New polyoxygenated cyclohexenes isolated from Uvaria rufa and cinnamtannin B1 isolated from Nephelium hypoleucum with TRAIL-resistance-overcoming activity

Bioactivity-guided isolation of Uvaria rufa leaves and Nephelium hypoleucum bark resulted in the successful isolation of nine compounds (1–9) bearing a new polyoxygenated cyclohexene scaffold: zeylenol-6-shikimate (1), (−)-zeylenol (2), microcarpin A (3), uvarigranol F (4), quercetin (5), kaempferol (6), and p-coumaric acid (7) from U. rufa, and epicatechin (8) and cinnamtannin B1 (9) from N. hypoleucum. The structures of the isolated compounds were elucidated using various spectroscopic techniques. All compounds, except for 7, exhibited weak-to-strong TRAIL-resistance-overcoming activity and an increased gastric cancer cell line (AGS) inhibition by 17–32% as compared to the treatment with the compounds alone. Compounds 3 and 9 were studied for their ability to overcome TRAIL resistance using western blot analysis, which indicated that they sensitised AGS cells to apoptosis via both extrinsic and intrinsic pathways by increasing the expression of several proapoptotic proteins (cleaved caspase-3, −8, and −9) and by decreasing the expression of anti-apoptotic protein Bcl-2.     

Chemical constituents from the roots of Pteroxygonum giraldii Damme et Diels

Twenty-four compounds were obtained from Pteroxygonum giraldii and were classified as five triterpenes (1–5), two sterols (6 and 7), two quinones (8 and 11), three stilbenes (9, 10 and 18) and twelve flavonoids (12–17, 19–24). Seventeen of these compounds were obtained from the genus Pteroxygonum for the first time. The chemotaxonomic significance of this plant was also discussed. Compounds 10, 12 and 23 can serve as the fingerprints for P. giraldii, and compounds 12, 13, 17 and 22–24 are recognized as typical metabolites of P. giraldii. Both Pteroxygonum and Polygonum might have the same origin and could be classified into the same tribe among Polygonaceae. Furthermore, due to the presence of stilbenes, Pteroxygonum may have some taxonomic relationships with Fallopia, Rumex and Reynoutria.     

Phytochemical and chemotaxonomic studies on the stems and leaves of Schisandra chinensis (Turcz.) Baill

A comprehensive phytochemical investigation of the stems and leaves of Schisandra chinensis (Turcz.) Baill. resulted in isolation of seventeen compounds, including five lignans: meso-dihydroguaiaretic acid (1), licarin-A (2), pregomisin (3), gomisin A (4), acutissimanide (5), three phenylpropanoids: 2-[4-(3-hydroxypropyl)-2-methoxyphenoxy]-propane-1,3-diol (6), 2-methoxy-4-(2-propenyl) phenyl β-D-glucopyranoside (7), erigeside 2 (8), six sesquiterpenoids: 7′-hydroxy-abscisic acid (9), burmannic acid (10), (3S,5R,6R,7E)-3,5,6-trihydroxy-7-megastigmen-9-one (11), 3-Cyclohexene-1,2-diol, 4-(3-hydroxybutyl)- 3, 5, 5-trimethyl- (12), (−)-loliolide (13), (3Z,5R,8R,11R)-Caryophyll-3-ene-5,8,15-triol (14), one monoterpenoid: (6R,3Z)-6,7-dihydroxy-3,7-dimethyl-2-octenoic acid (15) and two other compounds: methyl shikimate (16), 4-Hydroxydodec-2-enedioic acid (17). Their chemical structures were confirmed through NMR, HRESIMS and comparison with the data in the literature. This is the first report of compounds 5, 6, 8–15, 17 from the family Schisandraceae and compounds 2, 16 from the genus Schisandra. Furthermore, we performed a chemotaxonomic study of the separated compounds.     

