Glutathione S-transferase inhibitory,free radical scavenging,and anti-leishmanial activities of chemical constituents of Artocarpus nobilis and Matricaria chamomilla

Glutathione S-transferase (GST) inhibition-directed fractionations on the ethanolic extract of Artocarpus nobilis of Sri Lankan origin yielded four known triterpenoids, cyclolaudenyl acetate (1), lupeol acetate (2), β-amyrine acetate (3), and zizphursolic acid (4), along with five known flavonoids, artonins E (5), artobiloxanthone (6) artoindonesianin U (7), cyclocommunol (8) and multiflorins A (9). Our recent chemical studies on the methanolic extract of Matricaria chamomilla, collected from Manitoba, afforded one new compound, matriisobenzofuran (10), and six known natural products, fraxidin (11), scopoletin (12), apigenin (13), apigenin 7-O-β-glucopyranoside (14), palmatoside A (15) and p-hydroxyacetophenone (16). Compounds 1–16 were identified with the aid of extensive NMR and MS spectral data. Compounds 1–16 exhibited a wide range of GST inhibition activity. Compounds 5–9 exhibited significant anti-oxidant activity in DPPH free radical scavenging assay. Compounds 10 and 11 were also moderately active in anti-leishmanial assay.     

Three new arylbenzofurans from Lavandula angustifolia and their bioactivities

Three new arylbenzofurans, 2-(7-methoxy-2-(4-methoxyphenyl)-3-methylbenzofuran-5-yl)ethanol (1), 4-(5-(2-hydroxyethyl)-7-methoxy-3-methylbenzofuran-2-yl)phenol (2), and 2-(6-methoxy-2-(4- methoxyphenyl)-3-methylbenzofuran-5-yl)ethanol (3), together with three known ones (4–6) were isolated from the whole plant of Lavandula angustifolia. Their structures were determined by means of HRESIMS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1–3 and 5 were tested for their anti-tobacoo mosaic virus (TMV) activities, and Compounds 1–6 were tested for their cytotoxicity activities. In our assay, Compounds 1–3 showed high anti-TMV activity with inhibition rate of 38.2, 35.2, and 34.0%, which superior to positive control Ningnanmycin. Compounds 1–6 also showed weak inhibitory activities against some tested human tumor cell lines with IC50 values in the range of 2.2–8.2 μM.     

Phytochemical and chemotaxonomic study on Ziziphus Jujuba Mill. (Rhamnaceae)

Fourteen compounds were isolated from fruits of Ziziphus jujuba Mill., including two flavonoids (1–2), one phenolic glycosides (3), one lignan (4), four phenols (5–8), three alkaloid (9–10, 14), three sesquiterpenoid (11–13). The structures of all the compounds were established by the NMR techniques, as well as by comparison with previously reported data in literature. Compounds 2″-glucosyl-8-C-glucosyl-4′-O-methylapigenin (1), 3′, 4′, 5′-trimethoxycinnamyl alcohol (5), 2-{4-[(1E)-3-Hydroxyprop-1-en-1-yl]-2, 6-dimethoxy-phenoxy}propane-1, 3-diol (6), 1-(4-Hydroxyphenyl)ethane-1, 2-diol (8), (1S, 3S)-1-Methyl-l, 2, 3, 4-tetrahydro-β-carboline-3-carboxylic acid (9), (1R, 3S)-1-Methyl-l, 2, 3, 4-tetrahydro-β-carboline-3-carboxylic acid (10), grasshopper ketone (12), methyl (3R, 5R)-5-methoxy-3-phenylisoxazolidine-5-carboxylate (14) were firstly reported from the genus Ziziphus and the family Rhamnaceae. Furthermore, the chemotaxonomic significance of the isolates was discussed.     

Chromones from the stems of Cassia fistula and their anti-tobacco mosaic virus activities

Three new chromones, 5-methoxy-2,2-dimethyl-7-(2-oxopropyl)-2,3-dihydrochromen-4-one (1), 5-methoxy-2,2-dimethyl-8-(2-oxopropyl)-2,3-dihydrochromen-4-one (2), and 1-(3,4-dihydro-5-methoxy-2,2-dimethyl-2H-chromen-7-yl)propan-2-one (3), together with four known chromones (4–7) were isolated from the stems of Cassia fistula. Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D-NMR techniques. Compounds 1–5 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compound 5 exhibited high anti-TMV activity with inhibition rate of 30.8% at a concentration of 20 μM. The other compounds also exhibited potential anti-TMV activities with inhibition rates in the range of 15.6–22.1% at the same concentration.     

