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Four new furostanol saponins (1 – 4) and a new pregane-type saponin (5) along with six known steroidal saponins (6 – 11) were isolated from the rhizomes of Smilax china. The structures of 1 – 5 were elucidated by extensive analysis of NMR and HR-ESI-MS data in addition to enzymatic hydrolysis and other chemical methods. Compounds 1, 4, and 11 showed inhibitory activity against the expression of proinflammatory mediators, inducible nitric oxide synthase, interleukin-1β, interleukin-6, and tumor necrosis factor-α in lipopolysaccharide-induced RAW264.7 cells. Compound 1, at a concentration of 20 µM, decreased the production of inducible nitric oxide synthase, interleukin-1β, interleukin-6, and tumor necrosis factor-α by 36, 62, 72, and 67%, respectively, which is comparable to that of the positive control dexamethasone.

A polyketide-derived alkaloid featuring a unique 3,4-dihydro-2H-indeno[1,2-b]pyridine 1-oxide motif, named phomopsol A (1), and a highly oxidized polyketide containing a new 3,5-dihydro-2H-2,5-methanobenzo[e][1,4]dioxepine moiety, named phomopsol B (2), were isolated from the Thai mangrove endophytic fungus Phomopsis sp. xy21, together with the related biosynthetic polyketide 3. The structures of 1-3 were unambiguously established by single-crystal X-ray diffraction analysis (Cu Kα), and their neuroprotective effects in PC12 cells were evaluated. The biosynthetic origins of 1-3 are proposed.

Luteolin is an important flavonoid with low water solubility and oral bioavailability properties, which limit its further clinical applications. In the present study, two new cocrystals of luteolin monohydrate with isoniazid and caffeine have been synthesized successfully using liquid assisted grinding method. Solid characterizations including X-ray diffraction, thermal and spectroscopic analysis were carefully performed to identify the two new cocrystals. Temperature-composition phase diagrams for both cocrystals were plotted through differential scanning calorimetry data. The maximum and minimum extreme values of all the compounds on molecular electrostatic potential surfaces that can be converted into hydrogen driving forces were calculated and illustrated. The luteolin-isoniazid cocrystal presents the solubility (112.3 μg mL−1) about three times better than luteolin monohydrate. In the pharmacokinetic analysis, the integrated AUC0-∞ of luteolin-isoniazid and luteolin-caffeine cocrystals performed 2.7 folds and 1.4 folds respectively more enhancements than luteolin monohydrate.

Seven undescribed 22-hydroxylanostane triterpenoids were isolated from the fruiting bodies of Phellinus igniarius, together with three known sterols. Their structures were assigned by extensive spectroscopic and HRESIMS data analyses. The absolute configurations of C-22 were determined by X-ray crystallography, chemical methods, and spectroscopic data comparison. Phellinol G was a 25,26,27-trinorlanostane triterpenoid glycoside. 22S/22R-25,26,27- Trinorlanosta-8-en-3β,22,24-triols with the same side chain as that of phellinol G were stereoselectively synthesized from commercial lanosterol for the first time. The key step involved Sharpless asymmetrical epoxidation. Phellinols A, B, and F showed cardioprotective activity against oxygen-glucose deprivation/reoxygenation injury in H9c2 cells at a concentration of 20 μM.

A new axial chiral binaphtoquinone, hypocrellone (

A new axial chiral binaphtoquinone, hypocrellone (1), and a new perylenequinone, hypomycin F (2), were isolated from the stromata of Hypocrella bambusae, together with five known compounds, 3-7. The structures of 1 and 2 were assigned by spectroscopic and HRESIMS data analyses. The axial chirality of 1 was determined by electronic circular dichroism data analysis, and the absolute configurations of 2 and 3 were determined by X-ray crystallography. The axial chirality of 7 was determined by UV-induced photooxidation from 4. Compounds 1, 4, and 5 showed inhibitory activity against pseudotyped SARS-CoV-2 infection in 293T-ACE2 cells with IC50 values of 0.17, 0.038, and 0.12 μM. Compounds 4 and 5 were also active against live SARS-CoV-2 infection with EC50 values of 0.22 and 0.21 μM, respectively. Further cell-cell fusion assays, surface plasmon resonance assays, and molecular docking studies revealed that 4 and 5 could bind with the receptor-binding domain of SARS-CoV-2 S protein to prevent its interaction with human angiotensin-converting enzyme II receptor. Our results revealed that 4 and 5 are potential SARS-CoV-2 entry inhibitors.

