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Nauclea officinalis is a Chinese medicinal material with a high medicinal value, which contains various chemical constituents such as alkaloids, pentacyclic triterpenoids and their saponins, organic phenolic acids and their glycosides, iridoids, and flavonoids. It has antiviral, antibacterial, antipyretic, analgesic, anti-inflammatory, and immunoregulatory functions. This article systematically reviewed the reported chemical constituents and pharmacological effects of N. officinalis. According to the concept of quality markers, the quality markers of N. officinalis were predicted and analyzed from the aspects of plant kinship, specificity of chemical constituents, traditional drug efficacy, measurability of chemical constituents, plasma components, and different producing areas and harvest times, in order to provide a basis for the quality evaluation of N. officinalis.

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OBJECTIVE: To investigate the effects of Danmu Extract Syrup (DMS) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and explore the mechanism. METHODS: Seventy-two male Balb/C mice were randomly divided into 6 groups according to a random number table (n=12), including control (normal saline), LPS (5 mg/kg), LPS+DMS 2.5 mL/kg, LPS+DMS 5 mL/kg, LPS+DMS 10 mL/kg, and LPS+Dexamethasone (DXM, 5 mg/kg) groups. After pretreatment with DMS and DXM, the ALI mice model was induced by LPS, and the bronchoalveolar lavage fluid (BALF) were collected to determine protein concentration, cell counts and inflammatory cytokines. The lung tissues of mice were stained with hematoxylin-eosin, and the wet/dry weight ratio (W/D) of lung tissue was calculated. The levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-1 ß in BALF of mice were detected by enzyme linked immunosorbent assay. The expression levels of Claudin-5, vascular endothelial (VE)-cadherin, vascular endothelial growth factor (VEGF), phospho-protein kinase B (p-Akt) and Akt were detected by Western blot analysis. RESULTS: DMS pre-treatment significantly ameliorated lung histopathological changes. Compared with the LPS group, the W/D ratio and protein contents in BALF were obviously reduced after DMS pretreatment (P<0.05 or P<0.01). The number of cells in BALF and myeloperoxidase (MPO) activity decreased significantly after DMS pretreatment (P<0.05 or P<0.01). DMS pre-treatment decreased the levels of TNF-α, IL-6 and IL-1 ß (P<0.01). Meanwhile, DMS activated the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) pathway and reversed the expressions of Claudin-5, VE-cadherin and VEGF (P<0.01). CONCLUSIONS: DMS attenuated LPS-induced ALI in mice through repairing endothelial barrier. It might be a potential therapeutic drug for LPS-induced lung injury.

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Two new indole alkaloids, naucleamide H (1) and (±)-19-O-butylangustoline (8), along with seven known alkaloids, 3,14-dihydroangustine (2), (-)-naucleofficine D (3a), (+)-naucleofficine D (3b), nauclefine (4), angustidine (5),19-O-ethylangustoline (6) and angustine (7) were isolated from the water extract of Nauclea officinalis. The structures of these compounds were established by spectroscopic analysis. Among them, the cytotoxicity of 1, 2, 6 and 8 were evaluated against six human cancer cell lines (HepG-2, SKOV3, HeLa, SGC 7901, MCF-7 and KB) in vitro for the first time with 5-fluorouracil as a positive control drug. The new compound 1 had a strong inhibitory effect on the proliferation of HepG-2 with an IC50 value of 19.59 µg/mL. The new compound 8 had a strong inhibitory effect on HepG-2, SKOV3, HeLa, MCF-7 and KB, IC50 value was 5.530, 23.11, 31.30, 32.42 and 37.26 µg/mL, respectively.

