Antinociceptive Diterpenoids from the Leaves and Twigs of Rhododendron decorum

Recent Advances in Grayanane Diterpenes: Isolation, Structural Diversity, and Bioactivities from Ericaceae Family (2018-2024)

Diterpenes represent one of the most diverse and structurally complex families of natural products. Among the myriad of diterpenoids, grayanane diterpenes are particularly notable. These terpenes are characterized by their unique 5/7/6/5 tetracyclic system and are exclusive to the Ericaceae family of plants. Renowned for their complex structures and broad spectrum of bioactivities, grayanane diterpenes have become a primary focus in extensive phytochemical and pharmacological research. Recent studies, spanning from 2018 to January 2024, have reported a series of new grayanane diterpenes with unprecedented carbon skeletons. These compounds exhibit various biological properties, including analgesic, antifeedant, anti-inflammatory, and inhibition of protein tyrosine phosphatase 1B (PTP1B). This paper delves into the discovery of 193 newly identified grayanoids, representing 15 distinct carbon skeletons within the Ericaceae family. The study of grayanane diterpenes is not only a deep dive into the complexities of natural product chemistry but also an investigation into potential therapeutic applications. Their unique structures and diverse biological actions make them promising candidates for drug discovery and medicinal applications. The review encompasses their occurrence, distribution, structural features, and biological activities, providing invaluable insights for future pharmacological explorations and research.

An updated review of the genus Rhododendron since 2010: Traditional uses, phytochemistry, and pharmacology

Rhododendron, the largest genus of Ericaceae, consists of approximately 1000 species that are widely distributed in Europe, Asia, and North America but mainly exist in Asia. Rhododendron plants have not only good ornamental and economic value but also significant medicinal potential. In China, many Rhododendron plants are used as traditional Chinese medicine or ethnic medicine for the treatment of respiratory diseases, pain, bleeding and inflammation. Rhododendron is known for its abundant metabolites, especially diterpenoids. In the past 13 years, a total of 610 chemical constituents were reported from Rhododendron plants, including 222 diterpenoids, 122 triterpenoids, 103 meroterpenoids, 71 flavonoids and 92 other constituents (lignans, phenylpropanoids, phenolic acids, monoterpenoids, sesquiterpenoids, coumarins, steroids, fatty acids). Moreover, the bioactivities of various extracts and isolates, both in vitro and in vivo, were also investigated. Our review summarized the research progress of Rhododendron regarding traditional uses, phytochemistry and pharmacology in the past 13 years (2010 to December 2022), which will provide new insight for prompting further research on Rhododendron application and drug development.

Grayanane diterpenoids from Craibiodendron yunnanense with anti-inflammatory and antinociceptive activities

Twenty-five grayanane diterpenoids including six undescribed compounds (craibiodenoside A-F), were isolated from the leaves of Craibiodendron yunnanense W. W. Smith. The structures of the isolated compounds were determined by ¹D-NMR, ²D-NMR, and HR-ESI-MS spectrometric analyses. All compounds were evaluated for their anti-inflammatory activities by inhibiting the release of interleukin-6 (IL-6) in lipopolysaccharide (LPS)-induced RAW264.7 cells. The results demonstrated that three undescribed compounds craibiodenoside A, B, F, and three known compounds could inhibit the release of IL-6 significantly. In addition, the antinociceptive activities of compounds were assessed using acetic acid-induced writhing test. Craibiodenoside D, grayanoside D, and rhodojaponins VI exhibited notable antinociceptive activities. Specifically, rhodojaponins VI exhibited antinociceptive activity with the inhibition percentage of 87.6%.

The efficacy and toxicity of grayanoids as analgesics: A systematic review

ETHNOPHARMACOLOGICAL RELEVANCE

Grayanoids are natural diterpenoids that are mostly found in the Ericaceae family, such as Rhododendron molle (Blume) G. Don (Relevant herb: nao yang hua), Rhododendron micranthum Turcz (also known as: zhao shan bai), which have traditionally been used to treat abdominal pain, cephalgia, and rheumatoid arthritis.

AIMS OF THE REVIEW

The review investigated advancements in notable anti-nociception, toxicity, and probable mechanisms of grayanoids. Meanwhile some binding sites of these compounds on voltage-gated sodium channels (VSGCs) were also analyzed and evaluated.

