Abstract
Cordyceps cicadae, a medicinal and edible entomopathogenic fungus, has been widely used in traditional Chinese medicine for treating various ailments. This study aimed to validate its ethnopharmacological uses by investigating bioactive constituents and their antithrombotic and antioxidant activities. Through various chromatographic separations, one unreported flavonoid; quercetin-3-O-β-D-methylglucopyranoside (1); three known flavonoids (2–4); and one new dicarboxylic acid derivative, cicadae acid (5), were isolated from C. cicadae. Their chemical structures were elucidated by a comprehensive spectroscopic analysis (1D/2D NMR and HRESIMS), electronic circular dichroism (ECD) calculations, a DP4+ probability analysis, and the modified Mosher method. All compounds exhibited significant antithrombotic effects at a concentration of 20 μM in a zebrafish model. Compounds 1–4 exhibited potent antioxidant activity in the DPPH radical scavenging assay, with IC50 values ranging from 12.81 ± 3.42 to 20.16 ± 2.64 μM. These findings provide scientific evidence supporting the traditional application of C. cicadae, identifying specific flavonoids and dicarboxylic acids as potential therapeutic agents for thrombosis and oxidative stress-related disorders.
1. Introduction
Cordyceps cicadae (C. cicadae), an entomogenous fungus belonging to the family Clavicipitaceae and the genus Cordyceps, grows inside the nymph of hosts Cicadidae and forms fruiting bodies on the surface of these insects [1,2]. It is primarily distributed in southern China, including Sichuan, Jiangsu, Zhejiang, and Yunnan provinces, where the warm and humid climate is ideal for its growth. Although it has also been reported in Europe, the United States, and Japan, the yields in these regions remain substantially lower than those in China [3]. As a medicinal and edible fungus, C. cicadae was documented in ancient pharmacopeias such as the Compendium of Materia Medica and the Formulary of the Taiping People’s Welfare Pharmacy, as well as in modern authoritative compendiums, including Chinese Herbal Medicine and the Chinese Materia Medica [4]. For centuries, it has been used as a dietary supplement and folk medicine to treat diabetes, dizziness and chronic kidney diseases [5,6]. Recent studies on C. cicadae have identified its primary chemical constituents as nucleosides, sterols, cyclic peptides, polysaccharides, fatty acids and amino acids [7]. These compounds are the material basis for its diverse pharmacological activities [8,9]. For example, adenosine, a major bioactive constituent of C. cicadae, has demonstrated therapeutic potential in preclinical studies, particularly for the prevention and management of neurodegenerative disorders [10]. Similarly, ergosterol peroxide, a secondary metabolite isolated from C. cicadae, exhibited anti-cancer and renoprotective activities [11]. Furthermore, beauvericin J, which was isolated from C. cicadae, displayed potent in vitro antitumor activity against hepatocellular carcinoma (HepG2) cells and their multidrug-resistant variant (HepG2/ADM), suggesting potential applications for overcoming chemotherapy resistance [7].
The majority of cardiovascular diseases, such as acute myocardial infarction, ischemic heart disease, and peripheral vascular disease, are associated with thrombotic disorders, contributing to an estimated 20 million deaths each year [12]. The escalating burden of thrombotic disorders is exerting mounting pressure on healthcare systems worldwide [13]. Despite the widespread clinical use of antithrombotics, like acetylsalicylic acid, warfarin, and heparin, their application is limited by adverse effects such as hemorrhage and therapeutic resistance [14,15]. These challenges underscore the critical demand for novel antithrombotic agents with improved safety and efficacy profiles. The zebrafish has emerged as a powerful model organism for screening bioactive compounds due to its unique combination of a high-throughput capability and physiological relevance [16]. This species serves as a critical translational bridge between in vitro assays and mammalian models in modern drug discovery, particularly for thrombosis research [12]. The thrombus formation mechanism in zebrafish closely mirrors human pathophysiology [17]. Importantly, validation studies have confirmed a strong concordance between zebrafish and mammalian responses to clinical antithrombotics, supporting the model’s predictive validity for drug screening [17]. At the molecular level, the zebrafish exhibits an approximate 80% homology with human disease-associated genes, enabling a robust investigation of signalling pathways and targeted drug development [18]. Researchers routinely employ arachidonic acid (AA) to induce thrombus formation, making this model versatile for both high-throughput compound screening and mechanistic studies of antithrombotic agents [19].
Given the extensive ethnopharmacological uses of C. cicadae for cardiovascular and metabolic disorders coupled with the urgent need for safer antithrombotic agents, this study systematically investigated its bioactive constituents. Building on prior reports of its nucleosides and sterols (e.g., adenosine and ergosterol peroxide) exhibiting neuroprotective and antitumor properties [7,10,11], the objective of this study was to isolate and characterize previously unexplored secondary metabolites from Cordyceps cicadae and to evaluate their antithrombotic and antioxidant activities using a zebrafish thrombosis model. Subsequent studies resulted in the isolation of a new flavonoid, quercetin-3-O-β-D-methylglucopyranoside (1), three known flavonoids (2–4), and one unreported dicarboxylic acid derivative, cicadae acid (5). Herein, the details of the isolation, structural elucidation and biological activities of compounds 1–5 are reported.
