A new prenylated flavone from Pleione bulbocodioides

A new prenylated flavone, 3,5,7,3′-tetrahydroxy-8,4′-dimethoxy-6-(3-methylbut-2- enyl)flavone (1), together with three known flavone derivatives (2–4), two known dihydrophenanthrenes (5–6), two known lignin derivatives (7–8), and three known phenolic glycoside compounds (9–11) were isolated from the n-BuOH extract of Pleione bulbocodioides. High-resolution electrospray ionization mass spectroscopy (HRESIMS), FTIR spectroscopy, and NMR techniques were used to elucidate the structures of these compounds. Biological investigations showed that compound 5, 4,7-dihydroxy-2-methoxy-9,10-dihydrophenanthrene, exhibited potent anti-inflammatory activity on LPS-stimulated NO production in BV-2 microglial cells, with IC₅₀ value of 5.44 μM.     

Isoprenylated phenolic compounds with tyrosinase inhibition from Morus nigra

A new isoprenylated sanggenon-type flavanone, nigrasin K (1), together with three known analogs (2–4) and five known Diels–Alder adducts (5–9), were isolated from the twigs of Morus nigra. Their structures were elucidated by spectroscopic methods. Sanggenon M (2), chalcomoracin (5), sorocein H (6), kuwanon J (7), sanggenon C (8), and sanggenon O (9) showed significant inhibitory effects on mushroom tyrosinase.     

Apocynin derivatives from Iris tectorum

Phytochemical investigation of the rhizomes of Iris tectorum resulted in the isolation and characterization of three new apocynin derivatives, apocynin-4-O-β-D-(6′-O-syringyl)glucopyranoside (1), scrophenoside C-7-ethyl ether (2, 3), together with a new naturally occurring compound but known by synthesis, apocynin-4-O-β-D-xylopyranoside (4), and five known ones (5–9). Their structures were elucidated on the basis of spectroscopic data interpretation.     

A new megastigmane glucoside and a new amide alkaloid from the leaves of Clausena lansium (Lour.) Skeels

A new megastigmane glucoside (6S,7E,9S)-6,9,10-trihydroxy-4,7-megastigmadien-3-one 9-O-β-d-glucopyranoside (1) and a new amide alkaloid (E)-N-(4-methoxyphenethyl)-2-methylbut-2-enamide (2), together with three known amide alkaloids (3–5), were isolated from the leaves of Clausena lansium (Lour.) Skeels. Their structures were elucidated by their physicochemical properties and analysis of their spectral data.     

A new prenylated aurone from Artocarpus altilis

Phytochemical study of the methanol extract of Artocarpus altilis resulted in the isolation of a new prenylated aurone, artocarpaurone (1), together with eight known compounds including two prenylated chalcones (2 and 3), three prenylated flavanones (4–6), and three triterpenes (7–9). The structure of 1 was elucidated as 6-hydroxy-2-[8-hydroxy-2-methyl-2-(4-methyl-3-pentenyl)-2H-1-benzopyran-5-ylmethylene]-3(2H)-benzofuranone by spectroscopic methods including 1D and 2D NMR spectra and FT-ICR-MS. Compound 1 showed moderate nitric oxide radical scavenging activity, whereas 2 and 3 had moderate 2,2-diphenyl-1-picrylhydrazyl radical scavenging effect, compared with the positive control (+)-catechin.     

Diglycosidic indole alkaloid derivatives from an aqueous extract of Isatis indigotica roots

Six new indole alkaloid diglycosides named isatigotindolediosides A-F (1–6), along with three known analogs (7–9), were isolated from an aqueous extract of the Isatis indigotica roots (ban lan gen). Their structures including the absolute configurations were determined by comprehensive spectroscopic data analysis, combined with enzyme or acid hydrolysis, and comparison of experimental circular dichroism (CD) and calculated electronic circular dichroism (ECD) spectra. In the preliminary assays, compounds 3, 5, and 8 showed antiviral activity against Coxsackie virus B3.     

Three new norsesquiterpenoids from the seeds of Alpinia galanga

From the seeds of Alpinia galanga Willd., three new norsesquiterpenoid racemic mixtures, galanols A–C (1–3) were isolated, along with three known sesquiterpenoids (4–6). Their structures were elucidated by means of UV, IR, HR-ESI-MS, 1D NMR and 2D NMR spectroscopic data.     