MATERIALS AND METHODS

The substantial grayanoids literature published before 2022, in SCI Finder, PubMed, Science Direct, Springer, Scopus, Wiley Online Library, J-Stage, and other literature databases had been exhaustively consulted and thoroughly screened.

RESULTS

More than 50 compounds in grayanoids exhibited exceptionally significant anti-nociception (intraperitoneal injection, less than 1 mg/kg), and the alteration of several substituents that were closely associated to the change in activity were investigated. Multiple possible mechanisms of analgesic action and toxicity had been proposed, with VSGCs playing a key part in both. As a result, the binding locations of these compounds on VGSCs (mostly grayanotoxin I and III) had been summarized.

CONCLUSIONS

The considerable anti-nociception, toxicity, and probable mechanisms of grayanoids, as well as the investigation of the binding sites on VSGCs, were discussed in this review. Furthermore, the homology of toxicity and anti-nociception of these substances was considered, as well as the possibility of grayanoids being developed as analgesics.

Evaluation of Rhodojaponin III from Rhododendron molle G. Don on oral antinociceptive activity, mechanism of action, and subacute toxicity in rodents

ETHNOPHARMACOLOGICAL RELEVANCE

In Chinese traditional medicine, Rhododendron molle G. Don is a recognized herb to ease pain. Rhodojaponin III (RJ-III) has been identified as the main pharmacological activity and toxic component of the herb; however, oral antinociception and mechanism of RJ-III have not yet been investigated.

AIM OF THE STUDY

The significance of this study is to evaluate the effects of RJ-III on nociceptive and neuropathic pain, and to preliminarily explore the underlying mechanisms and subacute toxicity.

MATERIALS AND METHODS

The antinociception of RJ-III was evaluated by hot plate, tail-immersion, acetic acid writhing, formalin test and chronic constriction injury (CCI) model in rodents. An experimental validation was conducted using whole-cell patch clamp technique based on the most likely mechanisms of action after screening and prediction by molecular docking study. In addition, the oral subacute toxicity of RJ-III was assessed.

RESULTS

Behavioral experiments showed that RJ-III (0.20 mg/kg) reduced the latency of the nociceptive response in the hot plate and tail-immersion tests. Acetic acid and formalin-induced pain were significantly inhibited by RJ-III (0.10 and 0.05 mg/kg, respectively). Furthermore, 0.30 mg/kg of RJ-III improved hyperalgesia in the CCI-induced rats. Based on molecular docking results, electrophysiological experiments were used to demonstrate mild inhibition of voltage-gated sodium channel-related subtypes. Additionally, oral subacute toxicity that may cause leukopenia and abnormal liver function requires further attention in subsequent studies.

CONCLUSION

RJ-III mildly blocks voltage-gated sodium channel to inhibit nociceptive pain and peripheral neuralgia, but 0.375 mg/kg and above may cause side effect after long-term oral administration.

Two new diterpenoids from the stems of Rhododendron dauricum as GABAA receptor agonists

Two new diterpenoids, dauricumins A (1) and B (2), together with two known aromatic meroterpenoids (3 and 4), were isolated from the petroleum ether soluble fraction of the stems from Rhododendron dauricum through an HPLC-MS-SPE-NMR combination strategy. The absolute configurations of 1 and 2 were elucidated by ECD calculations and [Rh₂ (OCOCF₃)₄]-induced CD spectrum analysis. In a membrane potential FLIPR assay, confluentin (4) showed an agonistic effect on GABA_A receptor (EC₅₀ = 20 µM).

The Rhododendron Plant Genome Database (RPGD): a comprehensive online omics database for Rhododendron

Background

The genus Rhododendron L. has been widely cultivated for hundreds of years around the world. Members of this genus are known for great ornamental and medicinal value. Owing to advances in sequencing technology, genomes and transcriptomes of members of the Rhododendron genus have been sequenced and published by various laboratories. With increasing amounts of omics data available, a centralized platform is necessary for effective storage, analysis, and integration of these large-scale datasets to ensure consistency, independence, and maintainability.

Results

Here, we report our development of the Rhododendron Plant Genome Database (RPGD; http://bioinfor.kib.ac.cn/RPGD/), which represents the first comprehensive database of Rhododendron genomics information. It includes large amounts of omics data, including genome sequence assemblies for R. delavayi, R. williamsianum, and R. simsii, gene expression profiles derived from public RNA-Seq data, functional annotations, gene families, transcription factor identification, gene homology, simple sequence repeats, and chloroplast genome. Additionally, many useful tools, including BLAST, JBrowse, Orthologous Groups, Genome Synteny Browser, Flanking Sequence Finder, Expression Heatmap, and Batch Download were integrated into the platform.