Nine new ent-abietanes, named decandrols A-I (1-9), which could be categorized into three groups (1, 2-6, 7-9), were isolated from the roots of an Indian mangrove, Ceriops decandra, collected in the swamp of Godavari estuary, Andhra Pradesh, together with six previously reported abietanes (10-15), of which the absolute configurations were first determined. The relative and absolute configurations of these compounds were unambiguously established by HR-ESIMS, extensive 1D and 2D NMR investigations, single-crystal X-ray diffraction analysis with Cu Kα radiation, and quantum-chemical electronic circular dichroism (ECD) calculations. Decandrol A (1) is a rare C9-spirofused 7,8-seco-ent-abietane, whereas 2-15 are typically tricyclic ent-abietanes. Decandrols C (3) and E (5) exhibited significant NF-κB inhibitory activity at the concentration of 100 μM.

Mass-guided isolation of the dichloromethane/methanol extracts from a specimen of teleomorphic fungus of the family Cortinariaceae resulted in the identification of a new dimeric cyclobutane metabolite, achyrodimer F (1), along with the monomers hispidin (2) and bisnoryangonin (3). Their structures were determined by NMR and MS data analyses. Density Function Theory (DFT) NMR calculations was employed to confirm the chemical structure of achyrodimer F. Compound 1 inhibited tyrosyl-DNA phosphodiesterase I with an IC50 value of 1 μM.

The Smilax species, widely distributed in tropical region of the world and the warm areas of East Asia and North America, are extensively used as folk medicine to treat inflammatory disorders. Chemical investigation on Smilax species showed they are rich sources of steroidal saponins with diversified structure types, including spirostane, isospirostane, furostane, pregnane, and cholestane. This review mainly summarizes the steroidal saponins (1–104) reported from the genus Smilax between 1967 and 2016, and their biological activities. The relationship between structures of steroidal saponins and related biological activities were briefly discussed. Graphical Abstract

A polyketide-derived alkaloid featuring a unique 3,4-dihydro-2

A new oleanane triterpenoid, 2

Seven new furostanol saponins (1–7), chongrenosides A-G, were isolated from the rhizomes of Smilax china L., together with nine known furostanol saponins (8–16). The structures of the new furostanol saponins (1–7) were elucidated by extensive spectroscopic data analyses (1D and 2D NMR, HRESIMS) and chemical evidence. Compounds 1–6 and 8–16 were evaluated for TNF-α mRNA expression inhibitory activity on LPS induced RAW264.7 cells. Of them, 1, 4, 6, and 11 inhibited the TNF-α mRNA expression by 88%, 87%, 67%, and 93%, respectively, at the concentration of 10 µM.

Mass-directed isolation of the CH2Cl2/MeOH extract from the bark of an Australian plant, Macropteranthes leichhardtii, resulted in the purification of a new phenylpropanoid glucoside, macropteranthol (1), together with four known analogues (2-5). The structure of compound 1 was elucidated by NMR and MS data analyses and quantum chemical calculations. Compounds 3 and 5 showed inhibitory activity against tyrosyl-DNA phosphodiesterase I with IC50 values of ∼1.0 μM.

A new triflavanoid, kandelin B-5 (1), was isolated from the rhizomes of Smilax china L., together with six known phenylpropanoid substituted flavan-3-ols (2–7), nine flavonoids (8–16), two stilbenoids (17, 18), and two other compounds (19, 20). The structure of compound 1 was determined on the basis of 1D, 2D NMR and HR-ESI-MS data, as well as chemical method. Compounds 2–5, 8–12, 15, 17, and 19 were evaluated for anti-inflammatory activity. Only compounds 10, 15 and 17 showed slightly IL-1β expression inhibitory activities on LPS induced THP-1 cells, with inhibition rate of 15.8%, 37.3%, and 35.8%, respectively, at concentration of 50 μg/mL.

A new dimeric stilbene, gnetifolin P (1), was isolated from the lianas of Gnetum parvifolium, together with seven known compounds 2–8. The structure of compound 1 was determined by extensive NMR and HRESIMS data analyses, and quantum chemical calculations. All the compounds were evaluated for their anti-inflammatory activity. Compounds 1 and 6 inhibited the expression of IL-1β on LPS induced THP-1 cells with the inhibition rate of 35.78 and 64.67%, respectively, at concentration of 25 μg/mL.

