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Three new anthraquinone derivatives isolated from Symplocos racemosa and their antibiofilm activity

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Chinese Journal of Natural Medicines 2017年第12期15卷 944-949页

作者： Umar Farooq Sara khan Sadia Naz Ajmal khan afsar khan Ayaz Ahmed Abdur Rauf Syed Majid Bukhari Shujaat Ali khan Arfa Kamil Nadia Riaz Abdur Rahman khan Department of Chemistry COMSATS Institute of Information Technology Abbottabad-22060 Pakistan Dr. Panjwani Center for Molecular Medicine and Drug Research International Center for Chemical and Biological Sciences University of Karachi- 752 70 Pakistan Department of Geology University of Swabi Anbar-23430 KPK Pakistan Institute of Chemical Sciences University of Peshawar Peshawar 25120 Pakistan Department of Pharmaceutical Chemistry Faculty of Pharmacy Federal Urdu University of Arts Science and Technology Karachi Karachi 75300 Pakistan Department of Environmental Sciences COMSATS Institute of lnformation Technology Abbottabad-22060 Pakistan

Three new alkyl substituted anthraquinone derivatives, trivially named as symploquinones A-C(Compounds 1-3) were isolated from Symplocos racemosa. The structures of these compounds were determined on the basis of extensive spectroscopic analyses(UV, IR, Mass, ~1 H-and ^(13)C-NMR, and two-dimensional(2D) NMR techniques). The resulting data were also compared with the reported literature. These compounds were then subjected to antibacterial or antibiofilm testing. Compounds 1 and 3 exhibited good antibacterial activity in the concentration range of 160-83 μg·m L^(-1) against Streptococcus mutans, methicillin resistant Staphylococcus aureus and Proteus mirabilis. Both compounds were further screened for anti-biofilm activity, which revealed promising activities at sub-MIC concentrations. None of the compounds were found to be active against Klebsiella pneumoniae.

关键词： Symplocos racemosa Substituted anthraquinone Antibiofilm activity

Screening outcomes of household contacts of multidrug-resistant tuberculosis patients in Peshawar,Pakistan

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Asian Pacific Journal of Tropical Medicine 2016年第9期9卷 886-889页

作者： Arshad Javaid Mazhar Ali khan Mir Azam khan Sumaira Mehreen Anila Basit Raza Ali khan Muhammad Ihtesham Irfan Ullah afsar khan Ubaid Ullah Post Graduate Medical Institute Lady Reading Hospital Programmatic Management of Drug Resistant TB Unit Lady Reading Hospital Peshawar Medical College Kohat University of Science and Technology Kohat

Objective:To assess the profile of TB/multidrug-resistant TB(MDR-TB) among household contacts of MDR-TB ***:Close contacts of MDR-TB patients were traced in the cross-sectional *** clinical,radiological and bacteriological were performed to rule out the evidence of TB/***:Between January 2012 and December 2012,a total of 200 index MDR-TB patients were initiated on MDR-TB treatment,out of which home visit and contacts screening were conducted for 154 index *** 610 contacts who could be studied,41(17.4%) were diagnosed with MDR-TB and 10(4.2%) had *** most common symptoms observed were cough,chest pain and ***:The high incidence of MDR-TB among close contacts emphasize the need for effective contact screening programme of index MDR-TB cases in order to cut the chain of transmission of this disease.

关键词： Tuberculosis Household contacts MDR-TB Peshawar Pakistan

Chemical composition and pharmacological activity of seco-prezizaane-type sesquiterpenes

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Chinese Herbal Medicines 2024年第1期16卷 70-81页

作者： Ye Jin Yanqing Xie Peng Zhang afsar khan Zhihong Zhou Lu Liu Yunnan Yunzhong Institute of Nutrition and Health Yunnan University of Chinese MedicineKunming 650500China Department of Chemistry COMSATS University IslamabadAbbottabad CampusAbbottabad 22060Pakistan

The seco-prezizaane-type sesquiterpenes(SPS),as a special class of sesquiterpenes with a highly oxidative five-ring cage structure and seven consecutive chiral centers,are isolated from the genus Illicium,which have a variety of biological activities,including neurotoxicity and neurotrophic effects,*** review summarizes the chemical constituents and pharmacological effects of SPS,and discusses the potential trend and scope of future research.