Conclusions

RPGD is designed to be a comprehensive and helpful platform for all Rhododendron researchers. Believe that RPGD will be an indispensable hub for Rhododendron studies.

Structurally diverse diterpenoids with eight carbon skeletons from Rhododendron micranthum and their antinociceptive effects

Seventeen diterpenoids (1-17), classified into eight diverse carbon skeleton types, grayanane (1, 2, and 12), micranthane (3, 4, and 13), mollane (5-7 and 14), 1,5-seco-grayanane (8), kalmane (9-11), 1,5-seco-kalmane (15), A-homo-B-nor-ent-kaurane (16), and leucothane (17), respectively, were isolated from the leaves extract of Rhododendron micranthum. Among them, diterpenoids 1-9 are new compounds and their structures were elucidated via extensive spectroscopic methods, quantum chemical calculations including the ¹³C NMR-DP4+ analysis and electronic circular dichroism (ECD) calculations, and the single-crystal X-ray diffraction analysis. Micranthanol A (1) represents the first example of a 5αH,9αH-grayanane diterpenoid and a 6-hydroxy-6,10-epoxygrayanane diterpenoid, and micranthanone B (3) is the first 6,10-epoxymicranthane and the 5α-hydroxy-micranthane diterpenoids. 14-epi-Mollanol A (5) and mollanol B (6) represent the first examples of 14β-hydroxymollane diterpenoids. It is the first time to report mollane, 1,5-seco-kalmane, and A-homo-B-nor-ent-kaurane type diterpenoids from Rhododendron micranthum. All the seventeen diterpenoids showed significant antinociceptive activities at a dose of 5.0 mg/kg, and it is the first time to evaluate the antinociceptive activity of 1,5-seco-kalmane diterpenoid. Among them, compounds 3, 11, 14, and 15 exhibited significant antinociceptive activities even at a lower dose of 1.0 mg/kg. A preliminary structure-activity relationship for the antinociceptive effects of diterpenoids 1-17 is discussed, which provided a new basis to develop novel potent analgesics.

Poisonous delicacy: Market-oriented surveys of the consumption of Rhododendron flowers in Yunnan, China

ETHNOPHARMACOLOGICAL RELEVANCE

Plants from the family Ericaceae, and in particular those in the genus Rhododendron are frequently reported to contain grayanotoxins. Plant products such as honey and herbal medicines made from these plants occasionally contain grayanotoxins, and in turn may lead to intoxication. The balance between the benefits and risk of poisoning from Rhododendrons is of concerns. This study explores the ethnobotanical knowledge of the people in Yunnan, China as regards the consumption of Rhododendron flowers, and gives special focus to their assessment of the benefit-risk balance.

MATERIALS AND METHODS

An ethnobotanical survey was conducted across 14 county-level local markets in north and central Yunnan province, during which a total of 82 stalls selling Rhododendron flowers were visited and 204 people were interviewed. Voucher specimens were obtained under the guidance of collectors, and details about local practices and knowledge were recorded using semi-structured interviews and participatory observations.

RESULTS

The consumption of the corollas of Rhododendron decorum Franch. Flowers (RDf) or Rhododendron pachypodum Balf. f. & W.W. Sm. Flowers (RPf) as a seasonal delicacy is a long-standing tradition in the study area. RDf are widely consumed in northwest and northeast Yunnan, while RPf are more prevalent in the central regions of Yunnan, and there is a high consistency in the knowledge of the process for detoxification or palatability for each species. The main reasons for eating the flowers were listed as health benefits (mostly clear heat), wild collected, tradition and good flavor. All RPf consumers stated that the corolla from this species is not toxic, while 67.4% of the RDf consumers claim that the corolla from RDf is toxic. We compared the two species and analyzed their process intensities, poisoning cases and cautions, market trade forms and existing toxicity studies, which agreed well and consistently that the corolla of RDf deserve more toxicity attention than RPf.

CONCLUSION

Our study provides a window to look into the ways, beyond honey and herbal medicine, by which Rhododendron species have influenced human wellbeing. The local culture can justify eating Rhododendron flowers, and meanwhile, has developed a series of skills to avoid the side effects of eating them, and therefore the study also provides a good case to answer more general questions about the rationality of eating any plant products by assessing the trade-off between benefits and side effects.