Two new phloroglucinol-coupled sesquiterpenoids, eucalmaidials A and B (1 and 2), were isolated from the juvenile leaves of Eucalyptus maideni, along with eight known macrocarpals (3–10), eucalyptone (11), and three known triterpenoids (12–14). Eucalmaidials A and B represent a new skeleton of phloroglucinol-coupled iphionane. Their structures were elucidated by extensive NMR spectroscopic analysis and theoretical calculation of the 13C NMR chemical shifts. The biosynthetic pathway of 1 and 2 was also postulated. Compounds 1, 3, 5, 7, 8, and 10–14 were evaluated for their antifungal and antibacterial activities. Compound 1 exhibited antifungal activity against Candida glabrata with an IC50 value of 0.75 μg mL−1.

A new hopantenic acid derivative, (R)-methyl-4-(2,4-dihydroxy-3,3-dimethylbutanamido)butanoate (1), was isolated from the rhizomes of Heterosmilax japonica Kunth, together with three known compounds, (3S)-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (2), daucosterol (3), and ethyl-β-D-xylobioside (4). The structure of 1 was determined by extensive spectroscopic analyses, including 1D and 2D NMR and HR-ESI-MS. Compounds 2 and 4 are new for the genus Heterosmilax.

A polyketide-derived alkaloid featuring a rotationally hindered C-9–C-9a axial bond and a unique 3,4-dihydro-2H-indeno[1,2-b]pyridine-1-oxide motif, named phomopsol A (1), and a highly oxidized polyketide containing a new 3,5-dihydro-2H-2,5-methanobenzo[e][1,4]dioxepine moiety, named phomopsol B (2), were isolated from the Thai mangrove endophytic fungus Phomopsis sp. xy21, together with the known compound 3. The absolute stereostructures of 1–3 were unambiguously established by single-crystal X-ray diffraction analysis (Cu Kα). Biosynthetic origins of 1–3 are proposed.

Four different rose hybrid populations were analyzed by ISSR technique with nine polymorphic primers. All of the primers produced 64 bands, of which 59 were polymorphic. The average of polymorphic bands was 6.6 for each primer. The percentage of polymorphism ranged from 57.1% to 100%, with an average of 92.3%. An UPGMA dendrogram showed five groups. The primer numbered with PI9 and PI11 had relatively high resolution in identifying the F 1 offspring in this research.

Three new phenolic compounds, eucalmaidin F (1), (3S)-5-guaiacyl-3-hydroxypentanoic acid (2), and 8-beta-C-glucopyranosyl-5,7-dihydroxy-2-isobutylchromone (3), were isolated from the branches of E. maideni, together with 30 known compounds, including four phenylpropanoids, three lignans, four phloroglucinol glucosides, five dihydroflavonoids, seven simple phenolic compounds, six terpenoids, and glycerol. The new structures were established by spectroscopic studies (MS, and 1D- and 2D-NMR), chemical degradation, and modified Mosher's method. Compounds 3, guaiacylglycerol, 3-hydroxy-1-(4-hydroxyphenyl)propan-1-one, caffeic acid, (2E)-3-(4-hydroxyphenyl)prop-2-enoic acid, (7'S,8R,8'R)-lyoniresinol, (+)-lyoresinol 3a-O-a-L-rhamnopyranoside, garcimangosone, phlorocetophenone 2'-glucopyranoside, (+)-taxifolin 3a-O-a-L-rhamnopyranoside, (+)-aromadendrin, (+)-taxifolin, resveratrol, piceatannol, 3,4,5-trihydroxyphenol. Tachiaside, gallic acid, macrocapals A und G, and oleuropeic acid were evaluated for their cytotoxicities against five human cancer cell lines. Resveratrol, piceatannol, gallic acid, and macrocapal G exhibited moderate inhibitory effects on human myeloid heukemia HL-60 cell, with IC50 values of 22.05, 22.05, 7.75, and 31.93 mu M, respectively; and only macrocapal G showed inhibitory effect on hepatocellular carcinoma SMMC-7721 cell, with an IC50 value of 26.75 mu M.

Four new phenolic compounds 7 O methylcatechin 5 O-beta-D glucopyranoside (1), 6 O feruloyl D-glucopyranose (2), demethylpiperitol 4 O-beta D-glucopyranoside (3), and 2 episesaminol 2-O beta-D glucopyranoside (4) were isolated from the fresh leaves of Eucalyptus maideni, together with six hydrolyzable tannins 5-10, a flavonol glycoside, 11 three simple phenolics 12-14, a monoterpene glucoside 15 and a rosenoside, 16 Their structures were determined on the basis of detailed spectroscopic analysis, acidic hydrolysis and enzymatic hydrolysis The known compounds 10 and 13 were obtained from the genus Eucalyptus for the first time