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OBJECTIVE@#To investigate the effects of Danmu Extract Syrup (DMS) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and explore the mechanism.@*METHODS@#Seventy-two male Balb/C mice were randomly divided into 6 groups according to a random number table (n=12), including control (normal saline), LPS (5 mg/kg), LPS+DMS 2.5 mL/kg, LPS+DMS 5 mL/kg, LPS+DMS 10 mL/kg, and LPS+Dexamethasone (DXM, 5 mg/kg) groups. After pretreatment with DMS and DXM, the ALI mice model was induced by LPS, and the bronchoalveolar lavage fluid (BALF) were collected to determine protein concentration, cell counts and inflammatory cytokines. The lung tissues of mice were stained with hematoxylin-eosin, and the wet/dry weight ratio (W/D) of lung tissue was calculated. The levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-1 β in BALF of mice were detected by enzyme linked immunosorbent assay. The expression levels of Claudin-5, vascular endothelial (VE)-cadherin, vascular endothelial growth factor (VEGF), phospho-protein kinase B (p-Akt) and Akt were detected by Western blot analysis.@*RESULTS@#DMS pre-treatment significantly ameliorated lung histopathological changes. Compared with the LPS group, the W/D ratio and protein contents in BALF were obviously reduced after DMS pretreatment (P<0.05 or P<0.01). The number of cells in BALF and myeloperoxidase (MPO) activity decreased significantly after DMS pretreatment (P<0.05 or P<0.01). DMS pre-treatment decreased the levels of TNF-α, IL-6 and IL-1 β (P<0.01). Meanwhile, DMS activated the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) pathway and reversed the expressions of Claudin-5, VE-cadherin and VEGF (P<0.01).@*CONCLUSIONS@#DMS attenuated LPS-induced ALI in mice through repairing endothelial barrier. It might be a potential therapeutic drug for LPS-induced lung injury.

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The ethanol precipitation process of Nauclea officinalis extract was optimized based on the concept of quality by design(QbD). Single factor tests were carried out to determine the levels of test factors. The ethanol volume fraction, pre-ethanol precipitation drug concentration, and ethanol precipitation time were taken as critical process parameters(CPPs). With the comprehensive scores of strictosamide transfer rate and solid removal rate as the critical quality attributes(CQAs), Box-Behnken design was employed to establish the mathematical models and space design between CPPs and CQAs, and the obtained optimal operating space was validated. The optimal operating space included ethanol volume fraction of 65%-70%, pre-ethanol precipitation drug concentration of 22-27 mg·mL~(-1), and ethanol precipitation time of 12 h. Based on the concept of QbD, this study adopted the design space to optimize the ethanol precipitation process of N. officinalis extract, which provided a reliable theoretical basis for the quality control in the production process of N. officinalis preparations. Moroever, this study provided a reference value for guiding the research and industrial production of traditional Chinese medicines.

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The ethanol precipitation process of Nauclea officinalis extract was optimized based on the concept of quality by design(QbD). Single factor tests were carried out to determine the levels of test factors. The ethanol volume fraction, pre-ethanol precipitation drug concentration, and ethanol precipitation time were taken as critical process parameters(CPPs). With the comprehensive scores of strictosamide transfer rate and solid removal rate as the critical quality attributes(CQAs), Box-Behnken design was employed to establish the mathematical models and space design between CPPs and CQAs, and the obtained optimal operating space was validated. The optimal operating space included ethanol volume fraction of 65%-70%, pre-ethanol precipitation drug concentration of 22-27 mg·mL~(-1), and ethanol precipitation time of 12 h. Based on the concept of QbD, this study adopted the design space to optimize the ethanol precipitation process of N. officinalis extract, which provided a reliable theoretical basis for the quality control in the production process of N. officinalis preparations. Moroever, this study provided a reference value for guiding the research and industrial production of traditional Chinese medicines.

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Nauclea officinalis (N. officinalis), a medicinal plant of the genus Nauclea in the family Rubiaceae, is used in the treatment of fever, pneumonia, pharyngolaryngitis, and enteritis in China. Extracts of N. officinalis include alkaloids, phenolic acids, pentacyclic triterpenoids, and flavonoids, which exert all kinds of pharmacological effects, for instance anti-inflammatory, anti-tumor, antibacterial, and antiviral and therefore show good effectiveness. To gain a comprehensive and deep understanding, the medicinal chemistry and chemical biology of N. officinalis are summarized in this review to provide a theoretical basis. The pharmacological effects were reviewed to provide evidence or insights into potential opportunities for further studies and medicinal exploitation of N. officinalis.

