An Updated Review on Phytochemistry of Plumeria alba L. (Apocynaceae)

INTRODUCTION

Plumeria L. from the Apocynaceae family, are lactiferous, deciduous shrubs found in tropical regions from southern Mexico to northern South America, the Pacific islands, the Caribbean, and India (Rudrappa et al., 2022). The family comprises 366 genera, with about 133 Plumeria species listed, taxonomic revisions based on morphological and molecular data currently recognize only 11 validly accepted species (Bruna et al., 2024).

Plumeria alba is an ornamental evergreen plant in gardens because of its fragrant flower. It is a medium-sized tree that can reach a height of 5-8 feet, with many branches on the upper part. The leaves are lanceolate to oblanceolate; the flowers are white in color and fragrant in corymbose fascicles (Kumari et al., 2022). A few reviews on the phytochemical and pharmacological profile of the plant have been made. However, a systematic review comprising all updated information is required. Therefore, in the present review, a comprehensive summary of the phytochemistry of Plumeria alba was made. It includes a detailed classification of phytoconstituents isolated from different part of the plant by various extraction and isolation techniques reported in the literature till June, 2025. The aerial parts and bark of Plumeria alba containing alkaloids, carbohydrates, flavonoids, phenolic compounds, and tannins (Imrana et al., 2020). Traditionally, many parts of the plant considered medicinal. Its parts such as bark, leaves, latex, and flowers engage in various biological activities such as antibacterial (Radha et al., 2008), antioxidant (Kirsty et al., 2023), antitumor (Rudrappa et al., 2022), antiarthritic (Choudhary et al., 2014), hepatoprotective, and antidiabetic activities (Chowdhury et al., 2010). The bark is used as purgative, emmenagogue, and febrifuge. The latex of the plant has rubefacient and purgative properties (Kumari et al., 2012). It bears edible fruit; the seeds have demonstrated hemostatic properties. Latex has been used to treat herpes, ulcers, and scabies, and the powdered bark has been used as a plaster applied on hard tumors (Sura et al., 2016), while the other species of the Plumeria are used for cardiotonic, purgative, hypotensive, and diuretic applications (Gupta et al., 2016).

METHODOLOGY

A detailed literature search was conducted on this plant for its phytochemistry in different search engines like PubMed, PubMed Central, SciFinder, Google Scholar, J-gate, Library Search, Science Direct, Elsevier, Semantic Scholar, PubMed Central, ResearchGate and primary sources were searched since 1960 to June, 2025. Literature searches were performed using keywords such as “Plumeria alba phytochemistry,” “iridoids,” “essential oil composition”, etc. Only peer-reviewed articles reporting compound isolation or chemical characterization were included. Duplicate reports and secondary citations were excluded wherever possible. To plot the phytochemistry flow diagram, we have used XmindAI software.

RESULTS

Over the past seven decades, extensive phytochemical investigations on Plumeria alba have revealed a wide range of secondary metabolites isolated from different plant parts using diverse solvent systems and analytical techniques. Identified compounds include iridoids, flavonoids, terpenoids, alkaloids, phenolics, sterols, hydrocarbons, and other metabolites. Structural elucidation was achieved through NMR, MS, IR spectroscopy, and chemical degradation or biosynthetic studies. More than 200 compounds have been reported from roots, leaves, stems, bark, flowers, and aerial parts. The compiled phytochemical data are summarized in Tables 1-10 and Figure 1, many of which exhibit notable pharmacological relevance.

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Iridoids

Iridoids represent major secondary metabolites of Plumeria alba, showing wide distribution across plant parts. Plumieride and related derivatives were reported by Afifi et al., 2006, Leena et al., 2023, and Rangaswami et al., 1960 from bark, stems, and leaves, while John et al., 1983 identified plumericin from roots. Zhou et al., 2024 recently isolated novel iridoids including allamancins A and B from flowers, highlighting continued chemical discovery and pharmacological relevance. Details of reported iridoids are summarized in Table 1.

Flavonoids

Flavonoids have been consistently reported from methanolic leaf and floral extracts of Plumeria alba. Hassan et al., 2015 identified kaempferol derivatives and glycosides, while Santhi et al., 2009 confirmed quercetin, rutin, apigenin, catechin, and epicatechin in leaf extracts. These compounds are associated with antioxidant, anti-inflammatory, and antimicrobial activities. The identified flavonoids are summarized in Table 2.

