New unsaturated fatty acid and other chemical constituents from the roots of Cola rostrata K. Schum. (Malvaceae)

Phytochemical investigation of the roots of Cola rostrata K. Schum. led to the isolation of a new unsaturated fatty acid, named rostratanic acid (1), together with fourteen known compounds, lignoceric acid, friedelan (7), friedelanone (8), bauerenol (3), lupeol (4), herranone (9), acotatarone A (11), betulinic acid (6), betulin (5), nonanedioc acid (2), arjunolic acid (10) stigmasterol, β−sitosterol, and β−sitosterol-3-O-β-D-glucopyranoside. The structure of the new compound as well as those of the known compounds were established by means of spectroscopic methods: NMR analysis (¹H and ¹³C NMR, ¹H–¹H–COSY, HSQC and HMBC) and high-resolution mass spectrometry (HR-ESI-MS), and by comparison with previously reported data. Two of those known compounds were modified chemically to afford three new derivatives. All those compounds were tested for their cytotoxic activity against the human cervix carcinoma KB-3-1 cells and their antibacterial activity against Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa and Staphylococcus aureus. Although the crude extract gave weak antibacterial activity, none of the isolated compounds showed antibacterial activity, and, only the prenylated derivative showed weak cytotoxicity. In addition, the chemotaxonomic significance of the species Cola rostrata is discussed.     

Bioactive styryllactones,two new naphthoquinones and one new styryllactone,and other constituents from Goniothalamus scortechinii

Two new naphthoquinones, goniothalaminone A (1) and B (2), and a new styryllactone, (?)-8-epi-9-deoxygoniopypyrone acetate (12) together with one known naphthoquinone (3), one known indolequinone (4), one known 1-azaanthraquinone (5), six known styryllactones (6–11) and one known sesquiterpene (13) were isolated from the roots and leaves of Goniothalamus scortechinii. The structures of the new compounds were elucidated by spectroscopic analysis and of the known compounds by comparison of their physical, UV, IR, ¹H and ¹³C NMR data with those of published compounds. Antiplasmodial, antimycobacterial and cytotoxic activities of the styryllactones were evaluated. Compounds 6–10 exhibited cytotoxic against human cancer cell lines, KB, BC and NCI-H187 with IC₅₀ values ranging from 0.13 to 11.7 μg/ml.     

Artostyracins A–C,three new isoprenylated 2-arylbenzofurans from Artocarpus styracifolius

Three new isoprenylated 2-arylbenzofurans, namely artostyracins A–C (1–3, resp.), together with a known one (4), were isolated from the root of Artocarpus styracifolius Pierre. Their structures were determined by spectroscopic methods (1D and 2D NMR, UV, IR, and HR-ESI-MS). All of the compounds were evaluated for the anti-respiratory burst properties using a cellular model reproduced by chemical stimulation of rat neutrophils. Compounds 1 and 3 offered the potently inhibitory effects on respiratory burst of rat neutrophils with IC₅₀ values of 1.42 and 1.91 μM, while compounds 2 and 4 revealed moderate suppression activity with IC₅₀ values of 11.56 and 46.91 μM.     

Three new compounds from the bark of Antiaris toxicaria

Three new compounds, namely (+)-pranferol (1), antiarone M (2), and anticerol A (3), together with 9 known compounds, were obtained from the bark of Antiaris toxicaria. Their chemical structures were elucidated on the basis of spectroscopic methods including UV, IR, (HR) ESI–MS, ¹H, ¹³C NMR, HSQC, ¹H-¹H COSY, HMBC and X-ray crystallographic technique. The absolute configurations of compounds 1 and 2 were determined by modified mosher method and CD spectrum.     

Three new monoterpene glucosides and one new sorbitol ester identified from Sibiraea angustata with hypolipidemic activities in HepG2 cells

Three new monoterpene glycosides, sibiraglycoside L (1), M (2), N (3) and one new sorbitol ester, resibirate (4), together with four known compounds including caffeic acid glucitol ester (5), sibiscolacton C (6), geraniol-1-O-[α-l-rhamnopyranosyl-(1 → 6)-1-β-d-glucopyranoside] (7), and sibiraglycoside K (8), respectively, were isolated from an aqueous extract of the aerial portion of Sibiraea angustata. Their structures were elucidated on the basis of extensive spectroscopic data analysis (including ¹³CNMR,¹HNMR, HSQC, HMBC,¹H-¹H COSY, ROESY, HRESIMS, MS and CD experiments) and comparison to previously reported data. In addition, a preliminary evaluation of the hypolipidemic activities of these compounds is presented, some compounds showed moderate hypolipidemic activities in HepG2 cells.     