2. Results and Discussion
2.1. Structural Elucidation
Compound 1 was obtained as an amorphous yellow oil, and its molecular formula was determined as C22H22O12 based on the HRESIMS protonated ion peak at m/z 479.1187 [M + H]+ (Figure S1). The 1H-NMR, 13C-NMR and HSQC data (Table 1 and Figures S2–S4) showed that compound 1 had one methyl [δH 3.61 (s, H3-7″)], one methylene [δH 3.74 (dd, J = 12.2, 4.8 Hz, H-6″a), 3.90 (dd, J = 12.2, 4.8 Hz, H-6″b)], five methine [δH 5.05 (d, J = 7.7 Hz, H-1″), 3.49 (m, H-2″), 3.63 (d, J = 9.1 Hz, H-3″), 3.23 (t, J = 9.1 Hz, H-4″), 3.54 (ddd, J = 11.0, 5.6, 2.7 Hz, H-6″)], and five aromatic protons [δH 6.45 (d, J = 2.2 Hz, H-5), 6.73 (d, J = 2.2 Hz, H-7), 7.76 (d, J = 2.2 Hz, H-1′), 7.67 (dd, J = 8.5, 2.2 Hz, H-2′), δH 6.89 (d, J = 8.4 Hz, H-4′)]. The 13C-NMR data (Table 1 and Figure S3) displayed a total of 22 carbon signals, including one methyl carbon (δC 60.91), one methylene carbons (δC 62.01), five methine carbons (δC 74.9, 77.4, 77.9, 80.5 and 101.5), five aromatic carbons (δC 95.5, 100.1, 116.1, 116.2 and 121.9) and ten quaternary carbons. The 1H-1H COSY (Figure 1 and Figure S5) correlations of H-1″/H-2″/H-3″/H-4″/H-6″, together with the HMBC correlations (Figure 1 and Figure S6) from H-6″ to C-4″ and C-5″, from H-3″ to C-1″, and from H3-7″ (δH 3.61) to C-4″ confirmed the presence of methylglucoside. In the HMBC spectrum (Figure 1 and Figure S6), the correlations from H-5 to C-3 and C-4, from H-6 to C-7 and C-8, from H-4′ to C-5′, C-6′ and C-9, and from H-2′ to C-4′ and C-6′ confirmed that the aglycone of compound 1 is quercetin [20]. The key HMBC correlation (Figure 1 and Figure S6) from H-1″ to C-6 indicated that methylglucoside was located at the C-6 position. Thus, the planar structure of compound 1 was established and is shown in Figure 2.
Table 1.
1H (600 MHz) and 13C (150 MHz) NMR data of compound 1 in CD3OD.
Figure 1.
The 1H-1H COSY (blue bold line) and key HMBC (red arrow) data of compound 1 and 5.
Figure 2.
Chemical structures of compounds 1–5.
Given that the aglycone of compound 1 is quercetin, which is an achiral molecule, the absolute configuration of the entire molecule was determined by the glycosyl unit. H-1″ exhibited a distinct double peak at δH = 5.05, with a coupling constant of J = 7.7 Hz in the 1H NMR spectrum. This characteristic value corresponds to the β-configuration of the glucose pyranose ring [21]. Therefore, the relative configuration can be assigned as β. The absolute configuration was determined by an optical rotation analysis. The measured specific rotation for compound 1 was -24.7 (c 0.1, MeOH). As noted in the work of W. Korytnyk [22] and supported by previous studies [23], it was firmly established that the absolute configuration was the D-configuration. Thus, the compound 1 was confirmed as quercetin-3-O-β-D-methylglucopyranoside. The known flavonoids were identified as 7-hydroxy-2′,4′,5′-trimethoxyisoflavone (2) [24], olibergin A (3) [24] and (2R)-2,3-dihydro-7-demethylrobustigenin (4) [25] by comparing their spectral data with those reported in the literature.
