Isolation, Characterization and Antibacterial Activity of 4-Allylbenzene-1,2-diol from Piper austrosinense.

Isolation for antibacterial compounds from natural plants is a promising approach to develop new pesticides. In this study, two compounds were obtained from the Chinese endemic plant Piper austrosinense using bioassay-guided fractionation. Based on analyses of 1H-NMR, 13C-NMR, and mass spectral data, the isolated compounds were identified as 4-allylbenzene-1,2-diol and (S)-4-allyl-5-(1-(3,4-dihydroxyphenyl)allyl)benzene-1,2-diol. 4-Allylbenzene-1,2-diol was shown to have strong antibacterial activity against four plant pathogens, including Xanthomonas oryzae pathovar oryzae (Xoo), X. axonopodis pv. citri (Xac), X. oryzae pv. oryzicola (Xoc) and X. campestris pv. mangiferaeindicae (Xcm). Further bioassay results exhibited that 4-allylbenzene-1,2-diol had a broad antibacterial spectrum, including Xoo, Xac, Xoc, Xcm, X. fragariae (Xf), X. campestris pv. campestris (Xcc), Pectobacterium carotovorum subspecies brasiliense (Pcb) and P. carotovorum subsp. carotovorum (Pcc), with minimum inhibitory concentration (MIC) values ranging from 333.75 to 1335 µmol/L. The pot experiment showed that 4-allylbenzene-1,2-diol exerted an excellent protective effect against Xoo, with a controlled efficacy reaching 72.73% at 4 MIC, which was superior to the positive control kasugamycin (53.03%) at 4 MIC. Further results demonstrated that the 4-allylbenzene-1,2-diol damaged the integrity of the cell membrane and increased cell membrane permeability. In addition, 4-allylbenzene-1,2-diol also prevented the pathogenicity-related biofilm formation in Xoo, thus limiting the movement of Xoo and reducing the production of extracellular polysaccharides (EPS) in Xoo. These findings suggest the value of 4-allylbenzene-1,2-diol and P. austrosinense could be as promising resources for developing novel antibacterial agents.

New 2-(2-Phenylethyl)chromone derivatives from agarwood originating from Aquilaria sinensis.

Two new dimeric 2-(2-phenylethyl)chromones, aquilasinenones L and M (1 and 2), and one new monomer analogue, 5S, 6 R, 7S, 8 R-tetrahydroxy-[2-(3-methoxy-4-hydroxyphenyl)ethyl]- 5,6,7,8-tetrahydrochromone (3), together with two known compounds, were isolated from the artificial agarwood originating from Aquilaria sinensis. Compound 1 was the first structure found with C8-O-C4"' linkage among 2-(2-phenylethyl)chromone dimers. Their structures were unambiguously elucidated based on 1 D and 2 D NMR spectroscopy, as well as by comparison with the literature. The absolute configuration was determined by ECD calculation. None of the compounds exhibited acetylcholinesterase inhibitory activity.

Swietenine extracted from Swietenia relieves myocardial hypertrophy induced by isoprenaline in mice.

As a traditional plant medicine in tropical areas, Swietenia macrophylla seeds are usually applied for some chronic diseases, including hypertension, diabetes, and so on. Few studies have been carried out to identify the effective elements in seed extract and their indications. In this study, we first investigated the functions of the swietenine, an extract from S. macrophylla seeds, using a model of myocardial hypertrophy induced by isoprenaline (ISO). At cellular level, H9c2 cell hypertrophy was also established through the treatment with ISO. The cardiac pathological remodeling was evaluated by echocardiography and histological analysis. Western blot and RT-qPCR were used to detect the expression of possible hypertrophy-promoting genes. Here, our results indicated that swietenine remarkably attenuated ISO-induced myocardial hypertrophy in vivo and in vitro. Moreover, Akt phosphorylation, ANP and BNP mRNA expression were efficiently decreased. Based on these findings, we concluded that swietenine might be a promising anti-hypertrophic agent against cardiac hypertrophy.

