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Chinese Journal of Chemistry 2021年第5期39卷 1129-1137页

作者： Ji-Wu Huang Chuang-Jun Li Jing-Zhi Yang Chuan Li Yu Zhang Ke Liu Yue Yu Jian-Dong Jiang Dong-Ming Zhang State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China

Eight new polycyclic phloroglucinol meroterpenoids guajamers A-H(1-8),a methylated benzoylphloroglucinol meroterpenoid guajamer I(9)representing a new skeleton,and two known analogues(10 and 11)were isolated from the leaves of psidium *** structures of new molecules were elucidated by detailed analysis of spectroscopic data,and those of 1,2,8,and 9 were unambiguously confirmed by single-crystal X-ray diffraction ***,compounds 1-8 were sesquiterpene and monoterpene-based meroterpenoids with rearranged skeletons,while compound 9 was the first case of 3-alkyl-5-formyl-benzoylphloroglucinol-coupled sesquiterpene containing an unusual C-l-spiro-fused 6/6/9/4 polycyclic *** addition,all the isolated compounds were evaluated for their antibacterial activity against three bacterial strains,and most of them(compounds 2-7,10,and 11)showed antibacterial activity against Staphylococcus aureus and Staphylococcus epidermidis with MIC values of 8-32 μmol/*** findings suggested that meroterpenoids isolated from psidium guajava can be considered as potential antibacterial leading compounds for pharmaceutical industry.

关键词： psidium guajava Meroterpenoids X-ray crystal structure Structural elucidation Antibacterial activity

Psiguamers A-C, three cytotoxic meroterpenoids bearing a methylated benzoylphloroglucinol framework from psidium guajava and total synthesis of 1 and 2

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Chinese Chemical Letters 2021年第5期32卷 1721-1725页

作者： Jiwu Huang Chuangjun Li Jie Ma Yingda Zang Xingyan Sun Xiaoguang Chen Dongming Zhang State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicoChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China

Three sesquiterpene-based meroterpenoids psiguamers A-C(1-3)with new skeletons were isolated from psidium guajava ***(±)-1 and(±)-2 were two pairs of humulene-de「ived meroterpenoids bearing a rare methylated benzoylphloroglucinol unit,while 3 was an unprecedented adduct of bicyclogermacrene and methylated *** structures were determined based on comprehensive analyses of spectroscopic data,calculated electronic circular dichroism(ECD)spectra,total synthesis,and X-ray crystallographic *** biomimetic synthesis of(±)-1 and(±)-2 was ***(+)-1 exhibited cytotoxic activities against five human tumor cell lines(HCT-116,HepG2,BGC-823,A549,and U251),with IC_(50) values of 2.94,9.01,6.45,5.42,and 5.33 μmol/L,respectively.

关键词： psidium guajava Methylated benzoylphlorogiucinol Meroterpenoids Biomimetic synthesis Cytotoxic activities

Two new triterpenoids from psidium guajava

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Chinese Chemical Letters 2012年第7期23卷 827-830页

作者： Ji Cheng Shu Jian Qun Liu Gui Xin Chou Zheng Tao Wang The MOE Key Laboratory for Standardization of Chinese Medicines and SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines Institute of Chinese Materlaz Medica of Shanghai University of Traditional Chinese MedicineShanghai 201203China Key Laboratory of Modern Preparation of Traditional Chinese Medicines Ministry of EducationNanchang 330004China

Two new triterpenoids,named as 2 α,3 β,23-trihydroxylurs-12,20（30）-dien-28-oic acid β-D-glucopyranoside（1）,and 2 α,3 β,6 β,20 β,23,30-hexahydroxyurs-12-en-28-oic acid（2）,together with four known triterpenoids were isolated from the leaves of psidium guajava *** structures were elucidated on the basis of mass and spectral evidence.

