Differential analysis of phytochemistry and antioxidant activity in five citrus by-products based on chromatography, mass spectrometry, and spectrum-effect relationships.

The unripe fruit or peel of Citrus aurantium L., Citrus sinensis Osbeck, and Citrus reticulata Blanco are often disregarded due to perceptions of their marginal value. The present study was undertaken to explore the differences in phytochemical composition and bioactive properties of five citrus by-products in China and demonstrate their potential value. 214 compounds were systematically identified using LC-Orbitrap-MS analysis. Among them, narirutin, naringin, hesperidin, and neohesperidin were established as essential compounds for the discrimination and authentication of the five by-products via a combination of LC-MS, HPLC, and TLC techniques. Variations in the antioxidant activity of the by-products were observed, which correlated with their maturity and were attributable to differences in their active ingredients. Moreover, spectrum-effect relationship analysis revealed that the four previously identified differential markers, along with nobiletin and tangeretin, significantly contributed to the differences in antioxidant activity. The results highlight the potential for citrus by-product enhancement and utilization.

An integrated strategy for quality control of the multi-origins herb medicine of Gentianae Macrophyllae Radix based on UPLC-Orbitrap-MS/MS and HPLC-DAD.

Gentianae Macrophyllae Radix, the dried root of Gentiana macrophylla Pall., Gentiana crassicaulis Duthie ex Burk., Gentiana straminea Maxim., or Gentiana dahurica Fisch., is a traditional Chinese medicine with multi-origins and some adulterants. Liquid chromatography coupled to electrostatic orbitrap high-resolution mass spectrometry (LC-Orbitrap-MS) was used to search the different components of Gentianae Macrophyllae Radix of the four species. High-performance liquid chromatography (HPLC) combined with fingerprint analysis, principal components analysis (PCA), and partial least-squares discrimination analysis (PLS-DA) was also utilized to distinguish them and their adulterants based on the critical components identified by LC-MS. A single standard to determine the multi-components (SSDMC) method was established for the determination of the critical markers. A total of 93 compounds were identified from Gentianae Macrophyllae Radix, including 58 common ones. Their HPLC fingerprints show a significant difference with the adulterants. In addition, PCA and PLS-DA could make a distinction among the four species. Loganic acid, 6'-O-ß-d-glucosylgentiopicroside, swertiamarine, gentiopicroside, and sweroside were identified as the critical markers and then quantified by the SSDMC method. The developed strategy is powerful for the quality control and authentication of Gentianae Macrophyllae Radix.

Anti-inflammatory and antioxidant activities of chemical constituents from the flower buds of Buddleja officinalis.

Five new glycosides including mimenghuasu A and B (1-2), isolinarin (3), cyclocitralosides A and B (4-5), along with forty-seven known compounds were isolated from the flower buds of Buddleja officinalis. These structures were elucidated by extensive spectroscopic analysis (UV, IR, 1 D, 2 D NMR, and MS spectra). The anti-inflammatory activities of the isolated compounds were determined by enzyme-linked immunosorbent assay (ELISA) on the expression of TNF-α (LPS-activated RAW264.7 cells) and MTT experiment on LPS-induced HUVECs proliferation effects. Good suppressive effects on the expression of TNF-α were shown by 4 and 5 with IC50 values of 19.35 and 22.10 µM, respectively, compared to positive control indomethacin (IC50 16.40 µM). In addition to this, some isolated compounds exhibited excellent antioxidant activities including compounds 16, 18, 29, 39, and 47 (IC50 µM: 82.59, 72.94, 33.65, 46.67, and 20.81, respectively) with almost the same or stronger potency with reference to vitamin C as positive control (IC50 81.83 µM).

Two new ditetrahydrofuran lignans from Artemisia sieversiana.