Antinociceptive grayanane-derived diterpenoids from flowers of Rhododendron molle

Twelve new grayanoids (1-12) along with five known compounds were isolated from flowers of Rhododendron molle. Their structures were fully characterized using a combination of spectroscopic analyses, computational calculations, and single crystal X-ray diffraction. Rhomollone A (1) possesses an unprecedented 5/6/6/5 tetra-cyclic ring system (B-nor grayanane) incorporating a cyclopentene-1,3-dione scaffold. Rhodomollein XLIII (2) is a dimeric grayanoid, containing a novel 14-membered heterocyclic ring with a C ₂ symmetry axis. The antinociceptive activities of compounds 3, 4, 6, 7, and 12-17 were evaluated by an acetic acid-induced writhing test. Among them, compounds 3, 7, 12, 15 and 16 displayed significant antinociceptive activities at a dose of 20 mg/kg with inhibition rates ranging from 41.9% to 91.6%. Compounds 6 and 13 inhibited 46.0% and 39.4% of the acetic acid-induced writhes at a dose of 2 mg/kg, while compound 17 inhibited 34.3% of the writhes at a dose of 0.4 mg/kg.

Structurally diverse diterpenoids from Pieris japonica as potent analgesics

Sixteen diterpenoids (1-16) including 10 new ones, pierisjaponins A-J (1-10), were isolated and identified from Pieris japonica, and their structures were classified into eight diverse carbon skeletons. Pierisjaponins A (1) and B (2) represent the first 1,5-seco-grayanane diterpenoid glucosides and only showed 17 carbon resonances instead of 26 carbons in the ¹³C NMR spectra, their structures were finally defined by single-crystal X-ray diffraction, and the unusual NMR phenomena were explained. Pierisjaponin E (5) is the first mollane diterpene glucoside. This is the first time to report ent-labdane (3, 4, and 11) and ent-rosane (15) type diterpenoids from the Ericaceae plants, which provided the precursors of the Ericaceae diterpenoids and enlarged the chemical diversity of Ericaceae diterpenoids. All the 16 isolates showed potent analgesic activities, and this is the first time to describe the analgesic activities of 1,5-seco-grayanane, ent-labdane, mollane, and ent-rosane type diterpenoids. A preliminary structure-activity relationship is discussed, which provided new clues to design novel analgesics based on the Ericaceae diterpenoids.

Grayanane diterpenoid glucosides as potent analgesics from Pieris japonica

A total of fifteen grayanane diterpenoid glucosides including eight undescribed ones, pierisjaponosides A-H, were isolated from the leaves of Pieris japonica (Thunb.) D. Don ex G. Don (Ericaceae). Their structures were established by extensive spectros copic techniques including HRESIMS and NMR, as well as chemical methods. The absolute configurations of pierisjaponosides A, B, and D were finally established by single-crystal X-ray diffraction with Cu Kα radiation. This is the first time to report the crystal structure of a 5,9-epoxygrayanane diterpenoid glucoside. Pierisjaponoside E represents the first example of a 9β-hydroxygrayan-1(10)-ene diterpenoid. All the isolated grayanane diterpenoid glucosides were evaluated for their analgesic activities in the acetic acid-induced writhing models in mice, and showed significant analgesic effects. Pierisjaponosides A and C-H, micranthanoside A, pieroside A, and craiobiosides A and B displayed significant analgesic effects with the writhe inhibition rates over 50% at a dose of 5.0 mg/kg. Pierisjaponoside E exhibited significant analgesic activities with the percentage inhibitions of 81.7%, 70.4%, and 52.1% at the doses of 5.0, 1.0, and 0.2 mg/kg, respectively. The preliminary structure-activity relationships of grayanane diterpenoid glucosides as potent analgesics were discussed, giving some clues to design novel analgesics.