Six New Phragmalin Limonoids from the Stems of Chukrasia tabularis A. Juss.

Six new phragmalin limonoids, named moluccensin Z1 (1), moluccensin Z2 (2), carapanolide Y (3), tabulalin N (4), chukvelutilide A1 (5), and velutinasin J (6), as well as two known compounds, chukvelutilide A (7) and velutinasin D (8) were isolated from the stems of Chukrasia tabularis A. Juss. The structures of the new compounds 1⁻6 were confirmed by spectroscopic methods, including IR and HRESIMS, as well as 1D and 2D NMR, and by comparisons with the data of known analogues. All compounds were tested for α-glucosidase and acetylcholinesterase inhibitory activities. However, none of the compounds was active against α-glucosidase and acetylcholinesterase in vitro.

Metabolites with Insecticidal Activity from Aspergillus fumigatus JRJ111048 Isolated from Mangrove Plant Acrostichum specioum Endemic to Hainan Island.

Fungi residing in mangroves are considered to be a bank of novel bioactive natural products. In the screening for bioactive metabolites from mangrove-derived fungi, the ethyl acetate extract of the fermentation broth of Aspergillus fumigatus JRJ111048, a fungus isolated from the leaves of the mangrove plant Acrostichum specioum endemic to Hainan island, was found to possess insecticidal activity against Spodoptera litura. Bioactivity-guided isolation lead to the discovery of seven metabolites 1-7, including one new anhydride derivative aspergide (1), one new lipid amide 11-methyl-11-hydroxyldodecanoic acid amide (2), and five known compounds; α-ethyl glucoside (3), spiculisporic acid B (4), spiculisporic acid C (5), spiculisporic acid (6), and secospiculisporic acid B (7). Their structures were established by NMR spectroscopic and MS analyses, and by comparison of previously reported data. Insecticidal activity against S. litura and antifungal activity of these compounds were investigated. As a result, the new compound 1 showed potent insecticidal activity against newly hatched larvae of S. litura, and compound 4 displayed weak antifungal activity against Candida albicans.

Mexicanolide-Type Limonoids from the Roots of Trichilia sinensis.

Four new mexicanolide-type limonoids 1-4, along with two known limonoids 5-6, were isolated from the ethanolic extracts of roots of the Traditional Chinese Medicine Trichilia sinensis. Their structures were unambiguously determined by analysis of spectroscopic data, including 1D and 2D NMR as well as MS, and by comparison with literature data. In addition, the acetylcholinesterase (AChE) inhibitory activity of compounds 1-6 was evaluated by the Ellman method. All these compounds showed weak AChE inhibitory activity, with the inhibition percentages ranging from 18.5% to 27.8%.

A new antibacterial denitroaristolochic acid from the tubers of Stephania succifera.

A new denitroaristolochic acid, demethylaristofolin C (1), together with six known alkaloids, crebanine N-oxide (2), (-)-sukhodianine-ß-N-oxide (3), palmatine (4), corydalmine (5), dehydrocorydalmine (6), and corynoxidine (7), was isolated from the tubers of Stephania succifera. The structure of demethylaristofolin C was elucidated by spectroscopic techniques (UV, IR, 1D, and 2D NMR) and HR-ESI-MS analyses. These compounds exhibited antibacterial activities against Staphylococcus aureus and methicillin-resistant S. aureus strains in different degrees.

Two new acridone alkaloids from the branch of Atalantia buxifolia and their biological activity.

Two new acridone alkaloids, 3-methoxy-1,4,5-trihydroxy-10-methylacridone (1) and 2,3-dimethoxy-1,4,5-trihydroxy-10-methylacridone (2), were isolated from the ethanol extract of the branch of Atalantia buxifolia. Their structures were elucidated by spectroscopic methods including 1D and 2D NMR. Compounds 1 and 2 exhibited significant antibacterial activity against Staphylococcus aureus and weak inhibitory effect on acetylcholinesterase.

Seven new 2-(2-phenethyl)chromone derivatives from agarwood of Aquilaria walla.

