Isolation and Characterization of Anti-Inflammatory Lignans from Oenanthe javanica

Chemistry of Natural Compounds - A new lignan, named 1-phenylpropenoate-4,8′-lignan A (1), and three known lignans (2–4) were isolated from Oenanthe javanica (Blume) DC. for the first...     

蔬毛吴茱萸果实中新化合物吴茱萸塔宁的分离及结构表征

从传统中药蔬毛吴茱萸的干燥未成熟果实中分离得到一个稀有高氧化状态、新的柠檬苦素类化合物吴茱萸塔宁(evolimorutanin),同时还分离得到了已知结构的化合物柠檬苦素(limonin)。根据IR、MS、1DNMR(1HNMR,13C NMR,DEPT)和2D NMR(1H-1HCOSY,HSQC,HMBC)谱学数据确定了它们的结构,两者均归属为降三萜类化合物,A,A′,B,C,D五个环的取代和立体构型完全相同,只有E环氧化状态不同。此外,还分析了从柠檬苦素转化为吴茱萸塔宁的可能过程。     

Imperata cylindrica: A Review of Phytochemistry,Pharmacology, and Industrial Applications

Imperata cylindrica is a medicinal plant native to southwestern Asia and the tropical and subtropical zones. To date, 72 chemical constituents have been isolated and identified from I. cylindrica Among these compounds, saponins, flavonoids, phenols, and glycosides are the major constituents. Investigations of pharmacological activities of I. cylindrica revealed that this edible medicinal herb exhibits a wide range of therapeutic potential including immunomodulatory, antibacterial, antitumor, anti-inflammatory, and liver protection activities both in vivo and in vitro. The purpose of this review is to provide an overview of I. cylindrica studies until 2019. This article also intends to review advances in the botanical, phytochemical, and pharmacological studies and industrial applications of I. cylindrica, which will provide a useful bibliography for further investigations and applications of I. cylindrica in medicines and foods.     

Composition and Anti-Inflammatory and Antioxidant Activity of Essential Oil from Aucuba japonica var. variegata

Chemistry of Natural Compounds -     

Benzophenone Rhamnosides and Chromones from Hypericum seniawinii Maxim.

Two new benzophenone glycosides, hypersens A and B, along with four known compounds, (S)-(+)-5,7-dihydroxy-2-(1-methylpropyl) chromone (3), 5,7-dihydroxy-2-isopropylchromone (4), urachromone B (5), and 3-8′′ bisapigenin (6), were isolated from Hypericum seniawinii. The structures of new compounds (1 and 2) were elucidated according to comprehensive spectroscopic data analyses. The absolute configurations of 1 and 2 were determined by electronic circular dichroism (ECD) calculations. All isolated compounds were evaluated for their neuroprotective effect using corticosterone-induced PC12 cell injury. In addition, compounds 1–6 were evaluated for their anti-inflammatory activity in lipopolysaccharide-induced RAW 264.7 cells. Compound 6 was a biflavonoid and significantly inhibited the production of nitric oxide with an IC₅₀ value of 11.48 ± 1.23 μM.     

Purification and Characterization of a Chymosin from Rhizopus microsporus var. rhizopodiformis

Purification and characterization of a chymosin from Rhizopus microsporus var. rhizopodiformis were investigated in the present study. A newly isolated R. microsporus var. rhizopodiformis F518 produced a high level of milk-clotting activity (1,001 SU/mL). A chymosin from the fungus was purified 3.66-fold with a recovery yield of 33.2 %. The enzyme appeared as a single protein band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with a molecular mass of 37.0 kDa. It was optimally active at 60 °C and was stable up to 40 °C. The purified enzyme was an acid protease with an optimum pH of 5.2 and retained 80 % of residual activity within pH 2.0–8.0. The inhibition of 96 and 100 % by pepstatin A at 0.01 and 0.02 mM, respectively, revealed that the enzyme is an aspartic protease. Thus, high milk-clotting activity of the chymosin with good stability will strengthen the potential use of the chymosin as a substitute for calf rennet in cheese manufacturing.     

