Product	Rosmarinic Acid	Supplier
CAS No.	20283-92-5	Finetech Industry Limited
MF	C18H16O8	[email protected]
MW	360.31 g/mol
Synonyms	Rosemary acid; alpha-O-Caffeoyl-3,4-dihydroxyphenyllactic acid; (R)-3-(3,4-Dihydroxyphenyl)lactic acid 2-O-caffeate; Labiatenic acid; 3,4-Dihydroxyphenyllactic acid caffeate ester

 

Abstract

Rosmarinic acid (RA; CAS 20283-92-5) is a naturally occurring polyphenolic ester of caffeic acid and 3,4-dihydroxyphenyllactic acid, widely distributed across the Lamiaceae and Boraginaceae plant families. Since its first isolation by Scarpati and Oriente in 1958 from Rosmarinus officinalis, RA has attracted substantial scientific interest owing to its broad spectrum of pharmacological activities, including antioxidant, anti-inflammatory, neuroprotective, antimicrobial, anticancer, and antidiabetic properties. This article presents a comprehensive, evidence-based overview of the biological activities, mechanistic insights, and research applications of rosmarinic acid, with reference to recent peer-reviewed literature. Finetech Industry Limited supplies high-purity rosmarinic acid (≥98%) as a research-grade reference standard and pharmaceutical intermediate for academic, preclinical, and industrial research.

1. Chemical Identity and Physicochemical Properties

Rosmarinic acid (IUPAC name: (2R)-3-(3,4-dihydroxyphenyl)-2-[(3-(3,4-dihydroxyphenyl)acryloyl]oxypropanoic acid) is structurally defined as an ester of caffeic acid (3,4-dihydroxycinnamic acid) and 3,4-dihydroxyphenyllactic acid (DHPL). Its molecular architecture features two catechol rings connected through an ester and a central propanoic acid linker, which collectively underlie its potent radical-scavenging capability. Biosynthetically, RA is produced from the amino acids L-phenylalanine and L-tyrosine via the phenylpropanoid pathway, catalyzed by eight enzymatic steps including phenylalanine ammonia lyase (PAL) and cinnamic acid 4-hydroxylase (C4H). Chemical synthesis via esterification of caffeic acid and DHPL also provides access to this compound for research-scale production.

Property	Value
CAS Number	20283-92-5
Molecular Formula	C18H16O8
Molecular Weight	360.31 g/mol
Appearance	Yellow to pale yellow powder
Melting Point	171-175 °C
Solubility	DMSO, ethanol, methanol; sparingly soluble in water
LogP	1.49
Purity (Finetech)	≥98% (HPLC)

 

2. Natural Sources and Occurrence

RA is widely distributed in edible and medicinal plants, particularly concentrated in species of the Nepetoideae subfamily of Lamiaceae and in Boraginaceae, where it functions as a secondary metabolite with ecological and defensive roles. As comprehensively reviewed by Meng et al. (2025), RA's broad bioactivity profile across these plant sources reflects both its structural versatility and its evolutionary role as a phytoprotectant [1].

•       Rosemary (Salvia rosmarinus / Rosmarinus officinalis)

•       Perilla (Perilla frutescens)

•       Sage (Salvia officinalis)

•       Basil (Ocimum basilicum)

•       Mint (Mentha arvense, Mentha piperita)

•       Lemon balm (Melissa officinalis)

•       Oregano (Origanum vulgare)

•       Thyme (Thymus vulgaris)

 

Notable structurally related derivatives include lithospermic acid, salvianolic acid B, yunnaneic acid, and melitric acid, all of which share RA as a biosynthetic precursor.

3. Antioxidant and Free Radical Scavenging Activity

The antioxidant activity of rosmarinic acid ranks among the most thoroughly characterized of all natural phenolic compounds. RA demonstrates significant superiority over reference antioxidants including Trolox and α-tocopherol in multiple assays. Kowalczyk et al. (2024) demonstrated in a systematic PRISMA-based review that RA activates the Nrf2/ARE (nuclear factor erythroid 2-related factor 2 / antioxidant response element) signaling pathway, thereby inducing phase II detoxifying enzymes and providing cellular cytoprotection against oxidative damage [2]. The compound also exhibits hormetic dose-response behavior, where low concentrations enhance cellular antioxidant defense mechanisms while higher concentrations may elicit distinct biological outcomes, a phenomenon extensively characterized by Calabrese et al. (2024) across numerous biological models and cell types [3].

Key mechanistic features include:

•       Electron donation from the ortho-dihydroxyl (catechol) groups of both aromatic rings

•       Inhibition of lipid peroxidation and reactive oxygen species (ROS) generation

•       Modulation of antioxidant enzyme expression — upregulation of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx)

 

4. Anti-inflammatory Mechanisms

RA is a potent inhibitor of multiple inflammatory cascades, making it highly relevant to research in chronic inflammatory diseases, autoimmune disorders, and metabolic syndrome. The mechanistic breadth of RA's anti-inflammatory activity has been highlighted in a recent comprehensive review as a key driver of its utility in diabetes and neurodegenerative disease models [4].

