Complex Flavanones from Cryptocarya metcalfiana and Structural Revision of Oboflavanone A.

Nine new complex flavanones, cryptometcones A-I (1-9), along with four known analogues, were isolated from Cryptocarya metcalfiana. The structures of 1-9 including their absolute configurations were elucidated by spectroscopic data analysis and electronic circular dichroism (ECD) calculations. In addition, the structure of oboflavanone A was revised, while the absolute configurations of oboflavanone B, cryptoflavanone C, and cryptoflavanone D were determined, according to their spectroscopic data. Compounds 3-5, 8, and 9 exhibited cytotoxicity against the HCT-116 cancer cell line.

Two Novel Flavonoids and Cytotoxicity Evaluation from Cryptocarya yunnanensis.

Two new flavonoids, cryunchalcone (1) and cryptoyunnanone I (2), were isolated from the leaves and twigs of Cryptocarya yunnanensis. Their structures were elucidated by the detailed spectroscopic data analysis and electronic circular dichroism (ECD) calculations. Cryunchalcone (1) is a biflavonoid constructed by a dihydrochalcone coupled with a chalcone through an unprecedented C-2''-C-6 linkage. Cryptoyunnanone I (2) is a unique complex flavanone bearing a phenylpropanoid moiety.

Cryptoyunnanones A-H, Complex Flavanones from Cryptocarya yunnanensis.

Eight new complex flavanones with a novel linkage, cryptoyunnanones A-H (1-8), together with four known α-pyrones, were isolated from the leaves and twigs of Cryptocarya yunnanensis. The structures of 1-8 including their absolute configurations were characterized by spectroscopic data analysis and single-crystal X-ray crystallography. Plausible biosynthetic pathways for the formation of compounds 1-8 were proposed. Compounds 1-4 exhibited cytotoxicity against HCT-116, MDA-MB-231, and PC-3 cancer cells with IC50 values from 6.4 to 9.1 µM.

Iridoid Constituents of Viburnum brachybotryum.

Eleven new iridoids, brachybones A-K (1-11), were isolated from the twigs of Viburnum brachybotryum. Their structures including absolute configurations were determined by spectroscopic data analysis and from the electronic circular dichroism (ECD) spectra. All of the compounds 1-11 possess one or two acetoxysenecioate substituents. Furthermore, compounds 5-7 and 11 feature a Cl atom in the molecule, while compounds 9-11 exhibit a cagelike rigid skeleton through an unusual oxo bridge from C-3 to C-8 or C-10. The isolates were evaluated for cytotoxic activity against the HCT-116, A549, and Hela cell lines, and the results showed compounds 10 and 11 to be active against HCT-116 cells.

Neolignans and Sesquiterpenoid from Piper yunnanense.

Two biphenyl-type neolignans with a rare dibenzofuran skeleton, including a new one piyunneolignan A (1) and a known one piperneolignan D (2), together with a new sesquiterpenoid piyunin A (3), were isolated from the leaves and twigs of Piper yunnanense. Their structures were established on the basis of comprehensive spectroscopic data analysis and electronic circular dichroism (ECD) calculation. Piyunneolignan A (1) featured a rare C-2-C-2'/C-3-O-C-3' linkage. Compounds 1-3 were evaluated for their antimicrobial and cytotoxic activities against a panel of bacteria, fungi, and human cancer cell lines, respectively.

(±)-Meliviticines A and B: Rearranged prenylated acetophenone derivatives from Melicope viticina and their antimicrobial activity.

Two new prenylated acetophenone derivatives racemates, meliviticines A (1) and B (2) with unprecedented rearranged skeletons, were isolated from Melicope viticina. Subsequent chiral resolution led to the separation of two pairs of enantiomers, (±)-meliviticines A (1a/1b) and (±)-meliviticines B (2a/2b). Their structures including absolute configurations were elucidated by extensive spectroscopic data, electronic circular dichroism analysis, and X-ray crystallography. A plausible biosynthetic pathway of 1 and 2, involving ring cleavage and rearrangement of the prenylated acetophenone backbone was proposed. All the isolates showed moderate antimicrobial activities with MIC values of 25-50 µg/mL against several bacterial and fungal strains.

Phragmalin-type limonoids with NF-κB inhibition from Chukrasia tabularis var. velutina.

Chemical investigation on Chukrasia tabularis var. velutina led to the identification of eight new phragmalin-type limonoids (1-8), as well as 20 known analogues. Compounds 1-4 are a rare class of C-15-acyl phragmalin-type limonoids, and particularly compounds 2-4 also possess a δ-lactone ring formed between C-16 and C-30. All the isolates were evaluated for inhibitory effects on NF-κB production, and four of which showed significant inhibitions.