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BACKGROUND: Acute lung injury (ALI) is a severe inflammatory disease, underscoring the urgent need for novel treatments. Nauclea officinalis Pierre ex Pitard (Danmu in Chinese, DM) is effective in treating inflammatory respiratory diseases. However, there is still no evidence of its protective effect against ALI. METHODS: Metabolomics was applied to identify the potential biomarkers and pathways in ALI treated with DM. Further, network pharmacology was introduced to predict the key targets of DM against ALI. Then, the potential pathways and key targets were further verified by immunohistochemistry and western blot assays. RESULTS: DM significantly improved lung histopathological characteristics and inflammatory response in LPS-induced ALI. Metabolomics analysis showed that 16 and 19 differential metabolites were identified in plasma and lung tissue, respectively, and most of these metabolites tended to recover after DM treatment. Network pharmacology analysis revealed that the PI3K/Akt pathway may be the main signaling pathway of DM against ALI. The integrated analysis of metabolomics and network pharmacology identified 10 key genes. These genes are closely related to inflammatory response and cell apoptosis of lipopolysaccharide (LPS)-induced ALI in mice. Furthermore, immunohistochemistry and western blot verified that DM could regulate inflammatory response and cell apoptosis by affecting the PI3K/Akt pathway, and expression changes in Bax and Bcl-2 were also triggered. CONCLUSION: This study first integrated metabolomics, network pharmacology and biological verification to investigate the potential mechanism of DM in treating ALI, which is related to the regulation of inflammatory response and cell apoptosis. And the integrated analysis can provide new strategies and ideas for the study of traditional Chinese medicines in the treatment of ALI.

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A pair of new diastereoisomers neolignans (1-2) and a new alkaloid (7) were isolated from the stems of Nauclea officinalis: naucleaoxyneolignoside A (1), naucleaoxyneolignoside B (2), (2S,3S)-javaniside (7), together with nine known compounds, 2S-3,3-di-(4-hydroxy-3-methoxyphenyl)-propane-1,2-diol (3), threo-1,2-bis-(4-hydroxy-3-methoxyphenyl)-propane-1,3-diol (4), nauclefine (5), angustidine (6), naucleoxoside A (8), naucleoxoside B (9), angustoline (10), (3S,19S)-3,14-dihydroangustoline (11), and (3S,19R)-3,14-dihydroangustoline (12).The structures of 1, 2 and 7 were elucidated by extensive spectroscopic methods and the known compounds were identified by comparison of their data with those reported in the literature. The absolution configurations of 1, 2, 7,11 and 12 were confirmed by the quantum chemical CD calculation method. Compounds 1-9 showed weak to moderate inhibitory activity on nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro with IC50 values comparable to that of dexamethasone. In addition, compounds 1-9 were evaluated for the antibacterial and cytotoxic effects, and the results revealed that these compounds showed no anti-bacterial activity, and compounds 3-6 showed modest cytotoxic activity.

