Next Article in Journal
Pleurotus sajor-caju (Fr.) Singer β-1,3-Glucanoligosaccharide (Ps-GOS) Suppresses RANKL-Induced Osteoclast Differentiation and Function in Pre-Osteoclastic RAW 264.7 Cells by Inhibiting the RANK/NFκB/cFOS/NFATc1 Signalling Pathway
Previous Article in Journal
Strategies, Achievements, and Potential Challenges of Plant and Microbial Chassis in the Biosynthesis of Plant Secondary Metabolites
Previous Article in Special Issue
Protective Effect of Que Zui Tea on d-Galactose-Induced Oxidative Stress Damage in Mice via Regulating SIRT1/Nrf2 Signaling Pathway
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Molecules
Volume 29
Issue 9
10.3390/molecules29092112
molecules-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

A New Quinazolinone Alkaloid along with Known Compounds with Seed-Germination-Promoting Activity from Rhodiola tibetica Endophytic Fungus Penicillium sp. HJT-A-6

by
Dongliang Xiao
†,
Yan Wang
†,
Congcong Gao
,
Xuemei Zhang
,
Weixing Feng
,
Xuan Lu
* and
Baomin Feng
*
College of Life and Health, Dalian University, Dalian 116622, China
*
Authors to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Molecules 2024, 29(9), 2112; https://doi.org/10.3390/molecules29092112
Submission received: 12 April 2024 / Revised: 28 April 2024 / Accepted: 29 April 2024 / Published: 2 May 2024
(This article belongs to the Special Issue Isolation, Identification and Application of Biologically Active Natural Products—Second Edition)
Browse Figures
Versions Notes

Abstract

:
A new quinazolinone alkaloid named peniquinazolinone A (1), as well as eleven known compounds, 2-(2-hydroxy-3-phenylpropionamido)-N-methylbenzamide (2), viridicatin (3), viridicatol (4), (±)-cyclopeptin (5a/5b), dehydrocyclopeptin (6), cyclopenin (7), cyclopenol (8), methyl-indole-3-carboxylate (9), 2,5-dihydroxyphenyl acetate (10), methyl m-hydroxyphenylacetate (11), and conidiogenone B (12), were isolated from the endophytic Penicillium sp. HJT-A-6. The chemical structures of all the compounds were elucidated by comprehensive spectroscopic analysis, including 1D and 2D NMR and HRESIMS. The absolute configuration at C-13 of peniquinazolinone A (1) was established by applying the modified Mosher’s method. Compounds 2, 3, and 7 exhibited an optimal promoting effect on the seed germination of Rhodiola tibetica at a concentration of 0.01 mg/mL, while the optimal concentration for compounds 4 and 9 to promote Rhodiola tibetica seed germination was 0.001 mg/mL. Compound 12 showed optimal seed-germination-promoting activity at a concentration of 0.1 mg/mL. Compared with the positive drug 6-benzyladenine (6-BA), compounds 2, 3, 4, 7, 9, and 12 could extend the seed germination period of Rhodiola tibetica up to the 11th day.

Graphical Abstract

1. Introduction

Significant mutualistic relationships have been established between endophytic fungi and their host plants, attracting considerable attention due to their ecological and biotechnological potential [1]. Endophytic fungi can produce a variety of secondary metabolites on their own and can be involved in the biosynthesis and biotransformation of secondary metabolites in host plants, making them an important source of active natural products. Active natural products derived from endophytic fungi hold vast potential applications in biopharmaceuticals, agricultural production, and industrial fermentation [2,3,4,5]. Currently, the secondary metabolites isolated from endophytic fungi fermentation products include alkaloids, polyketides, terpenes, etc. [2,6], and some even possess activity in promoting seed germination [7].
Quinazolinones have great development prospects in medicinal chemistry [8], originating from a wide range of antibacterial [9], anti-inflammatory [10,11], antiviral [12,13], and antituberculosis [14] properties. So far, only a limited number of quinazolinones have been reported from endophytic fungi, including neosartoryadins and glyantrypines, antiviral agents from the mangrove-derived fungi Neosartorya udagawae and Cladosporium sp., respectively [15,16]; chaetominine, a cytotoxic agent from the endophytic fungus Chaetomium sp. [17]; aniquinazolines A–D, antibacterial and cytotoxic molecules from the mangrove-derived fungus Aspergillus nidulans [18]; and (–)-(1R,4R)-1,4-(2,3)-Indolmethane-1-methyl-2,4-dihydro-1H-pyrazino-[2,1-b]-quinazoline-3,6-dione, an antifungal agent from the endophytic fungus Penicillium vinaceum [19]. This denotes that endophytic fungi still represent an underexploited reservoir of novel bioactive quinazoline molecules.
Herein, as part of our ongoing studies on the bioactive secondary metabolites from Rhodiola tibetica endophytic fungi [20,21,22], we performed a Global Natural Products Social (GNPS) molecular networking analysis of the EtOAc extract of the endophytic fungus Penicillium sp. HJT-A-6. GNPS molecular networking has been widely applied in the analysis of natural products to cluster compounds with similar MS/MS spectra, expediting the dereplication process of known natural products [23,24,25]. The GNPS molecular networking analysis of the EtOAc extract led to the discovery of a new quinazolinone alkaloid, peniquinazolinone A (1), together with eleven known secondary metabolites (Figure 1). The seed-germination-promoting activities of the isolated compounds were also evaluated.