Phytochemical investigation on the fruiting body of Russula aruea Pers

Phytochemical investigation of ethyl acetate fraction from Russula aruea Pers fruiting body led to the isolation and identification of one new isolactarane sesquiterpene (1) and 11 known compounds, including four sesquiterpenes (2-5), four sterols (6–9), one allitol (10), and two fatty acids (11–12). The structure of compound 1 was elucidated by means of spectroscopic analysis, including 1D and 2D NMR, HR-ESI-MS, and X-Ray experiments. Compounds 1–3 and 5–12 are herein reported for the first time from Russula genus, while compound 4 is firstly described in R. aruea. The sesquiterpenes in R. aruea could serve as chemotaxonomic markers.     

Alkaloids from the leaves of Isatis indigotica fortune and their chemotaxonomic significance

From the leaves of Isatis indigotica Fortune, one new alkaloid, namely (2E)-N-(2-hydroxyphenyl)-2-(1-hydroxy-3-oxoindolin-2-ylidene) acetamide (1), together with four known ones, such as phaitanthrin D (2), methyl quindoline-11-carboxylate (3), cephalandole B (4) and 2,2-di (3-indolyl)-3-indolone (5) were isolated and identified. The structure of compound 1 was elucidated by means of spectroscopic analysis, including HRESIMS together with 1D and 2D NMR experiments. Compounds 1, 2 and 5 were obtained from this genus for the first time. Chemotaxonomic significance of these compounds is described herein.     

Phytochemical investigation of Eremostachys moluccelloides Bunge (Lamiaceae)

Phytochemical investigation of the aerial parts of Eremostachys moluccelloides Bunge led to the identification of a new diterpene, 2β,14-dihydroxy −11-formyl- 12-carboxy-13-des-isopropyl-13-hydroxymethyl-abieta-8,11,13- triene- 16(17)- lactone (1), along with the known compounds 12, 18-dicarboxy-14-hydroxy-13-des -isopropyl-13-hydroxymethyl- abieta-8,11,13-triene-16(17)-lactone (2), 5-hydroxy-3′,4′,7-trimethoxyflavone (3), 5-hydroxy-4’,7-dimethoxyflavone (4), luteolin-7-O-β-glucoside (5), verbascoside (6), luteolin 7-O-(6″-O-β-D-apiofuranosyl) -β-D-glucopyranoside (7), chlorogenic acid (8), echinacoside (9), apigenin-7-O-β-D-glucoside (10), p-coumaric acid (11), vanillic acid (12), apigenin-7-O-(6″-E-p-coumaroyl)-β-D-glucopyranoside (13), apigenin-7-O-(3″,6″-E-p-dicoumaroyl)-β-glucoside (14), lamalbide (15), 6β-hydroxy-7-epi-loganin (16), phloyoside II (17) The structures were elucidated on the basis of 1D and 2D NMR spectroscopy, UV, MS and by comparison with compounds previously reported in the literature. Compounds 1–4, 8, 9, 11, 12, 14 have not been reported previously from any species within the genus Eremostachys. Compounds 1–14, 17 were obtained from this species for the first time. The chemotaxonomic significance of the isolated compounds is discussed.     

Guaianolides and elemanolides from Vernonia anthelmintica

Two new guaianolides, (1R,4R,5S,6R,7R,8S)-8,15-dihydroxyguaia-10(14),11(13)-dien-12,6-olide (1) and (1R,4R,5S,6R,7R,8S,11S)-8,15-dihydroxyguaia-10(14)-en-6,12-olide (2), and two known elemanolides, (4S,5R,6R,7R,8S,10R,11S)-11,13-dihydrovernolepin (3) and (5R,6R,7R,8S,10R,11S)-melitensin (4) were isolated from the aerial parts of Vernonia anthelmintica Willd. The structures of these compounds were determined on the basis of IR, UV, MS, 1D-NMR and 2D-NMR, and their absolute configurations were deduced using the CD exciton chirality method and single-crystal X-ray diffraction. The possible biosynthetic relationships of compounds 1–4 are postulated. Compounds 1–4 were evaluated for their cytotoxicity against HL-60 and SMMC-7721 cell lines.     

