Aginoside saponin,a potent antifungal compound,and secondary metabolite analyses from Allium nigrum L.

The HPLC and spectral analyses of cysteine sulfoxides (CSOs), total polyphenols (TP), and total saponins revealed quantitative variations within the different organs of Allium nigrum L. A large accumulation of CSOs was detected in the bulb (0.367 mg/g fw), of TP in the leaf (116.05 mg CE/100 g fw), and of saponins in the root (19.38 mg/g dw). Phytochemical and chromatographical investigations of A. nigrum root extract led to the isolation of a spirostane-type glycoside or aginoside. The structure was elucidated by spectroscopic analysis (2D NMR, FABMS, HR-ESI-MS). The structure of the aginoside was identified as 25(R,S)-5α-spirostan-2α,3β,6β-trio1-3-O-β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-β-d-galactopyranoside. The highest content of aginoside, 2.9 mg/g dw, was detected in the root. The in vitro and in vivo antifungal activity of aginoside was evaluated for the first time against phytopathogens. This compound showed significant (P < 0.05) antifungal activity depending on the concentration.     

Seasonal Changes of Flavonoid Content in Melittis melissophyllum L. (Lamiaceae)

Melittis melissophyllum L., a medicinal plant currently used in the folk medicine, was analyzed for the content of flavonoid compounds. The plants were collected in two locations in Poland in May and September. MeOH Extracts from the leaves and flowers (separately) were analyzed by HPLC‐DAD. Eight compounds were identified in all the samples and quantitatively analyzed as cinaroside (=luteolin 7‐O‐glucoside), rutin, myricetin, quercitrin, quercetin, luteolin, kaempferol, and apigenin. M. melissophyllum accumulated the highest total amounts of flavonoids in May (flowers: from 258 to 271 mg/100 g dry weight (dw); leaves: from 143 to 155 mg/100 g dw) and significantly lower ones in September (leaves: from 83 to 92 mg/100 g dw). The main compound was cinaroside (May: up to 249 mg/100 g dw; September: up to 43 mg/100 g dw). Advanced multivariate statistical techniques (cluster analysis (CA) and principal component analysis (PCA)) were used to characterize the sample populations and to analyze the data. We report, for the first time, the results of the quantitative analysis of M. melissophyllum flavonoids and seasonal changes in their accumulation. Our results show that the time of harvesting has a significant influence on the flavonoid content in M. melissophyllum, while the geographical location does not have such an effect.     

Phytochemical diversity of Origanum vulgare L. subsp. vulgare (Lamiaceae) from Austria

This investigation was aiming at the phytochemical characterisation of Origanum vulgare subsp. vulgare from Austria. To study the qualitative and quantitative composition of essential oil compounds 374 individual plants were analysed via GC. The volatiles of Austrian O. vulgare subsp. vulgare were found to be complex mixtures of 53 mono- and sesquiterpenes. Among the sesquiterpenes β-caryophyllene, germacrene D, E-E-α-farnesene, germacrene D-4-ol and caryophyllene oxide were frequently present in higher amounts. The monoterpenes were mainly made up of sabinyl-compounds [mainly sabinene (up to 48.4%) and cis-sabinene hydrate (up to 57.8%)] and/or cymyl-compounds [mainly p-cymene (up to 49.7%), γ-terpinene (up to 21.5%) and carvacrol (up to 32.9%)] that were accompanied by usually smaller amounts of bornyl-compounds and acyclic compounds. Some exceptional (in O. vulgare rare) chemotypes were detected. The essential oil content of Austrian O. vulgare subsp. vulgare ranged between 0.1 and 1.8%. The content of rosmarinic acid was analysed by HPLC and ranged from 0.6 mg/g dry mass up to 37.2 mg/g dry mass. No arbutin could be detected in the analysed populations.     