Isoprenylated chromones from the stems of Harrisonia perforata

Three new isoprenylated chromones, named harriforatins A−C (1−3), along with 13 known compounds (4−16) were isolated from the stems of Harrisonia perforata. Their planar structures were elucidated by spectroscopic measurements. The experimental and calculated ECD curves were used to determine their absolute configurations. Most isolated compounds were evaluated for inflammation inhibition against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 macrophages. Only compounds 5 and 6 showed inhibitory effects on NO production, with IC₅₀ values of 42.8 and 47.0 μM, respectively, that were stronger than that of the positive control, indomethacin (IC₅₀ = 68.6 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 new pyrrole derivatives isolated from Salacia amplifolia Merr

Two new pyrrole derivatives Salaciamole (1), Salaciaglycoside A (2), long with one known compound 1H-pyrrole-3-carboxylic acid (3) were isolated from the roots of Salacia amplifolia Merr (Hippocrateaceae). The structures of the new compounds were deduced from their comprehensive spectroscopic analysis including IR, HR-EI-MS, ¹H NMR, ¹³C NMR, DEPT, COSY, HMBC and HMQC. And the structure of the known compound was identified by comparison of their spectral data with those reported in the literature.     

Staphylopeptide A,a new cyclic tetrapeptide from culture broth of Staphylococcus sp.

Re-investigation of the culture broth of the marine bacterium Staphylococcus sp. (no. P-100826-4-6) afforded a new cyclic tetrapeptide namely staphylopeptide A (1), along with five known compounds, cyclo (l-prolyl-l-valine) (2), cyclo (l-prolyl-l-tyrosine), (3), cyclo (l-prolyl-l-alanine) (4), l-phenylalanine (5), and l-tryptophan (6). The structures of the isolated compounds were determined by extensive IR, 1D (¹H and ¹³C) and 2D (¹H-¹H COSY, HSQC, HMBC, and NOESY) NMR and HRFABMS spectral measurements. The antimicrobial activity of the isolated compounds (1–6) was evaluated.     

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).     

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.     

Five new iridoïd dimers from the fruits of Canthium subcordatum DC (syn. Psydrax subcordata DC)

Five new iridoid dimers, canthiumosides 1–5 (1–4 and 5a), together with nine known compounds, shanzhigenin methyl ester (6), 1-epishanzhigenin methyl ester (6′), linearin (7), 1-epilinearin (7′), mussaenoside (8), shanzhiside methyl ester (9), 3′,4′,7-trihydroxyflavone (10), betulinic acid (11), and oleanolic acid (12) were isolated from the fruits of Canthium subcordatum DC (Syn. Psydrax subcordata (DC) Bridson). The structures of these compounds were established by interpretation of their spectral data, mainly HR-TOFESIMS, 1D NMR (¹H, ¹³C and DEPT) and 2D NMR (¹H–¹H COSY, HSQC, HMBC, and NOESY), and by comparison with the literature.     

Two new cycloartane-type triterpenoids and one new flavanone from the leaves of Dasymaschalon dasymaschalum and their biological activity

Two new cycloartane-type triterpenoids, 3β-hydroxy-21-O-acetyl-24-methylenecycloartane (3) and 3β,21-dihydroxy-24,31-epoxy-24-methylenecycloartane (4), one new flavanone, 7-hydroxy-6,8-dimethoxyflavanone (5), two new natural products, 2-hydroxybenzyl benzoate (7) and 2-phenyl-2-acetoxyethyl benzoate (8), and ten known compounds, 3β-hydroxy-24-methylenecycloartane (1), 3β,21-dihydroxy-24-methylenecycloartane (2), desmosdumotin B (6), artabotrene (9), (?)-senepoxide (10), (+)-crotepoxide (11), (?)-1,6-desoxypipoxide (12), rotundol (13), cassipourol (14) and (+)-spathulenol (15) were isolated from the leaves of Dasymaschalon dasymaschalum. The structures of the new compounds were elucidated by spectroscopic analysis and of the known compounds by comparison of their physical, UV, IR, ¹H and ¹³C NMR data with those of published compounds. Antimycobacterial, antiplasmodial and cytotoxic activities of the isolates, except 8 and 10 were evaluated. Compounds 1, 4, 5, 11, 12 and 15 exhibited potent cytotoxic activities against human lung cancer cell lines (NCI-H187) with respective IC₅₀ values of 4.67, 7.82, 1.85, 6.33, 3.07 and 6.68 μg/mL.     

