Ingredients7-Methylrosmanol — also widely referred to in the peer-reviewed literature as 7-O-Methylrosmanol or 7-O-methyl-epi-rosmanol (the latter name denoting the epimeric form at C-7) — is a naturally occurring phenolic abietane-type diterpene. It carries the molecular formula C21H28O5 and is registered in PubChem under Compound ID (CID) 9950773 (7-Methylrosmanol) and CID 23243692 (7-O-Methylrosmanol). The two CIDs reflect distinct stereochemical relationships at the C-7 oxygen-bearing position, and the names "7-Methylrosmanol" and "7-O-Methylrosmanol" are used interchangeably across supplier databases, patent documents, and primary literature to describe the same structural class of compound. The closely related epimeric variant, 7-O-methyl-epi-rosmanol (7MER), differs only in the configuration at C-7 and is frequently co-detected alongside 7-O-methylrosmanol in plant extracts and phytochemical analyses.
7-Methylrosmanol (CAS 24703-38-6 for one stereoisomer; CAS 113085-62-4 for another) is a natural compound isolable from Rosmarinus officinalis (now reclassified as Salvia rosmarinus Spenn.); its IUPAC name is (1R,8R,9S,10S)-3,4-dihydroxy-8-methoxy-11,11-dimethyl-5-propan-2-yl-16-oxatetracyclo[7.5.2.01,10.02,7]hexadeca-2,4,6-trien-15-one, and it appears as a powder with a purity of ≥98% in reference standard preparations. The compound belongs to the broader chemical class of abietane diterpenes — a group of bicyclic and polycyclic diterpenoids built on a 20-carbon abietane skeleton — and, more specifically, to the phenolic abietane-type subclass sharing structural features with carnosic acid, carnosol, and rosmanol. Key bioactive abietane-type metabolites in this class include carnosic acid (CA), carnosol (CS), 12-O-methylcarnosic acid (12MCA), rosmanol (RO), and 7-O-methyl-epi-rosmanol (7MER).
The primary natural source of 7-Methylrosmanol is Salvia rosmarinus Spenn. — commonly known as rosemary — which belongs to the family Lamiaceae. Rosemary (Rosmarinus officinalis) is an aromatic evergreen herb from the Lamiaceae mint family, native to the Mediterranean region, and is one of the many herbs that are an important component of the Mediterranean diet as a spice and flavoring agent. The compound has also been documented in other members of the genus Salvia. Carnosol, an abundant natural diterpene in Salvia species, serves as a biosynthetic precursor from which related rosmanol derivatives — including 7-O-methylrosmanol — can be derived.
Within Salvia rosmarinus, 7-O-methylrosmanol and its epimer 7MER are consistently identified as components of the plant's secondary metabolite profile. A 2024 quantitative profiling study using 1H-qNMR examined infusions, decoctions, turbulent flow extracts, tinctures, and oleolites from Salvia officinalis L. (common sage), Salvia fruticosa Mill. (Greek sage), and Salvia rosmarinus Spenn. (rosemary) and confirmed 7-O-methyl-epi-rosmanol (7MER) as one of the key target metabolites across all three species. The compound has additionally been identified in the context of broader Lamiaceae phytochemistry: a quantitative study evaluated carnosic acid, 12-O-methyl-carnosic acid, carnosol, rosmanol, and 7-O-methyl-epi-rosmanol in 61 Lamiaceae plants growing in Greece across 18 genera including Salvia and Mentha.
In terms of abundance, 7-Methylrosmanol occurs in rosemary at notably lower concentrations than the dominant phenolic diterpenes. The content of rosmanol (the parent compound) and rosmaridiphenol in rosemary or sage is much lower than that of carnosic acid; whereas dried leaves of rosemary or sage contain between 1.5 and 2.5% carnosic acid and about 0.3–0.4% carnosol, rosmanol and rosmaridiphenol are present in undetectable or trace concentrations, with the yield of rosmanol isolated from rosemary calculated at only 0.01%.
7-Methylrosmanol is structurally derived from rosmanol by O-methylation at position C-7. Rosmanol itself is a well-characterized oxidative degradation product of carnosic acid. Carnosic acid is the principal constituent of rosemary extracts but is not a very stable compound once extracted, and may undergo oxidation to form the γ-lactone diterpene carnosol; in addition to carnosol, the oxidation of carnosic acid also yields rosmanol, which differs from carnosol by possessing a free hydroxyl group at C-7 position and a γ-lactone formed via the C-20–C-6 route. 7-Methylrosmanol thus bears the methyl ether specifically at the C-7 hydroxyl that distinguishes rosmanol from carnosol. 7-Methyl-epirosmanol is classified among the minor degradation derivatives of carnosic acid, alongside epirosmanol and rosmanol-9-ethyl ether.