Production of tropane alkaloids by transformed root cultures of Atropa belladonna in stirred bioreactors with a stainless steel net

A scale up of transformed root cultures of Atropa belladonna from a 300-ml flask to a 30-l tank was accomplished without any reduction in alkaloid productivity. Cutting treatment of seed cultures showed no distinct effect on root growth, morphology, and alkaloid content in conical flasks during 1 month of culture. Randomly cut roots thus grown were further cultivated in 3-l and 30-l modified stirred bioreactors for a scale-up culture. After 1 month of culture, 1490 mg of tropane alkaloids was produced by a 30-l culture of A. belladonna transformed roots. These roots contained the same level of atropine (5.4 mg/ g dw) as the roots of this plant grown in the field for 12 months and still contained a considerable amount of other alkaloids including 1.6 mg/g dw of 6-β-hydroxyhyoscyamine, 0.9 mg/g dw of scopolamine, and 2.0 mg/g dw of littorine. Received: 12 June 1998 / Revision received: 31 August 1998 / Accepted: 27 October 1998     

Seed Polyphenolic Profile,Antioxidative Activity,and Fatty Acids Composition of Wild and Cultivated Carthamus Species

Total flavonoid content (TFC) and cyanidin‐3‐glucoside (Cyd‐3‐glu) of seed and seed coat extract of 16 genotypes from five species of Carthamus were studied, and their major polyphenolic compounds and antioxidant activity of the seed coat extracts were determined using HPLC analysis and DPPH assay, respectively. Additionally, fatty acids composition of the seed oil was analyzed by GC. In general, TFC and Cyd‐3‐glu content of seed coat extracts were higher than those of seed extracts. A novel breeding line with black seed coat (named A82) depicted lower TFC (3.79 mg QUE/g DW) but higher Cyd‐3‐glu (24.64 mg/g DW) compared to the white and other seed‐pigmented genotypes. DPPH radical scavenging activity showed a strong association with Cyd‐3‐glu content (r = 0.84), but no correlation with TFC (r = ?0.32). HPLC analysis of seed coat extracts revealed that four compounds were dominant constituents including rutin (7.23 – 117.95 mg/100 g DW), apigenin (4.37 – 64.88 mg/100 g DW), quercetin (3.09 – 14.10 mg/100 g DW), and ferulic acid (4.49 – 30.41 mg/100 g DW). Interestingly, the genotype A82 with an appropriate polyunsaturated/saturated fatty acids index (5.46%) and a moderate linoleic fatty acid content (64.70%) had higher nutritional and pharmaceutical value than all the other genotypes.     

Characterization and Analysis of Sesamolinol Diglucoside in Sesame Seeds

A new lignan glucoside was isolated from defatted sesame seed flour and its structure was established as sesamolinol diglucoside [2-(3-methoxy-4-(O-β-D-glucopyranosyl (1→6)-O-β-D-glucopyranoside)phenoxyl)-6-(3,4-methylenedioxyphenyl)-cis-3,7-dioxabicyclo-(3.3.0)-octane] by mass and nuclear magnetic resonance spectroscopy. A quantitative analysis of 65 sesame seed samples showed that this sesamolinol diglucoside ranged from <5 to 232 mg/100 g of seeds (98±57 mg/100 g) with no difference between white and black sesame seeds.     

Chemical Variability of Cleistopholis patens (Benth.) Engl. et Diels Leaf Oil from Ivory Coast

The chemical composition of 48 leaf oil samples isolated from individual plants of Cleistopholis patens (Benth .) Engl. et Diels harvested in four Ivoirian forests was investigated by GC‐FID (determination of retention indices), GC/MS, and ¹³C‐NMR analyses. The main components identified were β‐pinene (traces–59.1%), sabinene (traces–54.2%), (E)‐β‐caryophyllene (0.3–39.3%), linalool (0.1–38.5%), (E)‐β‐ocimene (0.1–33.2%), germacrene D (0.0–33.1%), α‐pinene (0.1–32.3%), and germacrene B (0–21.2%). The 48 oil compositions were submitted to hierarchical clustering and principal components analyses, which allowed the distinction of three groups within the oil samples. The oil composition of the major group (Group I, 33 samples) was dominated by (E)‐β‐caryophyllene and linalool. The oils of Group II (eight samples) contained mainly β‐pinene and α‐pinene, while those of Group III (seven samples) were dominated by sabinene, limonene, and β‐phellandrene. Moreover, the compositions of the Ivoirian C. patens leaf oils differed from those of Nigerian and Cameroonian origins.     