C18-Diterpenoid alkaloids from Delphinium anthriscifolium var. majus

Five new C₁₈-diterpenoid alkaloids, anthriscifoltines C-G (1–5), along with four known diterpenoid alkaloids anthriscifolcines C-F (6–9), were isolated from the extract of Delphinium anthriscifolium var. majus. Their structures were elucidated by extensive spectroscopic analyses (including 1D-, 2D-NMR, and HR-ESI-MS). Compounds 1–5 were also evaluated for their cytotoxic activity against MCF-7, HepG2, and H460 human cancer cell lines.     

Speciosaperoxide,a new triterpene acid,and other terpenoids from Chaenomeles speciosa

Investigation on the EtOH extract of the fruits of Chaenomeles speciosa led to the isolation of a new triterpene acid bearing an unusual hydroperoxyl substitute group at C-11, speciosaperoxide (1), along with six known triterpenoids, 3β-acetoxyurs-11-en-13β,28-olide (2), 3-O-acetyl ursolic acid (3), oleanolic acid (4), ursolic acid (5), masilinic acid (6), and tormentic acid (7), and three known norsesquiterpenoids, roseoside (8), vomifoliol (9) and (6S,7E,9R)-6,9-dihydroxy-4,7-megastigmadien-3-one 9-O-[β-d -xylopyranosyl (1 → 6)-glucopyranoside] (10). Their structures were elucidated on the basis of spectroscopic data and comparison with reference data. Besides compound 1, compounds 2, 8–10 were obtained from this genus for the first time. None of these compounds exhibited inhibitory activity against T-and B-lymphocyte proliferation.     

Three new alkaloids from the seeds of Nigella glandulifera

Three new alkaloids namely 8-(4-hydroxyphenyl)-6-methoxy-3,4-dihydroisoquinolin-1(2H)-one (1), 4-aminonigellidine (2), and N-[(4-hydroxy-2-isopropyl-5-methyl)]phenylurea (3), along with six known ones (4–9), were isolated from the seeds of Nigella glandulifera. The structures of 1–3 were determined through spectroscopic analyses (HRESIMS, 1D/2D NMR). Compound 1 was a rare isoquinolinone alkaloid with phenyl substituted at C-8.     

Lobophylins F-H: three new cembrene diterpenoids from soft coral Lobophytum crassum

Three new cembrenoids, lobophylins F-H (1–3), along with three known ones, lobophylins A-C (4–6), were isolated from the ethyl acetate extract of the Taiwan water soft coral Lobophytum crassum. The structures of isolated cembrenoids were elucidated on the basis of extensive spectroscopic methods such as IR, 1D, 2D NMR and HR–ESI–MS.     

Three new compounds from Cinnamomum cassia

Three new compounds, including two new diterpenoids, named epianhydrocinnzeylanol (1) and cinnacasiol H (2), and one hydroxylasiodiplodin, (3R,4S,6R)-4,6-dihydroxy-de-O-methyllasiodiplodin (3), together with five known diterpenoids (4–8) and two known phenolic glycosides (9–10) were isolated from the barks of Cinnamomum cassia. Their structures were elucidated by extensive spectroscopic analysis and comparison of the chemical shift values with those of related known compounds. The anti-inflammatory activities of the isolates were evaluated on nitric oxide production in lipopolysaccharide-induced BV-2 microglial cells and the compounds showed weak inhibition activities.     

Three new biphenyls from the twigs of Garcinia tetralata and their anti-tobacco mosaic virus activity

Phytochemical investigations on the ethanol extract of the twigs of Garcinia tetralata resulted in the isolation of three new biphenyls, tetralatabiphenyls A–C (1–3), along with three known biphenyl derivatives (4–6). Structural elucidations of 1–3 were performed by spectroscopic methods such as 1D and 2D NMR spectra, in addition to high-resolution mass spectra. Compounds 1–6 were also evaluated for their anti-tobacco mosaic virus (anti-TMV) activity. The results showed that compound 3 showed high anti-TMV activity with inhibition rate of 31.1%. Compounds 1, 2, and 4–6 also showed modest anti-TMV activities with inhibition rates in the range of 18.9–24.5%, respectively.     

A new sesquiterpene ester from the fruits of Celastrus orbiculatus

From the fruits of Celastrus orbiculatus Thunb., a new dihydroagarofuran sesquiterpene ester named 6α,13β-diacetoxy-1β,8β,9β-tribenzoyloxy-β-dihydroagarofuran (1) has been isolated, along with three known compounds: 1β,6α,8β-triacetoxy-9α-benzoyloxy-β-agarofuran (2), 1β,6α-diacetoxy-9α-benzoyloxy-β-dihydroagarofuran (3) and β-sitostrol (4). The structure of 1 was elucidated on the basis of spectroscopic methods.     

