Constituents of the Peel of Citrus Depressa Hayata

Eleven known compounds; methyl-3,4-dihydroxycinnamate, pyrocatechuic acid, isoimperatorin, naringenin, umbelliferone, pyrocatechol, meranzin hydrate, neohesperidin, narirutin, friedelin, β-sistosterol were isolated and characterized from the peel of Citrus depressa Hayata.     

A Green Extraction Method to Achieve the Highest Yield of Limonin and Hesperidin from Lime Peel Powder (Citrus aurantifolia)

Green extraction is aimed at reducing energy consumption by using renewable plant sources and environmentally friendly bio-solvents. Lime (Citrus aurantifolia) is a rich source of flavonoids (e.g., hesperidin) and limonoids (e.g., limonin). Manufacturing of lime products (e.g., lime juice) yields a considerable amount of lime peel as food waste that should be comprehensively exploited. The aim of this study was to develop a green and simple extraction method to acquire the highest yield of both limonin and hesperidin from the lime peel. The study method included ethanolic-aqueous extraction and variable factors, i.e., ethanol concentrations, pH values of solvent, and extraction temperature. The response surface methodology was used to optimize extraction conditions. The concentrations of limonin and hesperidin were determined by using UHPLC-MS/MS. Results showed that the yields of limonin and hesperidin significantly depended on ethanol concentrations and extraction temperature, while pH value had the least effect. The optimal extraction condition with the highest amounts of limonin and hesperidin was 80% ethanol at pH 7, 50 °C, which yields 2.072 and 3.353 mg/g of limonin and hesperidin, respectively. This study illustrates a green extraction process using food waste, e.g., lime peel, as an energy-saving source and ethanol as a bio-solvent to achieve the highest amount of double bioactive compounds.     

Composition of Peel Essential Oils from Eight Citrus Species

The peel essential oils from eight citrus species growing in Taiwan were analysed to determine the detailed composition of each oil.     

A Comparative Study of the Chemical Composition by SPME-GC/MS and Antiradical Activity of Less Common Citrus Species

Citrus secondary metabolites, such as terpene compounds, are very important for human health due to their bioactivity including anti-inflammatory, anti-cancer, and antioxidant effects. In this work, for the first time, the volatile chemical composition of peels and juices from four different Citrus species (C. junos, Citrus × aurantium, C. aurantium ‘Bizzarria’ and C. medica ‘Florentina’, commonly known as Yuzu jeune, Oni Yuzu, Bizzarria orange and Florence cedar, respectively) was investigated by Solid-Phase Microextraction-Gas Chromatography/Mass Spectrometry (SPME-GC/MS) technique and the antiradical activity was also examined. The results showed that limonene and γ-terpinene were the main volatile substances detected both in the juices and in the peels, followed by other minority compounds responsible for the phyto-complex of the unique aromas which characterize each individual analyzed Citrus species. Principal component analysis (PCA), performed on volatile compounds, showed both some correlation as well as a clear separation between the juice and the peel of each species. Among them, Oni Yuzu juice was found to be the richest in total polyphenols and flavonoids while its capacity to scavenge ABTS^•+ and DPPH^• radicals was similar to that of Yuzu Jeune and Bizzarria orange.     

Chemical Composition,Antioxidant, Anti-Bacterial,and Anti-Cancer Activities of Essential Oils Extracted from Citrus limetta Risso Peel Waste Remains after Commercial Use

Citrus plants are widely utilized for edible purposes and medicinal utility throughout the world. However, because of the higher abundance of the antimicrobial compound D-Limonene, the peel waste cannot be disposed of by biogas production. Therefore, after the extraction of D-Limonene from the peel wastes, it can be easily disposed of. The D-Limonene rich essential oil from the Citrus limetta risso (CLEO) was extracted and evaluated its radical quenching, bactericidal, and cytotoxic properties. The radical quenching properties were DPPH radical scavenging (11.35 ± 0.51 µg/mL) and ABTS scavenging (10.36 ± 0.55 µg/mL). There, we observed a dose-dependent antibacterial potential for the essential oil against pathogenic bacteria. Apart from that, the essential oil also inhibited the biofilm-forming properties of E. coli, P. aeruginosa, S. enterica, and S. aureus. Further, cytotoxicity was also exhibited against estrogen receptor-positive (MCF7) cells (IC₅₀: 47.31 ± 3.11 µg/mL) and a triple-negative (MDA-MB-237) cell (IC₅₀: 55.11 ± 4.62 µg/mL). Upon evaluation of the mechanism of action, the toxicity was mediated through an increased level of reactive radicals of oxygen and the subsequent release of cytochrome C, indicative of mitotoxicity. Hence, the D-Limonene rich essential oil of C. limetta is useful as a strong antibacterial and cytotoxic agent; the antioxidant properties exhibited also increase its utility value.     

