Phenylpropanoids and triterpenoids from Tripterygium regelii and their anti-inflammatory activities

Two new compounds named cleroserroside C (1), schisphenlignan O (2), as well as twenty-one known compounds (3–23) were isolated from the roots of Tripterygium regelii. The structures of the new compounds were determined by 1D and ²D NMR spectra and HR-ESI-MS data. The known compounds were determined by comparing the ¹D NMR data in the literature. All compounds were evaluated for anti-inflammatory activity using the LPS-induced RAW264.7 inflammatory cell model, and the results showed that compounds 1, 8-11, 15-16, and 20-21 had good anti-inflammatory activity (IC₅₀ < 20 μM). The cytotoxicity of all compounds was tested by CCK-8 assay, using RAW264.7 cells. The results showed that all compounds had no cytotoxicity to RAW264.7 in the range of 0 ~ 200 μM.     

Inhibitory constituents of the heartwood of Dalbergia odorifera on nitric oxide production in RAW 264.7 macrophages

Two new isoflavanones (1 and 13), along with 25 known compounds (2–12, 14–27), were isolated from the EtOAc-soluble fraction of the heartwood of Dalbergia odorifera by following their potential to inhibit the LPS-induced nitric oxide production in RAW 264.7 cells. The structures of the isolated compounds were established by spectroscopic data such as ¹D, ²D NMR and MS spectrometry. Among the isolated compounds, (2S)-pinocembrin (26), showed the most potent inhibitory effect with IC₅₀ value of 18.1 μM.     

Chemical constituents of Chimaphila japonica Miq

A phytochemical study of the whole plants of Chimaphila japonica Miq. led to the isolation of 23 compounds, including ten triterpenoids (1–10), six flavonoids (11–16), two sterols (17 and 18), two quinonoids (19 and 20), one saccharide derivative (21), one phenolic glycoside (22), and one megastigmane glycoside (23). The structures of these isolated compounds were identified using NMR spectroscopy (¹H and ¹³C) by comparison with previously reported data. All compounds, except 19 and 22, were reported from C. japonica for the first time. Among them, 16 compounds (1–4, 6–9, 12, 13, 15, 16, 18, 20, 21, and 23) were reported from genus Chimaphila for the first time, while compounds 12, 16, and 23 were isolated from the Ericaceae family for the first time. The chemotaxonomic significance of the isolates was also discussed.     

Three new compounds isolated from the bulbs of Fritillaria pallidiflora Schrenk and their anti-inflammatory activity

Three new compounds, 17β-cevanin-6-oxo-5α,20β-diol yibeinine (1), 2-(tetrahydro-5-(2-hydroxyphenyl)-2H-pyran-3-yl) phenol (2), 1,3-O-diferuloyl-2-methoxypropane diol (3), as well as four known compounds (4–7), have been isolated from the ethanol extract of dried bulbs of Fritillaria pallidiflora Schrenk. All structures were determined based on their spectroscopic data (1D and 2D NMR (including ¹H NMR, ¹³C NMR, ¹H-¹H COSY, HMBC, HSQC, HSQC-TOCSY, and NOESY experiments), and MS). Biological evaluation showed that compounds 1–4 inhibited the production of nitric oxide (NO) in LPS-stimulated RAW 264.7 cells with IC₅₀ values of 18.0, 38.7, 29.5, and 47.1 μM, respectively. These results indicated that compound 1 has potential anti-inflammatory activity.     

New α-Glucosidase inhibitors from the resins of Boswellia species with structure–glucosidase activity and molecular docking studies

Phytochemical investigation of the oleo-gum resins from Boswellia papyrifera afforded one new triterpene, named 3α-hydroxyurs-5:19-diene (1) together with twelve known compounds including eight triterpenoids (2–9), two diterpenoids (10 and 11) and two straight chain alkanes (12 and 13). Similarly ten more known compounds were isolated from the resin of Boswellia sacra including one triterpene (20) and nine boswellic acids (14–19 and 21–23). Herein the compound 2 was first time reporting from natural source along with complete NMR assignment, while compounds 3–11 are known, but reported for the first time from the resin of B. papyrifera. The structure elucidation was done by advance spectroscopic ¹D and ²D NMR techniques viz., ¹H, ¹³C, DEPT, HSQC, HMBC, and COSY, and NEOSY, ESI-MS and compared with the reported literature. All compounds were evaluated for their α-glucosidase inhibitory activity and as result eight of them 1, 3, 10, 11, 15, and 17–19 were found significantly active against α-glucosidase with an IC₅₀ value ranging from 15.0 ± 0.84 to 80.3 ± 2.33 µM, while 21 exhibited moderate activity with IC₅₀ of 799.9 ± 4.98 µM. Furthermore, two compounds 24 and 25 were synthesised from 16 and 17 to see the effect of carboxyl group in structural-activity relationship (SAR) study. Compounds 24 and 25 retained good α-glucosidase inhibition as compared to 16 and 17, indicating that carboxylic group play a key role in SAR. In addition, the aforementioned activity of all the active compounds was first time reported for their α-glucosidase inhibition potential. The molecular docking studies showed that all the active compounds well accommodate in the active site of the enzyme. Moreover pharmacokinetic properties of the compounds were predicted in silico, suggesting that the compounds possess drug like properties and excellent ADMET profile.     