Sesquiterpenes from Dysoxylum oliganthum and Dysoxylum excelsum.

Three new sesquiterpenes (1-3), (6R,7S,11R,10S)-15-hydroxy-sesquisabinene hydrate (1), (6R,7R,11S,10S)-15-hydroxy-sesquisabinene hydrate (2), and (6R,7R,10S)-15-hydroxy-zingiberenol (3), along with three known compounds, were isolated from the stems of Dysoxylum oliganthum; and three new isodaucane (salvionane) sesquiterpenes, namely isodauc-6-ene-10ß,14-diol (4), 4-epi-isodauc-6-ene-10ß,14-diol (5), and 4-epi-6α,10ß-dihydroxy-artabotrol (6) together with 15 known compounds were isolated from the twigs and leaves of D. excelsum. Their structures were established on the basis of extensive spectroscopic analysis and chemical shifts. The absolute configuration of C-10 in compounds 1-3 of a rare class was determined by using Snatzke's method.

Geranyl phenyl ethers from Illicium micranthum and their anti-HBV activity.

Fourteen new geranyl phenyl ethers (1-14) along with three known compounds (15-17) were isolated from Illicium micranthum, and their structures were elucidated by comprehensive spectroscopic methods. Illimicranins A-H (1-8) were characterized as geranyl vanillin ethers, while 9 and 10 were dimethyl acetal derivatives. Illimicranins I and J (11 and 12) were rare geranyl isoeugenol ethers. Illimicranins K and L (13 and 14) represented the first example of geranyl guaiacylacetone ether and geranyl zingerone ether, respectively. Compounds 1, 2 and 15 exhibited anti-HBV (hepatitis B virus) activity against HBsAg (hepatitis B surface antigen) and HBeAg (hepatitis B e antigen) secretion, and HBV DNA replication.

Cytotoxic α-pyrone derivatives from Cryptocarya yunnanensis.

Five new α-pyrone derivatives, cryptoyunnanes A - E (1 - 5), together with four known analogues, were isolated from the leaves and twigs of Cryptocarya yunnanensis. Their structures including absolute configurations were elucidated by extensive spectroscopic data and electronic circular dichroism (ECD) analyses. Compounds 4 and 6 showed significant cytotoxicity against A549, HCT-116, MDA-MB-231, PC-3 and HeLa with IC50 values from 2.25 to 8.97 µM. Compounds 1, 2 and 7 also displayed good cytotoxicity against HCT-116, MDA-MB-231 and PC-3 with IC50 values from 1.26 to 8.32 µM. This is the first time to report the isolation and bioactivity evaluation of chemical constituents from C. yunnanensis.

Six pairs of phenylpropanoid enantiomers from Cinnamomum mollifolium.

Six pairs of undescribed phenylglycerol benzoate enantiomers, (±)-mollifolines A-F, which can also be categorized into three two-pairs of epimers, were isolated from Cinnamomum mollifolium H. W. Li (Lauraceae). The relative configurations (threo or erythro) of the epimers were determined by conformational searching of the lowest energy conformers and analyses of the relationship between the dihedral angle of H-7'─C-7'─C-8'─H-8' and the 3JH-7', H-8' coupling constant according to the Karplus equation. Furthermore, intramolecular hydrogen bonds were proved to play an important role in stabilizing the lowest conformations by using reduced density gradient (RDG) method for noncovalent interactions. Chiral resolutions of these enantiomer pairs were accomplished by immobilized polysaccharide derivative-based chiral HPLC columns. Absolute configurations of the 12 optically pure isomers were finally determined by quantum chemical time-dependent density functional theory (TDDFT) calculations of their electronic circular dichroism (ECD) spectra.

Onoceranoid-type triterpenoids from Lansium domesticum.

A rare class of onoceranoid-type triterpenoids, represented by lamesticumin A (1), the ethanolysis product of lamesticumin A (2), lamesticumins B-F (3-7), lansic acid 3-ethyl ester (8), and ethyl lansiolate (9), along with four known analogues were isolated from the twigs of Lansium domesticum. Their structures were elucidated on the basis of extensive spectroscopic analysis, and the absolute configuration of C-21 in compound 7 was assigned by using Snatzke's method. Compounds 1-9 exhibited moderate antibacterial activity against Gram-positive bacteria.

Daphnane-type diterpenoids from Trigonostemon howii.