The Second Life of Citrus Fruit Waste: A Valuable Source of Bioactive Compounds

Citrus fruits (CF) are among the most widely cultivated fruit crops throughout the world and their production is constantly increasing along with consumers’ demand. Therefore, huge amounts of waste are annually generated through CF processing, causing high costs for their disposal, as well as environmental and human health damage, if inappropriately performed. According to the most recent indications of an economic, environmental and pharmaceutical nature, CF processing residues must be transformed from a waste to be disposed to a valuable resource to be reused. Based on a circular economy model, CF residues (i.e., seeds, exhausted peel, pressed pulp, secondary juice and leaves) have increasingly been re-evaluated to also obtain, but not limited to, valuable compounds to be employed in the food, packaging, cosmetic and pharmaceutical industries. However, the use of CF by-products is still limited because of their underestimated nutritional and economic value, hence more awareness and knowledge are needed to overcome traditional approaches for their disposal. This review summarizes recent evidence on the pharmacological potential of CF waste to support the switch towards a more environmentally sustainable society.     

Chemical Constituents with Nitric Oxide Inhibition from the Fruit Peel of Annona squamosa

Chemistry of Natural Compounds -     

Constituents of Roots of Rubia Lanceolata Hayata

A naphthohydroquinone and eight anthraquinones were isolated from the roots of Rubia lanceolata Hayata. Their structures were assigned as mollugin ( 1 ), l-hydroxy-2-methyl-9,10-anthraquinone ( 2 ), 2-methylquinizarin ( 3 ), 3-carbomethoxy-l-hydroxy-9,10-anthraquinone ( 4 ), lucidin ethyl ether ( 5 ), rubiadin ( 6 ), alizarin ( 7 ), ω-hydroxypachybasin ( 8 ) and digiferruginol ( 9 ) on the basis of spectral evidence. Among them, compounds 8 and 9 were isolated for the first time from Rubia species.     

Chemical Constituents of Umbelliferous Plants. XIV. Coumarins from the Root of Angelica Tarokoensis Hayata

Xanthotoxin and byak-angelicin were isolated from the root of Angelica tarokoensis Hayata. Imperatorin, bergapten and marmesin were also detected by thin layer chromatography.     

Chemical Constituents of Acanthochlamys bracteata

A novel nortriterpene, acanthochlamic acid (6), along with 18 known compounds has been isolated from the whole plants of Acanthochlamys bracteata P. C. Kao, a single species in family Acanthochlamydaceae which is endemic to the southwest of China. The structure of the novel nortriterpene was elucidated as 3,4-seco-3-norlup-4(23),20(29)-dien-2,28-dioic acid by spectroscopic techniques including 1D and 2D NMR spectroscopy and confirmed by X-ray crystallography.     

Analysis of Citrus Bioflavonoid Content and Dipeptidyl Peptidase-4 Inhibitory Potential of Commercially Available Supplements

Citrus bioflavonoids are polyphenolic plant-derived pigments found in high levels in oranges, lemons, grapefruits and other citrus fruits. The three most abundant types of citrus bioflavonoids are hesperidin, naringenin and eriocitrin. Citrus bioflavonoids have long been known to possess powerful free radical-scavenging properties and cardioprotective effects. The study involved the analysis of 10 commercially available citrus bioflavonoid supplements from three different countries: Australia, the United States and Canada. The supplements were tested for their citrus bioflavonoid content which varied from 0.8 to 33.3% w/w. The daily bioflavonoid dose varied from 19 mg to 560 mg. Hesperidin was the major citrus bioflavonoid in nine out of ten supplements. One supplement was found to contain less than 10% of the quantity of rutin claimed to have been added. The DPP-4 inhibitory potential, compared through an estimation of rutin equivalence, ranged from 1.9 mg to 400 mg per day. This data highlights the variability between the supplements in their potential to inhibit DPP-4 for subsequent health benefits.     