Compound 5 was obtained as an amorphous brown oil, and its molecular formula was determined as C10H18O6 based on the HRESIMS ion peak at m/z 257.1359 [M + Na]+ (Figure S7). The 1H-NMR, 13C-NMR, and HSQC data (Table 2 and Figures S8–S10) showed that compound 5 had four methyl groups [δH 1.04 (s, H3-8), 1.16 (d, J = 6.5 Hz, H3-10), 1.18 (d, J = 6.5 Hz, H3-9), 1.36 (d, J = 7.0 Hz, H3-7)] and three methine groups [δH 3.82 (q, J = 6.5 Hz, H-5), 3.84 (q, J = 6.5 Hz, H-6), 4.11 (q, J = 7.0 Hz, H-2)]. The 13C-NMR data (Table 2 and Figure S9) displayed a total of 10 carbon signals, including four methyl carbons (δC 17.5, 17.5, 17.7 and 18.5), three methine carbons (δC 55.5, 72.2 and 72.5) and three quaternary carbons. In the 1H-1H COSY (Figure S11) correlations between H-2 and H3-7 together with the HMBC correlations (Figure S12) from H3-7 to C-1 (δC 178.9) and C-3 (δC 159.6), we confirmed the main structure of the malonic acid. The 1H-1H COSY correlations (Figure 1 and Figure S11) of H-5/H3-9 and H-6/H3-10, together with the HMBC correlations (Figure 1 and Figure S12) from H3-9 to C-4 and C-5, from H3-10 to C-4 and C-6, and from H-6 to C-4, confirmed the presence of methylpentanediol on the right side. The chemical shift in C-4 (δC 76.3) and HRESIMS data (Figure S12) confirmed that methylpentanediol was connected to C-3 (δC 159.6) via an oxygen atom. Thus, the planar structure of compound 5 was established and is shown in Figure 2.
Table 2.
1H (600 MHz) and 13C (150 MHz) NMR data of compound 5 in CD3OD.
To determine the absolute configuration at C-5 and C-6, the modified Mosher method was used [26]. However, the 1H NMR chemical shift differences between the (R)-MTPA ester of compound 5 and the (S)-MTPA ester of compound 5 were very small (Figure 3, Figures S13 and S14), with a ΔδH (=δHS − δHR) of −0.01 at H3-9 and H3-10. The negligible ΔδH values suggest that the two hydroxyl groups might adopt opposite or quasi-symmetric spatial orientations, resulting in the cancellation of the anisotropic effects of the MTPA moiety and thus nearly unchanged 1H chemical shifts [27,28].
Figure 3.
Δδ (=δS − δR) values for (S)- and (R)-MTPA esters of compound 5.
Compound 5 possesses three stereogenic centres (C2, C5, C6), giving rise to four pairs of relative enantiomeric configurations: 2R*, 5R*, 6R*/2S*, 5S*, and 6S*; 2R*, 5R*, 6S*/2S*, 5S*, and 6R*; 2R*, 5S*, 6R*/2S*, 5R*, and 6S*; and 2R*, 5S*, 6S*/2S*, 5R*, and 6R*. Furthermore, 13C NMR calculations were performed for the four possible relative stereochemical configurations of compound 5: 2R*, 5R*, 6R*-; 2R*, 5R*, 6S*-; 2R*, 5S*, 6R*-; and 2R*, 5S*, 6S*-5. The result indicated that 2R, 5S, 6S-5 was a reasonable structure (Figure 4), with a better correlation coefficient (R2 = 0.9931) and a high DP4+ probability score at 98.31% (all data) (Figure S15). Eventually, the absolute configuration of compound 5 was established as 2R, 5S, 6S based on ECD calculations (Figure 5).
Figure 4.
DP4+ analysis of 2R*, 5R*, 6R*-5 (A); 2R*, 5R*, 6S*-5 (B); 2R*, 5S*, 6R*-5 (C); and 2R*, 5S*, 6S*-5 (D) in MeOH.
Figure 5.
Experimental and calculated ECD spectra of compound 5.
2.2. Antithrombotic Activity in Zebra Fish Model
The discovery of natural products with antithrombotic activity is of great importance for the development of novel and safer therapeutic agents against thrombotic diseases. Thus, a zebrafish thrombosis model was induced by arachidonic acid (AA) to assess the antithrombotic efficacy [12]. A comparative analysis revealed a significant reduction in the cardiac red blood cell (RBC) staining intensity in the AA model group compared with the control group (Figure 6A,B). This AA-induced decrease was effectively reversed by heparin, which was used as a positive control [29] (Figure 6A,B). The treatment with compounds 1–5 at 20 μM significantly restored the cardiac RBC staining intensity, showing effects comparable to those of heparin. In addition, compounds 1–5 significantly reduced caudal thrombus areas in zebrafish tails relative to the model group (Figure 6A,C). Taken together, these results indicate that compounds 1–5 exhibit antithrombotic activity in the AA-induced zebrafish thrombosis model.
Figure 6.
Compounds 1–5 (at a concentration of 20 μM) alleviated arachidonic acid (AA)-induced thrombosis in a zebrafish model. Compounds 1–5 inhibited thrombosis in zebrafish. (A) Typical images of erythrocyte staining both in the heart (up panel) and caudal vein (down panel). The ellipse indicates the heart area. (B,C) The quantitative analysis of the intensity of the erythrocyte staining in the heart (B) and caudal vein (C). The data are shown as the mean ± SD, and Student′ s t-test was performed to evaluate the differences between the model group and other groups. ** p < 0.01, *** p < 0.001, and **** p < 0.0001.