α-Glucosidase inhibitory constituents from Chrozophora plicata

Five new secondary metabolites have been isolated from Chrozophora plicata including an acacetin derivative (1), three pyrrole alkaloids plicatanins A–C (2–4, resp.) and the bilactone plicatanone (5). Together with these compounds, the known compounds, β-sitosterol (6), methyl p-coumarate (7), 4-hydroxyphenylacetic acid (8), succinic acid (9), speranberculatine A (10), β-sitosterol-3-O-β-d-glucopyranoside (11) and apigenin-5-O-β-d-glucopyranoside (12) have also been isolated. The structures of isolates 1–12 were established by 1D (¹H, ¹³C) and 2D NMR (HMQC, HMBC, COSY) spectroscopy and mass spectrometry (EIMS, HREIMS, FABMS, HRFABMS). The structure of plicatanin A (3) was further confirmed through single crystal X-ray technique. Compounds 1–12 were evaluated for their inhibitory activity against the enzyme yeast α-glucosidase. The compound 4 was found to be most potent with IC₅₀ value 27.8 μM.     

Xylarianins A-D from the endophytic fungus Xylaria sp. SYPF 8246 as natural inhibitors of human carboxylesterase 2

Eighteen secondary metabolites were isolated from the fermentation broth of the endophytic fungus Xylaria sp. SYPF 8246, including four new compounds, xylarianins A-D (1–4), three new natural products, 6-methoxycarbonyl-2′-methyl-3,5,4′,6′-tetramethoxy-diphenyl ether (5), 2-chlor-6-methoxycarbonyl-2′-rnethyl-3,5,4′,6′-tetramethoxy-diphenyl ether (6), and 2-chlor-4′-hydroxy-6-methoxy carbonyl-2′-methyl-3,5,6′-trimethoxy-diphenyl ether (7), and eleven known compounds (8–18). Their structural elucidations were conducted by using 1D and 2D NMR, HRESIMS, and Rh₂(OCOCF₃)₄-induced electronic circular dichroism (ECD) spectra analyses. The integrated ¹H and ¹³C NMR data of three new natural products 5–7 were reported for the first time. All the isolated compounds were assayed for their inhibitory activities against human carboxylesterase 2 (hCE 2). Compounds 1, 5–9, and 18 displayed significant inhibitory activities against hCE 2 with IC₅₀ values of 10.43 ± 0.51, 6.69 ± 0.85, 12.36 ± 1.27, 18.25 ± 1.78, 29.78 ± 0.48, 18.86 ± 1.87, and 20.72 ± 1.51 µM, respectively. The interactions between compounds 1 and 5 with hCE 2 were anaylzed by molecular docking.     

Compounds from the fruits of Nicandra physaloides and their potential anti-inflammatory activities

Twenty-one compounds were isolated and identified from the ethanol extract of the fruits of Nicandra physaloides, including four new (1–4) and 17 known compounds (5–21). All the compounds were isolated from the genus Physalis for the first time. In this study, NMR spectroscopy was used to study the compound structures by comparing their data with those reported in the literature. Moreover, the potential anti-inflammatory activity of RAW264.7 cells induced by lipopolysaccharide (LPS) was evaluated. Among the monoterpenoids, compounds (5–7, 9) exhibited weak anti-inflammatory activities, with IC₅₀ values ranging from 29.10 to 68.30 μM.     

Chemical constituents isolated from Valeriana officinalis L

Phytochemical investigations on the leaves of Valeriana officinalis L. led to the isolation of 18 compounds, including eight lignans (1–8), three sesquiterpenoids (9–11), five iridoids (12–16), and two aldehydes (17–18) The structure elucidation of isolated compounds was achieved on the basis of NMR and mass spectral data. Among them, three compounds (9–16, 18) are reported from V. officinalis for the first time and one compound (5) was isolated from the genus Valeriana for the first time. In addition, six compounds (2, 4, 6–8, 17) are isolated for the first time from Valerianaceae family. The chemotaxonomic significance of these isolated compounds has also been discussed.     