关键词： anisatin chemical composition Illicium genus majucin pharmacological activity seco-prezizaane-type sesquiterpenes

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镍铁基纳米结构材料的合成及析氧性能研究

镍铁基纳米结构材料的合成及析氧性能研究

作者： Muhammad afsar khan 扬州大学

学位级别：硕士

随着全球人口不断增加,自然资源和能源需求的压力越来越大,发展中国家的工业化也在加剧。电化学反应在能源生产、转换和储存中起着关键性作用。研究电催化活性材料成为一个重要的研究领域。例如,如何从间歇性可再生能源中储存能量是一... 详细信息

随着全球人口不断增加,自然资源和能源需求的压力越来越大,发展中国家的工业化也在加剧。电化学反应在能源生产、转换和储存中起着关键性作用。研究电催化活性材料成为一个重要的研究领域。例如,如何从间歇性可再生能源中储存能量是一项持续的挑战。电化学能源储存和转换装置在推进纯净、可行和具有成本效益的能源系统以满足社会的可持续发展方面发挥着关键作用。因此,为了满足工业上对电解水产生的能源需求,开发一种低价且具有成本效益的氧进化反应（OER）催化剂是至关重要的。例如IrO2和RuO2被认为最先进的OER电催化剂,但这种基于贵金属的催化剂因其稀缺性和高成本而受到严重限制。因此,开发低成本和高效率的OER催化剂是非常重要的。基于镍（Ni）、铁（Fe）和钴（Co）的过渡金属氧化物和氢氧化物已经显示出对OER有很好的电催化活性。然而,制备均匀的混合金属催化剂不是一个简单的过程。在用于制造催化剂的各种制备方法中,电化学方法提供了一种简单的方法来制造具有所需成分、形态和形状的均匀混合结构。其优点是可以在环境条件下通过简单的设置迅速进行合成。近几十年来,镍铁基催化剂显示出最高的OER活性,并可能被用于OER过程中。镍铁基氢氧（氧）化物和层状氢氧化物已被证明是碱性电解质溶液中高活性的OER催化剂之一,通过比较,在许多情况下超过了现有技术水平。然而,人们希望进一步提高催化活性,在设计镍铁基催化剂方面仍然存在挑战。（ⅰ）如何利用非贵金属（过渡金属）取代贵金属的含量?（ⅱ）如何优化电子结构?（ⅲ）如何改善镍基催化剂的强电子作用和活性位点,使其OER性能接近IrO2和RuO2。然而,为解决上述问题,通过对电子结构的调控,提高镍铁基材料的强电子作用,增加催化活性位点。在接下来的工作中,通过掺杂和电沉积外来元素（如S、Ce和Co）来调节和优化碱性OER反应物的强度,大大改善了碱性OER的性能。1.我们通过将硫化钴电沉积在氢氧化镍纳米片上（NiFe氢氧化物@CoS）,成功地合成了一种独特的复合电催化剂。由于氢氧化镍纳米片与CoS之间的强相互作用,电沉积后活性位点增加。因此,电沉积CoS使氢氧化镍纳米片对OER具有更好的活性,有利于低成本和稳定的电解水。CoS的沉积通过为镍和铁物种提供更高的金属价态来提高催化活性,这有望在OER反应过程中帮助吸收中间产物（*OH和*OOH）。总之,本研究中NiFe基氢氧化物@CoS的OER催化活性的提高是由于内在活性和催化剂表面积的增加。2.通过引入Ce和硫化过程,用三步水热法成功制备了 Ce@NiFeS,调节其电子结构,引入了额外的活性位点,实现了高催化性能。根据电化学活性测试,掺入Ce和硫化都明显改善了催化剂的OER性能。在碱性介质中,它表现出优异的OER性能,在10 mA cm-2的电流密度下显示出仅195 mV的过电位,而最先进的NiFe-LDH的过电位为270 mV。由于添加了 Ce界面和硫杂质,其电子结构得到显着调节,从而提高了本征催化活性并改善了碱性电解质中的OER性能。

关键词：电解水产生氢气析氧反应(OER) 电催化剂电沉积储能系统

Towards a comprehensive understanding of free-living nitrogen fixation

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Circular Agricultural Systems 2021年第1期1卷 89-99页

