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.     

Neolignans and phenylpropanoids from the roots of Piper taiwanense and their antiplatelet and antitubercular activities

Bioassay-guided fractionation of roots from Piper taiwanense led to isolation of three neolignans, diallylcatechol (1) and neotaiwanensols A, B (2, 3), two diphenylpropanoid ethers, taiwandimerols A, B (4, 5), with one phenylpropanoid, 2,3-diacetoxy-1-methoxy-5-allylbenzene (6), previously unknown in nature, together with 18 known compounds (7–24). Their structures were elucidated by spectroscopic evidence. Among the isolates, hydroxychavicol acetate (7), and 4-allylcatechol (8) showed potent inhibitory activities against platelet aggregation induced by collagen, with IC₅₀ values of 2.1, and 5.3 μM, respectively. Hydroxychavicol acetate (7), 4-allylcatechol (8), and trans-caffeicaldehyde (9) showed antitubercular activities against Mycobacterium tuberculosis H₃₇Rv, with MIC values of 30.3, 27.6, and 25.5 μg/mL, respectively.     

α-Pyrone and seiricuprolide derivatives from the mangrove-derived fungi Pestalotiopsis spp. PSU-MA92 and PSU-MA119

Investigation of the mangrove-derived fungi Pestalotiopsis spp. PSU-MA92 and PSU-MA119 resulted in the isolation of three new α-pyrones, pestalotiopyrones A–C (1–3), and two new seiricuprolides, pestalotioprolides A (4) and B (5), together with two known compounds. Their structures were identified by analysis of spectroscopic data. Compound 5 was isolated as its diacetate derivative (6). The antibacterial and antifungal activities of 2 were evaluated.     

Chemical constituents of Leucas zeylanica and their chemotaxonomic significance

Chemical study of the whole plant of Leucas zeylanica (L.) B. Br. has led to isolation of a new norditerpenoid isomer (1), along with 29 known compounds, including one norditerpenoid (2), three flavonoid glycosides (3–5), six flavonoids (6–11), two phytosterols (12–13), two phenylpropanoids (14, 19), two phthalate esters (15, 16), two phenolic compounds (17, 18), five terpenoids (20–24), one aliphatic glycoside (25), one nucleobase (26), one amino acid (27), two alkaloids (28–29), and one cytochalasin (30). The structures of these compounds were identified using NMR spectroscopic methods and comparing them with those previously reported. Twelve compounds (6, 15, 17–20, 22, 23, 26–29) were isolated for the first time from Leucas zeylanica and ten others (2, 4, 5, 7, 14, 16, 21, 24, 25, 30) from the Leucas genus. This study also discusses the chemotaxonomic relationships between Leucas zeylanica and other species of Leucas.     

Chemical constituents from Cistanche sinensis (Orobanchaceae)

Phytochemical investigation of 70% aqueous EtOH extract of Cistanche sinensis led to the isolation of fifteen compounds (1–15), including nine phenylethanoid glycosides (PhGs, 1–9), five iridoid glycosides (10–14), and one lignan glycoside (15). Their structures were determined on the basis of 1D- and 2D-NMR experiments and by comparison with physical data of known compounds. Among the isolated compounds, 1 was identified as a new compound, three compounds (9, 14, and 15) were firstly reported from the genus Cistanche, and seven compounds (2–6, 11, and 12) were isolated from C. sinensis for the first time. PhGs with a 6′-O-rhamnosyl moiety such as cistansinenside B (1), poliumoside (7), and 2′-O-acetylpoliumoside (9) could serve as chemotaxonomic markers to differentiate C. sinensis from other species of Cistanche.     

Bufadienolides and phytoecdystones from the rhizomes of Helleborus thibetanus (Ranunculaceae)

Two new bufadienolide glycosides with an A/B trans ring structure, 14β,16β-dihydroxy-3β-(β-d-glucopyranosyloxy)-5α-bufa-20,22-dienolide (1), and 14β,16β-dihydroxy-3β-[β-d-glucopyranosyl-(1→4)-(β-d-glucopyranosyloxy)]-5α-bufa-20,22-dienolide (2), two known ecdysteroids (polypodine B and 20-hydroxyecdysone) (3-4), and six known bufadienolide and its glycosides with 5β-OH (hellebrigenin, 16β-hydroxyhellebrigenin-3-O-α-l-rhamnoside, hellebrigenin 3-O-β-d-glucoside, hellebrin, 16β-hydroxyhellebrigenin-3-O-β-d-glucoside, and deglucohellebrin) (5-10) were isolated from the rhizomes of Helleborus thibetanus. The structures of compounds 1 and 2 were elucidated using various spectroscopic methods. All compounds were reported for the first time from the title plant and their chemotaxonomic significance for the genus Helleborus was discussed.     