In research settings, 7-Methylrosmanol is supplied as a powder, soluble in chloroform, dichloromethane, ethyl acetate, DMSO, and acetone, and is typically prepared at ≥98% purity as confirmed by HPLC, NMR, and mass spectrometry. Because the compound is present only in trace quantities in the intact plant, research preparations are most commonly obtained either by direct isolation from plant material using solvent extraction and chromatographic separation, or by semi-synthesis. 7-Methoxyrosmanol (including the 7-O-methylrosmanol isomers) has been obtained by partial synthesis from carnosol, an abundant natural product in Salvia species; the physical and spectroscopic data of these semisynthetic diterpenes were identical to those of authentic natural samples, and the semisynthetic approach represents an efficient alternative method because these compounds are present in the genus Salvia in low quantities.
In the context of botanical preparation types studied scientifically, decoctions appeared to be richer sources of the studied abietane-type metabolites than infusions among rosemary and sage. Regarding aqueous extracts from three Salvia species, decoctions appeared richer sources of studied metabolites than infusions; for S. rosmarinus, turbulent flow extraction under heating was the most efficient, and the optimum time for decoctions was found to be 15 minutes for rosemary. As a dietary supplement ingredient, 7-Methylrosmanol is not marketed in isolated form; it is encountered predominantly as a constituent of standardized rosemary leaf extracts.
7-Methylrosmanol has no documented history of traditional use as an isolated compound; it is a minor constituent identified through modern analytical chemistry. However, it is relevant to place the compound within the broader context of the traditional uses of its source plant, rosemary (Salvia rosmarinus), since many historically recognized properties of rosemary are now being investigated at the level of individual constituents including rosmanol-type diterpenes.
Rosemary has been sacred since antiquity for its virtues, and its use has continued through the ages as an aromatic and medicinal plant. It is a well-known aromatic plant used for thousands of years for ornamental, culinary, medicinal, and ritual purposes. Native to the Mediterranean basin, rosemary is a branchy, bushy evergreen shrub with persistent leaves. Its documented medicinal applications span multiple traditional systems and historical periods:
The plant is known to be employed in traditional medicines in many countries even far beyond its native Mediterranean region where it grows wild. Modern phytochemical science has identified the phenolic diterpenes — including the rosmanol-type compounds — as key contributors to many of the pharmacological properties historically attributed to rosemary.
7-Methylrosmanol belongs to a family of structurally related abietane phenolic diterpenes present in rosemary and sage. A phytochemical profile of rosemary extract identified a total of 57 compounds including 24 diterpenoids comprising carnosic acid, carnosol, and rosmanol derivatives. The principal members of this chemical family and their interrelationships include:
Rosemary, common sage, and Greek sage are recognized for their strong antioxidant activity and pharmacological properties — mostly attributed to the presence of phenolic compounds and abietane-type diterpenes.
The most specifically documented mechanism for 7-O-Methylrosmanol at the molecular level relates to hepatic glucose metabolism. Among phenolic diterpenes from rosemary, 7-O-Methylrosmanol effectively suppressed FSK (forskolin)-induced luciferase expression under the control of the CRE (cAMP response element), PEPCK-C, and G6Pase gene promoters; PEPCK-C and G6Pase, which play a key role in the homeostatic regulation of blood glucose levels, are important for managing type II diabetes mellitus. The ability of rosemary and its components to suppress cAMP responsiveness of the PEPCK-C or G6Pase gene may contribute to antihyperglycemic activity.
This mechanism is of pharmacological significance because PEPCK and G6Pase are thought to be the rate-limiting enzymes for gluconeogenesis and have been implicated as potential targets to reduce hepatic glucose production and blood glucose levels in type 2 diabetes mellitus. In the context of diabetes pathophysiology, insulin inhibits expression of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase), two rate-limiting genes in gluconeogenesis; these genes are induced by glucagon and reduced by insulin.
In cell-based assays, 7-O-methylrosmanol showed inhibitory activity against inflammatory mediators — specifically demonstrating 41.5% inhibition at 12.5 μM with no cytotoxicity. In the context of network pharmacology analyses, 7-Methylrosmanol has been identified as targeting IL-6, AKT, BACE1, CASP3, MAPK1, and TNF, thereby potentially preventing inflammation and apoptosis. These predicted molecular targets span classical inflammatory signaling (IL-6, TNF, MAPK1), cell survival pathways (AKT, CASP3), and neurodegeneration-related enzymes (BACE1), suggesting multi-target anti-inflammatory potential. It is important to note that these target identifications are derived from computational (in silico) network pharmacology analyses and require validation by wet-laboratory experimentation.