2. Results and Discussion

2.1. Molecular Networking-Guided Isolation Workflow

To target the isolation of the quinazolinone alkaloid, the crude EtOAc extract of Penicillium sp. HJT-A-6 was subjected to a full-scan HPLC-Q-TOF-MS/MS analysis. The obtained MS/MS data were used to generate the initial molecular network using the GNPS platform following the established protocol. This initial network was visualized and analyzed via Cytoscape 3.7.1 software.
As shown in Figure 2, the annotated nodes of the total secondary metabolites are displayed; the color of the node indicates the m/z of the parent ion. This process generated a network featuring 2373 nodes and 755 clusters; those representative highlighted clusters indicated several known natural products and a promising new compound. In cluster 1, highlighted in light red, the node m/z 276.062 was connected to the node m/z 260.069, which were supposed to be two known compounds, viridicatin (3) and viridicatol (4). Clusters 2 and 3, highlighted in light blue and light purple, respectively, were used to identify two classes of natural products, cyclopeptin analogues (5a/5b–7) and phenyl acetate derivates (10, 11). The orphan cluster 4 (m/z 247.144) in light green, which was not associated with any structurally known compound, indicates the presence of an unidentified compound. Thus, using m/z 247.144 as a guide, a new quinazolinone alkaloid, peniquinazolinone A (1), was isolated, along with known compounds 2–12.

2.2. Structure Elucidation of the Isolated Compounds

Compound 1 was obtained as a yellow oil. Its molecular formula was determined as C14H18N2O2 based on HRESIMS at m/z 269.1271 [M + Na]+ (calcd for 269.1266) (Figure S1), indicating seven degrees of unsaturation. The 1H NMR spectrum (Table 1 and Figure S3) revealed the resonances of four aromatic protons at δH 8.10 (d, J = 7.5 Hz, H-5), 7.77 (t, J = 7.5 Hz, H-3), 7.59 (d, J = 7.5 Hz, H-2), and 7.47 (d, J = 7.5 Hz, H-4), which indicated the presence of one 1,2-disubstituted phenyl group in 1; three methylene protons at δH 1.43–2.99; one oxygenated methine proton at δH 3.48 (m, H-13); and two methyl protons at δH 3.56 (s) and 0.90 (t, J = 7.5 Hz, H-15). The 13C NMR and HSQC spectra (Table 1 and Figures S6 and S7) of 1 displayed the presence of fourteen carbons, including one carbonyl carbon, seven aromatic/olefinic carbons, three methylenes, one oxygenated methine, and two methyls.
The planar structure of compound 1 was deduced by HMBC and 1H–1H COSY spectra (Figure 3 and Figures S8 and S9). The HMBC correlations from H-2 to C-6, from H-3 to C-1, from H-4 to C-6, from H-5 to C-3 and C-7, and from H-16 to C-7 and C-9 established the structural skeleton of quinazolinone. The proton spin systems of H-11/H-12/H-13/H-14/H-15 and H-13/13-OH, coupled with the HMBC correlations from H-11 to C-9, C-12, and C-13; from H-14 to C-13; and from H-15 to C-13 and C-14, confirmed the linkage of the quinazolinone group and the pentan-3-ol moiety at C-9. Consequently, the planar structure of compound 1 was constructed, named peniquinazolinone A.
The absolute configuration of C-13 was defined by the application of Mosher’s method. Compound 1 was reacted with both (R)-(–) and S-(+)-α-methoxy-α-(trifluoromethyl) phenylacetyl chlorides (MTPA-Cl) to afford the corresponding (S)- and (R)-Mosher esters (1a and 1b), respectively. The absolute configuration at C-13 in 1 was determined to be R by the observed chemical shift differences, Δδ(δS-δR) (Figure 4 and Figures S4 and S5).
The known compounds, 2-(2-hydroxy-3-phenylpropionamido)-N-methylbenzamide (2) [26], viridicatin (3) [27], viridicatol (4) [27], (±)-cyclopeptin (5a/5b) [28,29], dehydrocyclopeptin (6) [29], cyclopenin (7) [30], cyclopenol (8) [31], methyl-indole-3-carboxylate (9) [32], 2,5-dihydroxyphenyl acetate (10) [33], methyl m-hydroxyphenylacetate (11) [34], and conidiogenone B (12) [35], were identified based on their 1H NMR and 13C NMR spectra (Figures S12–S32) and compared with those reported in the previous literature.

