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.     

Synthesis of l-(4-2H)erythrose,l-)1-13C, 5-2H)arabinose and l-(2-13C, 5-2H)arabinose and identification of the intermediates by 2H and 13C-N.M.R. spectroscopy

l-(1-¹³C, 5-²H)Arabinose (6D) and l-(2-¹³C, 5-²H)arabinose (8D) have been synthesized by degradation of 2,3-O-isopropylidene-α-l-rhamnofuranose (2) to l-(4-²H)erythrose (5β,5αD), with subsequent chain elongation to 6D plus l-(1-¹³C, 5-²H)ribose (7D), the latter being converted into 8D. Intermediates were identified by complete assignment of the ¹³C chemical shifts employing carbon-carbon and carbon-deuterium coupling constants, deuteration shifts, differential isotope-shifts, and deuterium spectra. The anomeric carbon atoms of 2 and 2,3-O-isopropylidene-l-(1-²H) erythrose (4D) gave only single ¹³C resonances, suggesting that these two compounds exists in only one major anomeric configuration, clarifying previously reported work. The synthesis of 2,3-O-isopropylidene-l-(1-²H)rhmanitol (3D) facilitated the assignment of the signals in the ¹³C spectra of the nondeuterated analog. Specific deuterium-enrichment and the observed carbon-deuterium coupling (¹J_C,D ∼22 Hz) not only served to identify the deuterated carbon atom unambiguously in 3 but also permitted assignment of closely spaced resonances. The deuterium spectrum of 2,3-O-isopropylidene-l-(1-²H)erythrofuranose (4D) showed only a single resonance, indicating preponderance of one anomer, in accord with the observation of a single C-1 resonance in the ¹³C spectrum.     

Anti-inflammatory iridoid glycosides from fruits of Cornus officinalis

Three undescribed iridoid glycosides, cyc(7β-O-6′)-morroniside (1), 6′-methyl succinate-7β-O-methylmorroniside (2), and 7β-O-methyl phenyllactate morroniside (3) were isolated from 50% ethanol extract of Cornus officinalis fruits. The structures of the isolated compounds were determined by HRESIMS, ¹D NMR, ²D NMR, UV and IR spectroscopic methods. Compounds 1-3 exhibited moderate anti-inflammatory activities in vivo in a CuSO₄-induced zebrafish inflammation model (when evaluated at 50 μM).     

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.     

Two furanoxanthones from the bark of Cratoxylum cochinchinense

Two undescribed furanoxanthones, cratocochinones A (1) and B (2), along with eight known xanthones (3–10), were isolated from the bark of Cratoxylum cochinchinense. Their structures were elucidated using spectroscopic methods, mainly 1D and ²D NMR. The isolated compounds were investigated for α-glucosidase inhibitory activity. Seven compounds, 3-6 and 8-10, displayed stronger inhibitory effects than the positive control, acarbose. Especially, cochinxanthone A (6) showed remarkable inhibition with an IC₅₀ value of 59.6 μM, which was approximately 16-fold more potent than acarbose.     

Bioactive constituents from the leaves of Croton tiglium

Fifteen compounds, including five new phorbol esters (1-5) and ten known metabolites were isolated from the leaves of Croton tiglium. The structures of new compounds 1-5 were determined by comprehensive analysis of the HRESIMS, IR, 1D and 2D NMR spectral data. The isolates were assayed for their larvicidal and α-glucosidase inhibitory activity; results suggested the new compounds 1-4 possessed significant insecticidal activity, inhibiting the Plutella xylostella with LC₅₀ values ranging from 0.081 to 0.114 μg/mL, while the sesquiterpenoids 11 and 15 showed noticeable α-glucosidase inhibitory activity with IC₅₀ values of 11.27 and 8.13 μM, respectively.     

Ecdysteroids from the flowers of Aerva javanica

Four new ecdysteroids (1–4), along with three known steroids, β-ecdysone (5), 5-β-2-deoxyintegristerone A (6) and 24-epi-makisterone A (7) (Fig. 1), were isolated from the methanolic extract of the flowers of Aerva javanica by using normal and reverse phase chromatography. The structures of the new compounds (1–4) were determined due to 1D (¹H and ¹³C), 2D NMR (HSQC, HMBC, COSY, NOESY) techniques and high resolution mass spectrometry (HREIMS). The known compounds (5–7) were characterized based on the 1D NMR spectroscopy and mass spectrometry and by comparison with the literature values. All isolates were evaluated for their inhibitory activities against enzymes acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and lipoxygenase (LOX).     