Phytochemical Variation within Aerial Parts of Ferula cupularis Populations,an Endangered Medicinal Plant from Iran

Ferula cupularis (Boiss.) Spalik et S. R. Downie is an endangered endemic Iranian medicinal plant with occurrence restricted to Fars and Kohkilooyeh Boyerahmad provinces, Iran. F. cupularis is cited for strong antibacterial activity, usages in foodstuffs preservation, and has long been used by local peoples for ulcer treatment. In this research, the aerial parts of F. cupularis wild populations were collected from three natural habitats: Eqlid-Kaftar (FC1), Kakan (FC2), and Sepidan-Komohr (FC3), to assess phytochemical diversity and antioxidant activity. The quantity of essential oil (EO) ranged remarkably from 0.42 to 0.72 % v/w among the populations. Results obtained from the EO analysis by GC-FID and GC/MS detected up to 56 compounds. α-Pinene (21.65–31.53 %), sabinene (4.74–11.39 %), phellandrene (1.78–5.1 %), δ-3-carene (1.85–7.18 %), limonene (4.12–7.45 %), (Z)-β-ocimene (9.08–17.64 %), and elemicin (0.23–5.74 %) were the major compounds of EOs varied significantly among the populations. Moreover, total phenol content (250.54 to 387.45 mg gallic acid/100 g dry weight (DW)) and flavonoids (34.38 to 41.12 mg quercetin/100 g DW) of methanolic extracts varied substantially among the populations. Antioxidant activities of F. cupularis EOs and extracts were assessed by DPPH (2,2,1-diphenyl-1-picrylhydrazyl) radical scavenging method. EOs exhibited EC₅₀ values ranging from 8.88 to 9.67 μg mL⁻¹ and the EC₅₀ values for the extract ranged from 941.36 to 1335.96 μg mL⁻¹ within the populations. Results demonstrated significantly different levels of antioxidant capacities among the studied populations. Monitoring the data, the population collected from Eqlid-Kaftar (FC1) was selected as the most potent population concerning the highest EO content and antioxidant activity level. The obtained data provided new insights for an initial source of breeding plans and ultimately massive production for food and pharmaceutical industries.     

GC/MS Profiling,In Vitro and In Silico Pharmacological Screening and Principal Component Analysis of Essential Oils from Three Exotic and Two Endemic Plants from Mauritius

The chemical and pharmacological profiles of essential oils (EOs) hydrodistilled in yields of 0.03–0.77 % (w/w) from three exotic (Cinnamomum camphora, Petroselinum crispum, and Syzygium samarangense) and two endemic (Pittosporum senacia subsp. senacia and Syzygium coriaceum) medicinal plants were studied. GC-MS/GC-FID analysis of the EOs identified the most dominant components to be myristicin (40.3 %), myrcene (62.2 %), 1,8-cineole (54.0 %), β-pinene (21.3 %) and (E)-β-ocimene (24.4 %) in P. crispum, P. senacia and C. camphora, S. samarangense and S. coriaceum EOs, respectively. All EOs were found to possess anti-amylase (0.70–1.50 mM ACAE/g EO) and anti-tyrosinase (109.35–158.23 mg KAE/g) properties, whereas no glucosidase inhibition was displayed. Only Syzygium EOs acted as dual inhibitors of both acetyl- and butyryl-cholinesterases, while P. senacia and C. camphora EOs inhibited acetylcholinesterase selectively and P. crispum EO was inactive (AChE: 4.64–4.96 mg GALAE/g; BChE: 5.96 and 7.10 mg GALAE/g). Molecular docking revealed 1,8-cineole to present the best binding affinities with butyrylcholinesterase, amylase and tyrosinase, while both myristicin and β-pinene with acetylcholinesterase and finally β-pinene with glucosidase. In vitro antioxidant potency was also demonstrated in different assays (DPPH: 13.52–53.91 mg TE/g, ABTS: 5.49–75.62 mg TE/g; CUPRAC: 45.38–243.21 mg TE/g, FRAP: 42.49–110.64 mg TE/g; and phosphomolybdenum assay: 82.61–160.93 mM TE/g). Principal component analysis revealed the EOs to differ greatly in their bioactivities due to their chemodiversity. This study has unveiled some interesting preliminary pharmacological profiles of the EOs that could be explored for their potential applications as phytotherapeutics.     

