Antifungal constituents of the plant family Amaryllidaceae

Abstract

Globalization, the modern lifestyle, immuno-suppressive agents, invasive surgical procedures, the loss of efficacies of existing drugs, and multidrug resistance are some of the factors used to explain the rise in fungal infections in recent years. Significant advances have been made in attempts to replace existing antifungal schedules, especially with synthetic targets. The identification of other platforms for drug discovery is now entrenched in research programs across the globe. Plants offer significant benefits owing to their numerical superiority, exceedingly broad chemical basis and appealing sustainability characteristics. Furthermore, plants have a long and rich historical association with traditional approaches towards fungal diseases. These have in numerous instances served as markers in the bioassay-guided identification of the active constituents. Although the plant family Amaryllidaceae is conventionally associated with cancer and motor-neuron disease chemotherapies, around 30 of its species have been examined for antifungal activities with microgram per millilitre inhibitory activities detected in several instances. This review focuses on the nearly 40 constituents from the family, mainly isoquinoline alkaloids, which have been screened against around 50 fungal pathogens. Encouragingly, microgram per millilitre growth inhibitory activities were applicable for several of the compounds with a minimum inhibitory concentration of 4 μg/ml seen to be the lowest.

Lycorine: A prospective natural lead for anticancer drug discovery

“…Amaryllidaceae family plants are well known as an extensive source of pharmacologically active alkaloids [10][11][12][13], and lycorine was the first among these alkaloids to be isolated in 1877 from the plant Narcissus pseudonarcissus [14]. From then onwards, lycorine and its derivatives are drawing interest in the medicinal field due to their divergent chemical structures and strong biological effects [ Fig.…”

Antiplasmodial Lycorane Alkaloid Principles of the Plant Family Amaryllidaceae

“…The selectivity index of~3 for lycorine measured against its cytotoxicity in BL6 mouse melanoma cells (IC 50 of 1.8 µg/mL) again favored its antiplasmodial activity, although this value was orders of magnitude less than that calculated for artemisinin (> 25 000 and > 5000, respectively) [22]. The phytochemical analysis of B. radulosa yielded the four lycorane alkaloids lycorine (1), anhydrolycorin-6-one (10), sternbergine (11), and 1-O-acetylnorpluviine (12) [23]. As in the previous study by the same authors [22], the alkaloids were also subjected to a screen against the D10 and FAC8 strains of P. falciparum, which confirmed lycorine as the most active compound in the mini-panel (IC 50 s of 0.6 and 0.7 µg/mL, respectively) [23].…”

“…Apart from their significant array of structural diversity, these alkaloids are also characterized by a wide range of biological properties, particularly in the cancer and motor neuron disease arenas [9]. In the microbial area, promising antibacterial and antifungal activities have been described for several members of the family [10,11]. The lycorine alkaloids are the largest of the nine alkaloid groups discernible for the Amaryllidaceae [8].…”

“…are its two species that have been screened for anti-▶ FCR-3 0.49 [35] plasmodial lycorane alkaloid constituents [35,36]. The bulbs and aerial parts of the Japanese plant L. traubii yielded lycorine (1), sternbergine (11), ungiminorine (46), and 1-O-(3′S)-hydroxybutanoyllycorine (47) as the representative members of the lycorane alkaloid group [35]. In addition to these, a further eight derivatives were accessed from the parent compound lycorine via synthetic manipulation of the hydroxyl groups at C-1 and C-2, respectively [35].…”

“…These included 1-O-acetyllycorine 4 [35]. Although the subsequent screens against the sensitive (FCR-3) and resistant (K1) strains of P. falciparum did not involve lycorine (1), sternbergine (11), or ungiminorine (46), they were nevertheless insightful for the activities of the remaining acylated lycorine derivatives [35]. Overall, good activities were observed for most of these lycorine products in both P. falciparum strains, where IC 50 values ranged from 0.3 to 8.21 µg/mL, with the best activity demonstrated for 1-O-acetyllycorine (4) and 1-Opropanoyllycorine (48) (▶ Fig.…”