作者： Sehroon khan Sadia Nadir Shahid Iqbal Jianchu Xu Heng Gui afsar khan Lei Ye Department of Biotechnology Faculty of Natural SciencesUniversity of Science and TechnologyBannu 28100Khyber PakhtunkhwaPakistan Honghe Centre for Mountain Futures Kunming Institute of BotanyChinese Academy of SciencesHonghe 654400YunnanChina Department of Chemistry Faculty of Natural SciencesUniversity of Science and TechnologyBannu 28100Khyber PakhtunkhwaPakistan CIFOR-ICRAF China Country Program World Agroforestry CentreKunming 650201China Department of Chemistry COMSATS University Islamabad(Abbottabad Campus)-22060Pakistan

Free-living nitrogen fixation(FNF)is a ubiquitous phenomenon that plays a modest role in the(N)economy of an ***,sampling difficulties,methodological constraints and environmental controls have presented challenges for predicting the actual rate of ***,a deeper understanding of the accuracy to design models that consider dynamics,heterogeneity,influences,and other limitations is *** review presents an overview of the biology and diversity of microorganisms related to FNF as well as various ecological controls that influence these *** also discussed contributions of FNF to the N input of various ***,previous research has shown that considerable spatiotemporal variability exists in microbial types at both biome and microbiome scales,resulting in significant variation in *** this,rate of FNF is controlled by certain factors,such oxygen and metal ion availability,source of energy and soil nutrients,temperature,and *** evidence increasingly indicates a significant contribution of FNF to N inputs in natural,agricultural,and aquatic *** is inferred from this review that for the expanded exploitation of biological nitrogen fixation(BNF),we must pay additional attention to FNF because it occupies a central role within the ***,we propose a framework for the quantification of FNF alongside a suite of recommendations that would deepen our understanding of FNF.

关键词： ecosystems expanded fixation

Cytotoxic Acylphloroglucinol Derivatives from Callistemon salignus

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Natural Products and Bioprospecting 2017年第4期7卷 315-321页

作者： Xu-Jie Qin Tong Shu Qian Yu Huan Yan Wei Ni Lin-Kun An Pan-Pan Li Yin-E Zhi afsar khan Hai-Yang Liu State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunming 650201People’s Republic of China Yunnan Key Laboratory of Medicinal Chemistry Kunming 650201People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People’s Republic of China Institute of Medicinal Chemistry and Chemical Biology School of Pharmaceutical SciencesSun Yat-sen UniversityGuangzhou 510006People’s Republic of China Department of Chemistry COMSATS Institute of Information TechnologyAbbottabad 22060Pakistan

Callisalignenes G–I(1–3),three new meroterpenoids of b-triketone and monoterpene,along with two known analogues(4 and 5),were isolated from Callistemon *** structures and absolute configurations were unambiguously established by a combination of NMR and MS analysis and electronic circular dichroism(ECD)*** H(2)and I(3)have a rare sec-butyl moiety at *** 1–3 exhibited cytotoxicity against HCT116 cells with IC50 values of 8.51±1.8,9.12±0.3,and 16.33±3.3 lM,respectively.

关键词： Callistemon salignus Myrtaceae Meroterpenoids Cytotoxicity

Bio-catalyzed plastic degradation:a review

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Circular Agricultural Systems 2022年第1期2卷 23-29页

作者： Sehroon khan Sadia Nadir Shahid Iqbal Jianchu Xu Heng Gui afsar khan Masroor Hussain Ihsan Ullah Department of Biotechnology Faculty of Natural SciencesUniversity of Science and TechnologyBannu 28100Khyber PakhtunkhwaPakistan Department of Economic Plants and Biotechnology Yunnan Key Laboratory for Wild Plant ResourcesKunming Institute of BotanyChinese Academy of SciencesKunming 650201YunnanChina Honghe Centre for Mountain Futures Kunming Institute of BotanyChinese Academy of ScienceHonghe 654400YunnanChina East and Central Asia Regional Office World Agroforestry Centre(ICRAF)Kunming 650201YunnanChina Department of Chemistry COMSATS University IslamabadAbbottabad CampusAbbottabad 22060Pakistan Department of Botany Faculty of Natural SciencesUniversity of Science and TechnologyBannu 28100Khyber PakhtunkhwaPakistan

