,12,13,14,15,16 Phytochemical research on Sinninigia species has mainly reported the identification of terpenes, phenolic glycosides, and compounds from the quinone class, some with documented biological activities such as antioxidant, anti-inflammatory properties, and cytotoxic activity for cancer cell lines. 10,12,14,15,16,17,18,19,20,21,22 Sinningia magnifica (Otto & A. Dietr.)…”