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ETHNOPHARMACOLOGICAL RELEVANCE: Nauclea officinalis, a widely used Li medicine, has been used for the treatment of cold, fever, bronchitis, pneumonia, acute tonsillitis, and other ailments. Modern pharmacological studies have demonstrated that the most abundant and active components in N. officinalis are alkaloids, which possess various biological properties such as antibacterial and antitumor activities. AIM OF THE STUDY: To investigate the phytochemical profile of a selected group of alkaloids from the N. officinalis total alkaloids, and to determine the chemical profile of the alkaloids extracted from rat plasma. Further investigation was conducted to determine the pharmacokinetic behaviors of 11 selected major alkaloids, including pumiloside, naucleoxoside A, naucleoxoside B, nauclefine, angustidine, angustoline, (3S,19S)-3,14-dihydroangustoline,[α]D20: (-)191°, (3S,19R)-3,14-dihydroangustoline, [α]D20: (-) 294.7°, strictosamide, angustine, and 3,14-dihydroangustine. MATERIALS AND METHODS: N. officinalis total alkaloids were extracted with 79% ethanol and enriched with AB-8 macroporous resin. The phytochemical profile of alkaloids from the N. officinalis total alkaloids and the chemical profile of the alkaloids extracted from rat plasma were first analyzed by UPLC-Q-TOF-MS/MS. A simple, convenient, and sensitive LC-ESI-MS/MS method was subsequently developed and validated for the simultaneous determination of major active alkaloids in rat plasma after oral administration of N. officinalis total alkaloids. After addition of an internal standard (verapamil), plasma samples were pretreated first by protein precipitation with methanol and then underwent liquid-liquid extraction with ethyl acetate. Chromatographic separation was achieved using a Waters BEH C18 column (2.1 mm × 100 mm, 1.7 µm) at 30 °C, with gradient elution using a mobile phase consisting of 0.1% formic acid aqueous solution (A) and acetonitrile (B), a flow rate of 0.2 mL/min, and a total run time of 30 min. The detection was performed using an electrospray ionization triple quadrupole tandem mass spectrometer with multiple reaction monitoring and positive ionization mode. RESULTS: Based on the fragmentation patterns of 11 authentic alkaloids and previous reports, 55 alkaloids were identified or tentatively identified in the N. officinalis total alkaloids. Among them, 25 alkaloids were absorbed through the gastrointestinal tract in rats after administration of the N. officinalis total alkaloids. The 11 alkaloids were selected for quantitative analysis. The established quantitative method was fully validated and proved to be sensitive and specific. Satisfactory linearity of the 11 alkaloids obtained in the respective concentration ranges (r > 0.9931). The lower limits of quantification for strictosamide was 20.86 ng/ml, and the other ten alkaloids were all less than 4.47 ng/ml in rat plasma. The intra-and inter-day precision was less than 15% for all 11 alkaloids in terms of relative standard deviation, and the accuracies ranged from -11.4% to 11.1% in terms of relative error. Extraction recovery, matrix effect, and stability were within the required limits in rat plasma. CONCLUSION: The validated method was successfully applied to investigate the pharmacokinetics of the 11 alkaloids in rat plasma after oral administration of N. officinalis total alkaloids. Eleven alkaloids were rapidly absorbed to achieve a maximum plasma concentration with Tmax from 0.25 h to 1.5 h after oral administration. The pharmacokinetic parameters and plasma concentration-time profiles will prove valuable in pre-clinical and clinical investigations on the disposition of N. officinalis total alkaloids.

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The stems of Nauclea officinalis have been utilized as a crude drug in China, so other parts of the plant are abandoned, resulting in a waste of traditional Chinese medicine resources. To determine the distribution and content of the alkaloids, phenolic acids and iridoid in different organs (stem, branch, leaf and bark) of this plant, a reliable method has been established using LC-MS/MS. Nine constituents, namely strictosamide, vincosamide, chlorogenic acid, sweroside, naucleamide B, protocatechuic acid, pumiloside, vanillic acid and cryptochlorogenic acid, were simultaneously determined in 6 min. Meanwhile, the antipyretic, anti-inflammatory and analgesic activities were evaluated for comparative analysis of the pharmacological activity of different parts of N. officinalis. The results showed that the content of active components in other organs of N. officinalis was higher than that in stems, and the pharmacological effects of branches and leaves were also better. The established approach could be helpful for the quality control of N. officinalis, and also provide necessary information for the rational utilization of resources.

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A new indole alkaloid, namely naucleofficine H (1), was obtained from the aqueous extract of Nauclea officinalis, together with four known alkaloids, vincosamide (2), strictosamide (3), angustoline (4) and pumiloside (5). Their structures were characterized by analyzing their physicochemical data including NMR, and HRMS. In addition, five compounds were tested for their proliferation activities. The expression of vascular endothelial growth factor (VEGF), extra-cellular signal-regulated protein kinase 1 and 2 (ERK) and phosphorylation of ERK 1/2 (p-ERK) were also detected in HUVEC treated withbioactive compounds using western blotting. The result showed that these compounds could promote HUVEC cell proliferation. Compounds 3 and 5 could up-regulate VEGF and p-ERK in HUVEC.