Phytochemical and chemotaxonomic study on Dianella ensifolia (L.) DC

Phytochemical investigation of the roots of Dianella ensifolia led to the isolation of eleven known compounds, including two aromatics (1, 2), two chromones (3, 4), and seven flavonoids (5–11). The structures of these compounds were elucidated on the basis of spectral analysis and comparison with data reported in literature. In the present research, all of the isolated compounds 1–11 were reported for the first time in the species D. ensifolia. Compounds 1–4 and 7–11 were firstly isolated from the genus Dianella. Compounds 1, 2, 8, and 9 have not been reported from any species in Liliaceae family. The chemotaxonomic significance of the isolated compounds was summarized.     

New aromatic compounds from the rhizomes of Homalomena occulta

Three new aromatic compounds, identified as 1-(3′,4′-methylenedioxy-phenyl)-10-(3″-hydroxyphenyl)-decane (1), 1-(3′,4′-methylenedioxy-phenyl)-12-(3″-hydroxyphenyl)-dodecane (2), and 1-(3′,4′-methylenedioxy-phenyl)-12-(3″-hydroxyphenyl)-6Z-dodecylene (3), along with six known compounds (4–9) were isolated from the 95% EtOH extract of Homalomena occulta. Their structures were elucidated by chemical and spectral methods Compounds 4–9 were isolated for the first time from this plant. Compounds 1–3 exhibited inhibitory activity against BACE1, with IC₅₀ values of 0.82–1.09 μmol/L.     

Phenylpropanoid derivatives from Clausena harmandiana fruits

A new phenylpropanoid derivative, harmandianone (1), along with four known compounds: verimol B (2), (E)-3-(2-hydroxy-4-methoxy-phenyl)propanoate (3), (E)-methyl p-coumarate (4), and (E)-5-methoxy-2-(prop-1-enyl)phenol (5) was isolated from the acetone extract of Clausena harmandiana fruits. All structures were characterized by spectroscopic methods (UV, IR, NMR and ESI-TOF-MS). Compounds 1 and 3–5 demonstrated weak antibacterial activity against Escherichia coli TISTR 780, methicillin-resistant Staphylococcus aureus SK1, Salmonella typhimurium TISTR 292 and S. aureus TISTR1466, with MIC values between 64 and 128 μg/mL.     

Platachromone A–D: Cytotoxic 2-styrylchromones from the bark of Platanus × acerifolia (Aiton) Willd.

Four novel 2-styrylchromones, 4′,5,7-trihydroxy-6-isopentene-2-styrylchromone (1), 4′,5,7-trihydroxy-8-isopentene-2-styrylchromone (2), 4′,5,7-trihydroxy-6-(2-hydroxy-3-methylbut-3-enyl)-2-styrylchromone (3) and 4′,5,7-trihydroxy-8-(2-hydroxy-3-methylbut-3-enyl)-2-styrylchromone (4), were isolated from shed bark of Platanus × acerifolia (Aiton) Willd., as well as four known compounds, 4′,5,7-trihydroxy-2-styrylchromone (5), scutellarein (6), 4′,5,7-trihydroxy-6-prenylflavone (7), and 4′,5,7-trihydroxy-8-prenylflavone (8). The structures of compounds 1–4 were established by direct interpretation of their spectral data, mainly high resolution electrospray ionization mass spectrometry (HR-ESI-MS), 1D and 2D NMR (¹H–¹H COSY, HSQC and HMBC). The cytotoxicity of the compounds 1–8 was evaluated in four human carcinoma cell lines, including HepG2, SMMC-7721, MDA-MB-231, and KB. Compounds 1–4 exhibited significantly cytotoxic activity toward HepG2 and KB cells, with IC₅₀ values ranging from 3.0 to 9.7 μM.     