关键词： psidium guajava Triterpcnoid

Green synthesis of titanium dioxide nanoparticles using psidium guajava extract and its antibacterial and antioxidant properties

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Asian Pacific Journal of Tropical Medicine 2014年第12期7卷 968-976页

作者： Thirunavukkarasu Santhoshkumar Abdul Abdul Rahuman Chidambaram Jayaseelan Govindasamy Rajakumar Sampath Marimuthu Arivarasan Vishnu Kirthi Kanayairam Velayutham John Thomas Jayachandran Venkatesan Se-Kwon Kim Unit of Nanotechnology and Bioactive Natural Products Post Graduate and Research Department of ZoologyC.Abdul Hakeem CollegeMelvisharam-632509Vellore DistrictTamil NaduIndia Centre for Nanobiotechnology VIT UniversityVellore 632014.Tamil NaduIndia Department of Chemistry Pukyong National UniversityBusan-608737Republic of Korea

Objective:To determine the efficacies of antibacterial and antioxidant activities of aqueous leaf extract of psidium guajava mediated biosynthesis of titanium dioxide nanoparticles(TiO_2,NPs).Methods:Synthesized TiO_2 NPs were tested by disc diffusion method against against human pathogenic *** total antioxidant activity and phenolic content(Folin—Ciocalteau method) of synthesized TiO_2 NTs and aqueous plant extract were *** scavenging radicals were estimated hv DPPH *** synthesized TiO_2 NPs were characterized by XRD,*** and EDX,Results:FTIR spectra of synthesized TiO_2 NPs exhibited prominent peaks at 3410 cm^(-1)(alkynes),1 578 cm^(-1).1 451 cm^(-1)(alkanes),and 1 123 cm^(-1)(C-O absorption).The morphological characterization of synthesized TiO_2 NPs was analysed by FESEM which showed spherical shape and clusters with an average size of 32.58 *** maximum zone of inhibition was observed in the synthesized TiO_2 NPs(20 μg/mL) against Staphylococcus aureus(25 mm) and Escherichia coli(23 mm).The synthesized TiO_2 NPs showed more antibacterial activity than the standard antibiotic disk,tetracycline which drastically reduces the chances for the development of antibiotics resistance of bacterial *** plant aqueous extract and synthesized TiO_2NPs were found to possess maximum antioxidant activity when compared with ascorbic *** content of phenolic compounds(mg/g) in Leaf aqueous extract and synthesized TiO_2 NPs were found to be 85.4 and 18.3 mgTA/g,***:Green synthesized TiO_2 NPs provides a promising approach can satisfy the requirement of large-scale industrial production hearing the advantage of low—cost,eco—friendly and reproducible.

关键词： TiO_2 nanoparticles psidium guajava FTIR Electron microscopy Antibacterial activity Antioxidant activity

Guava extract (psidium guajava) alters the labelling of blood constituents with technetium-99m

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2006年第6期7卷 429-435页

作者： ABREU P.R.C. ALMEIDA M.C. BERNARDO R.M. BERNARDO L.C. BRITO L.C. GARCIA E.A.C. FONSECA A.S. BERNARDO-FILHO M. Department of Biophysics and Biometry Institute of Biology Roberto Alcantara Gomes University of Estate of Rio de Janeiro Rio de Janeiro 20551030 Brazil Department of Physiology Biological Sciences and Health Center Federal University of Sergipe So Cristóvo Sergipe 49100000 Brazil Department of Pharmacology and Psychobiology Institute of Biology Roberto Alcantara Gomes University of Estate of Rio de Janeiro Rio de Janeiro 20551030 Brazil

psidium guajava (guava) leaf is a phytotherapic used in folk medicine to treat gastrointestinal and respiratory dis-turbances and is used as anti-inflammatory medicine. In nuclear medicine, blood constituents (BC) are labelled with techne-tium-99m (99mTc) and used to image procedures. However, data have demonstrated that synthetic or natural drugs could modify the labelling of BC with 99mTc. The aim of this work was to evaluate the effects of aqueous extract of guava leaves on the labelling of BC with 99mTc. Blood samples of Wistar rats were incubated with different concentrations of guava extract and labelled with 99mTc after the percentage of incorporated radioactivity (%ATI) in BC was determined. The results suggest that aqueous guava extract could present antioxidant action and/or alters the membrane structures involved in ion transport into cells, thus decreasing the radiolabelling of BC with 99mTc. The data showed significant (P<0.05) alteration of ATI in BC from blood incubated with guava extract.