Six new dammarane-type triterpene saponins from the processed leaves of Panax notoginseng

Six new dammarane-type triterpenoid saponins, notoginsenosides SFt₅–SFt₁₀ (1–6) were isolated from the processed leaves of Panax notoginseng (Burk.) F.H.Chen (Araliaceae), together with eight known notoginsenosides (7–14), fourteen known ginsenosides (15−28), two known vinaginsenosides (29−30), and one known gypenoside (31). Their structures were established by detailed spectroscopic analysis (NMR, UV, IR, HRESI-MS) and acidic hydrolysis. Four compounds notoginsenoside SFt₁ (7), ginsenosides Rg₅ (17), C-Mc (23) and 20(R)–Rg₃ (25) have significant protective effects against L-glutamate-induced SH–SY5Y nerve injury (10 μM).     

Stilbene glucosides from the bulbs of Iris tingitana

Two new dimeric stilbene glucosides, tingitanol A (1) and tingitanol B (2) together with trans-resveratrol 3-O-glucopyranoside (3) in addition to three known isoflavones, 5-O-methylgenistein (4), 5-O-methylgenistein 7-O-β-d-glucopyranoside (5) and betavulgarin (6) have been isolated for the first time from the fresh bulbs of Iris tingitana Boiss. & Reut. Their structures were established on the basis of the spectral data and direct comparison with values from previously identified analogues. Additionally, the isolated compounds (1–6) were evaluated for the free radical scavenging activity.     

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.     

Daphnodorin dimers from Edgeworthia chrysantha with α-glucosidase inhibitory activity

Four daphnodorin dimers named herein as edgechrins A–D (1–4) were isolated from the stems and twigs of Edgeworthia chrysantha Lindl. along with four known compounds identified as daphnodorin A (5), B (6), C (7) and I (8). Their structures were established by spectroscopic methods, including IR, HR-MS, and 1D- and 2D NMR. All of these compounds showed potent in vitro α-glucosidase inhibitory activity with IC₅₀ values in the range of 0.4–20 μM.     

Phytochemistry and antiglycation activity of Aloe sinkatana Reynolds

A new anthraquinone along with 10 known compounds were isolated from the leaves of Aloe sinkatana Reynolds (Aloaceae), and their structures were elucidated as the new compound 2,8-dihydroxy-6-(hydroxymethyl)-1-methoxyanthracene-9,10-dione (1) and the known compounds Aloe-emodin (2), feralolide (3), 1-hydroxy-5-methoxy-3-methyl-9,10 dihydroanthracene 9,10-dione (4), β-sitosterol (5), β-sitosterol with glycosidic bond (6), microdontin (7), homoaloins A (8) and B (9) and aloins A (10) and B (11). Characterization of compounds 1–9 was based on spectral analyses and comparison with reported data, particularly the new compound 1 was identified by 1D- and 2D NMR, mass spectroscopic and X-ray crystallography analyses. Antiglycation activity of the extracts and isolated compounds were carried out using the hemoglobin-δ-gluconolactone and glucose–bovine serum albumin assays. The results obtained showed that MeOH and EtOAc extracts as well as compound 1 showed an inhibitory effect on early stage protein glycation. Compound 1 also showed significant inhibitory effects against glucose-induced advanced glycation end-products.     

New antiproliferative and immunosuppressive withanolides from the seeds of Datura metel

Two new withanolides baimantuoluoside H (1) and baimantuoluoline K (2), and one known withanolide glycoside (3) were isolated and identified from the ethyl acetate-soluble fraction of ethanol extract of Datura metel seeds. The structures of the new compounds were determined using 1D and 2D NMR spectroscopy, and mass spectrometry. All isolated compounds were evaluated for their antiproliferative activity against human gastric adenocarcinoma (SGC-7901), human hepatoma (Hepg2), and human breast cancer (MCF-7) cells, as well as their immunosuppressive properties. It was determined that compounds 1–3 exhibited medium antiproliferative and potential immunosuppressive effects.     

