Phytochemical Profile of Yellow Rain Lily (Zephyranthes citrina Baker) Flowers

Plants are popular source of food and have also been considered as the origin of medicines in many cultures around the world. They are an excellent source of phytochemicals exhibiting important biological activities (Naqvi et al., 2020; Khan and Javaid, 2013, 2022). These phytochemicals work as antioxidants and help to protect the human body against free radical damages (Boots et al., 2008; Khan and Javaid, 2019, 2020). These compounds also have antimicrobial, insecticidal, anticancer and anti-inflammatory activities (Javaid et al., 2021a; Jabeen et al., 2022). Using medicinal plants to treat different ailments is traditional in many countries like Japan, Pakistan, India, Thailand, China and Sri Lanka (Abdala et al., 2012; Singh et al., 2020). Currently, the use of plants to treat various diseases is increasing worldwide, due to the fact that use of plant products are safe for use (Michel et al., 2020). Pharmacological properties of medicinal plants are due to a large number of phytoconstituents belonging to various groups such as flavonoids, saponins, tannins, steroids, glycosides, alkaloids and terpenoids (Paul and Sinha, 2016; Javaid et al., 2022).

Yellow rain lily (Zephyranthes citrina) is a bulbous herb of family Amaryllidaceae (Figure 1). Although native to America but it is also cultivated as an ornamental plant for its beautiful flowers (Singh et al., 2010). The name “rain lily” is due to its tendency of blooming during rainy season. Only a few studies have been carried out regarding its biological and pharmacological activities. Its antimicrobial, antiprotozoal and cytotoxic activities are generally due to presence of alkaloids in different parts of this plant (Herrera et al., 2001; Singh et al., 2010; Prakash and Vedanayaki, 2019). Like other species of the genus Zephyranthes, Z. citrina also contains many Amaryllidaceae alkaloids. So far, more than 20 alkaloids have been reported from this plant including galanthine, haemanthamine, lycorine, haemanthidine, narcissidine, vittatine, oxomaritidine, maritidine, zephyramine, lycorenine and galanthaine (Kohelová et al., 2021). However, majority of the earlier studies were carried out on phytochemical analysis of bulbs of this plant while such studies on its flowers are rare. The objective of the present study was to identify bioactive phytoconstituents in flowers of yellow rain lily through GC-MS analysis.

Flowers of yellow rain lily were harvested during September 2022 from a grassy lawn of Botanical Garden, Punjab University Lahore, Pakistan. After washing with water, fresh flowers were dried in an electric oven at 40 ºC. The dried flowers were thoroughly crushed with the help of pastel and mortal. The crushed flowers were soaked in methanol (analytical grade) and left for 2 weeks for extraction of compounds. After that, it was filtered and stored in a closed test tube.

Phytochemicals present in methanolic flower extract of yellow rain lily were identified through GC-MS analysis following the procedure explained by Javaid et al. (2021a). Gas chromatography (GC) was carried out on 7890B Model Machine of Agilent Technologies with a DB-5ms column of dimensions 30 m × 0.25 μm × 0.25 μm. Helium gas was used as a carrier material. After injecting 1 µL of the methanolic extract, with an initial temperature of the oven set at 80 ºC, it was increased to 300 ºC at a rate of 10 ºC min-1. MS analysis was done on 5977A Model Machine with scan range of 50–500 m/z. The sample was run for 40 min. NIST library 2020 was used for phytochemical analysis. Identified compounds were set in an increasing order of retention times. Peaks heights was used for measurement of relative abundance of the compounds.

The chromatogram of GC-MS analysis is presented in Figure 2 that represents occurrence of 13 compounds in the flower extract of yellow rain lily whose details are given in Table 1. Heptacosan-9-ol (15.01%) was the predominant compound in the flower extract. The second major compound was 2-hexanamine (13.28%). Other abundantly occurring compounds identified in the present study were n-hexadecanoic acid (10.38%), eicosane (10.37%), and 4H-pyran-4-one, 2, 3-dihydro-3, 5-dihydroxy-6-methyl (9.69%). Among these, n-hexadecanoic acid has been found in many other plant species namely Tagetes erecta (Ferdosi et al., 2022), Chenopodium murale (Naqvi et al., 2022), Vinca major (Javaid et al., 2021b) and others. Being an important biomolecule, it has many biological activities. It has antifungal activity and can control the growth of many species of genus Candida as reported by Souza et al. (2015). Moreover, its cytotoxic (Ravi and Krishman, 2017), and anti-inflammatory (Aparna et al., 2012) have also been reported. Eicosane was also identified as an abundant compound in this study. Previously, Ahsan et al. (2017) identified this compound from a Streptomyces strain and found very effective against Rhizoctonia solani, isolated from tobacco leaves suffering from target leaf spot disease.

Table 1: List of compounds in methanolic flower extract of rain lily identified by GC-MS analysis.

Moderately abundant compounds in the flower extract were cyclohexane, 1,1’-(2-propyl-1, 3-propanediyl) bis- (8.81%), hexadecane-1, 2-diol (6.34%), pentadecanoic acid, 14-methyl-, methyl ester (5.76%), methyl linolenate (5.38%), octadecanoic acid (4.04%), and methyl linoleate (4.38%). Octadecanoic acid is a part of many vegetable oils. This compound and its derivatives are known to possess antibacterial activity (Silva et al., 2002; Ivanova et al., 2017). Methyl linoleate has been reported as urine acidifier and uric acid inhibitor (Duke, 1992). Likewise, methyl linolenate is recognized nematicidal, anti-inflammatory, antiandrogenic, anticancer and antihistaminic compound (Devi and Muthu, 2014).

Two compounds namely methyl (Z)-5, 11, 14, 17-eicosatetraenoate (3.56%), and linoleic acid (2.94%) were recognized as less abundant ones (Table 1). The later compound and possesses antioxidant activity (Krishna et al., 2012). It concludes that flowers of yellow rain lily contain important bioactive compounds such as n-hexadecanoic acid, eicosane, octadecanoic acid, methyl linoleate and methyl linolenate.

Authors are grateful to the management of Faculty of Agricultural Sciences for providing fascililities to complete this research work.

In this paper, phytochemical analysis of flowers of yellow rain lily, collected from Lahore, was carried. Previously, there is not any such study from this region.

Malik F.H. Ferdosi: Conceived the idea, collected the materials and supervised GC-MS analysis part.

Arshad Javaid: Supervised the work, added discussion and finalized the paper.

Iqra Haider Khan: Contributed in paper writing.

Muhammad Kaleem Naseem: Contributed in paper writing.

The authors have declared no conflict of interest.