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Naucleoffieine H, a natural indole alkaloid, was isolated and identified from Nauclea officinalis Pierrc ex Pitard which is a traditional Chinese medicine used for the treatment of various diseases, such as cold, fever, bronchitis, pneumonia, acute tonsillitis, etc. In the present study, the effect of naucleoffieine H on the anti-inflammatory activities was investigated in LPS-induced RAW 264.7 macrophages. The results showed that naucleoffieine H significantly inhibited the release of nitric oxide (the level of nitrite as a stable biomarker of NO production) and tumor necrosis factor-α (TNF-α). Interesting, naucleoffieine H down-regulated the overexpression of inflammatory protein induced nitric oxide synthase (iNOS), but no effect on the expression cyclooxygenase-2 (COX-2) protein. In addition, this bioactive alkaloid suppressed enzymatic activity of iNOS activated by LPS. The above results indicated that naucleoffieine H suppress NO and TNF-α overproduction via block the iNOS pathway in LPS-induced RAW 264.7 macrophages.

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A new indole alkaloid, 17-oxo-19-(Z)-naucline, and six known alkaloids 2-7 were isolated from the branches of Nauclea officinalis. The structure of the new compound 1 was characterised mainly by analysing its physical data including IR, 1 D, 2 D NMR, and HR-ESI-MS. Other compounds were identified by comparisons their data with those reported in the literature. Compound1, 4, 5, 6, 7 showed in vitro anti-inflammatory activity decrease the LPS-stimulated production of nitric oxide in RAW264.7 cell, while all compounds exhibited weak cytotoxicity against human tumour cell lines (LOVO, A549 and HepG2).

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Two new monoterpene indole alkaloids, naucleaoffines A (1) and B (2), together with six known alkaloids (3-8), were isolated from the stems and leaves of Nauclea officinalis. The structures of 1 and 2 were elucidated by extensive spectroscopic methods and the known compounds were identified by comparisons with the data reported in literature. All isolated compounds were evaluated for their anti-inflammatory activities and anti-HIV-1 activities. Compounds 1-8 exhibited significant inhibitory activities on nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro with IC50 values comparable to that of hydrocortisone. In addition, compounds 1-8 showed significant anti-HIV-1 activities with EC50 ranged from 0.06 to 2.08 µM. These findings suggest that the discoveries of these indole alkaloids with significant anti-inflammatory activities and anti-HIV-1 activities isolated from N. officinalis could be of great importance to the development of new anti-inflammatory and anti-HIV agents.

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OBJECTIVE： To establish HPLC fingerprints of Nauclea officinalis extract syrup， and to determine the contents of 9 components. METHODS： HPLC method was adopted. The determination was performed on Diamonsil C18（2）column with mobile phase consisted of acetonitrile-0.1％ phosphoric acid solution （gradient elution） at the flow rate of 1.0 mL/min. The detection wavelength was set at 240 nm， and column temperature was 30 ℃. The sample size was 10 μL. Using strictosamide as reference， HPLC chromatograms of 20 batches of N. officinalis extract syrup were drawn. The similarity of HPLC chromatograms were evaluated by using TCM Fingerprint Similarity Evaluation System （2004A edition） to confirm common peaks. The contents of 9 components were determined by standard curves. RESULTS： There were 26 common peaks in 20 batches of HPLC chromatograms， and the similarity was higher than 0.98. Compared with mixed control， 9 chemical components were identified， such as 3，4-dihydroxybenzoic acid， neochlorogenic acid， loganic acid， chlorogenic acid， cryptochlorogenic acid， swertioside， pumiloside， strictosamide and vincosamide. The linear range of 9 components were 17.24-275.84， 7.56-120.96， 15.40-246.40， 7.84-125.44， 8.64-138.24， 7.96-127.36， 8.40-134.40， 48.56-776.96， 4.16-66.56 μg/mL（all r≥0. 999）， respectively. The limits of detection were 0.043 1， 0.126 0， 0.038 5， 0.130 7， 0.144 0， 0.066 3， 0.070 0， 0.012 1， 0.052 0 μg/mL， respectively. The limits of quantitation were 0.215 5， 0.189 0， 0.077 0， 0.196 0， 0.288 0， 0.132 7， 0.105 0， 0.097 6， 0.138 7 μg/mL， respectively. RSDs of precision， stability and reproducibility tests were all lower than 2.0％ （n＝6）. Average recoveries were 99.6％、106.3％、100.1％、102.0％、98.4％、100.0％、99.3％、100.6％ and 101.2％， and RSDs were 1.20％、0.24％、0.59％、1.00％、0.73％、1.30％、1.10％、1.80％、1.90％（n＝6）. CONCLUSIONS： Established HPLC fingerprints and quantitative determination method of N. officinalis extract syrup are accurate， specific and sensitive. It can provides reference for quality control of N. officinalis extract syrup.