2.3. Seed-Germination-Promoting Activity of the Isolated Compounds

Compounds 2, 3, 4, 7, 9, and 12 were tested for their seed-germination-promoting activity. As shown in Figure 5, compounds 2, 3, and 7 showed an optimal promoting effect on the seed germination of Rhodiola tibetica at a concentration of 0.01 mg/mL, with a germination rate of about 62%, 70%, and 62%, respectively, compared to the germination rate of about 52% of the positive drug 6-BA. Compounds 4 and 9 exhibited a germination rate of about 72% and 58%, respectively, at the optimal concentration of 0.001 mg/mL, indicating a negative correlation between concentration and germination rate. Compared with other tested compounds, compound 12 showed the best germination rate of about 62% at the same concentration level (0.1 mg/mL). In addition, compounds 2, 3, 4, 7, 9, and 12 could delay the seed germination of Rhodiola tibetica up to the 11th day, while the positive drug 6-BA only affected the seed germination process until the 9th day (Figure 6). Compounds 2, 3, 7, and 12 did not show concentration-dependent activity, which probably activated the upregulation of certain genes responsible for seed germination at concentrations ranging from 0.001 to 0.01 mg/mL. When the concentration exceeded a certain level, the expression levels of the genes responsible for seed germination decreased, hence not exhibiting concentration dependence. Additionally, the expression levels of certain genes responsible for seed germination were also influenced by the duration of time. Compound 12, however, exhibited the opposite behavior.
Compound 1 was not tested for its seed-germination-promoting activity due to the trace amount. Compound 2 is a structural analogue of compound 1, generated by the ring opening of the quinazoline moiety of compound 1; further seed germination assays of compound 1 may verify whether the existence of the quinazoline moiety affects its seed-germination-promoting activity.

3. Materials and Methods

3.1. General Experimental Procedures

The UV spectrum was recorded on a Jasco V-560 spectrophotometer (JASCO Corporation, Kyoto, Japan). Optical rotation was obtained on an Autopol IV Polarimeter (Rudolph Research Analytical, Flanders, NJ, USA). CD spectrum was acquired on a Jasco J-810-150S spectropolarimeter (JASCO Corporation, Japan). High-resolution electrospray ionization mass spectrometry (HRESIMS) data were collected on an AB Sciex Triple TOF 4600 mass spectrometer (AB SCIEX, Framingham, MA, USA). NMR spectra were recorded on a Bruker Avance II 500 MHz NMR spectrometer (Bruker, Karlsruhe, Germany) with tetramethylsilane (TMS) as an internal standard. Agilent 1260 Infinity (Agilent Technologies Inc., Santa Clara, CA, USA), Waters 2535 (Waters Corporation, Milford, MA, USA), and Shimadzu LC-20AR (Shimadzu Corporation, Kyoto, Japan) semi-preparative HPLC systems were created using a Welch Ultimate XB-C18 column (250 mm × 10.0 mm, 5 μm). Silica gel (100−200 mesh and 200−300 mesh, Qingdao Marine Chemical Ltd., Qingdao, China) and Sephadex LH-20 (GE Healthcare Bio-Sciences AB, Uppsala, Sweden) were used for column chromatography. The silica gel GF254 (Qingdao Marine Chemical Co., Ltd., Qingdao, China) was used for analytical and preparative thin-layer chromatography (TLC).

3.2. Fungal Material

The fungus strain Penicillium sp. HJT-A-6 was obtained from the stem of Rhodiola tibetica collected in Langkazi County, Shannan City, Tibet, China, in July 2021. It was identified based on its morphological characteristics and its sequence in the internal transcribed spacer (ITS) analysis of rDNA, and the BLAST search result showed that the sequence was the most similar (99%) to the sequence of Penicillium sp. (compared to MN634462.1). The sequence data of the fungus were submitted to the GenBank database, accession number: OR346333.1. The fungus was deposited in the College of Life and Health, Dalian University, Dalian, China.

