Chemical constituents from Cymbaria dahurica L. (Scrophulariaceae)

Phytochemical study of Cymbaria dahurica L. afforded 16 compounds, including 12 flavonoids (1–12) and 4 iridoids (13–16). Structure elucidation of these compounds was generated by a combination of spectroscopic means (ESI-MS, ¹H and ¹³C NMR) and comparisons with the published data. This is the first report of isolation of compounds (1–6, 10–16) from C. dahurica and compounds (5, 10, 12) from the family Scrophulariaceae, respectively. The chemotaxonomic data can support the genus Cymbaria being accepted as a member of transitional taxa between the family Scrophulariaceae and Orobanchaceae.     

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.     

Chemical constituents from the seeds of Raphanus sativus L. and their chemotaxonomic significance

The phytochemical investigations on the seeds of Raphanus sativus L. led to the isolation and identification of 15 compounds, including eleven sinapoyl derivatives (1–11), two terpenes (12–13), and two phenolic acids (14–15). All chemical structures were elucidated via ¹H NMR and ¹³C NMR spectroscopic methods, and further supported by comparison with literature data. Compound 11 was isolated from the genus Raphanus for the first time. Notably, Compounds 7, 9, and 12–14 were reported in the Brassicaceae family for the first time. The chemotaxonomic significance of these compounds is discussed.     

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.     

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.     

New sesquiterpenes from the endophyte Microdiplodia sp. TT-12 and their antimicrobial activity

Four new compounds, phomadecalin F (1), 8α-monoacetoxyphomadecalin D (2), 3-epi-phomadecalin D (3), and 13-hydroxylmacrophorin A (4), were isolated from the endophyte, Microdiplodia sp. TT-12 together with two known compounds, phomadecalins C (5) and D (6). The structures of the compounds were elucidated by NMR spectroscopic and mass spectrometric analyses in combination with chemical means. The antibacterial activities of the isolated compounds were evaluated. Compound 4 was weakly active against Raffaelea quercivora.     

Chemical constituents from the rhizome of Menispermum dauricum DC. and their chemotaxonomic significance

The phytochemical investigations on the rhizome of Menispermum dauricum DC. led to the isolation of 18 compounds, including eleven alkaloids (1–11), four amides (12–15) and three fatty acids (16–18). All chemical structures were established on the basis of NMR (¹H NMR and ¹³C NMR) spectroscopic data. Meanwhile, compounds 5–6, 9–10 and 13–18 are reported for the first time from Menispermum genus, as well as the rhizome of Menispermum dauricum DC. Notably, this is the first study to report compounds 10, 15–18 from the family Menispermaceae. These compounds laid the foundation for the chemical classification of this species.     

Chemical constituents from Phlomis bovei Noë and their chemotaxonomic significance

A phytochemical investigation of the leaves and roots of Phlomis bovei Noë (Lamiaceae) led to the isolation of sixteen compounds, including iridoids (1, 2, 3), megastigmanes (4, 5), phenylpropanoids (6, 7, 8, 9, 10), lignans (11, 12, 13, 14), a nortriterpene (15), and a phenyl glucoside (16). Compounds (1, 2, 4, 5, 6, 10) were obtained from the leaves and compounds (1, 2, 3, 7, 8, 9, 11, 12, 13, 14, 15, 16) were isolated from the roots. Compounds 1 and 2 were found both in the leaves and in roots.The compounds were identified by analysis of 1D- (¹H, ¹³C), 2D-NMR (¹H–¹H COSY, TOCSY, ROESY, HSQC, HMBC) spectroscopic data, mass spectrometry (ESI- and HR-ESI-MS), and by comparison with previously reported spectral data.Compounds 5, 9, 10, 13 and 14 were isolated from the genus Phlomis for the first time. All these specialized metabolites were described here for the first time in the Algerian Phlomis bovei Noë species. To the best of our knowledge, no reports have appeared on the constituents of the roots of P.bovei Noë. The chemotaxonomic significance of these compounds was summarized.     

New phenolic glycosides isolated from Penthorum chinense Pursh

A phytochemical investigation from 80% ethanol extract of Penthorum chinense Pursh (Saxifragaceae) resulted in the isolation of three new phenolic glycosides (1–3), together with three known phenolic glycosides (4–6). 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 structures of known compounds 4–6 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.     

Cytosporones,coumarins, and an alkaloid from the endophytic fungus Pestalotiopsis sp. isolated from the Chinese mangrove plant Rhizophora mucronata

Chemical examination of the endophytic fungus Pestalotiopsis sp., isolated from the leaves of the Chinese mangrove Rhizophora mucronata, yielded 11 new compounds including cytosporones J–N (1–3, 5–6), five new coumarins pestalasins A–E (8–12), and a new alkaloid named pestalotiopsoid A (14), along with the known compounds cytosporone C (4), dothiorelone B (7), and 3-hydroxymethyl-6,8-dimethoxycoumarin (13). The structures of the new compounds were unambiguously elucidated on the basis of extensive spectroscopic data analysis.     