Isolation of two new phenolic compounds from the fruit of Chaenomeles speciosa (Sweet) Nakai

Phytochemical research on the anti-inflammatory activities of Chaenomeles speciosa (Sweet) Nakai (Rosaceae) to investigate the main components of 10% ethanol fraction of the crude extract of C. speciosa fruit in an attempt to find bioactive compounds or new compounds from this medicinal plant. The phytochemical investigation succeeded in isolating two new phenolic compounds, specpolyphenol A (1) and specphenoside A (2), together with three known phenyl glycosides (3–5) from the fraction. The structures of the new compounds were deduced from comprehensive spectroscopic analyses including IR, EI-MS, ¹H NMR, ¹³C NMR, DEPT, COSY, HMBC and HMQC. The structures of the three known compounds 3, 4 and 5 were identified by comparison of their spectral data with those reported in the literature.     

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.     

New purine alkaloids from the Red Sea marine tunicate Symplegma rubra

Investigation of the Red Sea marine tunicate Symplegma rubra Monniot, 1972 gave three new purine alkaloids namely 6-methoxy-7,9-dimethyl-8-oxoguanine (1), 6-methoxy-9-methyl-8-oxoguanine (2), and 2-methoxy-7-methyl-8-oxoadenine (4) together with seven known compounds: 6-methoxy-7-methyl-8-oxoguanine (3), 9-methyl-8-oxoadenine (5), 7-methyl-8-oxoadenine (6), 8-oxoadenine (7), 3-methylxanthine (8), inosine (9), and homarine (pyridinium-2-carboxylic acid-1-methyl) (10). Compound 6 was reported here for the first time from a natural source. The structure determination of the compounds was accomplished by extensive interpretation of their spectroscopic data including 1D (¹H and ¹³C) and 2D (¹H–¹H COSY, HSQC, and HMBC) NMR and high-resolution mass spectral data. The isolated compounds were evaluated for their protein kinase inhibitory activity against different kinases (CDK5, CK1, DyrK1A, and GSK3) at 10 μg/mL. The compounds showed moderate activity against these kinases.     

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.     

New flavonoids from the fruits of Cornus mas,Cornaceae

One new β-hydroxychalcone, 4-acetoxy-5,2′,4′,6′,β-pentahydroxy-3-methoxychalcone (1), one new flavanone, 7,3′-dihydroxy-5,4′-dimethoxyflavanone (2) and seven known compounds, 2R, 3R-trans-aromadendrin (3), naringenin-7-O-methylether (4), myricetin (5), quercetin-3-O-rutinoside (6), ursolic acid (7), gallic acid (8) and d-glucose (9) were isolated from the methanolic fruit extract of Cornus mas L. (=Cornus mascula L.), Cornaceae. The structures of the new compounds were elucidated on the basis of extensive spectroscopic methods, including 2D NMR experiments and of known compounds by comparison of physical and spectral data with literature.     

Brevistylumsides A and B,diterpene glycosides from Illicium brevistylum

A phytochemical investigation of 80% ethanol extract of Illicium brevistylum (Illiciaceae) resulted in the isolation of two new diterpene glycosides (1 and 2), together with three known diterpenes (3–5). The structures of the new compounds were deduced on the basis of comprehensive spectroscopic analysis including IR, HR-ESI–MS, ¹H NMR, ¹³C NMR, DEPT, COSY, HMBC and HSQC. The structures of known compounds 3–5 were identified by comparison of their spectral data with those reported in the literature.     

Terpenoids and other constituents from Euphorbia bupleuroides

The phytochemical investigation of the roots of Euphorbia bupleuroides Desf. (Euphorbiaceae) yielded three new compounds named 4,20-dideoxy(4α)phorbol-12-benzoate-13-isobutyrate (1), 25-hydroperoxycycloart-3β-ol (2), and 3β,7β-dihydroxy-4α,14α-dimethyl-8β,9β-epoxy-5α-ergosta-24(28)-ene (3), together with 17 known compounds 4–20. Their structures were established from analysis of 1D (¹H, ¹³C and DEPT) and 2D NMR (COSY, HSQC, HMBC and NOESY) data, and of mass spectrometry (HRESIMS), and by comparison with literature data.