2.3. Antioxidant Activity In Vitro
The DPPH·free radical scavenging assay is a fundamental method for evaluating antioxidant activity in vitro; this method has been widely used for the quantitative determination of the antioxidant capacity of biological samples, phenolic substances, and food [30]. As depicted in Figure 7, compounds 1–4 exhibited antioxidant activities comparable to that of the positive control, ascorbic acid (IC50 = 13.8 ± 0.94 μM), with IC50 values of 20.16 ± 2.64, 12.81 ± 3.42, 14.20 ± 1.07, and 14.05 ± 2.24 μM, respectively. Compound 5 showed weak antioxidant activity, with an IC50 value exceeding 100 μM.
Figure 7.
In vitro DPPH· radical scavenging activities of ascorbic acid and compounds 1–5 (A–F). Data are expressed as the mean ± standard deviation (SD) from three independent experiments (n = 3).
3. Materials and Methods
3.1. General Experimental Procedures
HRESIMS data were recorded using a Thermo-Fisher LTQ-Orbitrap-LC-MS spectrometer (Thermo Fisher Scientific, Palo Alto, CA, USA). The 1D and 2D NMR data were recorded on a Bruker Avance 600 MHz spectrometer (Bruker, Karlsruhe, Germany) at room temperature, utilizing residual solvent signals for calibration (MeOD δH/δC 3.31/49.7; CDCl3: δH/δC 7.26/77.1). Optical rotations were acquired on an MCP300 polarimeterd (Anton Paar GmbH, Graz, Austria). Silica gel (200–300 mesh, Qingdao Marine Chemical Factory, Qingdao, China) and Sephadex LH-20 (Amersham Pharmacia, Stockholm, Sweden) were employed as stationary phases for column chromatographic purification. Compounds 1–5 were purified by semi-preparative HPLC on a Thermo Scientific Ultimate 3000 BioRS platform (Thermo Fisher Scientific, Germering, Germany) fitted with a Chiralcel AY-H column (5 μm, 4.6 × 250 mm; Daicel Chemical Industries, Tokyo, Japan).
3.2. Extraction and Isolation
The C. cicadae strain used in this study was sourced from Guangzhou Jinchanhua Technology Co. Ltd. (Guangzhou, China). After appropriate cultivation and grinding, a total of 15 kg of powder was obtained for subsequent research. The powder was divided into two 20 L glass vessels. Each portion was extracted successively with MeOH twice, CH2Cl2:MeOH (1:1, v/v) once, and n-BuOH once. Each extraction lasted for one week. All resulting solutions were combined, concentrated under reduced pressure, and then partitioned with ethyl acetate (EtOAc). The EtOAc phase was concentrated to yield the crude extract. The crude extracts were separated using gradient elution with a petroleum ether/EtOAc mixture (from 9:1 to 0:1, v/v) on silica gel column chromatography, resulting in 15 fractions (Fr.1–Fr.15). Fr.10 (1200 mg) was further purified on Sephadex LH-20 with a CH2Cl2/MeOH (1:1, v/v) solvent system, yielding fractions Fr.10.1 to Fr.10.10. From Fr.10.5 (150 mg), compounds 2 (4.8 mg), 3 (4.3 mg), and 4 (5.1 mg) were isolated after further purification using silica gel with a gradient of CH2Cl2/MeOH (200:1 to 50:1). Fr.12 (380 mg) was subjected to silica gel column chromatography with a CH2Cl2/MeOH gradient (100:1 to 20:1), resulting in fractions Fr.12.1–Fr.12.8. Fr.12.8 (30 mg) was then separated on Sephadex LH-20 (Amersham Pharmacia, Stockholm, Sweden) using CH2Cl2/MeOH (1:1), yielding compound 1 (7.8 mg) and compound 5 (4.2 mg).
Quercetin-3-O-β-D-methylglucopyranoside (1): Amorphous yellow oil; -24.7 (c 0.1, MeOH); UV (c 0.1, MeOH) λmax (log ɛ): 370 nm (+1.83), 256 nm (+1.56); IR (KBr) νmax: 3412, 1608, 1520, 1311, 1242, 1026, 821 cm−1; HRESIMS: m/z 479.1187 [M + H]+ (calcd: C22H23O12, 479.1184); 1H-NMR (MeOD-d4, 600 MHz); and 13C-NMR (MeOD-d4, 150 MHz) in Table 1.
Cicadae acid (5): Amorphous brown oil; -14.5 (c 0.1, MeOH); UV (c 0.1, MeOH) λmax (log ɛ): 210 nm (+2.23); IR (KBr) νmax: 3412, 3256, 2825, 1735, 1710 cm−1; HRESIMS: m/z 257.1358 [M + Na]+ (calcd: C10H18O6, 257.1354); 1H-NMR (MeOD-d4, 600 MHz); and 13C-NMR (MeOD-d4, 150 MHz) in Table 2.