Anti-influenza diarylheptanoids from the bark of Alnus japonica

This study to investigate anti-influenza components from the bark of Alnus japonica resulted in the isolation of two rare acylated diarylheptanoids, named oregonoyl A (5) and oregonoyl B (6), along with nine known compounds (1–4 and 7–11). Their structures were elucidated on the basis of extensive spectroscopic and chemical methods. Antiviral testing of compounds 1–11 against KBNP-0028 (H9N2) avian influenza virus showed that platyphyllone (10) was strongly active, and platyphyllonol-5-xylopyranoside (9) was moderately active against KBNP-0028 as compared with the positive control, zanamivir, respectively.     

Chemical study of Anthospermum emirnense (Rubiaceae)

Chemical study of the aerial parts of Anthospermum emirnense led to the isolation of one original iridoid glycoside (1) along with six known iridoids (2–7), three lignans (8–10), two flavonoids (11–12), one coumarin (13), two anthraquinones (14–15), two benzoic acids (16–17) and three triterpenoids (18–20). These results are the first chemical data on non-volatile constituents of this genus. The chemotaxonomic significance of these compounds is discussed.     

Four new glycosides from the seeds of Cassia obtusifolia

Four new glycosides, including one anthraquinone glycoside (1), one naphthalene glycoside (2), and two naphthopyrone glycosides (3–4), with 10 known compounds (5–14) were isolated from the seeds of Cassia obtusifolia L. The new structures were determined by spectroscopic analysis and chemical transformations.     

Three new phthalide glycosides from the rhizomes of Ligusticum chuanxiong

Three new phthalide glycosides, named chuanxiongoside A (1), chuanxiongoside B (2) and ligusticoside B (3) together with two known glycosides, celephthalide A (4) and icariside F₂ (5), were isolated from the rhizomes of Ligusticum chuanxiong. This is the first report of compounds 4⿿5 from the title plant. The structures of compounds 1⿿3 were identified using various spectroscopic methods.     

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.     

Topoisomerase II inhibitors from the roots of Stellera chamaejasme L.

Three new compounds, including one daphnane diterpene (1), one sesquiterpene (6), and one lignan (7) have been isolated from the Stellera chamaejasme L., together with five other known compounds, including four daphnane diterpenenoids (2–5) and one lignan (8). The structures of the new compounds were elucidated by spectroscopic analysis. The cytotoxicities of compounds 1–8 towards human lung adenocarcinoma cells (A549 cells) were evaluated using a sulforhodamine B assay. All of the compounds displayed significant cytotoxicity, with IC₅₀ values in the ranging of 0.2 nM to 2.0 μM. Mechanistic studies revealed that the antitumor activities of compounds 1–3 and 7 were derived from their inhibition of topoisomerase II (Topo II). Furthermore, as a Topo II inhibitor, compound 1 was found to effectively induced G2-M phase cell cycle arrest and apoptosis in cancer cells.     

Neo-clerodane diterpenes from Ajuga turkestanica

The ethyl acetate extract of the aerial parts of Ajuga turkestanica afforded 6 neo-clerodane diterpenes, including two novel compounds, 14,15-dihydroajugachin B (1) and 14-hydro-15-methoxyajugachin B (2), in addition to the known diterpenoids chamaepitin (3), ajugachin B (4), ajugapitin (5) and lupulin A (6). Structures were established through exhaustive NMR spectroscopic analysis and chemical transformation in the case of 1. The full ¹H and ¹³C NMR assignment of the C-15 R and S configurations of 14-hydro-15-methoxyajugachin B and chamaepitin were elucidated.     

Chemical constituents from Chonemorpha griffithii

Chemical investigation of the aerial part of Chonemorpha griffithii has led to the isolation of 20 compounds, comprising six lignans (1–6), six triterpenoids (7–12), four phenolic acids (13–16), two flavonoids (17 and 18), one cyclitol (19) and one aliphatic acid (20). Among them, 5′-methoxy-7′-oxomatairesinol (1) was identified to be a new lignan. It is the first report of the presence of those compounds in this genus. Two 24-methyl-29-norcycloartane triterpenoids (10 and 11) were considered as the chemotaxonomic markers for the species C. griffithii.