Phytochemical and chemotaxonomic study on Piper pleiocarpum Chang ex Tseng

The phytochemical study of Piper pleiocarpum Chang ex Tseng led to the isolation of eighteen compounds (1–18), including ten lignanoids, galbelgin (1), (+) sesamin (2), denudatin A (3), hancinone (4), (7S,8S, 3′R)-Δ^8'-3,3′,4-trimethoxy-3′,6′-dihydro-6′-oxo-7.0.4′,8.3′-lignan[(2S,3S,3aR)-2-(3,4-dimethoxyphenyl)-3,3a-dihydro-3a-methoxy-3-methyl-5-(2-propenyl)-6(2H))-benzofuranone] (5), (−)-(7R,8R)-machilin D (6), (1R,2R)-2-[2-methoxy-4-((E)-prop-1-enyl)phenoxy]-1-(3,4-dimethoxyphenyl)propyl acetate (7), piperbonin A (8), machilin D (9), 4-methoxymachilin D (10), one amide alkaloid, Δ^α,β-dihydropiperine (11), six polyoxygenated cyclohexenes, ent-curcuminol F (12), uvaribonol E (13), ellipeiopsol A (14), 1S,2R,3R,4S-1-ethoxy-2-[(benzoyloxy)methyl]cyclohex-5-ene-2,3,4-triol, 3-acetate (15), (+)-crotepoxide (16), (+)-senediol (17), and one benzoate derivative, 2-acetoxybenzyl benzoate (18). Their structures were established by spectroscopic data and by comparison with the literature. All the compounds were firstly isolated from P. pleiocarpum, while ten compounds 6–7, 9–10, 12–15, 17–18 were isolated from the genus Piper and the family Piperaceae for the first time. The chemotaxonomic significance of these compounds was also discussed. The isolation of compounds 6–7, 9–10 may be used as chemotaxonomic markers for the genus of Piper.     

A prenylated xanthone and antiproliferative compounds from leaves of Pentadesma butyracea

A new prenylated xanthone, butyraxanthone F (1) together with 20 known compounds were isolated from the leaves of Pentadesma butyracea. Their identification was achieved by spectroscopic means and comparison of the data with literature or by direct comparison on TLC with authentic samples. To the best of our knowledge, this is the first report of 2-hydroxy-2,3-dihydrosqualene (17) from a natural source. Compounds 2–6 and 11–16 were found for the first time in this genus. The antiproliferative activity of the crude extract, fractions and some isolated compounds was evaluated against three human cancer cell lines, BGC-823, Hela and A549. The crude extract, fractions B and C showed weak activities. Globuxanthone (2) and 30-epi-cambogin (7) were found to be the most active compounds on the three cancer cells. The effect of 2 on Hela cells and that of 7 on BGC-823 cells were noteworthy. The antiproliferative potential of allanxanthone A (3), ergosta-4,6,8(14),22-tetraen-3-one (14) and 2-hydroxy-2,3-dihydrosqualene (17) against BGC-823 and Hela cells could be classified as moderate-to-weak.     

Phytochemical and chemotaxonomic study of Pulsatilla cernua (Thunb.) Bercht. ex J. Presl

Twenty-two compounds were isolated from the 70% EtOH–H₂O extract of Pulsatilla cernua (Thunb.) Bercht. ex J. Presl roots, and their structures were determined based on ¹H NMR, ¹³C NMR and MS spectroscopic data, including (+)-pinoresinol (1), matairesinol (2), 4-ethoxycinnamic acid (3), p-hydroxy ethyl cinnamate (4), 3-(4′-methoxyphenyl)-2(E)-propenoic acid (5), methyl 4-hydroxycinnamate (6), radicol (7), cryptomeridiol (8), fraxinellone (9), diolmycin B2 (10), hederagonic acid (11), hederagenin (12), oleanolic acid (13), 3-O-α-L-arabinopyranosyl-oleanolic acid (14), hederagenin 3-O-α-L-arabinopyranoside (15), 3-O-[α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl] oleanolic acid (16), hederasaponin B (17), kizutasaponin K₁₂ (18), patrinia saponin H3 (19), hederacholichiside F (20), cernuoside A (21) and cernuoside B (22). Eight compounds (3–10) were isolated and identified from the genus Pulsatilla for the first time.     

Phytochemical and chemotaxonomic study on Fallopia dentatoalata (Fr. Schm.) Holub

Phytochemical study of Fallopia dentatoalata gave seventeen compounds, two sterols (8 and 10), three anthraquinones (5, 16 and 17), one chromone (13), two stilbenes (3 and 4), two amides (11 and 12), six flavonoids (1, 2, 6, 7, 14 and 15) and one fatty acid (9). Their structures were elucidated by spectroscopic methods and in comparison with the reported data. Compound 11 was obtained from genus Fallopia for the first time, and all of the compounds were firstly isolated from F. dentatoalata. The chemotaxonomic significance of these compounds was also discussed, which demonstrated the relationships between F. dentatoalata and some other species of genus Fallopia.     

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.     