Terpenes and sterols

Monoterpenes dominate essential oils of leaves and flowers. Kirsty et al., 2023 reported linalool, geraniol, and α-terpineol, whereas Lawal et al., 2014 identified citronellol, sabinene, and limonene with ecological significance. El-Shiekh et al., 2024 confirmed floral volatiles such as geranyl benzoate and nerol through headspace analysis.

Sesquiterpenes are abundant in floral and leaf essential oils. Lawal et al., 2014 identified β-caryophyllene and (E)-nerolidol, while Sahoo et al., 2021 and Mamattah et al., 2023 reported germacrene B and muurolol. Additional sesquiterpenes including farnesol were detected by Rakhmawati et al., 2022 and Malik et al., 2023.These findings highlight the therapeutic and chemotaxonomic value of Plumeria alba mono and sesquiterpenes.

Diterpenes occur less frequently but remain biologically significant. Mamattah et al., 2023 and Lawal et al., 2014 identified phytol from essential oils, whereas Sahoo et al., 2021 reported (Z,E)-geranyl linalool. Their occurrence supports the use of Plumeria alba in skin and wound-healing preparations.

Triterpenes including lupeol, ursolic acid, lupenone, and amyrin derivatives were reported from stems, bark, and leaves by Leena et al., 2023, Rangaswami et al., 1960, and Bramadhayalaselvam et al., 1997. Leena et al., 2023 further identified acylated derivatives such as lup-20(29)-ene-3-yl-hexanoate and related compounds. These findings suggest that triterpenes contribute significantly to the anti-inflammatory, hepatoprotective, and antidiabetic properties attributed to the plant. Terpenoidal derivatives represent acylated triterpenes, which are often associated with enhanced lipophilicity and bioavailability.

Sterols were also reported widely, with β-sitosterol first identified by Rangaswami et al., 1960 and α-sitosterol derivatives later characterized by Leena et al., 2023. Terpenes and sterols are summarized in Table 3.

Alkaloids

Floral alkaloids were extensively characterized by Sibi et al., 2014 using petroleum ether fractions of ethanol extracts. Compounds including voacamine, curine, syrosingopine, and tubocurarine chloride, along with rare nitrogenous derivatives, demonstrated significant chemical diversity and pharmaceutical potential. They also identified rare nitrogenous compounds like benzo[f]quinazoline and naphthalenedione derivatives, indicating high chemical diversity. A comprehensive list of alkaloids reported from flowers of Plumeria alba was provided in Table 4. These findings highlight the pharmaceutical potential of floral alkaloids and expand the phytochemical profile of Plumeria alba beyond iridoids and terpenoids.

Phenolics, courmarins and aromatic compounds

Phenolic acids such as rosmarinic, ferulic, ellagic, and p-coumaric acids were identified from methanolic leaf extracts by Hassan et al., 2015, while Kirsty et al., 2023 reported volatile phenolics including 2-methoxy-4-vinylphenol. Coumarins including scopoletin were reported by Malik et al., 2023, Rangaswami et al., 1960, and Leena et al., 2023 from stems, bark, and flowers.

Benzene derivatives such as catechol and hydroquinone were identified by Kirsty et al., 2023, while Lawal et al., 2014 reported aromatic essential oil constituents. Furan derivatives including furfural and hydroxymethylfurfural were reported from aqueous flower extracts by Sahoo et al., 2021. Aromatic acids such as salicylic acid and benzoic acid were detected by Hassan et al., 2015 and Rakhmawati et al., 2022. These detailed list constituents were summarized in Table 5.

Hydrocarbons

Hydrocarbons including decane, heptadecane, and n-heneicosane were reported from essential oils by Kirsty et al., 2023 and Lawal et al., 2014. Long-chain alkanes such as hexadecane and hentriacontane were confirmed by Lawal et al., 2014, Kirsty et al., 2023, Anggoro et al., 2020, and Sahoo et al., 2021. Alkenes including cetene and docosene were reported by Lawal et al., 2014 and Kirsty et al., 2023, whereas alkynes such as 1,8-nonadiyne were identified by Sahoo et al., 2021. Non-polar hydrocarbon constituents identified primarily from essential oil fractions were compiled in Table 6.

Fatty Acids and their Derivatives

Fatty acids including octadecanoic, hexadecanoic, oleic, and linolenic acids were reported from solvent and essential oil extracts by Lawal et al., 2014 and Sahoo et al., 2021. Fatty acids and related carboxylic acid derivatives identified from solvent extracts were presented in Table 7. Kirsty et al., 2023 added 9,12,15-octadecatrienoic acid methyl ester and geranic acid, highlighting the plant’s rich lipid profile.