关键词： Antioxidant Blood constituents psidium guajava Technetium-99m

Effects of two medicinal plants psidium guajava L. (Myrtaceae) and Diospyros mespiliformis L. (Ebenaceae) leaf extracts on rat skeletal muscle cells in primary culture

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2006年第1期7卷 56-63页

作者： BELEMTOUGRI R.G. CONSTANTIN B. COGNARD C. RAYMOND G. SAWADOGO L. Laboratory of Physiological Animal University of Ouagadougou BP 7021 Burkina Faso Institute of Physiology & Biology Cell University of Poitiers France

Crude decoction, aqueous and ethanolic extracts of two medicinal plants （Psidiura guajava and Diospyros raespiliformis）, widely used in the central plateau of Burkina Faso to treat many diseases were evaluated for their antagonistic effects on caffeine induced calcium release from sarcoplasmic reticulum of rat skeletal muscle cells. These different extracts showed a decrease of caffeine induced calcium release in a dose dependent manner. Comparison of the results showed that Psidiura guajava leaf extracts are more active than extracts of Diospyros mespiliformis and that crude decoctions show better inhibitory activity. The observed results could explaine their use as antihypertensive and antidiarrhoeal agents in traditional medicine, by inhibiting intracellular calcium release.

关键词： psidium guajava Diospyros mespiliformis Myrtaceae Ebenaceae Medicinal plants Intracellular calcium Sarcoplasmic reticulum Caffeine

Guajadials C-F, four unusual meroterpenoids from psidium guajava

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Natural Products and Bioprospecting 2013年第1期3卷 14-19页

作者： Yuan GAO Gen-Tao LI Yan LI Ping HAI Fei WANG Ji-Kai LIU State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China BioBioPha Co. Ltd.Kunming 650201China University of Chinese Academy of Sciences Beijing 100049China

Guajadials C-F(1-4),four sesquiterpenoid-based meroterpenoids with unprecedented skeletons were isolated from the leaves of psidium *** structures and relative configurations were established by extensive spectroscopi... 详细信息

关键词： psidium guajava meroterpenoid guajadial

Phytochemical Composition and Antioxidant Capacity of psidium guajava Fresh Fruits and Flour

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Food and Nutrition Sciences 2014年第8期5卷 725-732页

作者： M.Alejandra Moreno I.Catiana Zampini Milena Costamagna Jorge E.Sayago Roxana M.Ordonez María I.Isla Instituto de Química del Noroeste Argentino(INQUINOA) CONICETSan Miguel de TucumánArgentina Cátedra de Elementos de Química Orgánica y Biológica Facultad de Ciencias Naturales e Instituto Miguel LilloUniversidad Nacional de TucumánSan Lorenzo 1469San Miguel de TucumánArgentina Cátedra de Fitoquímica Facultad de BioquímicaQuímica y FarmaciaUniversidad Nacional de TucumánAyacucho 471San Miguel de TucumánArgentina Fundación Miguel Lillo San Miguel de TucumánArgentina

psidium guajava fruits are consumed fresh or processed (beverages, syrup, ice cream, jams and jellies). Guayaba is a fruit highly perishable and susceptible to damage during the postharvest. One strategy to overcome this problem is its processing by using techniques that preserve its organoleptic, nutritive and functional properties and allow getting food with added value. The purpose of this study was to obtain flour from fresh fruits cultivated in Argentina Northwestern by lyophilization and to determine the antioxidant activity and the main phytochemicals present in fresh fruits and flour. Nutritional composition (sugar, protein and fat) and the bioactive phytochemicals (total phenolic compounds, flavonoid phenolic, condensed and hydrolizable tannin, ascorbic acid, pigments such as anthocyanin and carotenoids) as well as fiber content, were evaluated. The flour preserved flavor, aroma and color of pulp from fresh fruits. The flour contained around 30% of sugar, 20% of total protein, 0.5% of fat and high level of crude fiber. Carotenoids and ascorbic acid were the dominant phytochemicals in flour as well as in fresh fruits. The guayaba flour showed antioxidant activity with SC50 values similar to fresh fruits. The flour showed nutraceutical characteristics that are demanded by functional food and could be used as a dietary supplement.