Transfer Reaction Catalyzed by Exo-β-1,4-galactanase from Bacillus subtilis

A transfer reaction catalyzed by an exo-β-1,4-galactanase from Bacillus subtilis was studied. The enzyme had a broad acceptor specificity and transferred galactobiosyl residues to acceptors such as various alcohols, including hydroxy benzenes and saccharides. Transfer products of glycerol formed by the enzyme were compared with those formed by Escherichia coli β-galactosidase and by Penicillium citrinum endo-galactanase. E. coli enzyme transferred 90% of galactose residues to the primary hydroxyl groups of glycerol and P. citrinum endo-enzyme transferred 80% of saccharide residues to the secondary hydroxyl group. The B. subtilis exo-galactanase was less specific than the other two enzymes and formed two products (1-DG and 2-DG) with a 2-DG/l-DG ratio of about 2. The structures of the saccharides were examined by ¹³C-nuclear magnetic resonance analysis and by enzymatic hydrolysis. 1-DG and 2-DG were elucidated to be O-β-d-galactosyl-(l→4)-O-β-d-galactosyl-(1→1)-glycerol and O-β-d-galactosyl-(l→4)-O-β-d-galactosyl-(l→2)-glycerol, respectively. The efficiency of the transfer reaction was measured at various concentrations of glycerol using galactotriose as a donor. About 40–75% of galactobiosyl residues were transferred at an acceptor concentration range of 20–100 mg/ml.     

Hexane Extract of Echinops spinosissimus Turra subsp. spinosus from Tunisia: A Potential Source of Acetylated Sterols – Investigation of its Biological Activities

The hexane extract of Echinops spinosissimus Turra subsp. spinosus flower heads was analyzed for its fatty acid and sterol composition. Its physicochemical characteristics were also studied. The saponification, iodine and peroxide values were determined as 255 mg KOH/g, 42.57 g I₂/100 g and 110 m equiv. O₂/kg of oil, respectively. The oleic (C18:1; 61.14%), palmitic (C16:0; 21.36%) and linoleic (C18:2; 10.45%) acids were the dominant fatty acids. This extract was also found to contain high levels of β‐sitosterol and stigmasterol (44.97% and 34.95% of total sterols, respectively). On the other hand, the identification of terpenoid compounds was investigated by using GC/MS, which revealed fourteen major terpenoids mainly taraxasterol, lupeol, pseudotaraxasterol, lup‐22(29)‐en‐3‐yl acetate, taraxasteryl acetate, α‐amyrin, β‐amyrin, pseudotaraxasteryl acetate, hop‐20(29)‐en3‐β‐ol, α‐amirenone, along with β‐sitosterol and stigmasterol. Moreover, we have evaluated the in vitro antibacterial and antifungal activities of the unsaponifiable matter and a fraction isolated from this extract. These activities were conducted using the diffusion disc methods and broth microdilution assay. The resulted fraction from this extract showed the highest antibacterial activity with significant minimum inhibitory concentrations (MIC) values 125.0 μg/ml against Staphylococcus aureus, Micrococcus luteus and Bacillus cereus. However, it did exhibit no substantial antifungal activity.     