Rosmanol (the parent compound) is known to have antioxidant activity, which has given rise to applications as antioxidants in foods. 7-O-methyl-epi-rosmanol and related abietane diterpenoids of rosemary are highly interesting due to their anti-inflammatory, antioxidant, anti-tumor, anti-HIV, anti-microbial, anti-Alzheimer, anti-adipogenic, and neuroprotective properties. As a structural analogue of rosmanol with the C-7 hydroxyl methylated, 7-Methylrosmanol participates in the same class of phenolic-based radical scavenging chemistry attributed to polyphenolic abietane diterpenes.
Early research investigating rosemary diterpenes as antiviral agents tested 7-O-methylrosmanol as a semisynthetic derivative in HIV protease inhibition assays. In order to find new effective HIV protease inhibitors, carnosic acid and carnosol were isolated from rosemary (Rosmarinus officinalis L.), and rosmanol together with semisynthetic derivatives including 7-O-methylrosmanol were prepared; the inhibitory activity of all six compounds against HIV-1 protease was tested. Carnosic acid showed the strongest inhibitory effect (IC90 = 0.08 μg/ml) and was also assayed against HIV-1 virus replication (IC90 = 0.32 μg/ml). The tested compounds did not inhibit cellular aspartic proteases cathepsin D and pepsin at the concentration range up to 10 μg/ml. In this comparative study, carnosic acid was the most potent member; 7-O-methylrosmanol showed less potent activity, and the precise IC values for the methylrosmanol derivative were not separately detailed in available abstracts.
7-O-methylrosmanol, along with other semisynthetically prepared rosmanol derivatives, was evaluated for cytotoxic and antimicrobial activities. In one phytochemical study examining Salvia species diterpenes, these abietane diterpenes were noted to have very interesting biological activities. The antibacterial activity of 7-O-methylrosmanol was specifically highlighted in the context of plant pathogen inhibition: even though rosemary methanolic extracts showed a low antibacterial activity against a strain of Pectobacterium carotovorum subsp. carotovorum in the disk diffusion test, they showed ability in reducing the soft rot damage induced by the bacterium on potato tissue; 7-O-methylrosmanol, carnosol, and isorosmanol appeared to be the most active components. In silico studies indicated that these abietane diterpenoids may interact with P. carotovorum subsp. carotovorum pectate lyase 1 and endo-polygalacturonase, highlighting these rosemary components as starting points for the development of agents able to prevent soft rot progression.
The 7-O-methyl-epi-rosmanol (7MER) form was one of the metabolites assessed for activity at the aryl hydrocarbon receptor (AhR) pathway, a transcription factor implicated in skin carcinogenesis and inflammatory dermatological conditions. The isolated metabolites carnosic acid, carnosol, 7-O-methyl-epi-rosmanol, 4′,7-O-dimethylapigenin, and betulinic acid were assayed for their agonist and antagonist activity in the presence and absence of TCDD using the gel retardation assay (GRA). Most assayed metabolites exhibited dose-dependent antagonist activity toward AhR activation. The AhR pathway is relevant because the aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that responds to a wide range of chemicals including chemical carcinogens such as dioxins and carcinogenic polyaromatic hydrocarbons, and recent reports suggest that AHR plays an important role in carcinogenesis and maintenance of various types of skin cancers.
The most specifically characterized pharmacological activity of 7-O-methylrosmanol in the peer-reviewed literature relates to the modulation of hepatic glucose production. The key evidence is from in vitro reporter-gene cell-based assays:
Evidence for antimicrobial properties of 7-O-methylrosmanol is limited to one plant-pathogen model and associated in silico docking studies:
Network pharmacology analysis has identified 7-Methylrosmanol as targeting BACE1 (beta-secretase 1), AKT, CASP3, IL-6, MAPK1, and TNF — molecular targets associated with Alzheimer's disease pathology and neurodegeneration. BACE1 is the enzyme that cleaves amyloid precursor protein to generate amyloid-beta fragments, a key step in Alzheimer's pathogenesis. This computational identification is hypothesis-generating but lacks experimental validation in neuronal cell lines, animal models, or human subjects specifically for the isolated 7-Methylrosmanol compound. Broader rosemary diterpene research has demonstrated that rosemary diterpenes inhibit neuronal cell death induced by a variety of agents, both in vitro and in vivo, and that a scopolamine-induced dementia rat model showed memory-enhancing effects of rosemary extract (200 mg/kg orally) linked to direct effects on acetylcholinesterase activity. These findings, however, relate to rosemary extract rather than specifically isolated 7-Methylrosmanol.