Nine new daphnane-type diterpenoids (1-9), named trigohownins A-I, and four known analogues were isolated from Trigonostemon howii. Their structures were elucidated on the basis of extensive NMR and MS analyses. Trigohownins A (1) and D (4) exhibited moderate cytotoxic activity against the HL-60 tumor cell line, with IC50 values of 17.0 and 9.3 µM, respectively.

Limonoids and Diterpenoids from Toona ciliata Roem. var. yunnanensis.

Three new limonoids (toonaciliatins N-P, 1-3)and four new pimaradiene-type diterpenoids(toonacilidins A-D, 4-7) were isolated from the leaves and twigs of Toona ciliata Roem. var. yunnanensis.Their structures were elucidated on the basis of spectroscopic methods. Toonacilidin B(5)showed moderate inhibitory activity against H. pylori-SS1 with an MIC of 50 µg/mL.

Phragmalin-type limonoid orthoesters from the twigs of Swietenia macrophylla.

Eleven new phragmalin-type limonoids, swietenitins N-X (1-11), together with a known one, epoxyfebrinin B (12), were isolated from the twigs of Swietenia macrophylla. The structures of the new compounds were established on the basis of spectroscopic methods, and that of compound 1 was confirmed by single-crystal X-ray diffraction. The stereochemistry of epoxyfebrinin B (12) was fully assigned in this study.

Limonoids and triterpenoids from the seeds of Melia azedarach.

Three limonoids (1-3), and two triterpenes (4) and (5), along with twelve known compounds, were isolated from the seeds of Melia azedarach. Their structures were established on the basis of extensive spectroscopic analysis. Compound 3 showed moderate antimicrobial activity.

Limonoids and triterpenoids from Khaya senegalensis.

Seven new limonoids (1-7), named khayalenoids C-I, three new triterpenoids (8-10), named senegalenes A-C, and eight known limonoids have been isolated from stems of Khaya senegalensis. The structures of these compounds were elucidated on the basis of spectroscopic analyses.

Mesendanins A-J, limonoids from the leaves and twigs of Melia toosendan.

Ten new limonoids, namely, mesendanins A-J (1-10), together with 14 known compounds, have been isolated from the leaves and twigs of Melia toosendan. Their structures were established on the basis of spectroscopic data analysis.

Lignans and Neolignans with Antioxidant and Human Cancer Cell Proliferation Inhibitory Activities from Cinnamomum bejolghota Confirm Its Functional Food Property.

In the aim to evaluate the functional food property of Cinnamomum bejolghota, seven new lignans and neolignans, bejolghotins A-G (1-4 and 9-11), along with 14 known ones (5-8 and 12-21), were isolated and their structures including absolute configurations were elucidated by extensive spectroscopic data and electronic circular dichroism (ECD) analyses. All of the isolates were tested for antioxidant and human cancer cell proliferation inhibitory activities. Twenty compounds showed comparable antioxidant activity to the positive controls, and three significantly inhibited the growth of three cancer cell lines HCT-116, A549, and MDA-MB-231 with IC50 values of 0.78-2.93 µM, which confirmed its health benefits.

Anti-hepatitis B virus activity of swertisin isolated from Iris tectorum Maxim.

ETHNOPHARMACOLOGICAL RELEVANCE: Iris tectorum Maxim (I. tectorum, Yuan Wei in Chinese) is a common and traditional Chinese medicinal herb that be used to treat liver-related diseases. However, the anti-HBV activity of I. tectorum and its isolates has not been systemically studied. AIM OF THE STUDY: To screen the active part of I. tectorum and systemically evaluate their anti-HBV activity. MATERIALS AND METHODS: In this study, a series of compounds from I. tectorum were evaluated for their ability to inhibit HBV replication. Swertisin showed a significant inhibitory function on HBV replication. Then, the suppression effect of different concentrations of swertisin in HBsAg, HBeAg and HBV DNA level in HepG2.2.15 cells and HBV-infected HepG2-NTCP cells were comprehensive evaluated, respectively. Moreover, the anti-HBV effects of swertisin were confirmed in HBV transgenic mice model. RESULTS: Among these compounds, swertisin strongly inhibited the HBsAg, HBeAg and HBV DNA level in a dose-dependent manner in HepG2.2.15 cells and HBV-infected HepG2-NTCP cells. Furthermore, swertisin showed a significant inhibition role on HBV replication in HBV transgenic mice model, the inhibition effect of which was enhanced when combined with ETV. CONCLUSIONS: We have identified that swertisin can inhibit HBeAg and HBsAg production, as well as HBV DNA in vitro and in vivo. This study show that we may found a novel compound isolated from traditional Chinese medicines with potent anti-HBV function.