Constituents of Essential Oil from Vinca major var. variegata and its Antibacterial Activity

Chemistry of Natural Compounds -     

Chromones from the branches of Harrisonia perforata

Four new chromones, perforamone A, B, C, and D have been isolated together with six known compounds, peucenin-7-methyl ether, O-methylalloptaeroxylin, perforatic acid, eugenin, saikochromone A and greveichromenol, from the branches of Harrisonia perforata (Simaroubaceae). The structures were identified by spectroscopic data. The compounds were tested for antimycobacterial and antiplasmodial activities.     

Prenylated Flavonoids and C-15 Isoprenoid Analogues with Antibacterial Properties from the Whole Plant of Imperata cylindrica (L.) Raeusch (Gramineae)

The local botanical Imperata cylindrica in Cameroon was investigated for its antibacterial potency. The methanol extract afforded a total of seven compounds, including five hitherto unreported compounds comprising three flavonoids (1–3) and two C-15 isoprenoid analogues (4 and 5) together with known derivatives (6 and 7). The novelty of the flavonoids was related to the presence of both methyl and prenyl groups. The potential origin of the methyl in the flavonoids is discussed, as well as the chemophenetic significance of our findings. Isolation was performed over repeated silica gel and Sephadex LH-20 column chromatography and the structures were elucidated by (NMR and MS). The crude methanol extract and isolated compounds showed considerable antibacterial potency against a panel of multi-drug resistant (MDR) bacterial strains. The best MIC values were obtained with compound (2) against S. aureus ATCC 25923 (32 µg/mL) and MRSA1 (16 µg/mL).     

Structural Characterization and Assessment of Anti-Inflammatory Activities of Polyphenols and Depsidone Derivatives from Melastoma malabathricum subsp. normale

The roots of Melastoma malabathricum subsp. normale (D. Don) Karst. Mey have been used in traditional ethnic medicine systems in China to treat inflammation-triggered ailments, such as trauma, toothache, and fever. Therefore, the aim of this study is to screen for compounds with anti-inflammatory activity in the title plant. The extract of M. malabathricum subsp. normale roots was separated using various chromatographic methods, such as silica gel, ODS C18, MCI gel, and Sephadex LH-20 column chromatography, as well as semi-preparative HPLC. One new complex tannin, named whiskey tannin D (1), and an undescribed tetracyclic depsidone derivative, named guanxidone B (2), along with nine known polyphenols (2–10) and three known depsidone derivatives (12–14) were obtained from this plant. The structures of all compounds were elucidated by extensive NMR and CD experiments in conjunction with HR-ESI-MS data. All these compounds were isolated from this plant for the first time. Moreover, compounds 1–4, 8, and 10–14 were obtained for the first time from the genus Melastoma, and compounds 1, 2, and 11–14 have not been reported from the family Melastomataceae. This is the first report of complex tannin and depsidone derivatives from M. malabathricum subsp. normale, indicating their chemotaxonomic significance to this plant. Compounds 1–12 were investigated for their anti-inflammatory activities on the production of the nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells, and compounds 1, 11, and 12 showed anti-inflammatory activities with IC₅₀ values of 6.46 ± 0.23 µM, 8.02 ± 0.35 µM, and 9.82 ± 0.43 µM, respectively. The structure–activity relationship showed that the catechin at glucose C-1 in ellagitannin was the key to its anti-inflammatory activity, while CH₃O- at C-16 of aromatic ring A in depsidone derivatives had little effect on its anti-inflammatory activity. The study of structure–activity relationships is helpful to quickly discover new anti-inflammatory drugs. The successful isolation and structure identification of these compounds, especially complex tannin 1, not only provide materials for the screening of anti-inflammatory compounds, but also provide a basis for the study of chemical taxonomy of the genus Melastoma.     