Phenylpropanoid amides from Alisma orientalis and their protective effects against H2O2-induced damage in SH-SY5Y cells

Five new phenylpropanoid amides, including N-trans-feruloyl-N′-cis-feruloyl-cadaverine (1), N,N′-trans-diferuloyl-3-oxo-cadaverine (2), N-trans-feruloyl-N′-cis-feruloyl-3-hydroxy-cadaverine (3), N,N′-cis-diferuloyl-3-hydroxy-cadaverine (4), N-trans-p-coumaroyl-N′-trans-feruloyl-3-hydroxy-cadaverine (5), were isolated from Alisma orientalis together with four known analogues. Their structural elucidations were conducted by using 1D and 2D NMR and HRESIMS spectroscopic analyses. The isolated compounds were assayed for their inhibitory activities against HCE-2, anti-oxidant effects, and their protective effects on H₂O₂-induced damage in human dopaminergic neuroblastoma cells (SH-SY5Y). Compounds 3, 6, and 7 displayed moderate anti-oxidant activities with IC₅₀ values in the range of 36.9–40.7 μM. Compound 5 showed significant protective activity, while compounds 1, 2, 4, 7, and 8 showed moderate protective activities.     

Constituents of Desmodium salicifolium (Poir.) DC (Fabaceae) with antifungal activity

Phytochemical investigation of the roots of Desmodium salicifolium led to the isolation of two new compounds (Desmoflavanone A: 5,2',4'-trihydroxy-4'',4''-dimethyl-2H-dihydropyranoisoflavanone (1) and desmodioside A: (22R)-3β,22,23-trihydroxyolean-12-en-3-O-α- _L-rhamnopyranosyl-(1→2)-β-_D-glucopyranosyl-(1→2)-β-_D-glucuronopyranoside (2)) together with nine known secondary metabolites including kaikasaponin III (3), spinosin (4), isovitexin (5), β-sitosterol 3-O-β-_D-glucopyranoside (6), neorautenol (7), kaempferol (8), oleanolic acid (9), betulinic acid (10), and lupeol (11). The structures of these compounds were elucidated mainly by extensive spectroscopic analysis, particularly 1D and 2D NMR spectroscopy, electrospray ionization-mass spectrometry and by comparison of their spectroscopic data with those of related compounds reported in the literature. The methanolic extract, EtOAc and n-BuOH fractions as well as some isolated compounds were assessed for their antifungal activities against two fungi using microdilution method. The methanolic extract displayed weak activity against Candida albicans (MIC = 512 µg/mL). The EtOAc fraction also exhibited weak inhibitory effect with MIC of 256 µg/mL against Candida albicans and Candida glabrata. Compound 3 showed moderate effect against Candida glabrata with MIC value of 16 µg/mL while 1 was inactive against both fungi.     

Anti-inflammatory activity of flavonoids from Chrozophora tinctoria

Chemical investigation of Chrozophora tinctoria (L.) A. Juss. growing in Saudi Arabia revealed the isolation of two new acylated flavonoids identified as acacetin-7-O-β-d-[α-l-rhamnosyl(1 → 6)]3″-E-p-coumaroyl glucopyranoside (4) and apigenin-7-O-(6″-Z-p-coumaroyl)-β-d-glucopyranoside (5), in addition to amentoflavone (1), apigenin-7-O-β-d-glucopyranoside (2), apigenin-7-O-6″-E-p-coumaroyl-β-d-glucopyranoside (3) and rutin (6). The structures of isolated compounds were established by 1D, 2D NMR and HRESIMS spectral data, in addition to comparison with literature data. The anti-inflammatory activities of isolated compounds were assessed by measuring the levels of IL-1β, IL-6, TNF-α and PGE₂ in the supernatant media of human peripheral blood mononuclear cells (PBMCs) stimulated by phytohaemagglutinin (PHA). At a concentration of 100 μM, compounds 1, 2, 4 and 6 significantly decreased Il-1β, Il-6 and PGE₂ to nearly normal values. All tested compounds caused a dose-dependent decrease in TNF-α level but failed to reach that of the control values.     