Analgesic diterpenoids with diverse carbon skeletons from the leaves of Rhododendron auriculatum

Sixteen diterpenoids including nine undescribed ones, named rhodoauriculatols A-I, were isolated from the leaves of Rhododendron auriculatum Hemsl. Sixteen diterpenoids belong to seven diverse carbon skeletons, which were classified into 1,10-seco-grayanane, 1,10:2,3-diseco-grayanane, A-homo-B-nor-ent-kaurane, ent-kaurane, 4,5-seco-ent-kaurane, leucothane, and grayanane, respectively. Their structures were determined by the detailed HRESIMS, 1D and 2D NMR, UV, and IR data analysis, and their absolute configurations were established by single crystal X-ray diffraction analysis, electronic circular dichroism (ECD) data analysis, ECD calculation, as well as chemical methods. Rhodoauriculatols A-C possess a rare 1,10-seco-grayanane diterpene skeleton. Rhodoauriculatol D is the second example of the 1,10:2,3-diseco-grayanane diterpenoids, and rhodoauriculatol E is the fourth example of the A-homo-B-nor-ent-kaurane diterpenoids. Rhodomicranone E was reported as a natural product for the first time. All the isolated sixteen diterpenoids showed analgesic activities in the acetic acid-induced writhing test. Rhodoauriculatols B, E-G, rhodomicranone E, pierisformoside F, and micranthanoside A showed significant analgesic activities with the inhibition rates over 40%, and their preliminary structures-activity relationships were studied.

Characterization of Volatile Compounds in Four Different Rhododendron Flowers by GC×GC-QTOFMS

Volatile compounds in flowers of Rhododendron delavayi, R. agastum, R. annae, and R. irroratum were analyzed using comprehensive two-dimensional gas chromatography-mass spectrometry (GC×GC) coupled with high-resolution quadrupole time-of-flight mass spectrometry (QTOFMS). A significantly increased number of compounds was separated by GC×GC compared to conventional one-dimensional GC (1DGC), allowing more comprehensive understanding of the volatile composition of Rhododendron flowers. In total, 129 volatile compounds were detected and quantified. Among them, hexanal, limonene, benzeneacetaldehyde, 2-nonen-1-ol, phenylethyl alcohol, citronellal, isopulegol, 3,5-dimethoxytoluene, and pyridine are the main compounds with different content levels in all flower samples. 1,2,3-trimethoxy-5-methyl-benzene exhibits significantly higher content in R. irroratum compared to in the other three species, while isopulegol is only found in R. irroratum and R. agastum.

Grayanane Diterpenoids from the Leaves of Rhododendron auriculatum and Their Analgesic Activities

Twenty-four grayanane diterpenoids (1-24) including 12 new ones (1-12) were isolated from Rhododendron auriculatum. The structures of the new grayanane diterpenoids (1-12) were defined via extensive spectroscopic data analysis. The absolute configurations of compounds 2-4, 10-12, 14, and 16 were established by single-crystal X-ray diffraction analysis, and electronic circular dichroism data were used to define the absolute configurations of auriculatols D (8) and E (9). Auriculatol A (1) is the first example of a 5,20-epoxygrayanane diterpenoid bearing a 7-oxabicyclo[4.2.1]nonane motif and a trans/cis/cis/cis-fused 5/5/7/6/5 pentacyclic ring system. Auriculatol B (2) is the first example of a 3α,5α-dihydroxy-1-βH-grayanane diterpenoid. 19-Hydroxy-3-epi-auriculatol B (6) and auriculatol C (7) represent the first examples of 19-hydroxygrayanane and grayan-5(6)-ene diterpenoids, respectively. Diterpenoids 1-24 showed analgesic activities in the writhing test induced by HOAc, and 2, 6, 10, 13, 19, and 24 at a dose of 5.0 mg/kg exhibited significant analgesic effects (inhibition rates >50%). Grayanane diterpenoids grayanotoxins I (19) and IV (24) at doses of 0.2 and 0.04 mg/kg showed more potent analgesic activities than morphine.

Micranthanosides I and II, two novel 1,10-secograyanane diterpenoids and their antinociceptive analogues from the leaves and twigs of Rhododendron micranthum

