Hydrolyzable tannins from Balanophora polyandra

This study reports an investigation of the chemical constituents of Balanophora polyandra Griff.Fifteen compounds were isolated by column chromatography on silica gel,Toyo-pearl HW-40C,Sephadex LH-20 and by HPLC.Their structures were elucidated as 1,4-di-O galloy-2-O-[(E)-p-coumaroyl]-β-D-glucopyranose(1),1-O-galloyl-β-D-pyranglucose(2),1-p-coumaryl-β-D-pyranglu-cose(3),1-O-(E)-caffeoyl-β-D-pyranglucose(4),1,3-di-O-galloyl-β-D-pyranglucose(5),1,6-di-O-galloyl-β-D-pyranglucose(6),1-O-(E)-caffeoyl-4-O-galloyl-β-D-pyranglucose(7),1-O-(E)-caffeoy1-6-O galloyl-β-D-pyranglucose(8),1-0-(E)-caffeoy1-4,6-di-O-galloyl-β-D-pyranglucose(9),1-O-(E)-caffeoyl-4,6-(S)-HHDP-B-D-pyranglucose(10),1,23,6-tetra-O-galloyl-β-D-pyranglucose(11),4,6-(S)-hexahydroxydi-phenoyl-(α/β)-D-glucose(12),1-O-(E)-caffeoyl-4,6-[1′,1″-3′,3″,4′,4″-tetrahydroxydibenzofurandicar-boxyl)]-β-D glucopyranose(13),flavogallonic acid(14),and phloretin-4′-O-β-D-glucoside(15)on the basis of spectral analysis.Compound 1 was a new hydrolyzable tannin,9 was obtained from this genus for the first time,and compounds 5,6 and 11-14 were isolated from this plant for the first time.

Chemistry and ecological significance of tannins

This paper summarized of the chemistry characteristics of tannins and their various adverse effects onmammalian herbivore, including the chemical nature of hydrolyzable and condensed tannins, their analysis mathods, and the tannins antifeedant mechanisms.

Two New Phenolic Constituents from the Stems of Euphorbia griffithii

Phytochemical studies on MeOH extract of stems of Euphorbia griffithii led to the isolation of one new hydrolyzable tannin dimer,corilagiffithiin(1)and one new galloyl-glucoside(2),alongside six known ones(3-8).Their structures and absolute configurations were determined by in depth spectroscopic analyses and comparison of their 1D NMR and MS data with literature reported values.Configurations of sugar moieties were determined by acidic hydrolysis and subsequent GC analysis of their corresponding trimethylsilylated l-cysteine adduct.At a concentration of 50μM,compounds 1-3 showed no anti-inflammatory activities.

The Genus Terminalia(Combretaceae):An Ethnopharmacological,Phytochemical and Pharmacological Review

Terminalia Linn,a genus of mostly medium or large trees in the family Combretaceae with about 250 species in the world,is distributed mainly in southern Asia,Himalayas,Madagascar,Australia,and the tropical and subtropical regions of Africa.Many species are used widely in many traditional medicinal systems,e.g.,traditional Chinese medicine,Tibetan medicine,and Indian Ayurvedic medicine practices.So far,about 39 species have been phytochemically studied,which led to the identification of 368 compounds,including terpenoids,tannins,flavonoids,phenylpropanoids,simple phenolics and so on.Some of the isolates showed various bioactivities,in vitro or in vivo,such as antitumor,anti HIV-1,antifungal,antimicrobial,antimalarial,antioxidant,diarrhea and analgesic.This review covers research articles from 1934 to 2018,retrieved from SciFinder,Wikipedia,Google Scholar,Chinese Knowledge Network and Baidu Scholar by using“Terminalia”as the search term(“all fields”)with no specific time frame setting for the search.Thirty-nine important medicinal and edible Terminalia species were selected and summarized on their geographical distribution,traditional uses,phytochemistry and related pharmacological activities.

Termitomenins F and G,Two New Lignan Glucosides from Terminalia chebula var.tomentella(Kurz)C.B.Clarke

The extensive chemical investigation on the branches and leaves of Terminalia chebula var.tomentella(Combretaceae)led to the isolation of two new lignan glucosides with a furofuran skeleton,termitomenins F(1)and G(2).In addition,19 known compounds including five lignan glucosides(3-7),six hydrolyzable tannins(8-13)and eight simple phenolics(14-21)were also identified.Their structures were determined by comprehensive spectroscopic analyses.It is noted that 8 and 9 were C-glycosidic hydrolyzable tannins with one hexahydroxydiphenoyl and one gallagyl group linked to an open-chain glucosyl C-1/O-2/O-3 and O-4/O-6,respectively,which were rarely found in plants.Nine known compounds,6-9,13,and 18-21,were procured from the titled plant for the first time,while 3-5,10-12 and 14-17 were also found in the fruits.Notably,the known hydrolyzable tannins 8-13 exhibited strongerα-glucosidase inhibitory activities with IC_(50) values ranging from 0.10 to 3.12μM,than the positive control,quercetin(IC_(50)=9.38±0.33μM).

Exploring the Transcriptome Landscape of Pomegranate Fruit Peel for Natural Product Biosynthetic Gene and SSR Marker Discovery

Pomegranate fruit peel is rich in bioactive plant natural products, such as hydrolyzable tannins and anthocyanins. Despite their documented roles in human nutrition and fruit quality, genes involved in natural product biosynthesis have not been cloned from pomegranate and very little sequence information is available on pomegranate in the public domain. Shotgun transcriptome sequencing of pomegranate fruit peel cDNA was performed using RNA-Seq on the Illumina Genome Analyzer platform. Over 100 million raw sequence reads were obtained and assembled into 9,839 transcriptome assemblies （TAs） （〉200 bp）. Candidate genes for hydrolyzable tannin, anthocyanin, flavonoid, terpenoid and fatty acid biosynthesis and/or regulation were identified. Three lipid transfer proteins were obtained that may contribute to the previously reported IgE reactivity of pomegranate fruit extracts. In addition, 115 SSR markers were identified from the pomegranate fruit peel transcriptome and primers were designed for 77 SSR markers. The pomegranate fruit peel transcriptome set provides a valuable platform for natural product biosynthetic gene and SSR marker discovery in pomegranate. This work also demonstrates that next-generation transcriptome sequencing is an economical and effective approach for investigating natural product biosynthesis, identifying genes controlling important agronomic traits, and discovering molecular markers in non-model specialty crop species.