Flavonoid glycosides and triterpenoids from Atractylis flava

Two new flavonoid glycosides, together with twelve known compounds including seven flavonoids and five triterpenoids were isolated from the whole plant Atractylis flava Desf. The structures of new compounds have been elucidated as 6-hydroxykaempferol 6-methyl ether 7-O-β-glucopyranuronoside (1) and isorhamnetin 3-O-[(6″′-O-E-feruloyl)-β-d-glucopyranosyl-(1 → 2)]-β-d-galactopyranoside (2) named Atraflavoside A and B successively, on the basis of physical and spectroscopic analysis, including 1D and 2D NMR (¹H, ¹³C, COSY, TOCSY, HSQC, HMBC and NOESY) and mass spectrometry (HRESIMS) whereas those of the known compounds (3–14) were established by spectral comparison with those published in the literature.     

COX-1/COX-2 inhibition activities and molecular docking study of newly designed and synthesized pyrrolo[3,4-c]pyrrole Mannich bases

In the present paper we describe the biological activity of newly designed and synthesized series of pyrrolo[3,4-c]pyrrole Mannich bases (7a-n). The Mannich bases were obtained in good yields by one-pot, three-component condensation of pyrrolo[3,4–c]pyrrole scaffold (6a-c) with secondary amines and an excess of formaldehyde solution in C₂H₅OH. The chemical structures of the compounds were characterized by ¹H NMR, ¹³C NMR, FT-IR, and elemental analysis. Moreover, single crystal X-ray diffraction has been recorded for compound 7l. All synthesized derivatives were investigated for their potencies to inhibit COX-1 and COX-2 enzymes by colorimetric inhibitor screening assay. In order to analyse the intermolecular interactions between the ligands and cyclooxygenase, experimental data were supported with the results of molecular docking simulations. According to the results, all of the tested compounds inhibited the activity of COX-1 and COX-2.     

Anticancer and antifungal activity of copper(II) complexes of quinolin-2(1H)-one-derived Schiff bases

The condensation of substituted aromatic aldehydes with 7-amino-4-methyl-quinolin-2(1H)-one (1) has lead to the isolation of quinolin-2(1H)-one derived Schiff bases (2-14). The copper(II) complexes (2a-14a) of the ligands were also prepared, and together with their corresponding free ligands were fully characterised by elemental analyses, spectral methods (IR, ¹H and ¹³C NMR, AAS, UV-Vis), magnetic and conductance measurements. The bidentate ligands coordinated to the copper(II) ion through the deprotonated phenolic oxygen and the azomethine nitrogen of the ligands in almost all cases. X-ray crystal structures of two of the complexes, 5a and 8a, confirmed the bidentate coordination mode. All of the compounds were investigated for their antimicrobial activities against the fungus, Candida albicans, and against Gram-positive and Gram-negative bacteria. The compounds were found to have excellent anti-Candida activity but were inactive against Staphylococcus aureus and Escherichia coli. Selected compounds (2-8 and 2a-8a) were also screened for their in vitro anticancer potential using the human hepatic carcinoma cell line, Hep-G₂. Several derivatives were shown to be active comparable to that of cisplatin.     

Alkenylresorcinols and cytotoxic activity of the constituents isolated from Labisia pumila

Phytochemical investigation on the leaves of Labisia pumila (Myrsinaceae), an important medicinal herb in Malaysia, has led to the isolation of 1-O-methyl-6-acetoxy-5-(pentadec-10Z-enyl)resorcinol (1), labisiaquinone A (2) and labisiaquinone B (3). Along with these, 16 known compounds including 1-O-methyl-6-acetoxy-5-pentadecylresorcinol (4), 5-(pentadec-10Z-enyl)resorcinol (5), 5-(pentadecyl)resorcinol (6), (−)-loliolide (7), stigmasterol (8), 4-hydroxyphenylethylamine (9), 3,4,5-trihydroxybenzoic acid (10), 3,4-dihydroxybenzoic acid (11), (+)-catechin (12), (−)-epicatechin (13), kaempferol-3-O-α-rhamnopyranosyl-7-O-β-glycopyranoside (14), kaempferol-4′-O-β-glycopyranoside (15), quercetin-3-O-α-rhamnopyranoside (16), kaempferol-3-O-α-rhamnopyranoside (17), (9Z,12Z)-octadeca-9,12-dienoic acid (18) and stigmasterol-3-O-β-glycopyranoside (19) were also isolated. The structures of these compounds were established on the basis of 1D and 2D NMR spectroscopy techniques (¹H, ¹³C, COSY, HSQC, NOESY and HMBC experiments), mass spectrometry and chemical derivatization. Among the constituents tested 1 and 4 exhibited strongest cytotoxic activity against the PC3, HCT116 and MCF-7 cell lines (IC₅₀ values ⩽10 μM), and they showed selectivity towards the first two-cell lines relative to the last one.     