Polyhydroxyoleanane-type triterpenoids from Combretum molle and their anti-inflammatory activity

A new oleanane-type triterpene saponin, β-d-glucopyranosyl 2α,3β,6β-trihydroxy-23-galloylolean-12-en-28-oate (1), together with four known oleanane-type pentacyclic triterpenoids, combregenin (2), arjungenin (3), arjunglucoside I (4), and combreglucoside (5) were isolated from the stem bark of Combretum molle. Their structures were established mainly on the basis of 1D and 2D NMR spectral data. Compounds 1–3 exhibited more significant activity against carrageenan-induced paw edema in rat compared to compounds 4 and 5.     

Flavonoid glycosides from the aerial parts of Curcuma comosa

Four new flavonoid glycosides, curcucomosides A–D (1–4), three known flavonoid glycosides, 5–7, and four known diarylheptanoids, 8–11, were isolated from the ethanol extract of the aerial parts of Curcuma comosa. The structures of the new compounds were established as rhamnazin 3-O-α-l-arabinopyranoside (1), rhamnocitrin 3-O-α-l-arabinopyranoside (2), rhamnazin 3-O-α-l-rhamnopyranosyl-(1→2)-O-α-l-arabinopyranoside (3), and rhamnocitrin 3-O-α-l-rhamnopyranosyl-(1→2)-O-α-l-arabinopyranoside (4) by spectroscopic analysis and chemical reactions whereas those of the known compounds were identified by spectral comparison with those of the reported values.     

Characteristic lindenane sesquiterpenoid dimers and labdane diterpenoids from Chloranthus serratus

Chemical investigation on the roots of Chloranthus serratus (Chloranthaceae) afforded 11 terpenoids, including four lindenane-type sesquiterpenoid dimers (1–4), and seven labdane diterpenoids (5–11). The structures of these terpenoids were established by spectroscopic analysis (MS, ¹H, and ¹³C NMR). Compounds 4–11 were isolated from C. serratus for the first time. The chemotaxonomic significance of the isolated compounds was summarized herein.     

Triterpenoids from the seedpods of Holarrhena curtisii King and Gamble

Two new hydroperoxy pentacyclic triterpenoids, 3β-hydroxy-11α-hydroperoxyolean-12-en-28-oic acid (1) and 3β-hydroxy-11α-hydroperoxyursan-12-en-28-oic acid (2), together with nine known triterpenoids, squalene (3), β-amyrin acetate (4), α-amyrin acetate (5), lupeol acetate (6), lupeol (7), lanosta-7,24-dien-3β-ol (8), cycloeucalenol (9), oleanolic acid (11) and ursolic acid (12), a known phytosterol, 24-methylenepollinastanol (10), and two known flavanols, (–)-catechin (13) and (–)-gallocatechin (14), were isolated from the methanolic extract of the fresh seedpods of Holarrhena curtisii. Their structures were determined by spectroscopic analysis (one and two dimensional nuclear magnetic resonance, high resolution electrospray ionization mass spectrometry and attenuated total reflectance-Fourier transform infrared spectroscopy). All compounds (except squalene) were evaluated for their in vitro α-glucosidase inhibitory activity. Compounds 1, 2, 11 and 12, which had a pentacyclic triterpenoid acid skeleton, showed a strong in vitro α-glucosidase inhibitory activity compared to that of the standard control, acarbose.     

Chemical constituents from the fruits of Rhus typhina L. and their chemotaxonomic significance

This work describes the isolation and characterization of twenty-nine compounds from the fruits of Rhus typhina L., including eleven flavonoids (1–11), eleven phenols (12–22), two pentacyclic triterpenes (23–24), two organic acids (25–26), one lumichrome (27), one courmarin (28) and one pyrimidine (29) on the basis of their spectroscopic data. Compounds apigenin (1), daidzein (4), orobol (5), 3′, 5, 5′, 7-tetrahydroxyflavanone (6), naringenin (7), butein (8), (-)-catechin (9), quercetin-3-O-α-L-(3″-O-galloyl)-rhamnoside (11), 2-hydroxybenzoic acid (13), 4-hydroxybenzaldehyde (14), vanillin (15), methyl 3,4-dihydroxybenzoate (16), 3,5-dihydroxybenzamide (18), tyrosol (19), caffeic acid (20), 3-(2,4,6-trihydroxyphenyl)-1-(4-hydroxyphenyl)-propan-1-one (21), phlorizin (22), friedelin (23), oleanolic acid (24), 4,4-dimethyl-heptanedioic acid (25), anthranilic acid (26), lumichrome (27), scoparone (28) and uracil (29) have not been recorded before in this plant. This is the first report on the occurrence of compounds 4–7, 9, 11, 13–14, 16, 18–21, 25–29 from the genus Rhus. Moreover, the chemotaxonomic significance of these isolated compounds was also summarized.     