3.3. Antithrombotic Activity
3.3.1. Chemical Treatment
The wild-type AB strain zebrafish was utilized in this study. Embryos were cultured in Holt buffer (3.5 g NaCl, 0.05 g KCl, 0.025 g NaHCO3, 0.1 g CaCl2 per litre of distilled water) and maintained in an incubator at 28.5 °C. At 72 h post-fertilization (hpf), embryos were selected and distributed into 12-well plates, with 20 embryos per well. They were then randomly allocated into four experimental groups: a blank control group (Holt buffer only), a thrombosis model group (80 μM AA, Aladdin, Shanghai, China; A295131), a positive control group (80 μM AA + 100 U/mL heparin), and chemical treatment groups (80 μM AA + 20 μM compounds 1–5). Embryos were pre-incubated with heparin or compounds 1–5 for 6 h in the positive control and chemical-treated groups, respectively, whereas the blank control and model groups received Holt buffer instead. Following this incubation, the solution was carefully removed, and all embryos were washed twice with Holt buffer. Subsequently, all groups except the blank control were exposed to 80 μM AA for 1 h in the dark to induce thrombosis. The entire experiment was independently replicated three times.
3.3.2. Erythrocyte Staining and Intensity Analysis
Following AA treatment, zebrafish embryos were subjected to O-dianisidine staining to visualize erythrocyte distribution, as previously described [31]. Stained embryos were randomly selected from each group and imaged using a microscope with Axiocam ERc 5s (Zeiss, Jena, Germany). The staining intensity of erythrocytes in both the heart and caudal vein was subsequently quantified using ImageJ software (version 1.53k, National Institutes of Health, Bethesda, MD, USA).
3.3.3. Statistical Analysis
Statistical analysis was performed using Graphpad Prism 8.3.0 software. Data were presented as the mean ± SD, and differences between the model group and other groups were determined by Student′ s t-test. A p-value of less than 0.05 was defined as statistically significant.
3.4. Antioxidant Activity Assays In Vitro
The DPPH· radical scavenging activities of compounds 1–5 were evaluated following a literature method using a 96-well microplate assay [32]. Test samples (1.5625–100 μM, 100 μL) were mixed with DPPH· solution in MeOH (0.16 mM, 100 μL), with ascorbic acid employed as the positive control. After incubation in the dark for 30 min, absorbance was recorded at 517 nm, and the scavenging activity was calculated accordingly.
DPPH· radical scavenging activity (%) = [(Abscontrol − Abssample)/(Abscontrol − Absblank)] × 100%
3.5. Preparation of MTPA Esters of Compound 5 by the Modified Mosher Ester Method
Compound 5 (1.0 mg) was derivatized with (S)-α-methoxy-α-(trifluoromethyl) phenylacetyl chloride [(S)-MTPA-Cl, 50 μL] in pyridine-d5 (500 μL) at room temperature for 12 h, affording the corresponding (S)-MTPA ester (5a, 0.853 mg, 85.3% yield). Under identical conditions, treatment with (R)-MTPA-Cl produced the (R)-MTPA ester (5b, 0.842 mg, 84.2% yield). The 1H NMR spectra of the (R)- and (S)-MTPA esters (Figures S13 and S14) were recorded on a Bruker Avance 600 MHz spectrometer (Bruker, Karlsruhe, Germany) at ambient temperature. Proton resonances were assigned on the basis of the 1H NMR data and used for calculation of the Δδ S−R values [33].
(S)-MTPA ester for 5a: 1H NMR (pyridine-d5, 600 MHz) δH 4.31 (H-2), 3.65 (H-5), 3.64 (H-5), 1.47 (H3-7), 1.26 (H3-8), 1.46 (H3-9), 1.45 (H3-10).
(R)-MTPA ester for 5b: 1H NMR (pyridine-d5, 600 MHz) δH 4.31 (H-2), 3.65 (H-5), 3.64 (H-5), 1.47 (H3-7), 1.26 (H3-8), 1.45 (H3-9), 1.44 (H3-10).
3.6. ECD and 13C NMR Calculation Computation Methods
Compound conformers were generated using Spartan 14 (Wavefunction, Irvine, CA, USA), and those with Boltzmann populations >1% were optimized at the B3LYP/6-31+G(d,p) level in methanol using DFT in Gaussian 09. The resulting 13C NMR and ECD spectra were simulated and processed with SpecDis 1.6 (University of Würzburg, Würzburg, Germany) [34].
4. Conclusions
In summary, one previously undescribed flavonoid, 3-O-β-D-methylglucopyranoside (1); three known flavonoids (2–4); and one new dicarboxylic acid derivative, cicadae acid (5), were isolated from the fungus C. cicadae. In the bioactivity assays, compounds 1–5 exhibited potent antithrombotic activity at a concentration of 20 μM in the zebrafish thrombosis model, marking the first documentation of such activity for flavonoids derived from C. cicadae. In addition, compounds 1–4 demonstrated significant antioxidant activity in the DPPH· radical scavenging assay, with IC50 values ranging from 12.81 ± 3.42 to 20.16 ± 2.84 μM. These findings expanded the chemical diversity of C. cicadae and confirmed its potential as a valuable source for bioactive compounds with dual antioxidant and antithrombotic activities. Moreover, this research confirmed that C. cicadae could be used as a dietary and health supplement.