Flavonoid profiles of immature and mature fruit tissues of Citrus grandis Osbeck (Dangyuja) and overall contribution to the antioxidant effect

Citrus fruits are a valuable functional food and their peel is used in East Asian folk medicine. In this study, the polar components of the fruit tissues of Citrus grandis Osbeck were analyzed using high‐performance liquid chromatography–tandem mass spectrometry and compared with reported data. Among the 13 characterized compounds, eight flavonoids and one coumarin were identified for the first time in fruit tissues. The total amount of the identified components was the largest for the immature fruit peel, followed by mature fruit peel, mature fruit flesh, and immature fruit flesh. Naringin (2) and neohesperidin (3) were particularly rich in all samples. The antioxidant activity of the flavonoids extracted from fruit tissues increased in a dose‐dependent manner. The activity of the fruit peels was significantly higher than that of the fruit flesh. Copyright © 2014 John Wiley & Sons, Ltd.     

高效液相色谱法同时测定广陈皮药材中的11种化学成分

采用高效液相色谱法(HPLC)同时测定了广陈皮药材中5-羟甲基糠醛、维采宁-2、橙皮苷、橙皮素、异甜橙黄酮、甜橙黄酮、异黄芩配基甲醚、川陈皮素、3,5,6,7,8,3',4'-七甲氧基黄酮、橘皮素及5-去甲川陈皮素11种化学成分的含量。样品经50%(v/v)甲醇于70 ℃回流提取。在优化的色谱条件(Hanbon Benatach C18色谱柱(250 mm×4.6 mm, 5 μm)为分离柱,乙腈和0.2%甲酸水溶液为流动相,梯度洗脱,流速1.0 mL/min,柱温25 ℃,检测波长280 nm)下,提取液中的各成分分离良好,在选定的浓度范围内呈良好的线性关系(r>0.998),定量限(S/N=10)为0.0502~4.99 mg/L,检出限(S/N=3)为0.0125~1.25 mg/L,平均加标回收率(n=3)为96.4%~102.4%,相对标准偏差为0.25%~4.01%。该方法准确性高、重复性好,可用于广陈皮的质量控制。     

Constituents of Formosan Folk Medicine. IV. The Constituents of the Leaves of Phellodendron Wilsonii Hayata Et Kanehira

Phellamurin and amurensin were isolated from the leaves of Phellodendron wilsonii Hayata et Kanehira and it was confirmed that the latter coincided with 8-isopentenylkaempferol-7-glucoside, epimedoside C.     

The phytochemical analysis and antioxidant activity assessment of orange peel (Citrus sinensis) cultivated in Greece-Crete indicates a new commercial source of hesperidin

The flavonoid content of several methanolic extract fractions of Navel orange peel (flavedo and albedo of Citrus sinensis) cultivated in Crete (Greece) was first analysed phytochemically and then assessed for its antioxidant activity in vitro. The chemical structures of the constituents fractionated were originally determined by comparing their retention times and the obtained UV spectral data with the available bibliographic data and further verified by detailed LC-DAD-MS (ESI+) analysis. The main flavonoid groups found within the fractions examined were polymethoxylated flavones, O-glycosylated flavones, C-glycosylated flavones, O-glycosylated flavonols, O-glycosylated flavanones and phenolic acids along with their ester derivatives. In addition, the quantitative HPLC analysis confirmed that hesperidin is the major flavonoid glycoside found in the orange peel. Interestingly enough, its quantity at 48 mg/g of dry peel permits the commercial use of orange peel as a source for the production of hesperidin. The antioxidant activity of the orange peel methanolic extract fractions was evaluated by applying two complementary methodologies, DPPH(*) assay and the Co(II)/EDTA-induced luminol chemiluminescence approach. Overall, the results have shown that orange peel methanolic extracts possess moderate antioxidant activity as compared with the activity seen in tests where the corresponding aglycones, diosmetin and hesperetin were assessed in different ratios.     