Three new cucurbitane triterpenoids from Hemsleya penxianensis and their cytotoxic activities

Two new cucurbitane glycosides, hemslepenside A (1) and 16,25-O-diacetyl-cucurbitacin F-2-O-β-d-glucopyranoside (3), one new cucurbitacin, 16-O-acetyl-cucurbitacin F (2), along with three known cucurbitane compounds, were isolated from the roots of Hemsleya penxianensis. The structures of 1–6 were established on the basis of extensive spectroscopic and chemical methods. The isolated compounds were evaluated for their cytotoxic activities against different three human cancer cell lines, with IC₅₀ values in the low microgram range.     

Isolation and characterization of the chemical constituents from Plumeria rubra

Rubranonoside (=7-O-α-l-rhamnopyranosyl-4′-O-β-d-glucopyranosylnaringenin; (1), a new flavanone glycoside, rubranin (=(2S,3S,4R)-2-{[(2R,16E)-2-hydroxyhexaeico-16-en]amino}octadecane-1,3,4-triol-1-O-β-d-glucopyranoside; (2), a new sphingolipid, rubradoid (plumieridine-1-O-β-d-galactopyranoside; (3), a new iridoid galactoside, rubrajaleelol (4) and rubrajaleelic acid (5), two new nor-terpenoids together with known iridoids: 1-α-plumieride (6), plumieride p-Z-coumarate (7) and plumieride-p-E-coumarate (8) have been isolated from the EtOAc-soluble fraction of the MeOH extract of Plumeria rubra. Their structures were assigned from ¹H, ¹³C NMR spectra and 2D NMR analyses (COSY, NOESY, HMQC and HMBC experiments) in combination with HRMS experiments and comparison with literature data of related compounds. All the isolates (1–8) were tested for their antioxidant, antiurease, cytotoxic and phytotoxic activities and were found almost inactive.     

Assembly of three novel 2D frameworks with helical chains based on [H2W12O40] clusters and lanthanide - Organic complexes

Three novel polyoxotungstate-based rare earth compounds, [(C₆H₅NO₂)Ln(H₂O)₅]₂[H₂W₁₂O₄₀] · nH₂O (Ln = Ce³⁺ (1), Pr³⁺(2), n = 7; Nd³⁺ (3), n = 6), have been synthesized in aqueous solution and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectra and TG analysis. The structural feature of compounds 1-3 is that the α-metatungstate cluster [H₂W₁₂O₄₀]⁶⁻ anions are linked by the lanthanide (Ln) cation-organic coordination complexes, resulting in a two-dimensional (2D) structure with helical chains. The magnetic properties of compounds 1 and 2 have been studied by measuring their magnetic susceptibility in the temperature range 2-300 K, indicating the existence of spin-orbital coupling interactions and antiferromagnetic response. Furthermore, the electrochemical properties of 1-3 were studied.     

Antidiabetic triterpenoids from the leaves of Paeonia suffruticosa and Paeonia delavayi

Three new nor-oleanane triterpenoids, paeonenoides I-K (1-3), together with 13 known triterpenoids including nor-oleanane, oleanane, ursane, and cycloartane types, were isolated from the leaves of Paeonia suffruticosa and P. delavayi. The structures of the new compounds were elucidated with the aid of HRESIMS, 1D and 2D NMR, IR, and [α]_D spectroscopic methods. Nine compounds (5-6, 8-11, 13-14 and 16) showed inhibition against PTP1B with IC₅₀ values ranging from 36.5 to 192.6 μM, six compounds (5-6, 8-10 and 14) exhibited inhibitory activity against GPa with IC₅₀ values ranging from 39.8 to 108.0 μM, and five compounds (1, 6, 10, 15 and 16) could significantly stimulate GLP-1 secretion by 100.2–313.4% (20 μM). Docking study demonstrated that compounds 5 and 6 strongly bonded with Gpa and PTP1B by salt bridges, hydrogen bonds and hydrophobic interactions, verifying the importance of carboxyl and hydroxyl groups. Especially, compounds 5 and 14 could simultaneously inhibit PTP1B and GPa with IC₅₀ values of 57.8, 47.9 μM and 39.8, 45.2 μM, and compounds 6 and 10 could stimulate GLP-1 secretion by 293.6% and 313.4% at 20 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.