Supplementary Materials
The following supporting information can be downloaded at https://www.mdpi.com/article/10.3390/molecules31030558/s1: Figure S1: HRESIMS spectrum of 1; Figure S2: 1H NMR spectrum of 1; Figure S3: 13C NMR spectrum of 1; Figure S4: HSQC spectrum of 1; Figure S5: 1H-1H COSY spectrum of 1; Figure S6: HMBC spectrum of 1; Figure S7: HRESIMS spectrum of 5; Figure S8: 1H NMR spectrum of 5; Figure S9: 13C NMR spectrum of 5; Figure S10: HSQC1 spectrum of 5; Figure S11: H-1H COSY spectrum of 5; Figure S12: HMBC spectrum of 5; Figure S13: 1H NMR spectrum of (R)-MTPA ester of 5; Figure S14: 1H NMR spectrum of (S)-MTPA ester of 5; and Figure S15: DP4+ analysis of compound 2R*5R*6R*-, 2R*5R*6S*-, 2R*5S*6R*-, and 2R*5S*6S*-5. References [24,25] are cited in the supplementary materials.
Author Contributions
X.H. and G.W. performed the experiment and prepared the manuscript; T.C., X.Z. and J.W. participated in the experiment; G.S., R.C. and Z.S. directed the experiment and revised the manuscript. All authors have read and agreed to the published version of the manuscript.
Funding
This research was funded by the National Natural Science Foundation of China grant number [42276114 and 42306131].
Institutional Review Board Statement
The animal study protocol was approved by the Shantou University Animal Experimentation Ethics Committee (protocol code STU20251201001 and date of approval: 1 December 2025).
Informed Consent Statement
Not applicable.
Data Availability Statement
The original contributions presented in this study are included in the article/Supplementary Material. Further inquiries can be directed to the corresponding authors.
Acknowledgments
The authors thank the South China Sea Institute of Oceanology, Chinese Academy of Sciences (SCSIO, CAS) for providing access to CD. The authors thank Wencong Yang from the Instrumental Analysis and Research Center of Sun Yat-Sen University for NMR measurements and structural analysis.
Conflicts of Interest
The authors declare no conflicts of interest.
References
- Li, I.; Lin, S.; Tsai, Y.; Hsu, J.; Chen, Y.; Lin, W.; Chen, C. Cordyceps cicadae Mycelia and Its Active Compound HEA Exert Beneficial Effects on Blood Glucose in Type 2 Diabetic Db/Db Mice. J. Sci. Food Agric. 2019, 99, 606–612. [Google Scholar] [CrossRef] [Scilit]
- Fan, W.; Zhang, S.; Zhang, Y. The Complete Mitochondrial Genome of the Chan-hua Fungus Isaria cicadae: A Tale of Intron Evolution in Cordycipitaceae. Environ. Microbiol. 2019, 21, 864–879. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Olatunji, O.J.; Feng, Y.; Olatunji, O.O.; Tang, J.; Ouyang, Z.; Su, Z.; Wang, D.; Yu, X. Neuroprotective Effects of Adenosine Isolated from Cordyceps cicadae against Oxidative and ER Stress Damages Induced by Glutamate in PC12 Cells. Environ. Toxicol. Pharmacol. 2016, 44, 53–61. [Google Scholar] [CrossRef] [Scilit]
- Traditional Chinese Medicine. In Chinese Materia Medica (Zhonghua Bencao); Shanghai Science and Technology Press: Shanghai, China, 1999; Volume 1, pp. 499–500.