Triterpenoidal alkaloids from Buxus hyrcana and their enzyme inhibitory,anti-fungal and anti-leishmanial activities

From the aerial parts of Buxus hyrcana, three triterpenoidal alkaloids, 17-oxo-3-benzoylbuxadine (1), buxhyrcamine (2), and 31-demethylcyclobuxoviridine (3), along with 16 known compounds, cyclobuxoviridine (4), N_b-dimethylcyclobuxoviricine (5), E-buxenone (6), Z-buxenone (7), moenjodaramine (8), homomoenjodarmine (9), buxamine A (10), buxamine B (11), 31-hydroxybuxamine B (12), N₂₀-formylbuxaminol E (13), papillozine C (14), buxmicrophylline F (15), buxrugulosamine (16), cyclobuxophylline O (17), spirofornabuxine (18) and arbora-1,9(11)-dien-3-one (19) were isolated. Their structures were elucidated by using NMR spectroscopic methods. All of the compounds exhibited moderate to weak acetylcholinesterase, butyrylcholinesterase and glutathione S-transferase inhibitory activities. Compounds 1–19 also exhibited modest anti-fungal activities against Candida albicans. Compounds 1, 2, 8, 9 and 18 also exhibited weak anti-leishmanial activity.     

Phenolic compounds from the roots of Ochna schweinfurthiana and their antioxidant and antiplasmodial activities

An investigation of compounds extracted from Ochna schweinfurthiana roots with ethyl acetate led to the isolation of three new compounds 4⿴-methoxylophirone A (1), 4,4⿲,4⿴⿿trimethoxylophirone A (2) and (4E;7Z)-3,8-dicarboxy-1-(O-β-d-glucopyranosyl-(1 ⿿ 6)-O-β-d-glucopyranosyl-2,9-dihydroxyhexeicosa-4,7-diene (3). Six known compounds were also identified, including Calodenone (4), Calodenine B (5), Lophirone A (6), Gerontoisoflavone A(7), 16α,17-dihydroxy-ent-kauran-19-oic acid (8) and 3β-O-d-glucopyranosyl-β-sitosterol (9). This report describes the first time that compounds 4-8 have been isolated from this plant, while 8 has never been identified in the genus Ochna. Some of the isolated compounds were evaluated for their antiplasmodial activity against the chloroquine-sensitive Plasmodium falciparum strain 3D7 and antioxidant activity using DPPH radical scavenging and Ferric reducing-antioxidant power (FRAP) assays. Compound 5 exhibited prominent radical scavenging and FRAP activities, while 7 had weak activity. Compound 1 showed good in vitro anti-plasmodial activity. The structures of the isolated compounds were elucidated by spectroscopic methods and comparisons with prior data in the literature.     

Chemical constituents from Picrasma quassioides (D.Don) Benn. and their network analysis of chemotaxonomic significance

A phytochemical investigation of Picrasma quassioides (D.Don) Benn led to the isolation of seventeen compounds including five coumarins (1–5), six lignans (6–11), two alkaloids (12–13), two phenolic compounds (14–15), one megastigman glycoside (16) and one phenylpropanoid (17). The structures of those compounds were determined by spectroscopy data of NMR spectra. All of the compounds were isolated from P. quassioides for the first time. In this study, in order to discuss the chemotaxonomic significance of those compounds from P. quassioides, network analysis was carried out to determine the chemotaxonomic relationships among the Simaroubaceae family and the other families. The result showed that the Simaroubaceae family and the Rutaceae family, together with the Asteraceae family have some chemotaxonomic relationships.     

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.     

Pyrrole alkaloids from the fruits of Morus alba

Phytochemical investigation of the fruits of Morus alba afforded seventeen pyrrole alkaloids including five new compounds. The structures of five new pyrrole alkaloids, named morroles B–F (4, 5, 7, 16 and 17), were determined on the basis of spectroscopic interpretations. 4-[Formyl-5-(hydroxymethyl)-1H-pyrrol-1-yl]butanoate (2) was synthesized by chemical reaction but first isolated from nature. Among isolated compounds, compounds 6 and 14 significantly inhibited pancreatic lipase activity.     

Chemical constituents from the roots of Fallopia convolvulus (L.) A. Löve

Twenty compounds, including three sterols (1–3), three phenols (4, 14 and 15), four anthraquinones (5, 7, 8 and 16), one chromone (6), two stilbenes (9 and 10), three amides (11–13), three flavonoids (17–19) and one organic acid (20), were obtained by modern phytochemical isolation methods. Their structures were identified by spectroscopic methods and in comparison with the published data in the references. Among them, compound 2, 3, 11 and 13 were firstly discovered from genus Fallopia, and compounds 1, 5–8, 10, 14, 15, 17, 19 and 20 were obtained from F. convolvulus for the first time. The chemotaxonomic significance of these compounds was also discussed, which revealed the relationships between F. convolvulus and some other species of Polygonaceae family.     

