Microbial Transformation and Biological Activities of the Prenylated Aromatic Compounds from Broussonetia kazinoki

Broussonetia kazinoki has been used as a traditional medicine for the treatment of burns and acne, and its extracts have been found to show tyrosinase inhibitory and anticancer activities. In this study, the tyrosinase inhibitory and cytotoxic activities of B. kazinoki were explored, leading to the isolation of kazinol C (1), kazinol E (2), kazinol F (3), broussonol N (4), and kazinol X (5), of which the compounds 4 and 5 have not been previously reported. Microbial transformation has been recognized as an efficient tool to generate more active metabolites. Microbial transformation of the major compounds 1 and 3 was conducted with Mucor hiemalis, where four glucosylated metabolites (6–9) were produced from 1, while one hydroxylated (10) and one glucosylated (11) metabolites were obtained from 3. Structures of the isolated metabolites were determined by extensive spectroscopic analyses. All compounds were evaluated for their tyrosinase inhibitory and cytotoxic activities. Compound 3 and its metabolites, kazinol Y (10) and kazinol F-4″-O-β-d-glucopyranoside (11), exhibited the most potent tyrosinase inhibitory activities with the IC₅₀ values ranging from 0.71 to 3.36 µM. Meanwhile, none of the metabolites, except for kazinol C-2′,3″-di-O-β-d-glucopyranoside (7), showed moderate cytotoxic activities (IC₅₀ 17.80 to 24.22 µM) against A375P, B16F10 and B16F1 cell lines.     

Three New Isoprenylated Flavones from Artocarpus chama Stem and Their Bioactivities

Phytochemical investigation of Artocarpus chama stem was performed by chromatographic techniques, resulting from the isolation and structure elucidation of three new compounds, namely 3′-farnesyl-apigenin (1), 3-(hydroxyprenyl) isoetin (2), and 3-prenyl-5,7,2′,5′-tetrahydroxy-4′-methoxyflavone (3), and five known compounds, namely homoeriodictyol (4), isocycloartobilo-xanthone (5), artocarpanone (6), naringenin (7), and artocarpin (8). From the screening result, A. chama extract showed a potent tyrosinase inhibitory effect. Ihe isolated compounds 1, 4 and 6 also exhibited tyrosinase inhibition with IC₅₀ of 135.70, 52.18, and 38.78 µg/mL, respectively. Moreover, compounds 3, 4, 5, 6, and 8 showed strong activity against Staphylococcus epidermidis, S. aureus, methicillin-resistant S. aureus, and Cutibacterium acnes. This study is the first report on phytochemical investigation with new compounds and biological activities of A. chama. Skin infection can cause dark spots or hyperpigmentation. The isolated compounds that showed both anityrosinase and antimicrobial activities will be further studied in in vivo and clinical trials in order to develop treatment for hyperpigmentation, which is caused by infectious diseases by microorganisms.     

New flavonol glycosides from the leaves of Caragana brachyantha

Two new flavonol glycosides, brachysides C and D, together with three known flavonol glycosides, were isolated from the leaves of Caragana brachyantha. The structures of brachysides C and D were elucidated on the basis of detailed spectroscopic analysis as quercetin 5-O-[α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside]-7-O-[α-l-rhamnopyranoside] and quercetin 5-O-[α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside]-7-O-[α-l-rhamnopyranoside]-4′-O-[α-l-rhamnopyranoside], respectively. The presence of flavonol tetra- and triglycosides bearing a sugar moiety at position 5 was the first report from this genus Caragana.     

Euphane Triterpenes from the Bark of Broussonetia papyrifera

Four new euphane triterpenes, (3β)‐3‐(acetyloxy)eupha‐7,25‐dien‐24‐one ( 1 ), (3β,24R)‐3‐(acetyloxy)eupha‐7,25‐dien‐24‐ol ( 2 ), (3β,24S)‐eupha‐7,25‐diene‐3,24‐diol ( 3 ), and (3β,24R)‐eupha‐7,25‐diene‐3,24‐diol ( 4 ) were isolated from the barks of Broussonetia papyrifera, a tree whose roots, barks, and fruits were used as herbal drugs in China. The structures of 1 – 4 were elucidated on the basis of spectroscopic evidence and chemical methods.     

A novel dimeric flavonol glycoside from Cynanchum acutum subsp. sibiricum

A novel dimeric flavonol glycoside, Cynanflavoside A (1), together with six analogues, kaempferol-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (2), quercetin-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (3), kaempferol-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranoside (4), quercetin-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranoside (5), kaempferol-3-O-β-D-glucopyranosyl-7-O-α-L-rhamnopyranoside (6), and quercetin-3-O-galactoside (7) were isolated from the n-butyl alcohol extract of Cynanchum acutum subsp. sibiricum. Their structures were determined spectroscopically and compared with previously reported spectral data. All compounds were evaluated for their anti-complementary activity in vitro, and only compound 5 exhibited anti-complement effects with CH₅₀ value of 0.33 mM.     