Diterpenoids from the freshwater green algae Rhizoclonium hieroglyphicum with antibacterial activity

Three new isopimarane diterpenes 7β-hydroxy-19α-methylmalonyloxy-isopimara-8(14),15-diene (1), 7β-hydroxy-14-oxo-isopimara-8(9),15-dien-19oic acid (2), and 7β-hydroxy-14-oxo-19α-methylmalonyloxy-isopimara-9(11),15-diene (3) in addition to the known compounds isopimaric acid (4), 7oxo-13-epi-pimara-14,15-dien-18oic acid (5), 7oxo-13-epi-pimara-8,15-dien-18oic acid (6), and 6β-hydroxyisopimaric acid (7) were isolated from the hexane extract of Rhizoclonium hieroglyphicum. The structures of compounds 1–7 were established by 1D and 2D NMR techniques. The isolated diterpenoids were screened for antimicrobial activity against gram-positive and gram-negative bacteria and yeast strains.     

Two new dihydrobenzofuran lignans from Rabdosia lophanthoides (Buch.-Ham.ex D.Don) Hara

Two new dihydrobenzofuran lignanosides, (7R,8S)-4,3′,9′-trihydroxyl-3-methoxyl-7,8-dihydrobenzofuran-1′-propylneolignan-9-O-(6-O-syringoyl)-β-d-glucopyranoside, named lophanthoside B (1) and (7R,8S)-4,9,9′-trihydroxyl-3-methoxyl-7,8-dihydrobenzofuran-1′-propylneolignan-3′-O-β-d-glucopyranoside (2), an enantiomer of umbroside, along with four known dihydrobenzofuran lignans (3–6), were isolated from 50% acetone extract of Rabdosia lophanthoides (Buch.-Ham.ex D.Don) Hara. Their structures were elucidated by NMR and MS experiments.     

Antibacterial constituents from Stemona sessilifolia

Bioassay-guided fractionation led to the isolation of eight compounds from Stemona sessilifolia. Of the eight isolates, three new bibenzyls, stilbostemins M–O (1–3), and a new tocopherol, 6-methoxy-3,4-dehydro-δ-tocopherol (4) were revealed together with four known compounds 3,5-dihydroxy-2′-methoxy bibenzyl (5), 3,5-dihydroxy bibenzyl (6), β-tocopherol (7), and γ-tocopherol (8). Compounds 5, 6, and 8 exhibited strong antibacterial activities against Staphylococcus aureus and S. epidermidis.     

Two new flavonol glycosides from the leaves of Cleome chelidonii L.f.

From the leaves of Cleome chelidonii L.f., two new flavonol glycosides, named cleomesides A (1) and B (2), and four known compounds, quercetin 3-O-β-glucopyranosyl(1 → 2)-α-rhamnoside-7-O-α-rhamnoside (3), ethyl α-galactopyranoside (4), adenine (5) and glycerol monostearate (6), were isolated. The structures of all isolated compounds (1–6) were determined by NMR spectroscopy and mass spectrometry. The data of known compounds (3–6) were further compared with the reported data for these compounds.     

Microbial transformation of pseudoprotodioscin by Gibberella fujikuroi

Abstract

Three new (6, 9, and 12) and nine known steroidal saponins were obtained from the fermentation broth of pseudoprotodioscin (PPD) incubated with a fungus Gibberella fujikuroi CGMCC 3.4663. Structures of the metabolites were elucidated by 1-D (¹H, ¹³C), 2-D (HMBC, HSQC, NOESY) NMR, and HR-MS analyses. The biotransformation pathway of pseudoprotodioscin by Gibberella fujikuroi CGMCC 3.4663 was proposed. Compounds 1–11 were tested in vitro for their cytotoxic activities against two human cancer cell lines (HepG2 and Hela). Compounds 1, 6, 9, and 10 exhibited cytotoxic activity against HepG2 cells. Compound 10 exhibited cytotoxicity to Hela cells.     

Four new C20-diterpenoid alkaloids from Aconitum rotundifolium

Four new C₂₀-diterpenoid alkaloids, rotundifosines D-G (1–4), along with eight known ones (5–12) were isolated from the whole plant of Aconitum rotundifolium Kar. & Kir. The structures of the compounds were elucidated on the basis of spectroscopic analyses, including HR-ESI-MS and 1D, 2D NMR. Rotundifosine F (3) is a rare C₂₀-diterpenoid alkaloid with quaternary ammonium salt. Alkaloids 1–4, 5, 6, 9, and 12 were evaluated for cytotoxicity against MCF-7, HCT-116 and HepG2 human cancer cell lines.