Two new ditetrahydrofuran lignans, named sieverlignans A and B (1 and 2), together with six known ones (3-8), were isolated from the aerial parts of Artemisia sieversiana. Their structures were established on the basis of spectroscopic analysis including HRMS, NMR spectra and circular dichroism experiments. All the compounds were evaluated for their anti-neuroinflammatory effects on the lipopolysaccharides (LPS)-induced nitric oxide production in BV-2 murine microglial cells. Compound 2 exhibited the significant activity with its IC50 value of 11.9 ± 0.8 µM, respectively, compared to a positive control quercetin with its IC50 value of 16.0 ± 1.1 µM.

Flavonoid glycosides from the rhizomes of Pronephrium penangianum.

Six flavonoid glycosides jixueqisus A-F, together with nine known flavonoids, were isolated from the rhizomes of the fern Pronephrium penangianum. Among them, two red pigments jixueqisus A and B possess the same rare 6,8-dimethyl-2-phenyl-7H-1-benzopyran-7-one skeleton (a long conjugated system). Jixueqisu Cwas a dihydrochalcone glycoside, jixueqisu D was a chalcone glycoside, jixueqisu E was an aurone glycoside, and jixueqisu F was a flavonone glycoside. Interestingly, jixueqisus D-F, (2S)-5,2',5'-trihydroxy-7-methoxyflavanone and 5,2',5'-trihydroxy-7-methoxyflavone possessed a 2,5-dihydroxy substituted benzene ring (B-ring). Their structures were elucidated by various spectroscopic and chemical methods. Furthermore, the plausible biosynthetic pathways of jixueqisus A-F were discussed, respectively. All isolated compounds were evaluated for their activities against the proliferation of MCF-7, HepG-2, HCT-116 and BGC-823 tumor cell lines, four known flavane-4-ol glycosides, abacopterins A and C, eruberin B and triphyllin A, exhibited moderate activities to various cell lines.

Lignans from Tujia Ethnomedicine Heilaohu: Chemical Characterization and Evaluation of Their Cytotoxicity and Antioxidant Activities.

Heilaohu, the roots of Kadsura coccinea, has a long history of use in Tujia ethnomedicine for the treatment of rheumatoid arthritis and gastroenteric disorders, and a lot of work has been done in order to know the material basis of its pharmacological activities. The chemical investigation led to the isolation and characterization of three new (1⁻3) and twenty known (4⁻23) lignans. Three new heilaohulignans A-C (1⁻3) and seventeen known (4⁻20) lignans possessed dibenzocyclooctadiene skeletons. Similarly, one was a diarylbutane (21) and two were spirobenzofuranoid dibenzocyclooctadiene (22⁻23) lignans. Among the known compounds, 4⁻5, 7, 13⁻15 and 17⁻22 were isolated from this species for the first time. The structures were established, using IR, UV, MS and NMR data. The absolute configurations of the new compounds were determined by circular dichroism (CD) spectra. The isolated lignans were further evaluated for their cytotoxicity and antioxidant activities. Compound 3 demonstrated strong cytotoxic activity with an IC50 value of 9.92 µM, compounds 9 and 13 revealed weak cytotoxicity with IC50 values of 21.72 µM and 18.72 µM, respectively in the HepG-2 human liver cancer cell line. Compound 3 also showed weak cytotoxicity against the BGC-823 human gastric cancer cell line and the HCT-116 human colon cancer cell line with IC50 values of 16.75 µM and 16.59 µM, respectively. A chemiluminescence assay for antioxidant status of isolated compounds implied compounds 11 and 20, which showed weak activity with IC50 values of 25.56 µM and 21.20 µM, respectively.

7α-Hydroxyfriedelan-3-one-26-ol-29-oic acid and other Constituents from Pileostegia viburnoides var. glabrescens.