3.3. Fermentation and Isolation

The fungal strain was cultured on an autoclaved rice medium (one hundred 500 mL Erlenmeyer flasks, each containing 80 g rice, 110 mL water) in the stationary phase at 28 °C for 40 days. After 40 days, the fermentation material was cut into small pieces and extracted with 95% EtOH three times. The extract was concentrated under reduced pressure to afford an aqueous solution and then partitioned with petroleum ether, EtOAc and n-BuOH to obtain the EtOAc-soluble extract (64 g). The extract was subjected to silica gel column chromatography with CH2Cl2/MeOH (100:0–0:100) to afford fourteen fractions (Fr. A–N).
Fr. B (10.5 g) was chromatographed on a silica gel column with gradient elution (PE/EtOAc, 5:1–1:2) to yield 8 subfractions (Fr. B1–Fr. B8). Fr. B5 was further purified by semi-preparative HPLC with MeOH/H2O (40:60, 0–35 min, 3 mL/min) to obtain compound 11 (1.6 mg, tR = 29 min).
Fr. C (6.3 g) was eluted with gradient petroleum (PE/EtOAc, 5:1–1:1) to afford 9 subfractions (Fr. C1–Fr. C9). Fr. C1 and Fr. C4 were subjected to the Sephadex LH-20 gel column and preparative TLC, respectively, to obtain compounds 3 (250 mg) and 12 (4.6 mg). Fr. C5 was chromatographed by the Sephadex LH-20 gel column using isocratic elution with CH2Cl2/MeOH (1:1), yielding Fr. C5b, which was purified by semi-preparative HPLC with CH3CN/H2O (30:70, 0–30 min, 3 mL/min) to give rise to compound 6 (13.6 mg, tR = 22 min). Fr. C7 was purified by semi-preparative HPLC with MeOH/H2O (60:40, 0–40 min, 3 mL/min) to obtain compound 7 (193 mg, tR = 14 min) and a mixture of 5a and 5b in a 1:1.7 molar ratio (13.8 mg, tR = 17 min). Fr. C8 was applied to the Sephadex LH-20 gel column with CH2Cl2/MeOH (1:1) to give rise to Fr. C8e, which was purified by semi-preparative HPLC with the gradient MeOH/H2O (20:80–60:40, 0–30 min, 3 mL/min) to obtain compound 9 (20 mg, tR = 25 min).
Fr. E (6.3 g) was chromatographed on a silica gel column with gradient elution (PE/EtOAc, 7:1–1:2), affording 20 fractions (Fr. E1–Fr. E20). Fr. E13 was purified by semi-preparative HPLC with the gradient MeOH/H2O (20:80–95:5, 0–40 min, 3 mL/min) to yield compound 1 (1.6 mg, tR = 26 min). Fr. E14 was purified by semi-preparative HPLC with MeOH/H2O (40:60, 0–40 min, 3 mL/min) to obtain compound 2 (3.4 mg, tR = 16 min) and compound 4 (120 mg, tR = 32 min). Fr. E16 was purified by semi-preparative HPLC with CH3CN/H2O (45:55, 0–25 min, 3 mL/min) to afford compound 8 (6 mg, tR = 12 min).
Fr. G (6.7g) was chromatographed on a silica gel column with gradient elution (PE/EtOAc, 10:1–1:1) to afford 5 subfractions (Fr. G1–Fr. G5). Fr. G4 was applied to the Sephadex LH-20 gel column with CH2Cl2/MeOH (1:1) to yield Fr. G4d, which was purified by semi-preparative HPLC with the gradient MeOH/H2O (20:80–95:5, 0–30 min, 3 mL/min) to obtain compound 10 (5.8 mg, tR = 10 min).
Peniquinazolinone A (1): yellow oil; [ α ] D 20 +20 (c 0.2, MeOH); UV (CH3OH) λmax (log ε) 223 (4.24), 267 (3.74) nm; ECD (CH3OH) λmax (Δε) 220 (–7.0) nm; 1H NMR (DMSO-d6, 500 MHz); and 13C NMR (DMSO-d6, 125 MHz) data (see Table 1); HRESIMS m/z 269.1271 [M + Na]+ (calculated for C14H18N2O2Na, 269.1266).

3.4. Mosher Esterification of Compound 1

Compound 1 (0.5 mg) was dissolved in 100 μL of CDCl3 in an NMR tube, and sequentially, 9 μL of pyridine and 15 μL of (R)-(–)-α-methoxy-α-(trifluoromethyl)phenylacetyl chloride ((R)-(–)-MTPA-Cl) were added. The mixture was stirred at room temperature for 1 h to afford the corresponding (S)-Mosher ester (1a) and subsequently diluted with 300 μL of CDCl3 to acquire a 1H NMR spectrum. The (R)-Mosher ester (1b) of 1 was prepared from (S)-(+)-MTPA-Cl using the same method.

3.5. Seed-Germination-Promoting Assay

Compounds 2, 3, 4, 7, 9, and 12 were dissolved in a 0.2% DMSO aqueous solution to yield a stock solution with a concentration of 0.06 mg/mL. Then, 5 µL, 50 µL, and 500 µL of compounds 2, 3, 4, 7, 9, and 12 were added to a 30 mm filter paper placed in a 6-well plate. After the evaporation of the solvent, the filter paper was immersed in 300 µL of distilled water, and then 20 seeds of Rhodiola tibetica were displayed in each 30 mm filter paper and incubated with a light–dark regime of 16:8 h at 20 °C for 7 days. The germination rate of the seeds was calculated after incubation. The experimental data were collected from three independent experiments. Further experiments on the relationship between the number of germinated seeds and germination time for compounds 2, 3, 4, 7, 9, and 12 were also conducted; the germination period was set up to 11 days.

4. Conclusions

In this work, the chemical investigation of the Rhodiola tibetica endophytic fungus Penicillium sp. HJT-A-6 led to the isolation and identification of a new quinazolinone alkaloid named peniquinazolinone A (1) and eleven known compounds. Compound 1 was identified through an extensive spectroscopic analysis and the modified Mosher’s method. Compounds 2, 3, and 7 showed an optimal promoting effect on the seed germination of Rhodiola tibetica at a concentration of 0.01 mg/mL. Compounds 4 and 9 had optimal seed-germination-promoting activity at a concentration of 0.001 mg/mL, while the optimal concentration for compound 12 to promote Rhodiola tibetica seed germination was 0.1 mg/mL. Additionally, all the tested compounds assuredly delayed the seed germination of the host plant. Furthermore, the mechanism of these known compounds with seed-germination-promoting activity will be investigated using biochemical and transcriptomic methods. These above results not only broadened the structural diversity of quinazoline metabolites derived from fungi but also provided data support for understanding the interactive relationship between endophytic fungi and host plants.