Among rosemary diterpenes, three agents in particular have received the most attention for anti-cancer activity: carnosic acid, carnosol, and rosmanol, with promising results of anti-cancer activity. Thanks to some components including carnosol, rosmaridiphenol, rosmanol, and rosmarinic acid, rosemary is considered as a cancer therapy candidate. 7-O-methylrosmanol was included in a structural class evaluation of semisynthetic abietane diterpenes for cytotoxic and antimicrobial activities; these compounds, along with eight known analogues, were evaluated for cytotoxic and antimicrobial activities. The specific cytotoxic potency of isolated 7-O-methylrosmanol against cancer cell lines has not been separately quantified in the available publicly accessible literature reviewed here.
Based on the peer-reviewed and indexed literature reviewed, 7-Methylrosmanol and its structural class are associated with the following body systems and health areas:
There are no published human clinical trials establishing a dosage for isolated 7-Methylrosmanol as a standalone supplement or drug candidate. All dosage information found in the peer-reviewed literature concerns either whole rosemary extract or the broader class of rosemary phenolic diterpenes; the compound itself has been studied exclusively in in vitro systems and computational analyses.
The following concentrations were used in the laboratory studies identified:
No established recommended daily intake, tolerable upper limit, or therapeutic dose for isolated 7-Methylrosmanol has been defined by any regulatory or health body reviewed.
No dedicated human safety studies, toxicokinetic analyses, or adverse event data exist in the peer-reviewed literature for isolated 7-Methylrosmanol as a supplement ingredient. The compound has been studied exclusively in in vitro and computational research contexts, where it has not demonstrated cytotoxicity at the tested concentrations. 7-O-methylrosmanol showed inhibitory activities with no cytotoxicity at the concentrations tested in cell-based assays.
The safety record of the parent plant and its primary diterpene constituents offers indirect context. Recently, rosemary extracts standardized to diterpenes such as carnosic acid and carnosol have been approved by the European Union (EU) and given a GRAS (Generally Recognized as Safe) status in the United States by the Food and Drug Administration (FDA). Rosemary extracts and the phytochemicals therein appear to be well tolerated in different animal models as evidenced by the extensive studies performed for approval by the EU and the FDA as an antioxidant food preservative.
Suppliers of purified 7-O-methylrosmanol for research purposes uniformly classify it as a research chemical only. This product category is designated for research use only, not for human use.
As with other phenolic diterpenes in its class, 7-Methylrosmanol is sensitive to oxidation, light, and heat. The compound should be stored under appropriate conditions. Its parent compound, rosmanol, and the broader carnosic acid family are known to undergo redox transformations under standard processing conditions. Carnosic acid is not a very stable compound once extracted and may undergo oxidation, and similar considerations apply to the minor metabolites including 7-Methylrosmanol, which is itself partly an oxidative product of carnosic acid degradation.
No specific drug interaction studies for isolated 7-Methylrosmanol exist. At the class level, rosemary diterpenes have been examined for P-glycoprotein inhibition: phytochemical investigations of rosemary have explored inhibition of the anticancer drug efflux transporter P-glycoprotein. This remains a research-level observation and has not been formalized into clinical interaction guidance for any individual diterpene constituent including 7-Methylrosmanol.
7-Methylrosmanol is a subject of early-stage, primarily in vitro and computational pharmacological investigation. All published evidence reviewed here is preclinical: there are no registered or completed human clinical trials specifically examining 7-Methylrosmanol as an isolated compound. The compound's identification as a discrete bioactive entity is relatively recent, and its presence in rosemary at very low concentrations (in contrast to carnosic acid and carnosol) has limited both the quantity of extract-focused research attributable to it and the feasibility of isolating it in quantities sufficient for in vivo animal experimentation.
Only limited clinical studies support traditional uses of rosemary as an antibacterial, anti-inflammatory, and spasmolytic, and none of these specifically characterize 7-Methylrosmanol's contribution. The most robustly studied diterpenes in rosemary remain carnosic acid, carnosol, and rosmanol; 7-Methylrosmanol is consistently described in the literature as a structurally related minor constituent whose biological properties warrant further investigation.
Evidence for all pharmacological activities attributed to 7-Methylrosmanol is currently at the following maturity levels:
Health conditions that 7-methylrosmanol may help support.
Body systems that 7-methylrosmanol may help support.
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