Chemical constituents from Ficus natalensis hochst (Moraceae) and their chemophenetic significance

Phytochemical investigation of the stem bark of Ficus natalensis afforded eleven compounds including one ceramide (1), two anthraquinones (2, 3), four triterpenes (4–7), two polyols (8, 9) and two steroids (10, 11). The structures of the compounds were determined by spectroscopic analyses including IR, UV, MS, 1D- and 2D- NMR (¹H, ¹³C, ¹H–¹H COSY, HMQC, HMBC and NOESY), as well as by comparison with literature data. The antibacterial activity and the cytotoxicity of the extract, fractions and some isolated compounds (3, 5, 8 and 9) were evaluated. Some fractions and sub-fractions from various column chromatography displayed moderate antibacterial activity with diameter zone of inhibition (DZI) ranging from 7 to 10 mm. None of the compounds tested had activity. In the present study, all the compounds are isolated for the first time from the species F. natalensis. Compounds 2, 4–7, 10 and 11 were previously reported from the genus Ficus. The chemophenetic significance of the isolated compounds is discussed.     

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.     

Novel metabolites from the roots of Cadaba natalensis

From an extract of the roots of Cadaba natalensis Sond. the novel macrocyclic dibenzo-diazacyclododecanedione 1 was isolated together with (S)-2-ethyl-2-methyloxazolidin-5-one (2a). In addition, the five known compounds were obtained. Of these, (R)-5-ethyl-5-methyloxazolidin-2-one (3) is reported as a natural product for the first time. The structures of the isolated compounds were elucidated by analysis of the spectral data, 1D NMR (¹H, ¹³C, and DEPT), 2D NMR (COSY, HMQC, HMBC, and NOESY), and HRESIMS, as well as by the comparison with previously reported data.     

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.     

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.     

Investigation of chemical compounds from Chlamydomonas sp. KSF108 (Chlamydomonadaceae)

Nine compounds (1–9) including one norisoprenoid (1), one polyol-glycoside (2), three sterols (3–5), three phenols (6, 8, and 9), and one fatty acid (7) were isolated from Chlamydomonas sp. KSF108. Their chemical structures were established using NMR spectroscopic techniques and compared with published data. None of the compounds have been previously reported from the genus Chlamydomonas and they may therefore serve as chemotaxonomic markers for Chlamydomonas sp. KSF108 within the genus.     

Investigation of chemical constituents from Spiraea prunifolia var. simpliciflora and their biological activities

Quantum mechanics (QM)-based calculations for elucidating full structures of natural compounds are growing in importance and reliability. Two new phenolic glycosides (1 and 2) and 11 known compounds were isolated from the twigs of Spiraea prunifolia var. simpliciflora. The chemical structures of the new compounds (1 and 2) were initially established through different NMR techniques (¹H and ¹³C NMR, COSY, HSQC, and HMBC), HRMS data analysis, and chemical hydrolysis. These structure assignments were further verified by QM-based NMR chemical shift calculations. All of the purified compounds (1–13) were evaluated for their cytotoxicity against four human cancer cell lines (A549, SK-OV-3, SK-MEL-2, and BT549). Those phytochemicals were also evaluated for both anti-inflammatory activity through the measurement of nitric oxide (NO) production levels in lipopolysaccharide (LPS)-stimulated murine microglia BV-2 cell lines and neuroprotective effects via induction of nerve growth factor (NGF) in C6 glioma cells.     

A new sesquiterpenoid from Sclerorhachis platyrachis (Boiss.) Podlech ex Rech.f

A new eudesmane-type sesquiterpenoid together with two known flavonoids were isolated from the chloroform extract of the aerial part of Sclerorhachis platyrachis. The structure of the new compound was deduced from its comprehensive spectroscopic analysis including IR, EI-MS, ¹H NMR, ¹³C NMR, DEPT, COSY, HMBC and HMQC and was shown to be 4R^*-hydroxy-6S^*-tigloyloxyeudesma-7S^*-11 (13)-en-12-oic acid (1). Finally, the structure of the new compound was unambiguously confirmed by single-crystal X-ray analysis. The structure of known compounds 2 and 3 were identified by comparison of their spectral data with those reported in the literature.     

Design and synthesis of positional isomers of 5 and 6-bromo-1-[(phenyl)sulfonyl]-2-[(4-nitrophenoxy)methyl]-1H-benzimidazoles as possible antimicrobial and antitubercular agents

In this Letter, we report the structure–activity relationship (SAR) studies on series of positional isomers of 5(6)-bromo-1-[(phenyl)sulfonyl]-2-[(4-nitrophenoxy)methyl]-1H-benzimidazoles derivatives 7(a–j) and 8(a–j) synthesized in good yields and characterized by ¹H NMR, ¹³C NMR and mass spectral analyses. The crystal structure of 7a was evidenced by X-ray diffraction study. The newly synthesized compounds were evaluated for their in vitro antibacterial activity against Staphylococcus aureus, (Gram-positive), Escherichia coli and Klebsiella pneumoniae (Gram-negative), antifungal activity against Candida albicans, Aspergillus flavus and Rhizopus sp. and antitubercular activity against Mycobacterium tuberculosis H37Rv, Mycobacterium smegmatis, Mycobacterium fortuitum and MDR-TB strains. The synthesized compounds displayed interesting antimicrobial activity. The compounds 7b, 7e and 7h displayed significant activity against Mycobacterium tuberculosis H37Rv strain.