Supplementary Materials

The following supporting information can be downloaded at https://www.mdpi.com/article/10.3390/molecules29092112/s1: Figure S1: Positive-mode HRESIMS spectrum of 1; Figure S2: UV spectrum of 1; Figure S3: 1H NMR (DMSO-d6, 500 MHz) spectrum of 1; Figure S4: 1H NMR (DMSO-d6, 500 MHz) spectrum of 1a; Figure S5: 1H NMR (DMSO-d6, 500 MHz) spectrum of 1b; Figure S6: 13C NMR (DMSO-d6, 125 MHz) spectrum of 1; Figure S7: HSQC (DMSO-d6, 500 MHz) spectrum of 1; Figure S8: HMBC (DMSO-d6, 500 MHz) spectrum of 1; Figure S9: 1H-1H COSY (DMSO-d6, 500 MHz) spectrum of 1; Figure S10: NOESY (DMSO-d6, 500 MHz) spectrum of 1; Figure S11: CD spectrum of 1; Figure S12: 1H NMR (DMSO-d6, 500 MHz) spectrum of 2; Figure S13: 13C NMR (DMSO-d6, 125 MHz) spectrum of 2; Figure S14: 1H NMR (DMSO-d6, 500 MHz) spectrum of 3; Figure S15: 13C NMR (DMSO-d6, 125 MHz) spectrum of 3; Figure S16: 1H NMR (DMSO-d6, 500 MHz) spectrum of 4; Figure S17: 13C NMR (DMSO-d6, 125 MHz) spectrum of 4; Figure S18: 1H NMR (DMSO-d6, 500 MHz) spectrum of 5a/5b; Figure S19: 13C NMR (DMSO-d6, 125 MHz) spectrum of 5a/5b; Figure S20: 1H NMR (DMSO-d6, 500 MHz) spectrum of 6; Figure S21: 13C NMR (DMSO-d6, 125 MHz) spectrum of 6; Figure S22: 1H NMR (DMSO-d6, 500 MHz) spectrum of 7; Figure S23: 13C NMR (DMSO-d6, 125 MHz) spectrum of 7; Figure S24: 1H NMR (DMSO-d6, 500 MHz) spectrum of 8; Figure S25: 13C NMR (DMSO-d6, 125 MHz) spectrum of 8; Figure S26: 1H NMR (DMSO-d6, 500 MHz) spectrum of 9; Figure S27: 1H NMR (DMSO-d6, 500 MHz) spectrum of 10; Figure S28: 13C NMR (DMSO-d6, 125 MHz) spectrum of 10; Figure S29: 1H NMR (DMSO-d6, 500 MHz) spectrum of 11; Figure S30: 13C NMR (DMSO-d6, 125 MHz) spectrum of 11; Figure S31: 1H NMR (DMSO-d6, 500 MHz) spectrum of 12; Figure S32: 13C NMR (DMSO-d6, 125 MHz) spectrum of 12.