Two rare flavonoid-2-(2-phenylethyl)chromones and five new dimeric 2-(2-phenylethyl)chromones were isolated from ethanol extract of agarwood of Aquilaria walla by LC-MS-guided fractionation procedure. Their structures were established based on extensive spectroscopic methods including HRESIMS, 1D and 2D NMR, as well as by comparison with the literature. Compound 1 showed cytotoxic activity against five human cancer cell lines with IC50 values ranging from 13.40 to 28.96 µM with cisplatin as the positive control.

Swietenine Alleviates Vascular Remodelling by Enhancing Mitophagy of Pulmonary Arterial Smooth Muscle Cells in Experimental Pulmonary Hypertension.

BACKGROUND: Vascular remodelling during pulmonary hypertension (PH) is characterized by the phenotypic transformation of pulmonary arterial smooth muscle cells (PASMCs). Swietenine (Swi), extracted from the seeds of traditional medicine Swietenia mahagoni, has been used to treat cardiac remodelling, but the effect of Swi on PH is unknown. This study aims to evaluate the effect of Swi on hypoxia-induced phenotypic transformation of PASMCs in experimental PH. METHODS: In our research, C57BL/6 mice were treated with SU5416 and exposed to hypoxia for 4 weeks to establish HySu-PH model. Mice in the Swi treatment group were subjected to HySu with daily administration of Swi. Hemodynamic parameters, echocardiography, and degree of vascular muscularization were measured to evaluate the PH model. Proliferation of PASMC was assessed by Ki67 and EdU assay. Cell migration was detected by wound-healing assay. Mitophagy levels were evaluated by mito-tracker and lyso-tracker, autophagic flux, and protein expression of Pink1 and Lc3 II. The molecular docking was used to validate the interaction of Swi with Nrf2. Immunofluorescence and immunohistochemical staining were applied to determine the subcellular localization of Nrf2. RESULTS: The results showed that Swi attenuated hypoxia-induced increase of right ventricle systolic pressure, Fulton index, and vascular remodelling and decreased PASMC proliferation, migration, and enhanced mitophagy. Furthermore, the interaction of Swi with Nrf2 promoted the translocation of Nrf2 into the nucleus, resulting in the induction of Pink1. CONCLUSIONS: This study demonstrates that Swi prevents vascular remodelling in experimental PH through inhibition of phenotypic transformation and hyperproliferation of PASMCs caused by reversing hypoxia-induced inhibition of mitophagy.

A new ergostane derivative from the leaves of Heynea trijuga Roxburgh.

During the course of searching for structurally interesting and bioactive compounds, a further chemical investigation of the leaves of Heynea trijuga Roxburgh was performed, which led to the isolation of a new ergostane derivative, named 3ß, 4ß, 20S-trihydroxyergosta-5, 24(28)-dien-16-one (1), together with five known sterides (3ß, 23S)-ergosta-5, 24(28)-diene-3, 23-diol (2), ergosta-5, 24(28)-diene-3ß-diol (3), stigmast-5-ene-3ß, 7α-diol (4), sitoindoside I (5) and stigmast-3ß, 5α, 6ß-triol (6). The structure of the new compound was elucidated using a combination of 1 D, 2 D NMR techniques and HR-EI-MS analyses. All the compounds were evaluated for cytotoxic activity against tumor cell line BEL-7402 by MTT method.

Limonoids from the roots of Trichilia sinensis and their cytotoxicities.

Six new compounds (1-4, 8, 10), along with six known limonoids (5-7, 9, 11, 12), were isolated from the roots of Trichilia sinensis. Their structures were elucidated on the basis of extensive spectroscopic methods including 1H NMR, 13C NMR, DEPT, HSQC, HMBC, 1H-1H COSY and ROESY experiments, as well as by comparison with the literature. All the compounds were evaluated for cytotoxicities against K562, SGC-7901 and BEL-7402 cell lines. Compounds 2, 7, 10, 11, and 12 showed weak inhibitory activity to the selected cell lines.