Phytochemical,Antiplasmodial, Cytotoxic and Antimicrobial Evaluation of a Southeast Brazilian Brown Propolis Produced by Apis mellifera Bees

Seven phenolic compounds (ferulic acid, caffeic acid, 4-methoxycinnamic acid, 3,4-dimethoxycinnamic acid, 3-hydroxy-4-methoxybenzaldehyde, 3-methoxy-4-hydroxypropiophenone and 1-O,2-O-digalloyl-6-O-trans-p-coumaroyl-β-D-glucopyranoside), a flavanonol (7-O-methylaromadendrin), two lignans (pinoresinol and matairesinol) and six diterpenic acids/alcohol (19-acetoxy-13-hydroxyabda-8(17),14-diene, totarol, 7-oxodehydroabietic acid, dehydroabietic acid, communic acid and isopimaric acid) were isolated from the hydroalcoholic extract of a Brazilian Brown Propolis and characterized by NMR spectral data analysis. The volatile fraction of brown propolis was characterized by CG-MS, composed mainly of monoterpenes and sesquiterpenes, being the major α-pinene (18.4 %) and β-pinene (10.3 %). This propolis chemical profile indicates that Pinus spp., Eucalyptus spp. and Araucaria angustifolia might be its primary plants source. The brown propolis displayed significant activity against Plasmodium falciparum D6 and W2 strains with IC₅₀ of 5.3 and 9.7 μg/mL, respectively. The volatile fraction was also active with IC₅₀ of 22.5 and 41.8 μg/mL, respectively. Among the compounds, 1-O,2-O-digalloyl-6-O-trans-p-coumaroyl-β-D-glucopyranoside showed IC₅₀ of 3.1 and 1.0 μg/mL against D6 and W2 strains, respectively, while communic acid showed an IC₅₀ of 4.0 μg/mL against W2 strain. Cytotoxicity was determined on four tumor cell lines (SK-MEL, KB, BT-549, and SK-OV-3) and two normal renal cell lines (LLC-PK1 and VERO). Matairesinol, 7-O-methylaromadendrin, and isopimaric acid showed an IC₅₀ range of 1.8–0.78 μg/mL, 7.3–100 μg/mL, and 17–18 μg/mL, respectively, against the tumor cell lines but they were not cytotoxic against normal cell lines. The crude extract of brown propolis displayed antimicrobial activity against C. neoformans, methicillin-resistant Staphylococcus aureus, and P. aeruginosa at 29.9 μg/mL, 178.9 μg/mL, and 160.7 μg/mL, respectively. The volatile fraction inhibited the growth of C. neoformans at 53.0 μg/mL. The compounds 3-hydroxy-4-methoxybenzaldehyde, 3-methoxy-4-hydroxypropiophenone and 7-oxodehydroabietic acid were active against C. neoformans, and caffeic and communic acids were active against methicillin-resistant Staphylococcus aureus.     

Glycosidic Aroma Precursors of 2–Phenylethyl and Benzyl Alcohols from Jasminum sambac Flowers

Benzyl 6-O-β-D-xylopyranosyl-β-D-glucopyranoside (β-primeveroside) (1), 2-phenylethyl β-primeveroside (2), and 2-phenylethyl 6-O-α-L-rhamnopyranosyl-β-D-glucopyranoside (β-rutinoside) (3) were isolated as aroma precursors of benzyl alcohol and 2-phenylethanol from flower buds of Jasminum sambac Ait. The isolation was guided by an enzymatic hydrolysis and GC and GC-MS analyses.     