Author Contributions

Conceptualization, D.X., X.L. and B.F.; methodology, D.X., Y.W., X.L. and B.F.; validation, D.X., Y.W., X.L. and B.F.; formal analysis, D.X., X.L. and B.F.; investigation, D.X., Y.W., C.G., X.Z., W.F., X.L. and B.F.; resources, X.L. and B.F.; data curation, D.X., X.L. and B.F.; writing—original draft preparation, D.X. and Y.W.; writing—review and editing, D.X. and X.L.; visualization, X.L. and Y.W.; supervision, D.X., X.L. and B.F.; project administration, X.L. and B.F.; funding acquisition, D.X., C.G. and X.L. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by grants from the Dalian Science and Technology Innovation Fund Project (2022JJ12WZ059), the Dalian University Research Platform Project (202101YB08), and the Liaoning Provincial Department of Education Basic Scientific Research Project (JYTQN2023100, LJKFZ20220287).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Data are contained within the article and Supplementary Materials.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Kusari, S.; Spiteller, M. Are we ready for industrial production of bioactive plant secondary metabolites utilizing endophytes? Nat. Prod. Rep. 2011, 28, 1203–1207. [Google Scholar] [CrossRef] [PubMed]
  2. Zheng, R.H.; Li, S.J.; Zhang, X.; Zhao, C.Q. Biological activities of some new secondary metabolites isolated from endophytic fungi: A review study. Int. J. Mol. Sci. 2021, 22, 959. [Google Scholar] [CrossRef] [PubMed]
  3. Daley, S.K.; Cordell, G.A. Biologically significant and recently isolated alkaloids from endophytic fungi. J. Nat. Prod. 2021, 84, 871–897. [Google Scholar] [CrossRef]
  4. Strobel, G.; Daisy, B.; Castillo, U.; Harper, J. Natural products from endophytic microorganisms. J. Nat. Prod. 2004, 67, 257–268. [Google Scholar] [CrossRef]
  5. Zhao, Y.; Cui, J.; Liu, M.Y.J.; Zhao, L. Progress on terpenoids with biological activities produced by plant endophytic fungi in China between 2017 and 2019. Nat. Prod. Commun. 2020, 15, 1–18. [Google Scholar] [CrossRef]
  6. Ye, K.; Ai, H.L.; Liu, J.K. Identification and bioactivities of secondary metabolites derived from endophytic fungi isolated from ethnomedicinal plants of Tujia in Hubei province: A review. Nat. Prod. Bioprospect. 2021, 11, 185–205. [Google Scholar] [CrossRef]
  7. Bie, Q.; Chen, C.M.; Yu, M.Y.; Guo, J.R.; Wang, J.P.; Liu, J.J.; Zhou, Y.; Zhu, H.C.; Zhang, Y.H. Dongtingnoids A-G: Fusicoccane diterpenoids from a Penicillium species. J. Nat. Prod. 2019, 82, 80–86. [Google Scholar] [CrossRef]
  8. Jafari, E.; Khajouei, M.R.; Hassanzadeh, F.; Hakimelahi, G.H.; Khodarahmi, G.A. Quinazolinone and quinazoline derivatives: Recent structures with potent antimicrobial and cytotoxic activities. Res. Pharm. Sci. 2016, 11, 1–14. [Google Scholar] [PubMed]
  9. Habib, O.M.O.; Hassan, H.M.; El-Mekabaty, A. Novel quinazolinone derivatives: Synthesis and antimicrobial activity. Med. Chem. Res. 2013, 22, 507–519. [Google Scholar] [CrossRef]
  10. Manivannan, E.; Chaturvedi, S.C. Analogue-based design, synthesis and molecular docking analysis of 2,3-diaryl quinazolinones as non-ulcerogenic anti-inflammatory agents. Bioorg. Med. Chem. 2011, 19, 4520–4528. [Google Scholar] [CrossRef]
  11. Abdel-Aziz, A.A.; Abou-Zeid, L.A.; ElTahir, K.E.H.; Ayyad, R.R.; El-Sayed, M.A.; El-Azab, A.S. Synthesis, anti-inflammatory, analgesic, COX-1/2 inhibitory activities and molecular docking studies of substituted 2-mercapto-4(3H)-quinazolinones. Eur. J. Med. Chem. 2016, 121, 410–421. [Google Scholar] [CrossRef] [PubMed]
  12. Brown, C.E.; Kong, T.; McNulty, J.; D’Aiuto, L.; Williamson, K.; McClain, L.; Piazza, P.; Nimgaonkar, V.L. Discovery of potent antiviral (HSV-1) quinazolinones and initial structure-activity relationship studies. Bioorg. Med. Chem. Lett. 2017, 27, 4601–4605. [Google Scholar] [CrossRef] [PubMed]
  13. Wang, Z.W.; Wang, M.X.; Yao, X.; Li, Y.; Tan, J.; Wang, L.Z.; Qiao, W.T.; Geng, Y.Q.; Liu, Y.X.; Wang, Q.M. Design, synthesis and antiviral activity of novel quinazolinones. Eur. J. Med. Chem. 2012, 53, 275–282. [Google Scholar] [CrossRef] [PubMed]