Studies on the constituents of Broussonetia species X. Six new alkaloids from Broussonetia kazinoki Sieb.

Six new alkaloids, broussonetines W, X, M1, U1, J3, and J2 (1-6) were isolated from the branches of Broussonetia kazinoki SIEB. (Moraceae) as minor constituents. They were formulated as (2R,3R,4R,5R)-2-hydroxy-methyl-3,4-dihydroxy-5-17-(cyclohexy-2-on-1(6)-enyl)heptyllpyrrolidine (1), (2R,3S,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-17-(cyclohexy-2-on-1(6)-enyl)heptyl]pyrrolidine-4-O-beta-D-glucopyranoside (2), (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(9R)-9,13-dihydroxytridecyl]- pyrrolidine (3), (2S,3S,4S)-2-hydroxymethyl-3,4-dihydroxy-5-(10-oxo-13-hydroxytridecyl)-5- pyrroline (4), (2R)-2-[(IS,2S)-1,2-dihydroxy-8-1(2R,3R,4R,5R)-5-(2-hydroxymethyl-3,4-dihydroxy-1-acetylpyrrolidinyl)loctyl]piperidine (5), (2R)-2-[(1S,2S)-1,2-dihydroxy-8-[(2R,3R, 4R,5R)-5-(2-hydroxymethy]-3,4-dihydroxypyrrolidinyl)]octyl]piperidine (6).     

中药枸骨叶中三萜皂苷和黄酮苷类成分研究

A new triterpene glycoside, pomolic acid 3-O-6″-methyl-β-D-glucuronopyranosyl-（1→3）-α-L-arabino- pyranoside, and a new flavonol glycoside, quercetin 3-O-β-D-glucopyranosyl-（1→2）-α-L-arabinopyranoside together with three known triterpene saponins and two flavonol glycosides, were isolated from the leaves of Ilex cornuta. Their structures were established on the basis of spectroscopic analysis.     

构树叶中黄酮类化合物的提取及测定——介绍一个大学综合化学实验

A new comprehensive chemical experiment for college students is introduced. This experiment is from the achievements of scientific research. It includes obtaining absorption spectrum and calibration curve of Rutin, and ultrasonic-assisted ethanol extraction and spectrophotometric determination of flavonoids from Broussonetia papyrifera (L.) Vent. Leaves. The experiment involves several basic analytical chemistry procedures and the effective components in plant sample are analyzed. Through the experiment, the students' experimental skills, comprehensive and innovative abilities are improved; furthermore, the specialty requirements are satisfied in agriculture or forestry universities. Thus, it is recommended to be included in the comprehensive analytical chemistry laboratory for students of non-chemistry majors.     

A New Flavonol Oligosaccharide from the Seeds of Aesculus chinensis

Aesculus chinensis is a traditional chinese medicinal plant widely distributed in China, which has been used to treat stomach disease. From recent research its seeds contain many flavonoids and proanthocyanidin A2, which have potential venotonic and vasoprotective action and powerful antioxidant activity. In this paper, we report the isolation and the structure elucidation of a new flavonol oligosacchride. Bioassay results showed that the compound exhibited an antivirus activity. …     

A new acylated flavonol from the aerial parts of Asteriscus maritimus (L.) Less (Asteraceae)

Phytochemical investigation of the flowering aerial parts of Asteriscus maritimus (L.) Less (Asteraceae) led to the isolation of a new compound: patuletin 7-O-β-D-[(2″′S) 6″(3″′-hydroxy-2″′-methyl-propanoyl)] glucopyranoside, together with five known metabolites; β-sitosterol 2, chlorogenic acid 3, P-hydroxy -methylbenzoate 4, luteolin 5 and protocatechuic acid 6. The structures of the isolated compounds were determined by comprehensive analyses of its 1D and 2D NMR, HRMS and compared with previously known analogues. The ethanolic extract of the flowering aerial parts of A. maritimus was found to be safe (LD₅₀ = 4.6 mg/kg) and possess significant antioxidant and anti-inflammatory activities and this was in accordance with its high phenolic content (107.36 ± 0.051 mg GAE/g extract).     

A New Antimicrobial Flavonol Glycoside from Alchornea Davidii

A new flavonol glycoside,isorhamnetin-3-O- β-D-xyloside,was isolated from the extract of leaves and twigs of Alchornea davidii (Euphorbiaceae).Its structure was established on the basis of the spectral analysis and chemical degradation.Antimicrobial assay showed that it moderately inhibited the growth of test bacteria (Staphylocoocu aureus,Bacillus subtilis and Pseudomonas fluorescens)and fungi (Candida albicans,Aspergillus niger and Trichophyton rubrum) with MICs at 50μg/ml.     

New Isoprenylated Aurones from the Flowers of Rosa damascena

A phytochemical investigation of the flowers of Rosa damascena resulted in the isolation of three new isoprenylated aurones, damaurones C–E ( 1 – 3 , resp.), together with six known compounds, 4 – 9 . The structures of the new compounds were elucidated by spectroscopic methods, including extensive 1D‐ and 2D‐NMR experiments.     