- Ke, B.-J.; Lee, C.-L. Cordyceps Cicadae NTTU 868 Mycelium Prevents CCl 4 -Induced Hepatic Fibrosis in BALB/c Mice via Inhibiting the Expression of pro-Inflammatory and pro-Fibrotic Cytokines. J. Funct. Foods 2018, 43, 214–223. [Google Scholar] [CrossRef] [Scilit]
- Liu, T.; Liu, Z.; Yao, X.; Huang, Y.; Qu, Q.; Shi, X.; Zhang, H.; Shi, X. Identification of Cordycepin Biosynthesis-Related Genes through de Novo Transcriptome Assembly and Analysis in Cordyceps cicadae. R. Soc. Open Sci. 2018, 5, 181247. [Google Scholar] [CrossRef] [Scilit]
- Wang, J.; Zhang, D.-M.; Jia, J.-F.; Peng, Q.-L.; Tian, H.-Y.; Wang, L.; Ye, W.-C. Cyclodepsipeptides from the Ascocarps and Insect-Body Portions of Fungus Cordyceps cicadae. Fitoterapia 2014, 97, 23–27. [Google Scholar] [CrossRef] [Scilit]
- Nxumalo, W.; Elateeq, A.A.; Sun, Y. Can Cordyceps Cicadae Be Used as an Alternative to Cordyceps militaris and Cordyceps sinensis?–A Review. J. Ethnopharmacol. 2020, 257, 112879. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Sun, Y.; Wink, M.; Wang, P.; Lu, H.; Zhao, H.; Liu, H.; Wang, S.; Sun, Y.; Liang, Z. Biological Characteristics, Bioactive Components and Antineoplastic Properties of Sporoderm-Broken Spores from Wild Cordyceps Cicadae. Phytomedicine 2017, 36, 217–228. [Google Scholar] [CrossRef] [Scilit]
- Nakav, S.; Chaimovitz, C.; Sufaro, Y.; Lewis, E.C.; Shaked, G.; Czeiger, D.; Zlotnik, M.; Douvdevani, A. Anti-Inflammatory Preconditioning by Agonists of Adenosine A1 Receptor. PLoS ONE 2008, 3, e2107. [Google Scholar] [CrossRef] [Scilit]
- He, L.; Shi, W.; Liu, X.; Zhao, X.; Zhang, Z. Anticancer Action and Mechanism of Ergosterol Peroxide from Paecilomyces Cicadae Fermentation Broth. Int. J. Mol. Sci. 2018, 19, 3935. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Xin, S.; Zhang, M.; Li, P.; Wang, L.; Zhang, X.; Zhang, S.; Mu, Z.; Lin, H.; Li, X.; Liu, K. Marine-Fungus-Derived Natural Compound 4-Hydroxyphenylacetic Acid Induces Autophagy to Exert Antithrombotic Effects in Zebrafish. Mar. Drugs 2024, 22, 148. [Google Scholar] [CrossRef] [Scilit]
- Raskob, G.E.; Angchaisuksiri, P.; Blanco, A.N.; Buller, H.; Gallus, A.; Hunt, B.J.; Hylek, E.M.; Kakkar, A.; Konstantinides, S.V.; McCumber, M.; et al. Thrombosis: A Major Contributor to the Global Disease Burden. J. Thromb. Haemost. 2014, 12, 1580–1590. [Google Scholar] [CrossRef] [Scilit]
- Nakanishi, M.; Oota, E.; Soeda, T.; Masumo, K.; Tomita, Y.; Kato, T.; Imanishi, T. Emergency Cardiac Surgery and Heparin Resistance in a Patient with Essential Thrombocythemia. JA Clin. Rep. 2016, 2, 35. [Google Scholar] [CrossRef] [Scilit]
- Stupnisek, M.; Franjic, S.; Drmic, D.; Hrelec, M.; Kolenc, D.; Radic, B.; Bojic, D.; Vcev, A.; Seiwerth, S.; Sikiric, P. Pentadecapeptide BPC 157 Reduces Bleeding Time and Thrombocytopenia after Amputation in Rats Treated with Heparin, Warfarin or Aspirin. Thromb. Res. 2012, 129, 652–659. [Google Scholar] [CrossRef] [Scilit]
- Siddiqui, S.; Siddiqui, H.; Riguene, E.; Nomikos, M. Zebrafish: A Versatile and Powerful Model for Biomedical Research. BioEssays 2025, 47, e70080. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Griffin, M.S.; Dahlgren, A.R.; Nagaswami, C.; Litvinov, R.I.; Keeler, K.; Madenjian, C.; Fuentes, R.; Fish, R.J.; Neerman-Arbez, M.; Holinstat, M.; et al. Composition of Thrombi in Zebrafish: Similarities and Distinctions with Mammals. Thromb. Haemost. 2024, 22, 1056–1068. [Google Scholar] [CrossRef] [Scilit]
- Liang, Y.; Zhu, X. Analysis of Zebrafish Homologs within the Human Genome Provides Valuable Insights into Exploring Pan-Cancer Alternative Splicing Events as Prognostic Markers and Therapeutic Targets. Med. Omics 2025, 14, 100046. [Google Scholar] [CrossRef] [Scilit]
- Zhang, Y.; Guo, S.Y.; Zhu, X.Y.; Zhou, J.; Liao, W.; Zheng, G.L.; Zuguang, Y.; Li, C.Q. Arachidonic Acid Induced Thrombosis in Zebrafish Larvae for Assessing Human Anti-Thrombotic Drugs. JSM Cell. Dev. Biol. 2017, 5, 1023. [Google Scholar]