  14. Zhu, S.R.; Wang, J.; Chandrashekar, G.; Smith, E.; Liu, X.J.; Zhang, Y.S. Synthesis and evaluation of 4-quinazolinone compounds as potential antimalarial agents. Eur. J. Med. Chem. 2010, 45, 3864–3869. [Google Scholar] [CrossRef] [PubMed]
  15. Yu, G.H.; Zhou, G.L.; Zhu, M.L.; Wang, W.; Zhu, T.J.; Gu, Q.Q.; Li, D.H. Neosartoryadins A and B, fumiquinazoline alkaloids from a mangrove-derived fungus Neosartorya udagawae HDN13-313. Org. Lett. 2016, 18, 244–247. [Google Scholar] [CrossRef] [PubMed]
  16. Peng, J.X.; Lin, T.; Wang, W.; Xin, Z.H.; Zhu, T.J.; Gu, Q.Q.; Li, D.H. Antiviral alkaloids produced by the mangrove-derived fungus Cladosporium sp. PJX-41. J. Nat. Prod. 2013, 76, 1133–1140. [Google Scholar] [CrossRef] [PubMed]
  17. Jiao, R.H.; Xu, S.; Liu, J.Y.; Ge, H.M.; Ding, H.; Xu, C.; Zhu, H.L.; Tan, R.X. Chaetominine, a cytotoxic alkaloid produced by endophytic Chaetomium sp. IFB-E015. Org. Lett. 2006, 8, 5709–5712. [Google Scholar] [CrossRef]
  18. An, C.Y.; Li, X.M.; Li, C.S.; Wang, M.H.; Xu, G.M.; Wang, B.G. Aniquinazolines A-D, four new quinazolinone alkaloids from marine-derived endophytic fungus Aspergillus nidulans. Mar. Drugs. 2013, 11, 2682–2694. [Google Scholar] [CrossRef] [PubMed]
  19. Zheng, C.J.; Li, L.; Zou, J.P.; Han, T.; Qin, L.P. Identification of a quinazoline alkaloid produced by Penicillium vinaceum, an endophytic fungus from Crocus sativus. Pharm. Biol. 2012, 50, 129–133. [Google Scholar] [CrossRef]
  20. Lu, X.; Tang, X.Y.; Wang, H.X.; Huang, W.J.; Feng, W.X.; Feng, B.M. Polyketone metabolites isolated from Rhodiola tibetica endophytic fungus Alternaria sp. HJT-Y7 and their SARS-CoV-2 virus inhibitory activities. Bioorg. Chem. 2021, 116, 105309. [Google Scholar] [CrossRef]
  21. Tang, X.Y.; Zhao, Y.X.; Wang, X.D.; Ye, C.T.; Feng, B.M.; Tang, C.; Lu, X. Polyketides with anti-inflammatory activity from Rhodiola tibetica endophytic fungus Alternaria sp. HJT-Y7. Phytochemistry 2022, 203, 113383. [Google Scholar] [CrossRef]
  22. Lu, X.; Qi, J.K.; Tang, X.Y.; Wang, X.D.; Ye, C.T.; Bai, J.; Tang, C.; Xi, Y.F.; Wu, B.; Wan, X.; et al. Polyketides with anti-inflammatory activity isolated from Rhodiola tibetica endophytic fungus Penicillium sp. HJT-A-10. Fitoterapia 2023, 164, 105361. [Google Scholar] [CrossRef]
  23. Gaudêncio, S.P.; Pereira, F. Dereplication: Racing to speed up the natural products discovery process. Nat. Prod. Rep. 2015, 32, 779–810. [Google Scholar] [CrossRef] [PubMed]
  24. Wang, M.; Carver, J.J.; Phelan, V.V.; Sanchez, L.M.; Garg, N.; Peng, Y.; Nguyen, D.D.; Watrous, J.; Kapono, C.A.; Luzzatto-Knaan, T.; et al. Sharing and community curation of mass spectrometry data with Global Natural Products Social Molecular Networking. Nat. Biotechnol. 2016, 34, 828–837. [Google Scholar] [CrossRef] [PubMed]
  25. Aron, A.T.; Gentry, E.C.; McPhail, K.L.; Nothias, L.F.; Nothias-Esposito, M.; Bouslimani, A.; Petras, D.; Gauglitz, J.M.; Sikora, N.; Vargas, F.; et al. Reproducible molecular networking of untargeted mass spectrometry data using GNPS. Nat. Protoc. 2020, 15, 1954–1991. [Google Scholar] [CrossRef] [PubMed]
  26. Smith, H.W.; Rapoport, H. Mechanism of the transformation of cyclopenin to viridicatin. J. Am. Chem. Soc. 1969, 91, 6083–6089. [Google Scholar] [CrossRef]
  27. Kobayashi, Y.; Harayama, T. A concise and versatile synthesis of viridicatin alkaloids from cyanoacetanilides. Org. Lett. 2009, 11, 1603–1606. [Google Scholar] [CrossRef]
  28. Zhang, C.C.; Ding, S.S.; Shi, W.S.; Cao, F.; Zhu, H.J.; Wen, M.L. A new quinolinone from freshwater lake-derived fungus Myrothecium verrucaria. Nat. Prod. Res. 2017, 31, 99–103. [Google Scholar] [CrossRef] [PubMed]
  29. Framm, J.; Nover, L.; El-Azzouny, A.; Richter, H.; Winter, K.; Werner, S.; Luckner, M. Cyclopeptin and dehydrocyclopeptin. Intermediates in the biosynthesis of cyclopeptin-viridicatin alkaloids in Penicillium cyclopium Westling. Eur. J. Biochem. 1973, 37, 78–85. [Google Scholar] [CrossRef] [PubMed]
  30. Hodge, R.P.; Harris, C.M.; Harris, T.M. Verrucofortine, a major metabolite of Penicillium verrucosum var. cyclopium, the fungus that produces the mycotoxin verrucosidin. J. Nat. Prod. 1988, 51, 66–73. [Google Scholar] [CrossRef]