Chemical constituents from the pericarps of Zanthoxylum bungeanum and their chemotaxonomic significance

The phytochemical study of the pericarps of Zanthoxylum bungeanum Maxim under the guidance of bioactivity led to the isolation of 18 compounds, including a new isobutylhydroxyamide (1) and 17 known compounds, i.e. six alkylamides (2–7), five coumarins (8–12), one benzene derivative (13), three flavonoids (14–16), and two sterols (17–18). Their structures were elucidated based on extensive spectroscopic methods (HRESIMS, 1D and 2D NMR experiments) and by comparison with literature data. New compound (1) and known compound (2) are cis-trans isomeric isobutylhydroxyamides. Among them, compounds 9, 10, and 12 were isolated for the first time from Z. bungeanum, compound 11 was firstly recovered from the genus Zanthoxylum, and compound 14 was reported for the first time from the Rutaceae family. The chemotaxonomic significance of isolated compounds from Z. bungeanum is discussed.     

Bioactivity-guided isolation of chemical constituents against H2O2-induced neurotoxicity on PC12 from Cimicifuga dahurica (Turcz.) Maxim.

Three new compounds (1, 6, 9), with six known compounds (2–5, 7–8) were obtained from water-soluble extract of Cimicifuga dahurica (Turcz.) Maxim. by bioactivity-guided isolation. Their structures were elucidated by chemical and spectral analysis, including 1D, 2D NMR data and HRESIMS. H₂O₂-induced neurotoxicity on PC12 cells model were conducted to evaluate the neuro-protective capability of these compounds. The piscidic acid derivatives compounds 4–7 showed marked neuro-protective effect at certain concentration.     

Synthesis,state-of-the-art NMR-binding and molecular modeling study of new benzimidazole core derivatives as Pin1 inhibitors: Targeting breast cancer

New series of benzimidazole ring core conjugated with either dithiocarbamate or thiopropyl linkers, hybridized with different secondary amines were synthesized; 5–15 and 22–31; respectively. The new compounds were characterized by different spectroscopic techniques (¹H, ¹³C 1D & 2D NMR, ESI-MS and IR). They were screened for in vitro anticancer activity against breast cancer using MCF7 cell line. The results obtained revealed that compounds 5, 12, 15 and 25 were the most active among the synthesized series exhibiting IC₅₀ < 10 µg/ml against DOX. To characterize targeting breast cancer on molecular level, binding to ¹⁵N-labeled Pin1 enzyme was conducted using state-of-the-art 2D NMR binding experiments. Results showed promising binding between compounds 5, 12, and 25 by chemical shift perturbation (peak shifting or peak disappearance). Molecular docking study were quite valuable to explain the binding mode of active derivatives via hydrogen bonding. Additional contact preferences and surface mapping studies stated the similarity pattern between active candidates which may pave the way for more precise anti breast cancer target optimization.     

Triterpenes and triterpene glucosides with their oxidative stress injury protective activity from Rubus lambertianus

Two new 18,19-secoursane triterpenes and three triterpene glucosides, together with twelve known compounds, were isolated from the aerial parts of Rubus lambertianus Ser. The structures of the new compounds were determined by spectroscopic analyses (HR-ESI-MS, 1D/2D NMR). The protective effects of compounds 1–17 on high glucose-induced oxidative stress injury in human umbilical vein endothelial cells (HUVECs) were evaluated using cell viability assay. Compounds 1, 2, 7, 10, 12, 15 and 17 significantly attenuated high glucose-induced oxidative damage on HUVECs at the concentration of 3.10 μM.     

Cytotoxic and anti-angiogenic effects of lanostane triterpenoids from Ganoderma lucidum

Two new lanostane triterpenes, 3α,12β,15α-triacetoxy-5α-lanosta-7,9(11),24-trien-26-oic acid (1) and 5α-lanosta-8,24-diene-26,27-dihydroxy-3,7-dione (2), together with sixteen known compounds (3–18) were isolated from the fruiting bodies of the Vietnamese mushroom Ganoderma lucidum. Their chemical structures were determined by extensive spectroscopic (IR, HR-EI-MS, 1D and 2D NMR) analyses. Potential cytotoxic activities of these compounds were evaluated against human non-small cell lung adenocarcinoma (A549), breast adenocarcinoma (MCF-7), and prostatic small cell carcinoma (PC-3). Among the compounds, 3α,12β,15α-triacetoxy-5α-lanosta-7,9(11),24-trien-26-oic acid (1) showed significant cytotoxic activity against PC-3 cells with an IC₅₀ of 11.5 μM. In studies of anti-angiogenesis activity, ganoderic acid F (17) was found to have the most potent inhibitory effect on the formation of capillary-like structures of human umbilical vein endothelial cells.     