Phytochemical investigation of the roots and rhizomes of Pileostegia viburnoides var. glabrescens led to the isolation and identification of 31 compounds (1-31), 25 of which (1-2, 4-7, 9-12, 15-18, 21-31) were isolated from the Pileostegia genus for the first time. 7α-Hydroxyfriedelan-3-one-26-ol-29-oic acid (1) is a new friedelane-type triterpene. The structure of n-butyl-ß-D-fructopyranoside (2) was determined by single-crystal X-ray diffraction. Compounds 4 and 12 displayed marginal cytotoxicity against the P388 murine leukemia cell line with IC50 values of 13.4 µM and 25.0 µM, respectively. Compound 23 exhibited marginal anti-inflammatory activity by the inhibition of lipopolysaccharide induced nitric oxide production in RAW 264.7 macrophage cells, with an IC50 value of 32.0 µM. Compounds 3, 8-10, 25, and 27 were phytotoxic to the dicot Lactuca sativa (lettuce) and/or the monocot Agrostis stolonifera (bentgrass).

A coumarin lignanoid from the stems of Kadsura heteroclita.

Coumarinlignan (1), possessing a unique coumarin-containing lignan skeleton, was isolated from the stems of Kadsura heteroclita. Its structure and absolute configuration were determined by spectroscopic techniques, especially 2D NMR and X-ray crystallographic data analyses. The proposed biosynthetic pathway is discussed. This new compound showed good anti-HBV activity against HBeAg and HBsAg, and moderate anti-fibrotic and neuroprotective activities.

[HPLC Fingerprint of QingGuangAn and Determination of the Main Components].

OBJECTIVE: To establish an HPLC fingerprint of ethanol extract of QingGuangAn, and to determine the contents of paeoniflorin and calycosin-7-glucosid. METHODS: HPLC analysis was performed on an Agilent 1260 Infinity LC system and carried out at 35 degrees C on a column of GRACE Alltima C18 (250 mm x 4.6 mm, 5 µm). A binary gradient elution system was composed of acetonitrile (phase A) and water solution (phase B). Detection was performed at the wavelength of 254 nm, the mobile flow rate was 0.8 mL/min. A matrix including 20 variations (characteristic peaks area) and 10 samples was constructed for similarity evaluation. RESULTS: The results showed that the collected samples had a good similarity. A specificity fingerprint was produced and 20 characteristic peaks were designated. The content of paeoniflorin and calycosin-7-glucosid was 0.368 and 0.049 mg/g, respectively. CONCLUSION: It is a reliable, available and quick method for quality control of QingGuangAn,which provides some reference for the comparison of different extracting methods of QingGuangAn and the differences of pharmacodynamic.

Two new bicyclic sesquiterpenes from the stems of Kadsura heteroclita.

Two new bicyclic sesquiterpenes, namely 6α,9α-dihydroxycadinan-4-en-3-one (1) and guai-3-en-10α-ol (2), together with one known sesquiterpene were isolated from the stems of Kadsura heteroclita, which is a Tujia ethnomedicine called 'Xue Tong'. Their structures were elucidated by using spectroscopic analyses and by comparing the NMR data with those reported previously.

[Chemical constituents of Pileostegia viburnoides var. glabrescens].

OBJECTIVE: To study the chemical constituents of Pileostegia viburnoides var. glabrescens. METHODS: The compounds were isolated and purified by various techniques. Their structures were determined by physicochemical properties and spectral analysis. RESULTS: Five compounds were isolated and identified as friedelin (1), beta-sitosterol (2), umbelliferone (3), daucosterol (4) and skimmin (5). CONCLUSION: All the compounds were isolated from this genus for the first time.

[Study on chemical constituents of volatile oil from rhizomes and leaves of Pileostegia viburnoides var. glabrescens by GC-MS].

OBJECTIVE: To analyze the chemical constituents of volatile oil from the rhizomes and leaves of Pileostegia viburnoides var. glabrescens by GC-MS. METHODS: The volatile oil was extracted from the rhizomes and leaves of Pileostegia viburnoides var. glabrescens by steam distillation. The constituents of volatile oil were identified by GC-MS technology. RESULTS: 37 compounds were identified from the oil of rhizomes. 36 compounds were identified from the oil of leaves. The rhizomes and leaves volatile oil had 18 compounds in common. CONCLUSION: This study is the first one to report the volatile components of Pileostegia viburnoides var. glabrescens. It can provide a scientific basis for rational use of the rhizomes and leaves of Pileostegia viburnoides var. glabrescens.