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In this work, we studied the potential photoprotective effect of Ipomoea horsfalliae Hook., Convolvulaceae, flower extract. Ipomoea horsfalliae is a plant that grows in tropical and subtropical regions. I. horsfalliae ethanolic extracts were analyzed by ultra-high efficiency liquid chromatography-high-resolution mass spectrometry. Dicaffeoylquinic acid, chlorogenic acid, scopoletin, glycosylated cyanidin, pelargonidin, and kaempferol were identified as major components of I. horsfalliae flower extract. In vitro biossays were used to evaluate cytotoxic and sensitizing effects of the extracts, and their photoprotective effect was evaluated in BALB/c mice. Morphological and histopathological observation of the skin tissues from mice suggested that UV-B-induced edema was significantly inhibited by treatment with I. horsfalliae flower extract. It was not cytotoxic for both cancerous and normal cells, and no sensitizing effect was observed. I.horsfalliae flower extract appears to be a good starting point for research programs leading to the development of natural skin care products.

Hibiscus rosa-sinensis plants are mainly cultivated as ornamental plants, but they also have food and medicinal uses. In this work, 16 H. rosa-sinensis cultivars were studied to measure their colorimetric parameters and the chemical composition of hydroethanolic extracts obtained from their petals. These extracts were characterized using UHPLC-ESI+-Obitrap-MS, and their antioxidant activity was evaluated using the ORAC assay. The identified flavonoids included anthocyanins derived from cyanidin, glycosylated flavonols derived from quercetin and kaempferol, and flavan-3-ols such as catechin and epicatechin. Cyanidin-sophoroside was the anthocyanin present in extracts of lilac, pink, orange, and red flowers, but was not detected in extracts of white or yellow flowers. The total flavonol concentration in the flower extracts was inversely proportional to the total anthocyanin content. The flavonol concentration varied according to the cultivar in the following order: red < pink < orange < yellow ≈ white, with the extract from the red flower presenting the lowest flavonol concentration and the highest anthocyanin concentration. The antioxidant activity increased in proportion to the anthocyanin concentration, from 1580 µmolTrolox®/g sample (white cultivar) to 3840 µmolTrolox®/g sample (red cultivar).

Stickiness of vegetative tissues has evolved multiple times in different plant families but is rare and understudied in flowers. While stickiness in general is thought to function primarily as a defense against herbivores, it may compromise mutualistic interactions (such as those with pollinators) in reproductive tissues. Here, we test the hypothesis that stickiness on flower petals of the High-Andean plant, Bejaria resinosa (Ericaceae), functions as a defense against florivores. We address ecological consequences and discuss potential trade-offs associated with a repellant trait expressed in flowers that mediate mutualistic interactions. In surveys and manipulative experiments, we assess florivory and resulting fitness effects on plants with sticky and non-sticky flowers in different native populations of B. resinosa in Colombia. In addition, we analyze the volatile and non-volatile components in sticky and non-sticky flower morphs to understand the chemical information context within which stickiness is expressed. We demonstrate that fruit set is strongly affected by floral stickiness but also varies with population. While identifying floral stickiness as a major defensive function, our data also suggest that the context-dependency of chemical defense functionality likely arises from differential availability of primary pollinators and potential trade-offs between chemical defense with different modes of action.

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