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.     

Prenylflavonoids from Glycyrrhiza uralensis and their protein tyrosine phosphatase-1B inhibitory activities

Two new 2-arylbenzofurans, glycybenzofuran (1) and cyclolicocoumarone (2), together with 10 known flavonoids including licocoumarone (3), glycyrrhisoflavone (4), glisoflavone (5), cycloglycyrrhisoflavone (6), isoliquiritigenin (7), licoflavone A (8), apigenin (9), isokaempferide (10), glycycoumarin (11), and isoglycycoumarin (12), were isolated from the roots of Glycyrrhiza uralensis and their structures were determined by extensive spectroscopic analyses. Compounds 1 and 5 showed significant protein tyrosine phosphatase-1B (PTP1B) inhibitory activity in vitro with the IC₅₀ values of 25.5 and 27.9 μM, respectively. The structure–activity relationship indicated that the presence of prenyl group and ortho-hydroxy group is important for exhibiting the activity. Kinetic analysis indicated that compound 1 inhibits PTP1B by a competitive mode, whereas compound 5 by a mixed mode.     

Fatty acid derivatives and dammarane triterpenes from the glandular trichome exudates of Ibicella lutea and Proboscidea louisiana

Ibicella lutea and Proboscidea louisiana, both of the Martyniaceae family, are known for rich glandular trichomes on their leaves and stems. Chemical investigations of the glandular trichome exudates on leaves of the two plants furnished three types of secondary metabolites, glycosylated fatty acids, glycerides (2-O-(3,6-diacetyloxyfattyacyl)glycerols and 2-O-(3-acetyloxyfattyacyl)glycerols) and dammarane triterpenes. The glycosylated fatty acids from I. lutea were determined to be 6(S)-(6-O-acetyl-β-d-glucopyranosyloxy)-octadecanoic acid (1A), -eicosanoic acid (1B) and -docosanoic acid (1C), as well as their respective deacetyl congeners (2A, 2B and 2C), whereas P. louisiana furnished 8(S)-(6-O-acetyl-β-d-glucopyranosyloxy)-eicosanoic acid (3A) and -docosanoic acid (3B) and their respective deacetyl congeners (4A and 4B), together with 2B. Both plants contained 12 identical 2-O-[(3R,6S)-3,6-diacetyloxyfattyacyl]glycerols (5A-L), in which the fatty acyl moieties contained between 17 and 21 carbon atoms. The corresponding mono-acetyloxy compounds, 2-O-[(3R)-3-acetyloxyfattyacyl]glycerols (6A–L) were detected in both plants. Among these glycerides, ten compounds (5A, 5C, 5F, 5H, 5K, 6A, 6C, 6F, 6H and 6K) had iso-fattyacyl structures and four (5E, 5J, 6E and 6J) had anteiso-fattyacyl structures. A previously unknown dammarane triterpene, betulatriterpene C 3-acetate (7), was isolated together with three known dammarane triterpenes, 24-epi-polacandrin 1,3-diacetate (8), betulatriterpene C (9) and 24-epi-polacandrin 3-acetate (10) from I. lutea, whereas 12 dammarane triterpenes, named probosciderols A–L (12–23), and the known compound betulafolienetriol (11) were isolated from P. louisiana. The structures of these compounds were elucidated by spectroscopic analysis including 2D-NMR techniques and chemical transformations. The 6-O-acetylglucosyloxy-fatty acids 1A–C (42%) and the dammarane triterpenes 7–10 (31%) were the two most abundant constituents in the glandular trichome exudate of I. lutea, whereas the dammarane triterpenes 11–23 (47%) and the glucosyloxy-fatty acids (4A, 4B and 2B) (38%) were the most abundant constituents in the glandular trichome exudate of P. louisiana.