关键词： Fresh Fruit Flour psidium guajava Nutritional Properties Functional Properties

Growth Kinetics of Vegetative and Reproductive Organs of Guava(psidium guajava L.)in Iguala Guerrero,Mexico

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Agricultural Sciences 2014年第14期5卷 1468-1475页

作者： Agustin Damian Nava Victor A.Gonzalez Hernandez Manuel Nava Jaimes Elias Hernandez Castro Dolores Vargas Alvarez Gemima Diaz Villasenor Francisco Palemon Alberto Blas Cruz Lagunas Academic Unit of Agricultural and Environmental Sciences The Autonomous University of GuerreroGuerreroMéxico Institute of Genetic Resources and Productivity Graduate CollegeTexcocoMexico

In the Mexican tropics the guava trees can grow and produce in any season, so they can be har-vested out of the period of high competition marketing (Summer). It?studied the growth kinetics of leaves and fruits of guava trees at the dry tropical conditions of the State of Guerrero, in guava trees of four years old and was evaluated a non-destructive method for measuring leaf area from November to May. 100 sheets of 10 randomly selected trees were cut. It was found that leaf length X the width X 0.72581647 (conversion factor) gave an estimated leaf area which?was significantly correlated with that obtained by the integrator of leaf area. Both in length and width the leaf growth kinetics were sigmoid with three growth stages: In Stage I (15 days) leaves grew 21.2% and 21.5%;in Stage II (26 days) grew 73.6% and 68%;and in Stage III (30 days). They Increased 5.2% and 10.5% in the primary and secondary sprouts. The fruit growth in its equatorial and polar diameters corresponded to a double sigmoid kinetics. In Stage I (61 days) it reached 1.9 and 2.3 cm;in Stage II (62 - 102 days) it reached 3.09 and 3.62 cm;and in Stage III (103 to 126 days) it reached 4.63 and 5.13 cm, as well the physiological maturity of fruit.

关键词： psidium guajava Growth Kinetics Phenological Events

Antibacterial Activity of psidium guajava Leaf and Stem Bark Extracts on Selected Bacteria in Ugbokolo, Benue State, Nigeria

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Advances in Microbiology 2022年第10期12卷 569-578页

作者： Peter Adikwu Emmanuel Godwin Oyiwona Adejor Johnson Yuana Awua Amina Ojochide Hassan Terkaa Oluwakemisola Adenugba Ene Theresa Ebiega Biological Science Department Benue State University Makurdi Nigeria Department of Science Laboratory Technology Benue State Polytechnic Ugbokolo Nigeria Benue State Ministry of Energy Science and Technology Makurdi Nigeria Department of Microbiology Federal University of Agriculture Makurdi Nigeria

Aim: In recent years, there has been a growing interest in researching and developing new antimicrobial agents from various sources to combat microbial resistance. The study was aimed at determining the phytochemical constituents and in vitro antibacterial activity of methanol and aqueous extracts of psidium guajava leaves and stem bark on Escherichia coli, Salmonella typhi, Staphylococcus aureus and Proteus sp. in Ugbokolo, Nigeria. Materials and Methods: The phytochemical screening of the plant materials for various bioactive components was conducted between July and December, 2019 using standard laboratory techniques. The extracts were purified using column chromatography. The identity of the test isolates were confirmed using morphological characteristics, gram stain, motility and appropriate biochemical tests such as indole, catalase, coagulase, triple sugar iron agar. The susceptibility of the isolates to each bioactive component was determined using the agar well diffusion method. The broth dilution method was employed for the determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extracts. Results: The result of the study showed the presence of phenol, tannins, flavonoids and saponins as bioactive compounds. The antibacterial susceptibility of the isolates to aqueous and methanol extracts of leaf and stem bark of psidium guajava varied significantly (P Staphylococcus aureus was the most susceptible isolate at 200 mg/ml concentration with average zone of inhibition of 13.05 mm for leaf extract and 15.34 mm for stem bark extract. Proteus sp. is the least susceptible with average zone of inhibition of 8.88 mm for the leaf extract and 12.36 mm for the stem bark extract respectively. Minimum Inhibitory Concentration and Minimum Bactericidal Concentration of aqueous and methanol extract of P. guajava leaf and stem bark showed that dilutions of various concentrations of aqueous and methanol extracts can inhibit a

关键词： Antibacterial psidium guajava Leaf Extract Stem Bark Extract