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A new indole alkaloid, 17-O-methyl-19-(Z)-naucline (1), together with seven known alkaloids (2-8), were isolated from the stems and leaves of Nauclea officinalis. The structure of 1 was elucidated by extensive spectroscopic methods and the known compounds were identified by comparisons their data with those reported in the literature. 17-O-methyl-19-(Z)-naucline (1) showed significant inhibitory activity on nitric oxide production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro with an IC50 value of 3.6 µM.

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OBJECTIVE:To establish the quality standard for the leaves of Nauclea officinalis. METHODS:Microscopic identi-fication and TLC methods were used for qualitative identification of N. officinalis. The moisture and ash of medicinal materials were determined. HPLC method was adopted to determine the content of strictosamide in medicinal materials. The determination was per-formed on Lichrospher C18 column with mobile phase consisted of acetonitrile-0.1% phosphoric acid solution(gradient elution)at the flow rate of 1 mL/min,injection volume was 10 μL. The detection wavelength was set at 226 nm,and the column temperature was 30 ℃. RESULTS:Microscopic identification of the leaves of N. officinalis had strong characteristics,and TLC sports were clear and well-separated without interference from negative control. The linear range of strictosamide were 0.0105-0.21 mg/mL(r=0.9995);RSDs of precision,stability and reproducibility tests were all lower than 2.0%. Average recoveries were 96.25-101.82%(RSD=1.86%,n=9). Total ash of medicinal materials was 5.27%-6.44%,acid insoluble ash was 0.23%-0.36%,water content was 9.48%-11.46%,strictosamide was 0.124%-1.003%. CONCLUSIONS:Established standard can be used for quality evaluation of N. officinalis.

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Objective: To study the chemical constituents from stems and leaves of Nauclea officinalis. Methods: The chemical constituents from N. officinalis were separated and purified by silica gel, ODS, Sephadex LH-20 gel column chromatographies, and preparative HPLC. Their structures were identified by physicochemical properties, spectroscopic analysis, as well as comparisons with the data in literature. Results: Eighteen compounds were isolated from 85% ethanol extract from N. officinalis, and identified as dihydroactinidiolide (1), loliolide (2), 3,4,5-trimethoxyphenol (3), 4-hydroxy-3,5-dimethoxybenzaldehyde (4), methyl-2,4-dihydroxy- 3,6-dimethyl-benzoate (5), p-methoxy cinnamic acid (6), caffeic acid methyl ester (7), ethyl caffeate (8), methyl isoferulate (9), ethyl ferulate (10), secoxyloganin (11), secologanoside (12), 1H-indole-3-aldehyde (13), 1,2,3,4-tetrahydronorharman-1-one (14), vinmajine I (15), 19-O-methyl-3,14-dihydroangustoline (16), naucleidinal (17), and strictosamide (18). Conclusion: Compounds 1-15 were isolated from the genus Nauclea Linn. for the first time.

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Three new indole alkaloids, named naucleamide G (1), and nauclealomide B and C (5 and 6), were isolated from the n-BuOH-soluble fraction of an EtOH extract of the leaves of Nauclea officinalis, together with three known alkaloids, paratunamide C (2), paratunamide D (3) and paratunamide A (4). The structures with absolute configurations of the new compounds were identified on the basis of 1D and 2D NMR, HRESIMS, acid hydrolysis and quantum chemical circular dichroism (CD) calculation. According to the structures of isolated indole alkaloids, their plausible biosynthetic pathway was deduced.

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