New Acetylated Flavonol Glycosides from Knoxia corymbosa

Two new diacetylated flavonol glycosides, kampferol-3-O-β-3“, 6“-diacetylglucopyrano-side and quercetin-3-O-β-3“, 6“-diacetylglucopyranoside were isolated from knoxia corymbosa. Their structures were elucidated by spectroscopic evidents.     

A new flavonol triglycoside derived from Anoectochilus elwesii on stimulating glucose uptake in insulin-induced human HepG2 cells

A novel flavonol triglycoside (4), isorhamnetin-3-O-β-d-glucopyranosyl (1→2)-α-l-rhamnopyranosyl (1→6)-β-d-glucopyranoside, named elwesoside A, together with six known flavonols (1–3, 5–7) was isolated from Anoectochilus elwesii (Clarke ex Hook. f.) King et Pantl. and its structure was elucidated by extensive spectroscopic methods and comparison with the literature data. All compounds were first reported in this plant and two of them (4 and 5) were the first examples of flavonol triglycosides isolated from Anoectochilus genus. The effects of 1–7 were evaluated on insulin-treated human HepG2 cells under high glucose conditions for stimulating glucose uptake activities. The novel compound (4) displayed highly potent dose-dependent effect on the stimulation of glucose uptake in insulin-resistant human HepG2 cells.     

A New Biphenyl Glycoside from the Leaves of Eriobotrya japonica

The leaves of Eriobotrya japonica (Thunb.) Lindl (Rosaceae) have been widely used as a folk medicine (known as “Pipaye”) to treat stomachache and promote antitussive, anti-inflammatory and diuretic effects in China. A number of triterpenoids1,2, sesquit…     

Genome-Wide Analysis of the UGT Gene Family and Identification of Flavonoids in Broussonetia papyrifera

Broussonetia papyrifera is a multifunctional deciduous tree that is both a food and a source of traditional Chinese medicine for both humans and animals. Further analysis of the UGT gene family is of great significance to the utilization of B. papyrifera. The substrates of plant UGT genes include highly diverse and complex chemicals, such as flavonoids and terpenes. In order to deepen our understanding of this family, a comprehensive analysis was performed. Phylogenetic analysis showed that 155 BpUGTs were divided into 15 subgroups. A conserved motif analysis showed that BpUGT proteins in the same subgroups possessed similar motif structures. Tandem duplication was the primary driving force for the expansion of the BpUGT gene family. The global promoter analysis indicated that they were associated with complex hormone regulatory networks and the stress response, as well as the synthesis of secondary metabolites. The expression pattern analysis showed that the expression level of BpUGTs in leaves and roots was higher than that in fruits and stems. Next, we determined the composition and content of flavonoids, the main products of the BpUGT reaction. A total of 19 compounds were isolated and analyzed by UPLC-ESI-MS/MS in 3 species of Broussonetia including B. kazinoki, B. papyrifera, and B. kazinoki × B. papyrifera, and the number of compounds was different in these 3 species. The total flavonoid content and antioxidant capacities of the three species were analyzed respectively. All assays exhibited the same trend: the hybrid paper mulberry showed a higher total flavonoid content, a higher total phenol content and higher antioxidant activity than the other two species. Overall, our study provides valuable information for understanding the function of BpUGTs in the biosynthesis of flavonoids.     

Two New Spirostanol Steroidal Sapogenins from Fermented Leaves of Agave americana

The genus Agave is well known as rich sources of steroidal saponins and sapogenins 1. More than ten steroidal sapogenins have been isolated from Agave americana L.2-4 In this paper, we describe the structural determination of two new steroidal sapogenins from fermented leaves of A. americana L. The methanolic extracts of dried residues of fermented leaves of A. americana L. produced in Ruili County of Yunnan Province at January 2000, were subjected to repeated column chromatography of …     

A New Pregnane Glycoside from Fermented Leaves of Agave americana

A new minor pregane glycoside was isolated from the fermented leaves of Agave americana.Its structure was elucidated as (20S)-5α-pregnane-3β，20-diol 20-O-β-D-glucopyrano-side(1)by spectral methods.     

A novel diarylheptanoid bearing flavonol moiety from the rhizomes of Alpinia officinarum Hance

<正>A novel diarylheptanoid bearing flavonol moiety,named officinin A(1),along with two known compounds galangin and kaempferide were isolated from the rhizomes of Alpina officinarum Hance.The structure elucidation was accomplished by HRESI -MS,1D and 2D NMR methods.     

A New Monoterpene Glucoside from the Leaves of Betula platyphylla Suk.

Betula platyphylla Suk., whose bark and juice are used as anti-inflammatory and cough relieving agent1, is widespread in China. Previous investigations of this plant have led to the isolation of various compounds2,3. We herein report structural elucidation of a new monoterpene glucoside (1) isolated from the leaves of Betula platyphylla Suk.. Only two monoterpene glucosides isolated from Betula L. have been published until now4.Compound 1 was obtained as colorless needles (EtOAc), mp 64.5~…