Novel Floral Scent Compounds from Night-Blooming Araceae Pollinated by Cyclocephaline Scarabs (Melolonthidae, Cyclocephalini)

Abstract

Nocturnal flowering plants often release strong scents to attract their pollinators. Among night active flower visitors are cyclocephaline scarab beetles, which have been demonstrated to respond to uncommon volatile organic compounds released in high amounts by their host plants. In Araceae, the molecular structure of several such compounds is yet to be unveiled. We investigated headspace floral scent samples of Philodendron squamiferum, Thaumatophyllum mello-baretoanum, and Xanthosoma hylaeae by a variety of approaches, leading to the identification of novel compounds. Dehydrojasmone, (Z)-4-methylene-5-(pent-2-en-1-yl)cyclopent-2-en-1-one (1), (Z)-3-methylene-2-(pent-2-en-1-yl)cyclopentyl acetate (isojasmyl acetate, 3), and (E)-4,8-dimethylnona-1,3,7-trien-5-yl acetate (4) had not been previously reported, while full analytical data of the recently described (Z)-3-methylene-2-(pent-2-en-1-yl)cyclopentan-1-ol (isojasmol, 2) are presented here. All these compounds are derived from more common precursors, (Z)-jasmone and (E)-4,8-dimethyl-1,3,7-nonatriene, likely through biosynthetic "post-processing".

Nocturnal pollination: an overlooked ecosystem service vulnerable to environmental change

“…Floral scent is important in many nocturnal plant-pollinator mutualisms [75]. Floral volatile chemistry has been characterized for taxa pollinated by moths [76][77][78], beetles [38,79,80], nocturnal bees [63,67,81], and to a lesser extent smaller nocturnal and crepuscular pollinators, such as mosquitoes [82] and thrips [47,83]. Parallels can be drawn between floral scent profiles of plants associated with nocturnal pollinator taxa; for example, moth-pollinated flowers often emit a combination of acyclic terpene alcohols (e.g.…”

Distant populations of a Xanthosoma (Araceae) species have different floral scents but the same cyclocephaline beetle pollinators

“…1). This high overall intraspecific variation in scent was unexpected given that within-species variation in scent is limited in other species pollinated by cyclocephaline beetles (e.g., Gottsberger et al 2012;2013;Maia et al 2013b;2019a).…”

“…Beside these two compounds, Milet-Pinheiro et al (2017) found another four compounds that contributed in one of their samples at least 2 % to the total scent discharge: butan-2-yl acetate, (Z)-jasmone, dihydro-β-ionone, and two unknown compounds (Milet-Pinheiro et al 2017). Based on retention index and mass spectral information given by these authors, and recently published papers on novel scents in cyclocephaline pollinated plants (Maia et al 2019a;b) and in floral chemistry of Cyclanthaceae (Teichert et al 2018), these unknown compounds are isojasmol and dehydrojasmone. None of these compounds were detected in our samples (Tab.…”

The Diurnal and Nocturnal Floral Scent of Dracaena fragrans (L.) Ker Gawl. in Thailand

“…The scents are used for communicating between plants and the other pollinators (Knudsen et al, 2006). Some night emitting compounds are attractive for pollinators such as moths (Morinaga et al, 2009;Dotterl et al, 2012), beetles (Maia et al, 2018).…”