- Ahmedova, A.; Paradowska, K.; Wawer, I. 1H, 13C MAS NMR and DFT GIAO Study of Quercetin and Its Complex with Al(III) in Solid State. J. Inorg. Biochem. 2012, 110, 27–35. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Roslund, M.U.; Tähtinen, P.; Niemitz, M.; Sjöholm, R. Complete Assignments of the 1H and 13C Chemical Shifts and JH,H Coupling Constants in NMR Spectra of d-Glucopyranose and All d-Glucopyranosyl-d-Glucopyranosides. Carbohydr. Res. 2008, 343, 101–112. [Google Scholar] [CrossRef] [Scilit]
- Korytnyk, W. 129. Modification of Hudson’s Rules of Isorotation for Sugar Derivatives Containging Highly Polarisable Aglycones. J. Chem. Soc. 1959, 1959, 650–656. [Google Scholar] [CrossRef] [Scilit]
- Do, K.M.; Nakashima, Y.; Kodama, T.; Lee, Y.; Nguyen, H.M.; Ikumi, N.; Morita, H. Phenolic Derivatives with Anti-Acetylcholinesterase Inhibitory Activities from Galeola nudifolia in Vietnam. Chem. Biodivers. 2023, 20, e202301482. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Arthan, S.; Posri, P.; Walunchapruk, S.; Senawong, T.; Yenjai, C. Structural Modification of Olibergin A, an Isoflavonoid, from Dalbergia stipulacea Roxb. and Its Cytotoxicity. RSC Adv. 2022, 12, 17837–17845. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Zarev, Y.; Foubert, K.; Lucia De Almeida, V.; Anthonissen, R.; Elgorashi, E.; Apers, S.; Ionkova, I.; Verschaeve, L.; Pieters, L. Antigenotoxic Prenylated Flavonoids from Stem Bark of Erythrina latissima. Phytochemistry 2017, 141, 140–146. [Google Scholar] [CrossRef] [Scilit]
- Aly, A.H.; Edrada-Ebel, R.; Indriani, I.D.; Wray, V.; Müller, W.E.G.; Totzke, F.; Zirrgiebel, U.; Schächtele, C.; Kubbutat, M.H.G.; Lin, W.H.; et al. Cytotoxic Metabolites from the Fungal Endophyte Alternaria Sp. and Their Subsequent Detection in Its Host Plant Polygonum senegalense. J. Nat. Prod. 2008, 71, 972–980. [Google Scholar] [CrossRef] [Scilit]
- Hoye, T.R.; Jeffrey, C.S.; Shao, F. Mosher Ester Analysis for the Determination of Absolute Configuration of Stereogenic (Chiral) Carbinol Carbons. Nat. Protoc. 2007, 2, 2451–2458. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Shi, G.; Gu, Z.; He, K.; Wood, K.V.; Zeng, L.; Ye, Q.; MacDougal, J.M.; McLaughlin, J.L. Applying Mosher’s Method to Acetogenins Bearing Vicinal Diols. The Absolute Configurations of Muricatetrocin C and Rollidecins A and B, New Bioactive Acetogenins from Rollinia mucosa. Bioorg. Med. Chem. 1996, 4, 1281–1286. [Google Scholar] [CrossRef] [Scilit]
- Hogwood, J.; Mulloy, B.; Lever, R.; Gray, E.; Page, C.P. Pharmacology of Heparin and Related Drugs: An Update. Pharmacol. Rev. 2023, 75, 328–379. [Google Scholar] [CrossRef] [Scilit]
- Gao, H.; Liang, M.; Xiao, R.; Wei, H.; Li, W.; Yang, H.; Song, M.; Lei, X.; Zhang, N. Chemical Composition, Antioxidant Activity of Acanthopanax sessiliflorus Leaves Extract. Chem. Biodivers. 2025, 22, e202500231. [Google Scholar] [CrossRef] [Scilit]
- Paf, N.N.; Zon, L.I. Analysis of hematopoietic development in the zebrafish. Methods Mol Med. 2005, 105, 171–198. [Google Scholar] [CrossRef] [Scilit]
- Zou, G.; Tan, Q.; Chen, Y.; Yang, W.; Zang, Z.; Jiang, H.; Chen, S.; Wang, B.; She, Z. Furobenzotropolones A, B and 3-Hydroxyepicoccone B with Antioxidative Activity from Mangrove Endophytic Fungus Epicoccum nigrum MLY-3. Mar. Drugs 2021, 19, 395. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Diyabalanage, T.; Ratnayake, R.; Bokesch, H.R.; Ransom, T.T.; Henrich, C.J.; Beutler, J.A.; McMahon, J.B.; Gustafson, K.R. Flabelliferins A and B, Sesterterpenoids from the South Pacific Sponge Carteriospongia flabellifera. J. Nat. Prod. 2012, 75, 1490–1494. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Ke, T.-Y.; Wang, S.-W.; Lin, Z.-Y.; Ganesan, G.; Lai, C.-T.; Yen, J.-Y.; Chu, T.-H.; Lin, Y.-C.; Cheng, Y.-B. Polyketide Derivatives from the Macroalga-Associated Fungus Penicillium sclerotiorum Exhibiting Anti-Lymphangiogenic Effect. J. Nat. Prod. 2025, 88, 2757–2767. [Google Scholar] [CrossRef] [Scilit] [PubMed]
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