Phytochemical and chemotaxonomic studies on Pteris wallichiana J. Agardh

A systematic phytochemical investigation of Pteris wallichiana J. Agardh resulted in the isolation of twenty compounds, including five sesquiterpenes (1–5), six flavonoids (6–11), seven phenolic acids (12–18) and two fatty acids (19 and 20). Their structures were deduced from MS, NMR and ORD data. This is the first report of compounds dehydropterosin B (2), (2R,3S)-pterosin C (4), (2R,3R)-pterosin L (5), apigenin (6), luteolin (7), luteolin-7-O-glucoside (10), caffeic acid (13), vanillin (14), 3,4-dihydroxybenzaldehyde (15), chlorogenic acid (17), 3,5-dicaffeoylquinic acid (18), suberic acid (19) and azelaic acid (20) from P. wallichiana and of compounds 15, 19 and 20 from the family Pteridaceae. Furthermore, a chemotaxonomic study of the isolates was performed.     

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 fruits of Vitex trifolia L. (Verbenaceae) and their chemotaxonomic significance

One new labdane-type diterpenoid (1) named viterotulin D, along with twenty-three known compounds, including fourteen diterpenoids (2–15), one monoterpenoid (16), three steroids (17–19), one flavonoid (20), and four phenols (21–24) were isolated from the fruits of Vitex trifolia L. The structures of these compounds were identified based on spectroscopic data interpretation and comparison with previously reported values in the literature. This is the first report on the isolation of compounds (1, 6, 14, 15, 17, and 22) and (2, 9, and 10) from the family Verbenaceae and Vitex trifolia, respectively. The chemotaxonomic significant of the isolates was also discussed.     

Vernoguinamide: A new ceramide and other compounds from the root of Vernonia guineensis Benth. and their chemophenetic significance

The chemical investigation of the roots of Vernonia guineensis Benth. (Asteraceae) resulted in the isolation of a new ceramide, named vernoguinamide (1), together with fifteen known compounds, including three anthraquinones, physion (2), erythroglaucin (3) and emodin (4), three triterpenoids, hop-17(21)-en-3β-yl acetate (5), lupeol (6) and betulinic acid (7), six steroids, vernoguinoside A (8), vernoguinoside (9), β-sitosterol 3-O-β-D-glucoside (10), stigmasterol 3-O-β-D-glucoside (11), stigmasterol (12) and β-sitosterol (13) and three fatty acid derivatives, tetracosanoic acid (14), tricosanic acid (15) and arachidic acid glycerol ester (16). The structure of the new compound as well as those of the known compounds were established by spectrometric analysis including HRESI-MS, 1D and 2D-NMR and by comparison with the previously reported data. Among these compounds, the anthraquinones 2–4 and the triterpene 5 were isolated for the first time from Vernonia genus and compounds 6, 7 and 14–16 were extracted for the first time from the species. The isolated compounds were tested for their antibacterial activity and 3, 8 and 9 were the most active compounds against the tested bacteria. Furthermore, the chemophenetic relationships of the isolated compounds and their significance were also discussed.     

Chemical constituents from the heartwood of Toxicodendron vernicifluum (Stokes) F.A. Barkley

A phytochemical investigation of the heartwood of Toxicodendron vernicifluum (Stokes) F.A. Barkley led to the isolation of twenty-five compounds, including sixteen flavonoids (1–15), one flavonolignan (16), one chromone (17), four benzoic acid derivatives (18–21), two triterpenes (22–23) and two sterols (24–25). The structures of these compounds were elucidated on the basis of spectroscopic analysis and comparison with previous literature data. Among them, 8 and 21were isolated from the genus Toxicodendron and 5, 9, 13, 17–20, 22 from the family Anacardiaceae for the first time. Furthermore, 21 had been identified only by LC/MS before. 20 was a synthetic product used as anthelmintics, newly identified as a natural product. Furthermore, the chemotaxonomic value of these isolates was also discussed in detail.     

Chemical constituents from Orobanche cernua Loefling

Phytochemical study of Orobanche cernua Loefling afforded 17 compounds, including eleven phenylpropanoid glycosides (1–11), two flavonoids (12, 13), one lignan (14), and three phenolic acids (15–17) were isolated from the fresh whole plant of O. cernua. Their structures were identified by spectroscopic analyses and by comparison of their spectral data with those reported in the literature. This is the first report of isolation of compounds (6, 8, 9, 11, 14–16) from O. cernua and compounds (14, 15) from the family Orobanchaceae, respectively. Compound 14 was obtained from natural source for the first time, the chemotaxonomic significance of these compounds was summarized.