Chemical Variability of the Needle Oil of Juniperus communis ssp. alpina from Corsica

The composition of 109 samples of essential oil isolated from the needles of Juniperus communis ssp. alpina growing wild in Corsica was investigated by GC (in combination with retention indices), GC/MS, and ¹³C‐NMR. Forty‐four compounds accounting for 86.7–96.7% of the oil were identified. The oils consisted mainly of monoterpene hydrocarbons, in particular, limonene (9.2–53.9%), β‐phellandrene (3.7–25.2%), α‐pinene (1.4–33.7%), and sabinene (0.1–33.6%). The 109 oil compositions were submitted to k‐means partitioning and principal component analysis, which allowed the distinction of two groups within the oil samples. The composition of the major group (92% of the samples) was dominated by limonene and β‐phellandrene, while the second group contained mainly sabinene beside limonene and β‐phellandrene.     

β-galactosidase-catalyzed synthesis of 3-O-β-D-galactopyranosyl-sn-glycerol: Optimization by response surface methodology

In this study, the synthesis of 3-O-β-D-galactopyranosyl-sn-glycerol (GG) was performed by the reverse hydrolysis of D-galactose and glycerol using β-galactosidase from Kluyveromyces lactis. Four process variables, reaction temperature (30.0–45.0?°C), reaction time (24–48?h), enzyme concentration (150.00–350.00?U/mL), and substrate molar ratio (glycerol:D-galactose, 7.5:12.5?mmol/mmol) were investigated and optimized via response surface methodology (RSM) for optimal GG synthesis. Both quadratic equations and the optimal reaction conditions were established. Results showed that the four variables, i.e., reaction temperature, reaction time, enzyme concentration, and substrate molar ratio had significant (p?β-galactosidase concentration and 8.65:1.00 of substrate molar concentration ratio (glycerol: D-galactose) at 39.8?°C and 48?h of reaction. Under these conditions, the GG concentration was 140.03?g/L and GG yield was 55.71%, which both were close to the predicted values (143.26?g/L and 56.73%). This finding proves the RSM to be a useful tool in optimizing process conditions for GG synthesis.     

Comprehensive Study of Mediterranean (Croatian) Propolis Peculiarity: Headspace,Volatiles, Anti‐Varroa‐Treatment Residue,Phenolics, and Antioxidant Properties

Eight propolis samples from Croatia were analyzed in detail, to study the headspace, volatiles, anti‐Varroa‐treatment residue, phenolics, and antioxidant properties. The samples exhibited high qualitative/quantitative variability of the chemical profiles, total phenolic content (1,589.3–14,398.3 mg GAE (gallic acid equivalent)/l EtOH extract), and antioxidant activity (11.1–133.5 mmol Fe²⁺/l extract and 6.2–65.3 mmol TEAC (Trolox^® equivalent antioxidant capacity)/l extract). The main phenolics quantified by HPLC‐DAD at 280 and 360 nm were vanillin, p‐coumaric acid, ferulic acid, chrysin, galangin, and caffeic acid phenethyl ester. The major compounds identified by headspace solid‐phase microextraction (HS‐SPME), simultaneous distillation extraction (SDE), and subsequent GC‐FID and GC/MS analyses were α‐eudesmol (up to 19.9%), β‐eudesmol (up to 12.6%), γ‐eudesmol (up to 10.5%), benzyl benzoate (up to 28.5%), and 4‐vinyl‐2‐methoxyphenol (up to 18.1%). Vanillin was determined as minor constituent by SDE/GC‐FID/MS and HPLC‐DAD. The identified acaricide residue thymol was ca. three times more abundant by HS‐SPME/GC‐FID/MS than by SDE/GC‐FID/MS and was not detected by HPLC‐DAD.     