Micranthanosides I and II (1-2), two diterpenoid glucosides featuring a new 1,10-secograyanane skeleton, thirteen new diterpenoid glycosides (3-15), and 21 known analogues were obtained from the ethanol extract of the leaves and twigs of Rhododendron micranthum. Micranthanoside XII (12) represent the first example of 3,5-epoxy-4,5-seco-ent-kaurane diterpenoid. The structures of these compounds were determined by spectroscopic data analysis and quantum chemical calculations. To clarify the chemical basis and provide reference for rational use of this medicinal plant, the antinociceptive and the anti-inflammatory activities of the compounds were tested. In the acetic acid-induced writhing test, compounds 17 and 19 showed significant antinociceptive activity at a dose of 3 mg kg-1 and compounds 2, 6 and 32 showed significant antinociceptive activity at a dose of 10 mg kg-1. Toxic reactions such as nausea and convulsion were observed when 17, 19, 29, and 31 at a dose of 10 mg kg-1 or 30 and 33 at a dose of 1 mg kg-1 were administered. The anti-inflammatory activities of the isolated compounds were evaluated by measuring the inhibitory effects of LPS-induced NO production in BV2 cells. At 10 μM, micranthanoside IX (9) and rhodomicranoside F (26) showed moderate anti-inflammatory activities with inhibition rates of 56.31% and 72.43%, respectively.

Rhodomicranosides A-I, analgesic diterpene glucosides with diverse carbon skeletons from Rhododendron micranthum

Nine previously undescribed diterpene glucosides, rhodomicranosides A-I, comprising leucothane, 4,5-seco-ent-kaurane, and grayanane types, respectively, were isolated from the leaves of Rhododendron micranthum, along with seven known diterpenoids. Their structures were elucidated based on extensive spectroscopic analyses such as HRESIMS, 1D and 2D NMR, UV, and IR, and their absolute configurations were determined by various methods including X-ray diffraction analysis, electronic circular dichroism spectroscopy (ECD), calculated ECD, and Mo₂(OAc)₄-induced ECD, as well as chemical methods. This is the first time to report the crystal structures of leucothane diterpene glycosides. Rhodomicranosides A-C represent the first examples of 15α-hydroxy-leucothane diterpenoids, leucothane diterpene diglucosides, and 9β-hydroxy-leucothane diterpenoids, respectively. Rhodomicranosides D and E are the second and third examples of 4,5-seco-ent-kaurane diterpenoids, and this is the first time to report 4,5-seco-ent-kaurane-type diterpenoids from the genus of Rhododendron. Rhodomicranosides F and G are the first examples of 5α-H-grayan-1(10),9(11)-diene-6-one diterpenoids. Some isolated diterpenoids were evaluated for their analgesic activity in an acetic acid-induced writhing test, and rhodomicranosides A-E and H, pierisformoside F, iso-grayanotoxin II, and grayanotoxins I, III, and IV showed significant analgesic effects with the percentage inhibitions over 50% at the dose of 1.0 mg/kg. In particular, grayanotoxins I and III exhibited more potent analgesic activity than morphine at a dose of 0.2 mg/kg, and they showed significant analgesic activity even at a lower dose of 0.04 mg/kg with the inhibition rates of 71.5% and 69.3%, respectively. Their preliminary structure-activity relationships were discussed.

Grayanane Diterpenoid Glucosides from the Leaves of Rhododendron micranthum and Their Bioactivities Evaluation

Thirteen new grayanane diterpenoid glucosides, 3- epi-grayanoside B (1), micranthanosides A-E (2-6), 7α-hydroxygrayanoside C (7), micranthanoside F (8), 14β-acetyoxymicranthanoside F (9), micranthanoside G (10), 14- O-acetylmicranthanoside G (11), 14β-hydroxypieroside A (12), and micranthanoside H (13), and six known analogues (14-19) were isolated from the leaves of Rhododendron micranthum. The structures of 1-19 were elucidated based on spectroscopic analysis, comparison with literature, and chemical methods. The absolute configurations of 3- epi-grayanoside B (1) and micranthanosides A (2) and C (4) were defined by single-crystal X-ray diffraction analysis. This is the first report of the crystal structures of grayanane diterpenoid glucosides. 3- epi-Grayanoside B (1) represents the first example of a 3α-oxygrayanane diterpenoid glucoside, and micranthanosides A-D (2-5) are the first examples of 5α-hydroxy-1-β H-grayanane diterpenoids. In addition, micranthanosides C-F (4-6 and 8) and 14β-acetyoxymicranthanoside F (9) represent the first examples of grayanane glucosides with the glucosylation at C-16. All the grayanane diterpenoid glucosides 1-19 were assayed for their anti-inflammatory, antitumor, and PTP1B inhibitory activities, but did not show significant activities at 40 μM. Grayanane diterpenoid glucosides 1-18 were evaluated for their antinociceptive activity, and compounds 2, 3, 7-10, 12, 13, and 16 showed significant antinociceptive effects with percentage inhibitions in excess of 50%.