Chemical Constituents of Macaranga occidentalis,Antimicrobial and Chemophenetic Studies

Medicinal plants are known as sources of potential antimicrobial compounds belonging to different classes. The aim of the present work was to evaluate the antimicrobial potential of the crude extract, fractions, and some isolated secondary metabolites from the leaves of Macaranga occidentalis, a Cameroonian medicinal plant traditionally used for the treatment of microbial infections. Repeated column chromatography of the ethyl acetate and n-butanol fractions led to the isolation of seventeen previously known compounds (1−17), among which three steroids (1−3), one triterpene (4), four flavonoids (5−8), two stilbenoids (9 and 10) four ellagic acid derivatives (11−14), one geraniinic acid derivative (15), one coumarine (16), and one glyceride (17). Their structures were elucidated mainly by means of extensive spectroscopic and spectrometric (1D and 2D NMR and, MS) analysis and comparison with the published data. The crude extract, fractions, and isolated compounds were all screened for their antimicrobial activity. None of the natural compounds was active against Candida strains. However, the crude extract, fractions, and compounds showed varying levels of antibacterial properties against at least one of the tested bacterial strains, with minimal inhibitory concentrations (MICs) ranging from 250 to 1000 μg/mL. The n-butanol (n-BuOH) fraction was the most active against Escherichia coli ATCC 25922, with an MIC value of 250 μg/mL. Among the isolated compounds, schweinfurthin B (10) exhibited the best activity against Staphylococcus aureus NR 46003 with a MIC value of 62.5 μg/mL. In addition, schweinfurthin O (9) and isomacarangin (6) also exhibited moderate activity against the same strain with a MIC value of 125 μg/mL. Therefore, pharmacomodulation was performed on compound 6 and three new semisynthetic derivatives (6a–c) were prepared by allylation and acetylation reactions and screened for their in vitro antimicrobial activity. None of the semisynthetic derivatives showed antimicrobial activity against the same tested strains. The chemophenetic significance of the isolated compounds is also discussed in this paper.     

海涂柑桔缺铁敏感性差异机理研究

通过田间调查取样和砂培试验，分别测定不同桔苗砧穗组合的根系还原力和铁吸收动力学由，对比研究了海涂不同砧木柑桔缺铁失绿的敏感性差异。试验证明，抗缺铁能力较强的构头橙砧（Ｃ．ａｕｒａｎｔｉｕｍＬｉｎｎ）的桔苗的叶片中的“全铁”和“活性铁”含量和根系还原力均高于抗缺铁能力弱的枳砧（Ｐ．ｔｒｉｆｏｌｉａｔｅＬ．）桔苗；同时，其铁吸收动力学曲线表现出具有较大的Ｖｍａｘ和较小的Ｋｍ值；在ＨＣＯ３－逆境条件下，枳砧苗的Ｖｍａｘ下降较为明显，而构头橙砧的变化幅度相对比较小。     

Chemical Constituents from the Flowers of Carthamus tinctorius L. and Their Lung Protective Activity

A new flavonoid, saffloflavanside (1), a new sesquiterpene, safflomegastigside (2), and a new amide, saffloamide (3), together with twenty-two known compounds (4–25), were isolated from the flowers of Carthamus tinctorius L. Their structures were determined based on interpretation of their spectroscopic data and comparison with those reported in the literature. The protective effects against lipopolysaccharide (LPS)-stimulated damage on human normal lung epithelial (BEAS-2B) cells of the compounds were evaluated using MTT assay and cellular immunofluorescence assay. The results showed that compounds 2–3, 8–11, and 15–19 exhibited protective effects against LPS-induced damage to BEAS-2B cells. Moreover, compounds 2–3, 8–11, and 15–19 can significantly downregulate the level of nuclear translocation of NF-κB p-p65. In summary, this study revealed chemical constituents with lung protective activity from C. tinctorius, which may be developed as a drug for the treatment of lung injury.     

耳壳藻化学成分研究

从耳壳藻中分离得到5种化合物,它们的结构经波谱分析确定为3-十六烷酰氧基-2-(11Z)-二十碳烯酰氧基-丙三醇-1-β-D-半乳糖甙(1)、马尾藻甾醇(2)、岩藻甾醇(3)、α十六烷酸甘油酯(4)、二十一烷酸十八烷酯(5).其中(1)为新化合物.