  31. Cai, X.Y.; Wang, J.P.; Shu, Y.; Hu, J.T.; Sun, C.T.; Cai, L.; Ding, Z.T. A new cytotoxic indole alkaloid from the fungus Penicillium polonicum TY12. Nat. Prod. Res. 2022, 36, 2270–2276. [Google Scholar] [CrossRef]
  32. Bano, S.; Ahmad, V.U.; Perveen, S.; Bano, N.; Shafiuddin, S.; Shameel, M. Marine natural products; II. Chemical constituents of red alga Botryocladia leptopoda. Planta Medica 1987, 53, 117–118. [Google Scholar] [CrossRef]
  33. Tan, D.P.; Chou, G.; Wang, Z.T. Phenolic compounds from Senecio scandens. Biochem. Syst. Ecol. 2010, 38, 122–124. [Google Scholar] [CrossRef]
  34. Xu, L.; Wang, X.H.; Luo, R.Y.; Lu, S.Q.; Guo, Z.J.; Wang, M.A.; Zhou, L.G. Secondary metabolites of rice sheath blight pathogen Rhizoctonia solani Kühn and their biological activities. J. Integr. Agric. 2015, 14, 80–87. [Google Scholar] [CrossRef]
  35. Gao, S.S.; Li, X.M.; Zhang, Y.; Li, C.S.; Wang, B.G. Conidiogenones H and I, two new diterpenes of Cyclopiane class from a marine-derived endophytic fungus Penicillium chrysogenum QEN-24S. Chem. Biodivers. 2011, 8, 1748–1753. [Google Scholar] [CrossRef] [PubMed]
Molecules 29 02112 g001
Figure 1. Chemical structures of compounds 1–12.
Figure 1. Chemical structures of compounds 1–12.
Molecules 29 02112 g001
Molecules 29 02112 g002
Figure 2. Molecular networking-guided chemometric discovery of peniquinazolinone A (1) and several known compounds (3–7, 9, 10).
Figure 2. Molecular networking-guided chemometric discovery of peniquinazolinone A (1) and several known compounds (3–7, 9, 10).
Molecules 29 02112 g002
Molecules 29 02112 g003
Figure 3. Key 1H-1H COSY and HMBC correlations of 1.
Figure 3. Key 1H-1H COSY and HMBC correlations of 1.
Molecules 29 02112 g003
Molecules 29 02112 g004
Figure 4. ∆δ(δS−δR) values for MTPA esters of 1.
Figure 4. ∆δ(δS−δR) values for MTPA esters of 1.
Molecules 29 02112 g004
Molecules 29 02112 g005
Figure 5. Rhodiola tibetica seed germination rate of 2, 3, 4, 7, 9, and 12. Columns represent the mean ± SD; n = 3; *** p < 0.001, ** p < 0.01, and * p < 0.05 vs. the blank control water.
Figure 5. Rhodiola tibetica seed germination rate of 2, 3, 4, 7, 9, and 12. Columns represent the mean ± SD; n = 3; *** p < 0.001, ** p < 0.01, and * p < 0.05 vs. the blank control water.
Molecules 29 02112 g005
Molecules 29 02112 g006
Figure 6. Effects of all the tested compounds, 6-BA, and the blank control water on the seed germination period of Rhodiola tibetica.
Figure 6. Effects of all the tested compounds, 6-BA, and the blank control water on the seed germination period of Rhodiola tibetica.
Molecules 29 02112 g006
Table 1. 1H and 13C NMR data for compound 1 in DMSO-d6.
Table 1. 1H and 13C NMR data for compound 1 in DMSO-d6.
PositionδH (mult., J in Hz)δC, Type
1—147.4, C
27.59 (d, 7.5)127.1, C
37.77 (t, 7.5)134.6, C
47.47 (t, 7.5)126.6, C
58.10 (d, 7.5)126.6, C
6—120.2, C
7—161.9, C
8——
9—158.6, C
10——
112.99 (m)31.6, CH2
2.85 (m)
121.92 (m)33.7, CH2
1.73 (m)
133.48 (m)71.0, CH
141.43 (m)30.4, CH2
150.90 (t, 7.5)10.6, CH3
163.56 (s)30.4, CH3
13-OH4.57 (s)—
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Xiao, D.; Wang, Y.; Gao, C.; Zhang, X.; Feng, W.; Lu, X.; Feng, B. A New Quinazolinone Alkaloid along with Known Compounds with Seed-Germination-Promoting Activity from Rhodiola tibetica Endophytic Fungus Penicillium sp. HJT-A-6. Molecules 2024, 29, 2112. https://doi.org/10.3390/molecules29092112

AMA Style

Xiao D, Wang Y, Gao C, Zhang X, Feng W, Lu X, Feng B. A New Quinazolinone Alkaloid along with Known Compounds with Seed-Germination-Promoting Activity from Rhodiola tibetica Endophytic Fungus Penicillium sp. HJT-A-6. Molecules. 2024; 29(9):2112. https://doi.org/10.3390/molecules29092112

Chicago/Turabian Style

Xiao, Dongliang, Yan Wang, Congcong Gao, Xuemei Zhang, Weixing Feng, Xuan Lu, and Baomin Feng. 2024. "A New Quinazolinone Alkaloid along with Known Compounds with Seed-Germination-Promoting Activity from Rhodiola tibetica Endophytic Fungus Penicillium sp. HJT-A-6" Molecules 29, no. 9: 2112. https://doi.org/10.3390/molecules29092112

Article Metrics

Back to TopTop