1.     Inhibition of COX-1/2 and 5-LOX, reducing prostaglandin and leukotriene biosynthesis

2.     Downregulation of NF-κB signaling, reducing TNF-α, IL-1β, IL-6, and IL-8 transcription

3.     Suppression of complement cascade activation

4.     Inhibition of T-cell receptor-mediated signaling via PLCγ1 and Itk kinase pathways

5.     Reduction of leukocyte migration into sites of inflammation, documented in carrageenan-induced pleurisy animal models

 

5. Neuroprotective Properties and Alzheimer's / Parkinson's Disease Research

Neuroprotective research represents one of the most rapidly expanding application areas for rosmarinic acid. As reviewed by Petralia et al. (Applied Sciences, 2024), RA and its parent plant Rosmarinus officinalis demonstrate multifaceted neuroprotective effects directly relevant to Alzheimer's disease (AD) and Parkinson's disease (PD) [5].

•       Inhibition of AChE and BChE — relevant to cholinergic neurotransmission deficits in Alzheimer's disease

•       Suppression of β-amyloid (Aβ) aggregation — RA disaggregates preformed amyloid fibrils, a critical hallmark of AD pathology

•       Attenuation of neuroinflammation via microglial activation suppression and MAPK pathway modulation

•       Reduction of α-synuclein aggregation — relevant to Parkinson's disease pathophysiology

•       Modulation of GABAergic and serotoninergic systems, contributing to anti-seizure, antidepressant-like, and anxiolytic activity profiles

•       Cognitive enhancement — plant extracts rich in RA have been reported to improve cognitive performance in healthy individuals and early-stage Alzheimer's patients

 

While RA's native blood-brain barrier (BBB) penetration is limited, nanotechnology-based delivery systems — including liposomes, polymeric nanoparticles, and cyclodextrin inclusion complexes — are actively being investigated to enhance CNS bioavailability. Cyclodextrin complexes (particularly HP-γ-CD) have been shown to significantly improve both aqueous solubility and AChE/BChE inhibitory activity [5].

6. Anticancer Activity

Rosmarinic acid has demonstrated broad-spectrum anticancer activity across multiple tumor cell lines. A systematic PRISMA-based review by Kowalczyk et al. (2024), covering in vitro, in vivo, and in silico studies from 2019 to 2024, identified the following key mechanisms [2]:

•       Induction of apoptosis via mitochondrial and death receptor pathways, with upregulation of Bax and downregulation of Bcl-2

•       Cell cycle arrest at G0/G1 and G2/M checkpoints

•       Inhibition of tumor angiogenesis via VEGF suppression

•       Suppression of metastasis and invasion through MMP inhibition and EMT blockade

•       Modulation of PI3K/Akt/mTOR and MAPK signaling pathways

 

Anti-tumorigenic activity has been documented across breast, colon, liver, lung, and cervical cancer models. The broad safety profile of RA as an approved food additive, combined with these mechanistic insights, positions it as an attractive natural scaffold for oncology research and lead compound development.

7. Antidiabetic and Metabolic Effects

Dhanya (2023) published a comprehensive review in Frontiers in Pharmacology characterizing RA's antidiabetic mechanisms, concluding that its multi-target engagement with oxidative stress, inflammation, and glucose metabolism pathways warrants further clinical investigation [4].

•       Inhibition of α-glucosidase and α-amylase — key enzymes in postprandial glucose regulation

•       Enhancement of insulin secretion and sensitivity through AMPK pathway activation

•       Attenuation of diabetic nephropathy and oxidative damage in pancreatic β-cells

•       Regulation of adipogenesis and lipid metabolism — relevant to obesity and metabolic syndrome research

 

8. Antimicrobial and Antiviral Properties

RA exhibits activity against a broad spectrum of pathogenic microorganisms, as systematically reviewed by Ekpenyong & Akpan (Antibiotics, 2023) [4].

Antibacterial Activity

•       Active against Gram-positive bacteria including Staphylococcus aureus (including MRSA), Streptococcus spp., and Bacillus spp.

•       Activity documented against selected Gram-negative species

•       Documented synergistic effects when co-administered with conventional antibiotics

Antifungal Activity

•       Inhibitory effects against Candida albicans, Aspergillus spp., and other clinically relevant fungal pathogens

Antiviral Activity

•       Inhibition of HIV-1 reverse transcriptase, herpes simplex virus (HSV), and influenza virus replication reported in vitro

•       Potential SARS-CoV-2 inhibitory activity under computational and early in vitro investigation

 

Chemically synthesized RA derivatives — including propyl ester, methyl ester, and hexyl ester forms — exhibit enhanced antimicrobial potency compared to the parent compound, expanding the pharmacological space for antimicrobial lead development.