The widespread use and production of plastic have led to increased accumulation of plastic waste in the environment which threatens terrestrial and marine *** methods for management of plastic waste remain a key *** of plastics is considered an environmentally safe method,but is still limited to laboratory *** previous studies have reported microbial enzymes capable of degrading *** discoveries offer a promising starting point for the development of biocatalyzed plastic degradation *** this review,we discuss recent advancements and applications of biocatalyst *** also describe the different steps for development of biocatalyzed plastic degradation technology and the major issues related to each *** in research into biocatalyzed plastic degradation would lead to new opportunities for sustainable alleviation of the worldwide problem of plastic waste accumulation.

关键词： starting steps plastics

Three New Pyridine Alkaloids from Vinca major Cultivated in Pakistan

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Natural Products and Bioprospecting 2017年第4期7卷 323-327页

作者： Xin Wei afsar khan Da Song Zhi Dai Ya-Ping Liu Hao-Fei Yu Bei Wang Pei-Feng Zhu Cai-Feng Ding Xu-Dong Zhao Yi-Fen Wang Xiao-Dong Luo State Key Laboratory of Phytochemistry and Plant Resources of West China Kunming Institute of BotanyChinese Academy of SciencesKunming 650201People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People’s Republic of China Yunnan Key Laboratory of Natural Medicinal Chemistry Kunming 650201People’s Republic of China Department of Chemistry COMSATS Institute of Information TechnologyAbbottabad 22060Pakistan Yunnan College of Business Management Kunming 650106People’s Republic of China Key Laboratory of Animal Models and Human Disease Mechanisms Chinese Academy of Sciences&Yunnan ProvinceKunming Institute of ZoologyKunming 650223YunnanPeople’s Republic of China

Three new pyridine type alkaloids,(-)-vinmajpyridines A–C(1–3),along with two known alkaloids,have been isolated from the aerial parts of Vinca major cultivated in *** structures have been elucidated by means of NMR and HRESIMS spectroscopic *** new alkaloids were evaluated for their cytotoxicity against glioma initiating cell lines(GITC-3#and GITC-18#),glioblastoma cell lines(U-87MG and T98G),and lung cancer cell line A-549,but none of them was active at 20 lg/mL concentration.

关键词： Vinca major Apocynaceae Pyridine alkaloids Cytotoxicity

Indole Alkaloids Inhibiting Neural Stem Cell from Uncaria rhynchophylla

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Natural Products and Bioprospecting 2017年第5期7卷 413-419页

作者： Xin Wei Li-Ping Jiang Ying Guo afsar khan Ya-Ping Liu Hao-Fei Yu Bei Wang Cai-Feng Ding Pei-Feng Zhu Ying-Ying Chen Yun-Li Zhao Yong-Bing Chen Yi-Fen Wang Xiao-Dong Luo State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunming 650201People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People’s Republic of China Key Laboratory of Animal Models and Human Disease Mechanisms Kunming Institute of ZoologyChinese Academy of SciencesKunming 650223People’s Republic of China Department of Chemistry COMSATS Institute of Information TechnologyAbbottabad 22060Pakistan Yunnan Key Laboratory of Natural Medicinal Chemistry Kunming 650201People’s Republic of China

Uncaria rhynchophylla is commonly recognized as a traditional treatment for dizziness,cerebrovascular diseases,and nervous disorders in ***,the neuro-protective activities of the alkaloids from *** were intensively *** current work,three new indole alkaloids(1–3),identified as geissoschizic acid(1),geissoschizic acid N4-oxide(2),and 3b-sitsirikine N4-oxide(3),as well as 26 known analogues were isolated from ***,in the neural stem cells(NSCs)proliferation assay for all isolated compounds,geissoschizic acid(1),geissoschizic acid N4-oxide(2),isocorynoxeine(6),isorhynchophylline(7),(4S)-akuammigine N-oxide(8),and(4S)-rhynchophylline N-oxide(10)showed unexpected inhibitory activities at 10 μ*** previous neuro-protective reports,as a warning or caution,our finding showcased a clue for possible NSCs toxicity and the neural lesions risk of ***,while the structure–activity relationships of the isolated compounds were discussed also.

关键词： Uncaria rhynchophylla Indole alkaloids NSCs proliferation