Oxygenated volatile constituents

Oxygenated constituents including cyclic ketones, alcohols, aldehydes, esters, and pyranone derivatives were reported from solvent and essential oil extracts. Kirsty et al., 2023, Lawal et al., 2014, Rangaswami et al., 1960, and Sahoo et al., 2021 documented multiple aroma-active and antimicrobial compounds contributing to fragrance and biological activity. Though present in low amounts, their volatility and reactivity may contribute to both aroma and antimicrobial activity. Aliphatic carboxylic acids which are known for its antioxidant potential and UV-protective effects. Esters commonly used in perfumery for their fragrance-fixative properties. Oxygenated volatile compounds, including alcohols, aldehydes, ketones, esters, were detailed in Table 8.

Primary metabolites

Hassan et al., 2015 reported sugars including fucose, rhamnose, arabinose, glucose, and mannose along with polysaccharide complexes from hot water leaf extracts. The same study identified seventeen amino acids within protein-bound polysaccharides, indicating nutritional relevance. Primary metabolites such as sugars, amino acids, and polysaccharide complexes identified from aqueous leaf extracts are summarized in Table 9.

Miscellaneous Compounds

A small but diverse group of miscellaneous compounds has been identified in Plumeria alba, highlighting its broad phytochemical profile. These include lignans, vitamin E, aromatic ethers, apocarotenoids, sulfur compounds, and pyranone derivatives were reported by Rangaswami and Rao, 1960; Anggoro et al., 2020; Kirsty et al., 2023; and Sahoo et al., 2021. Phthalate esters were also detected in floral extracts by Lawal et al., 2014 and Sahoo et al., 2021. These constituents, though present in low amounts, add to the plant’s pharmacological and industrial relevance. The list of phytoconstituents under this category were presented in Table 10.

DISCUSSION

The compiled phytochemical evidence establishes Plumeria alba L. as a metabolically rich Apocynaceae species characterized by a consistent secondary metabolite profile. Iridoids, particularly plumieride, plumericin, and related derivatives, represent defining chemotaxonomic markers of the genus, consistent with biosynthetic patterns observed in closely related taxa such as Allamanda. Several iridoids and terpenoids exhibit defined stereochemical configurations influencing biological activity, as demonstrated by NMR and optical rotation studies; however, stereochemical characterization remains limited for many recently reported metabolites.

Flavonoids and phenolic compounds, predominantly localized in leaves and flowers, indicate a conserved antioxidant framework, while mono- and sesquiterpenes in floral essential oils emphasize ecological roles in pollinator attraction and defense. Polar solvents such as methanol and ethanol preferentially extracted flavonoids, phenolics, sugars, and amino acids, whereas non-polar solvents including petroleum ether and hexane favored sterols, triterpenes, hydrocarbons, and fatty acids, with essential oil constituents primarily obtained through steam distillation. Accordingly, leaves and flowers represent the most chemically diverse and pharmacologically promising plant parts.

The presence of triterpenes, sterols, alkaloids, and modified terpenoid derivatives further expands the chemical space of P. alba, although most studies remain descriptive with limited mechanistic evaluation. Overall, the phytochemical consistency across plant parts and decades supports its placement within iridoid- and terpenoid-rich Apocynaceae and highlights opportunities for bioactivity-guided and translational research.

CONCLUSION

This comprehensive review highlights the diverse phytochemical profile of Plumeria alba, as reported in literature spanning from the 1960s to recent years. Major compound classes include iridoids, flavonoids, terpenoids (mono-, sesqui-, di-, and triterpenes), alkaloids, phenolics, coumarins, and fatty acids, each contributing distinct pharmacological activities. Numerous volatile compounds such as aldehydes, alcohols, esters, and hydrocarbons enhance its aromatic and therapeutic value. Floral parts were especially rich in volatile oils and alkaloids, while leaves yielded abundant phenolics and fatty acids. Several bioactive molecules, including scopoletin, ursolic acid, quercetin, and plumericin, support traditional medicinal uses. Antimicrobial, antioxidant, anti-inflammatory, and cytoprotective properties were commonly associated across classes. The presence of rare and structurally diverse compounds like apocarotenoids, sulfur derivatives, and lignans further adds to its pharmacological potential. Many constituents also suggest applications in cosmetics, perfumery, and nutraceuticals. The findings lay a solid foundation for future research aimed exploring their biological effects through well-designed pharmacological and mechanistic studies. Establishing robust links between specific phytochemicals and their bioactivities will be crucial for validating the therapeutic potential of Plumeria alba and guiding its applications in medicine, cosmetics, and nutraceuticals.