Chemical Composition and Antibacterial Activity of Essential Oils from Different Parts of Litsea cubeba

The composition of the essential oils obtained by hydrodistillation of different parts of Litsea cubeba, including roots, stems, leaves, alabastra (flower buds), flowers, and fruits, were investigated by GC (RI) and GC/MS. The antimicrobial activity of the oils was assessed with disc diffusion and microbroth dilution assays. The results showed large variations in the composition among the different oils. The major components in the oils from roots and fruits, from stems, leaves, and alabastra, and from flowers were citral B (neral), β‐phellandrene, and β‐terpinene, respectively. The inhibition zone (DD) and MIC values for the bacterial strains tested, which were all sensitive to the essential oil of L. cubeba, were in the range of 10.1–35.0 mm and 100–1000 μg/ml, respectively. Hence, the oils of the various parts showed moderate activity against the tested bacteria. This investigation showed that the antibacterial activity of L. cubeba was attributed to the essential oils, thus they can be a potential medicinal resource.     

Chemical Compositions,Antioxidant and Antimicrobial Activities of Essential Oils of Psidium guajava L. Leaves from Different Geographic Regions in China

Hydrodistilled essential oils (EO) of Psidium guajava L. leaves from different regions in China were analyzed by GC and GC/MS. The samples from Guangdong Province displayed high EO yields (0.61 – 0.75%, v/w). A total of 50 components, representing over 98.00% of the EOs, were identified and semi‐quantitatived. The major constituents of EOs included β‐caryophyllene (17.17 – 31.38%), γ‐gurjunene (9.17 – 15.22%), τ‐cadinol (1.35 – 10.02%) and calamenene (2.13 – 7.80%). The terpenoids in all sample oils were dominated by sesquiterpenes hydrocarbons (70.18 – 84.35%), followed by oxygenated sesquiterpenes (9.89 – 22.19%). The similarities and differences among EOs from different samples were evaluated by hierarchical cluster analysis and principal component analysis methods. The IC₅₀ values of EOs from different regions were between 18.52 – 33.72 mg/ml (DPPH) and 13.12 – 25.15 mg/ml (ABTS⁺). The FRAP value of EO from Guangdong Province was 7.34 – 9.13 mmol Vc/g DM, while the FRAP value of EO from Taiwan Province was 2.29 – 2.36 mmol Vc/g DM. The antimicrobial tests revealed that EO had a higher antimicrobial activity against all Gram‐positive bacteria and two fungi. Moreover, EO from P. guajava leaves of Guangdong Province showed the highest antimicrobial activity. These properties can be considered in the design of industrial products and for further application in the food, pharmaceutical and cosmetic industries.     

Chemical Composition and Antioxidant Activity of Tuber indicum from Different Geographical Regions of China

Tuber indicum, an endemic truffle species in eastern Asian, is an edible mushroom that is both an important export and widely distributed across China. Many existing studies on truffles focus on analyzing their taxonomy, population genetics, volatile organic compounds and artificial cultivation of the truffles, while little information is available about their nutrient composition and pharmacological activity, especially the relationship between chemical composition in ascocarps and their geographic distributions. This study presents a comprehensive investigation of the chemical composition of T. indicum, including free sugars, fatty acids, organic acids, phenolic acids, flavonoids, and polysaccharides, and tracks the antioxidant activity of T. indicum ascocarps collected from five geographical regions of four provinces in P. R. China: Hebei, Tibet, Yunnan, and Liaoning province. Our results showed that T. indicum collected from Qujing, Yunnan province, possessed the highest amount of free sugars (23.67 mg/g dw), total flavonoids (2.31 mg/g dw), total phenolics (4.46 mg/g dw) and the highest DPPH and ABTS radical‐scavenging activities. The amount of water‐soluble polysaccharides was the highest (115.24 mg/g dw) in ascocarps from Tibet, the total organic acids was the highest (22.073 mg/g dw) in ascocarps from Gongshan, and polyunsaturated fatty acids were most abundant in those from Hebei province. This study reveals that the quantity of chemical compounds in T. indicum varies by geographical origin. Detecting differences in chemical composition may provide important data for understanding the relationship between environmental factors and truffle formation, as well as quality evaluation of the commercial species T. indicum throughout China.