Flowers in Australia: Phytochemical Studies on the Illawarra Flame Tree and Alstonville

Abstract

The first reported phytochemical studies on two species of flowers in Australia enabled the identification of six secondary metabolites from Illawarra flame tree flower (Brachychiton acerifolius) and seven secondary metabolites from the flowers of the Alstonville (Tibouchina lepidota). Pelargonidin 3-(6-coumarylglucoside)-5-(6-acetylglucoside) was found to be responsible for the red colour of B. acerifolius, whereas malvidin 3-(coumarylglucoside)-5-(acetylxyloside) was responsible for the purple colour of (T. lepidota) flowers. (2S)-4,5-Dihydroxyflavanone 7-O-β-d-glucuronide methyl ester was isolated for the first time from B. acerifolius, and its absolute configuration was determined by circular dichroism spectroscopy. Some of the traditional uses of B. acerifolius could also be correlated with the known activity of the isolated metabolites. AbstractThe first reported phytochemical studies into two species of flowers in Australia resulted in the identification of six secondary metabolites from Illawarra flame tree flower (Brachychiton acerifolius) and seven from the flowers of the Alstonville (Tibouchina lepidota). Pelargonidin 3-(6-coumarylglucoside)-5-(6-acetyl-glucoside) was found to be responsible for the red colour from B. acerifolius while malvidin 3-(coumarylglucoside)-5-(acetylxyloside) for the purple colour from (T. lepidota) flowers. (2S)-4,5-Dihydroxylavanone 7-O-β-D-glucuronide methyl ester was isolated for the first time from B acerifolius and its absolute configuration was determined by circular dichroism spectroscopy. Some of the traditional uses of B. aerifoius could also be correlated to the known activity of the isolated metabolites.Before European settlement of Australia, the indigenous people used plants and flowers for numerous purposes including as nutrients, medicine, and dyes. [1] Australia has over 30,000 described species of vascular plants which grow in a wide range of climatic types encompassed by the continent allowing a diversity of plants and flowers unlike any other country. [2] However, there is limited information available pertaining to the phytochemical studies of Australian flowers.

Acylated Flavonoid Glycosides are the Main Pigments that Determine the Flower Colour of the Brazilian Native Tree Tibouchina pulchra (Cham.) Cogn.

“…The other anthocyanin, malvidin p -coumaroylhexoside acetylpentoside ( 24 ), exhibited a fragment of m / z 813.2243 [M + H] + , whose fragmentation resulted in m / z 639.1716 [M − 174] + , m / z 505.1336 [M − 308] + and m / z 331.0812 [M − 482] + consistent with the loss of acetylpentoside and p -coumaroylhexoside from malvidin ( Figure S1 ). Although previously reported in T. lepdota and T. urvilleana [ 27 , 29 ], acylated anthocyanins were identified here for the first time in T. pulchra .…”

First accurate profiling of antioxidant anthocyanins and flavonols of Tibouchina urvilleana and Tibouchina mollis edible flowers aided by fractionation with Amberlite XAD‐7

“…Cogn, whereas other derivatives of malvidin and malvidin 3-(pcoumarylglucoside)-5-acetylxyloside stood out as major anthocyanins of Tibouchina lepidota (Bonpl.) Baill (Hendra &Keller, 2016), andT. urvilleana (P erez-Castorena, 2014), respectively.…”

“…Cogn, whereas other derivatives of malvidin and malvidin 3‐( p ‐coumarylglucoside)‐5‐acetylxyloside stood out as major anthocyanins of Tibouchina lepidota (Bonpl.) Baill (Hendra & Keller, 2016), and T. urvilleana (Pérez‐Castorena, 2014), respectively. Peonidin 3‐sophoroside, peonidin 3‐sambubioside, malvidin 3,5‐diglucoside, and malvidin 3‐( p ‐coumaroyl)‐sambubioside‐5‐glucoside were identified in Tibouchina ciliaris (Vent.)…”

“…Cogn were rich in hexoside derivatives of quercetin, myricetin, and kaempferol (Motta et al ., 2005), quercetin‐3‐ O‐ glucoside was established as the major flavonol of T. lepidota (Bonpl.) Baill (Hendra & Keller, 2016), and different quercetin derivatives were identified in Tibouchina semidecandra L. (Sirat et al ., 2010). However, the genus Tibouchina spp.…”

Phytochemical Studies on Two Australian Anigozanthos Plant Species

“…We have an ongoing interest in colors from Nature, concentrating particularly on flowers that are endemic to Australia, 9 as well as any relationship between the isolated compounds and indigenous uses. Although the aforementioned studies investigated the roots of Anigozanthos sp.…”