**1. Introduction**

*Hibiscus acetosella*, a member of the Malvaceae family, is an amphidiploid plant native to Africa and is usually consumed as a green vegetable. In the traditional medicine of western and central Africa, decoction drinks have been prepared from extracts of the leaves and shoots because of their anti-anemic and antipyretic properties [1]. The presence of a wide variety of biochemical compounds, such as polyphenols, flavonoids, and anthocyanins have been reported in Hibiscus species [2,3]. Two examples, *H. cannabinus* and *H. sabdari*ff*<sup>a</sup>*, have been studied most regarding the relationship between their

biochemical compounds in the plant leaves and their biofunctional activity [4–7], while *H. acetosella* has been much less studied.

Phenolic compounds found in Hibiscus plants consist of phenolic acids such as hibiscus, protocatechuic, gallic, chlorogenic and caffeic acids, and the organic acid, citric acid. Flavonoids such as kaempferitrin, gallocatechin, quercetin, and luteolin are also present in these plants. Anthocyanins, detected mostly in flowers with calyces and some of the red-colored leaves, include cyanidin-3-glucoside, delphinidin-3-galactoside, delphinidin-3-glucoside, cyanidin-3-sambubioside, and delphinidin-3-sambubioside [8–10]. These compounds possess antioxidant properties shown by their effective scavenging activity on reactive oxygen species (ROS) and free radicals. Generally, to investigate the antioxidant activity of Hibiscus plants based on phenolic compound levels, the 2,2--azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) hydroxyl radical scavenging assay and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) free radical assay have been widely used [4,7,11]. Kapepula et al. [12] investigated the ability of *H. cannabinus*, *H. sabdari*ff*<sup>a</sup>*, and *H. acetosella* to scavenge free radicals and reported IC50 values ranging from 43 to 186 μg/mL from ABTS and DPPH assays, although the three species differed in the composition of their phenolic compounds.

In terms of pharmacological effects, Hibiscus plants have also attracted interest because of their biological activities, which include antibacterial, anti-inflammatory, antigenotoxic, hepatoprotective, and antimutagenic activities [13–16]. In particular, the antibacterial activity of *H. sabdari*ff*a* has been well-studied as well as other biological activities of extracts of its leaves and flowers [4,17,18], while *H. acetosella* has been reported as having anti-inflammatory [12] and antimutagenic activity [16], but no antibacterial activity.

The present study therefore aimed to determine the composition of phenolic compounds in the extracts of leaves from 18 *H. acetosella* accessions using UPLC analysis and to assess their bioactive properties, antioxidant and antibacterial activities, using the ABTS assay and agar-well diffusion test, respectively. The relationship between phenolic extracts and their biofunctional properties will also be evaluated using statistical analysis.