9. Pharmaceutical and Industrial Research Applications

Application Area	Role of Rosmarinic Acid
Drug discovery & lead optimization	Natural scaffold for anti-inflammatory and neuroprotective drug design
Cosmeceutical R&D	Active ingredient in anti-aging and photoprotective formulations
Nutraceutical development	Bioactive reference standard for dietary supplement quality control
Food science	Natural antioxidant and preservative; EU-approved food additive
Phytopharmaceutical analysis	HPLC reference standard for herbal product authentication
Biochemistry & cell biology	Tool compound for Nrf2, NF-κB, AChE/BChE pathway studies
Nanotechnology	Model payload for CNS-targeted drug delivery system development

 

10. Common Search Terms and Related Products

Alternative Names / Search Synonyms

•       Rosmarinic acid | Rosemary acid | RA

•       alpha-O-Caffeoyl-3,4-dihydroxyphenyllactic acid

•       3,4-Dihydroxyphenyllactic acid caffeate | Labiatenic acid

•       (R)-3-(3,4-Dihydroxyphenyl)lactic acid 2-O-caffeate

•       Rosmarinic acid powder | Rosmarinic acid 98% | Rosmarinic acid CAS 20283-92-5

•       Rosmarinic acid buy | Rosmarinic acid supplier

Structurally Related Compounds Available from Finetech Industry Limited

•       Caffeic acid (CAS 331-39-5)

•       Chlorogenic acid (CAS 327-97-9)

•       Salvianolic acid B (CAS 115939-25-8)

•       Lithospermic acid (CAS 96574-01-5)

•       Ferulic acid (CAS 1135-24-6)

•       p-Coumaric acid (CAS 501-98-4)

•       Carnosic acid (CAS 3650-09-7)

•       Carnosol (CAS 5957-80-2)

 

11. Product Specifications — Finetech Industry Limited

Specification	Details
Product Name	Rosmarinic Acid
CAS Number	20283-92-5
Molecular Formula	C18H16O8
Molecular Weight	360.31 g/mol
Purity	≥98% (HPLC)
Appearance	Yellow to pale yellow crystalline powder
Grade	Research grade / Pharmaceutical reference standard
Available Quantities	1 g to bulk quantities (kg scale)
Storage	Store at 2-8 °C, protected from light and moisture
Shelf Life	2 years (properly stored)
Documentation	COA, MSDS/SDS, HNMR, HPLC trace available upon request

 

12. Conclusion

Rosmarinic acid (CAS 20283-92-5) represents a structurally elegant and pharmacologically versatile natural polyphenol with well-documented activities spanning antioxidant, anti-inflammatory, neuroprotective, anticancer, antidiabetic, and antimicrobial domains. Its favorable safety profile, broad bioactivity, and structural accessibility for synthetic modification position RA as a high-value research compound at the interface of natural product chemistry, pharmacology, and translational medicine. Recent advances in delivery technology — particularly nanotechnology-based and cyclodextrin-based formulations — are actively addressing bioavailability limitations, expanding its utility in both preclinical and clinical research settings [3, 5].

Finetech Industry Limited offers high-purity rosmarinic acid (≥98%) with full analytical documentation for academic research, pharmaceutical development, and nutraceutical quality control. Inquiries for pricing, bulk availability, and technical specifications are welcome.

 

References

1.  Meng Z, Li C, Liu R, Xiao Z. Unveiling Rosmarinic Acid: Understanding Its Broad Spectrum of Bioactivities. Phytomedicine. 2025; 190:156388. https://pubmed.ncbi.nlm.nih.gov/41161308/

2.  Kowalczyk A, Tuberoso CIG, Jerković I. The Role of Rosmarinic Acid in Cancer Prevention and Therapy: Mechanisms of Antioxidant and Anticancer Activity. Antioxidants. 2024; 13(11):1313. https://doi.org/10.3390/antiox13111313

3.  Calabrese EJ, Pressman P, Hayes AW. The chemoprotective hormetic effects of rosmarinic acid. Biomedicine & Pharmacotherapy. 2024; 180:117473. https://doi.org/10.1016/j.biopha.2024.117473

4.  Ekpenyong MG, Akpan UE. Application of Rosmarinic Acid with Its Derivatives in the Treatment of Microbial Pathogens. Antibiotics. 2023; 12(5):867. https://doi.org/10.3390/antibiotics12050867

5.  Petralia MC, Rampello L, Pennisi M. Neuroprotective Benefits of Rosmarinus officinalis and Its Bioactives against Alzheimer’s and Parkinson’s Diseases. Applied Sciences. 2024; 14(15):6417. https://doi.org/10.3390/app14156417