Chemical constituents from Baphia leptobotrys Harms (Fabaceae) and their chemophenetic significance

The chemical investigation of the CH₂Cl₂/MeOH (1:1) extract of the trunk bark and leaves of Baphia leptobotrys Harms (Fabaceae) led to the isolation of nineteen compounds (1–19). Their structures were elucidated based on the analysis of their NMR and MS data. Except for compounds 3–5, 14 and 15, all the isolated compounds are reported from the genus Baphia for the first time. Furthermore, compounds 8, 10, 16, 17 are isolated from the Fabaceae family for the first time. The crude extract and isolated compounds were screened in vitro for their antileishmanial activity against Leishmania donovani 1S (MHOM/SD/62/1S) promastigotes and cytotoxicity towards Raw 264.7 macrophage cells. The crude extract of B. leptobotrys exhibited moderate activity (IC₅₀ = 63.40 μg/mL). Amongst the tested compounds, ergosterol peroxide (9) and germanicol caffeoyl ester (8) exhibited good activity with IC₅₀ values of 9.43 and 10.24 μM, respectively and showed acceptable selectivity towards macrophage cells (SI > 3.85). The chemophenetic significance of these compounds is also discussed.     

Antimicrobial phenolic metabolites from the aerial parts of Orthosiphon aristatus

Two new compounds oraristatin A (1) and oraristatinoside A (2), one new natural compound (2 S)-methyl-6,7-dihydroxytropate (3), and 11 known phenolic metabolites were isolated from the aerial parts of Orthosiphon aristatus. Their chemical structures were identified by 1D- and ²D NMR and HRESIMS spectroscopic analyses. The absolute configurations of 1 and 3 were determined by TD-DFT ECD spectroscopic analyses. Of the isolates, compound 2 weakly inhibited both Gram-positive and -negative bacteria (MIC = 150–300 μM), while 6 and 7 suppressed the growth of three Gram-positive bacteria and a yeast (MIC = 75–150 μM). This is the first report of the isolation of 6 − 9, 12, and 14 from the genus Orthosiphon and the antimicrobial effects of compounds 3, 7, 9, 12, and 14.     

Inhibitory constituents from the aerial parts of Polygala tenuifolia on LPS-induced NO production in BV2 microglia cells

Five new phenolic glycosides, tenuisides A–E (1?5), and a new megastigmane glycoside, tenuiside F (6), along with seventeen known compounds (7–23) were isolated from the aerial parts of Polygala tenuifolia Willd. Their structures were established by detailed analysis of NMR and HRESIMS spectroscopic data, and the absolute configurations of compounds 5 and 6 were determined by CD spectra and in-NMR-tube Mosher’s method. The inhibitory effects of these compounds were evaluated on NO production in LPS-activated BV-2 microglia cells. Compound 17 showed the strongest activity, with an IC₅₀ value of 7.4 μM, while compounds 1, 8, 14, and 18 showed the moderate activities, with IC₅₀ values of 16.2–38.5 μM. And their primary structure–activity relationships (SARs) of NO inhibitory effects were also briefly discussed.     

Two new coumarins and a new xanthone from the leaves of Rhizophora mucronata

Two new coumarins (1, 2) and a new xanthone (3), together with 14 known compounds—eight coumarins (4, 5, 9, 10, 12–15), three xanthones (11, 16, 17), a benzoic acid (6) and two flavonones (7, 8)—were isolated from the leaves of Rhizophora mucronata. The structures of the compounds were elucidated by spectroscopic (IR, MS, and NMR) analyses. The isolated compounds were tested for cytotoxicity against human cancer cell lines HL-60 and HeLa. Among these compounds, only compound 16 inhibited the growth of both HeLa (IC₅₀?=?4.8?μM) and HL-60 (IC₅₀?=?1.0?μM) cells. Compounds 4, 7, 10, and 12 exhibited moderate activity against HeLa cells (IC₅₀?=?3.8–8.3?μM). Compounds 5, 9, 11, and 17 showed moderate activity against HL-60 cells (IC₅₀?=?2.2–6.3?μM). Higher selectivity against HL-60 cell lines was observed for compounds 5, 9, 11, and 16 with SI values (NIH 3T3/HL-60) of 8.6, 19.2, 9.4, and 10.2, respectively.     

Three new cytotoxic sesquiterpenoids from Solanum lyratum

In our continuing effort to discover more new cytotoxic sesquiterpenoid from Solanum lyratum collected from different districts of China, three new sesquiterpenoids, attributable to eudesmane-type (1, named solajiangxin D) and vetispirane-type (2–3, named solajiangxins E and 2-hydroxysolajiangxin E), respectively, were isolated. Their structures were elucidated on the basis of integrated spectroscopic techniques, mainly HR-FABMS, 1D and 2D NMR (¹H–¹H COSY, HMQC, HMBC and ROESY). In vitro, compounds 1–3 were found to show significant cytotoxicities against three human cancer lines (P-388, HONE-1, and HT-29), and gave ED₅₀ values in the range 2.1–3.7 μg/ml.