Structural Characterization and Assessment of Anti-Inflammatory and Anti-Tyrosinase Activities of Polyphenols from Melastoma normale

Polyphenols, widely distributed in the genus Melastoma plants, possess extensive cellular protective effects such as anti-inflammatory, anti-tyrosinase, and anti-obesity, which makes it a potential anti-inflammatory drug or enzyme inhibitor. Therefore, the aim of this study is to screen for the anti-inflammatory and enzyme inhibitory activities of compounds from title plant. Using silica gel, MCI, ODS C18, and Sephadex LH-20 column chromatography, as well as semipreparative HPLC, the extract of Melastoma normale roots was separated. Four new ellagitannins, Whiskey tannin C (1), 1-O-(4-methoxygalloyl)-6-O-galloyl-2,3-O-(S)-hexahydroxydiphenoyl-β-d-glucose (2), 1-O-galloyl-6-O-(3-methoxygalloyl)-2,3-O-(S)-hexahydroxydiphenoyl-β-d-glucose (3), and 1-O-galloyl-6-O-vanilloyl-2,3-O-(S)-hexahydroxydiphenoyl-β-d-glucose (4), along with eight known polyphenols were firstly obtained from this plant. The structures of all isolates were elucidated by HRMS, NMR, and CD analyses. Using lipopolysaccharide (LPS)-stimulated RAW2 64.7 cells, we investigated the anti-inflammatory activities of compounds 1–4, unfortunately, none of them exhibit inhibit nitric oxide (NO) production, their IC₅₀ values are all > 50 μM. Anti-tyrosinase activity assays was done by tyrosinase inhibition activity screening model. Compound 1 showed weak tyrosinase inhibitory activity with IC₅₀ values of 426.02 ± 11.31 μM. Compounds 2–4 displayed moderate tyrosinase inhibitory activities with IC₅₀ values in the range of 124.74 ± 3.12–241.41 ± 6.23 μM. The structure–activity relationships indicate that hydroxylation at C-3′, C-4′, and C-3 in the flavones were key to their anti-tyrosinase activities. The successful isolation and structure identification of ellagitannin provide materials for the screening of anti-inflammatory drugs and enzyme inhibitors, and also contribute to the development and utilization of M. normale.     

Isolation of a potent anti-MRSA sesquiterpenoid quinone from Ulmus davidiana var. japonica

A highly potent anti-MRSA sesquiterpenoid has been isolated from Ulmus davidiana var. japonica, which has been traditionally used to treat infectious diseases in Korea. This naturally occurring antibiotic was identified as mansonone F (1). This compound has been found to be highly active specifically against MRSA and showed an MIC range of 0.39-3.13 microg/ml which is comparable to that of vancomycin.     

Fatty Acid Composition of the Seeds of Vicia faba var. major Genotypes from Turkey

Chemistry of Natural Compounds -     

Isolation and Characterization of a Bioactive Polysaccharide from Panax Quinquefolium L.

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Isolation and Structure of 1-Deoxybaccatin VI from the Root of Taxus chinensis, Rehd. var. mairei

Deoxybaccatin Ⅵ (4α,7β,9α,10β,13α-penta-acetoxy-2α-benzoyloxy-5β,20-epoxytax-11-ene) was isolated from the roots of Taxus chinensis, Rehd. var. mairei. The structural assignments of the compound were based on their spectral data, including 2D NMR experiments and chemical correlation. The X-ray crystallographic analysis of 1-deoxybaccatin Ⅵ provided unambiguous characterization for the structures. In the structure, the six-membered A ring exhibits boat conformation, the eight-membered B ring adopts boat-chair conformation, and the six-membered C ring exhibits a sofa conformation.     

Two New C—glucoside Flavonoids from Leaves of Crataegus pinnatifida Bge. var. major N.E.Br.

Two new C-glucoside flavonoids,namely 8-C-β-D-（2″-O-acetyl) glucofuranosyl apigenin and 3″-O-acetylvitexin, were isolated from beaves of Crataegus pinnatifida Bge. var. major N.E.Br.Their structures were elucidated by the spectroscopic means and chemical evidence.     

A New Flavonoid Ketohexofuranoside from Leaves of Crataegus pinnatifida Bge.var. major N.E.Br.

Crataegus pinnatifida Bge.var.major N.E.Br. is widely distributed in the northeast part of China. It is used as a medicinal plant to improve digestion, remove retention of food, promote blood circulation and resolve blood stasis both in traditional and folk medicine 1. Preparations of Crataegus leaves improve the heart function, the coronary blood supply and arrhythmia2. Up to now, fifty flavonoids have been isolated from Crataegus3,4. In our previous paper, some new flavonoid glycosides we…