A new insecticidal havanensin-type limonoid from the roots of Trichilia sinensis Bentv.

One new havanensin-type limonoid (1) named trisinlin A with two known compounds (4E,8E)-2-[2'-hydroxyhexadecanoyl amino]-4,8-octadecadiene-1,3-diol (2), 9-octadecenoic acid-2',3'-dihydroxypropyl ester (3) were isolated from the roots of Trichilia sinensis. The structure of the new compound was unambiguously determined through comprehensive spectroscopic analyses including 1D and 2D NMR, and mass spectrometry, as well as by comparison with the literature. Trisinlin A showed significant insecticidal activity against newly hatched larvae of Spodoptera litura.

A new dolabellane diterpenoid and a sesquilignan from Aglaia odorata var. microphyllina.

One new diterpenoid, 11alpha,12betaH-dolabella-4,8(17)-dien-3alpha,7beta,18-triol (1) and one new sesquilignan, 9-methoxy-7',8'-cis-7",8"-cis-buddlenol B (2), together with three known compounds, (+)-diasyringaresinol (3), N-methyl-5- hydroxy-delta3-pyrrolin-2-one (4) and marmin (5), have been isolated from Aglaia odorata var. microphyllina. Their structures were determined using 1D and 2D NMR spectroscopy. Compound 1 exhibited cytotoxic activity against the K562 cell line with an IC50 value of 12.5 microg/mL.

New sesquiterpenoids from Aglaia odorata var. microphyllina and their cytotoxic activity.

One new norsesquiterpene (1), and four new sesquiterpenes (2 - 5), along with four known ones, were isolated from the twigs of Aglaia odorata var. microphyllina C. DC. Monogr. Their structures were established based on spectroscopic methods including HR-ESI-MS, 1D, and 2D NMR. Compounds 1, 3, and 6 showed cytotoxic activity against SGC-7901 tumor cell.

Ethnobotanical study on medicinal plants around Limu Mountains of Hainan Island, China.

AIM OF THE STUDY: The main objectives were to document traditional knowledge on the use of medicinal plants and compare medicinal plant traditions between Li and Hmong living around Limu Mountains of Hainan Island. MATERIAL AND METHODS: Information was obtained from semi-structured interviews, personal conversation and guided fieldtrips with herbalists. Quantitative methods, such as the coefficient of similarity (S), Chi-square analysis and the 'informant agreement ratio' were applied for the comparison of medicinal plant tradition between Li and Hmong. RESULTS: In all, 224 plant species grown in the study areas are still traditionally used for the treatment of various diseases. Euphorbiaceae (17 species), Rubiaceae (16 species), Papilionaceae and Poaceae (11 species, respectively), Verbenaceae (10 species) and Compositae (7 species) are predominant families used by herbalists. The most species were reported to be used for injuries (25.1% of all the medicinal use-reports), digestive system disorders (24.8%), infections/infestations (14.7%) and muscular-skeletal system disorders (12.3%). The coefficient of similarity (29.0%) shows a relatively high overlap of medicinal plants used by Li and Hmong. Using Chi-square analysis, it was found that habit mentions were dependent upon the culture. Infections/infestations, injuries and muscular-skeletal system disorders scored high IAR value and mention in both Li and Hmong communities. CONCLUSIONS: Medicinal plants are of importance to indigenous people around Limu Mountains who still rely on medicinal plants to treat a wide range of illnesses. There is a close relationship of medicinal plant tradition between Li and Hmong who are culturally distinct.

Two new types of bisindole alkaloid from Trigonostemon lutescens.

Six unprecedented bisindole alkaloids, trigolutesins A and B (1-2) with a unique polycyclic skeleton and trigolutes A-D (3-6) with another polycyclic skeleton, were isolated from the twigs of Trigonostemon lutescens. Their structures and relative configurations were elucidated by spectroscopic data and single-crystal X-ray diffraction crystallography. Trigolutesin A (1) showed weak AChE inhibitory activity.