http://rulrepository.ru.ac.bd/handle/123456789/78 2026-04-07T21:44:31Z http://rulrepository.ru.ac.bd/handle/123456789/995 Chemical Investigations on Lac and Its Derived Products Haque, Muhammad Zahurul Allah, the Almighty has created each and everything in this universe. There are creatures, most negligible in shape and size that has tremendous importance. One of such a creature is !~c inse~t1 Ke_rrig_ lacca. Its size is 0.35 mm but its importance considering industrial value is of magnificent nature. Its resinous secretion obtained on the branches of some selected host plants is of vital industrial importance in many fields and is benefiting the human beings. This secretion from the glands of the lac insect is called lac. This is one of Allah's Qudrat that such a small insect (creature) can produce a widely applicable secretion, the lac. Hence a piece of research work in this field is unde1iaken in order to investigate the properties of different lac products and to study the chemistry of lac. In the beginning of the thesis is given a General Introduction comprising of the origin and history of lac, lac production in Bangladesh etc. For convenience of presentation, the experimental work has been divided into four small chapters. Each chapter is complete within itself and has been written in the conventional fonn of a paper. Effort has been made for literature coverage upto dclte. The thesis is appended with a list of paper and also reprint of publications. I express my sincere gratitude and indebtedness to my respected teachers, Dr. M. Umar Ali, Professor, Department of Chemistry, Rajshahi University, Rajshahi and Dr. M. Omar Faruq, Director (Retd), Bangladesh Council of Scientific and Industrial Research (BCSIR) Laboratories, Rajshahi for their keen interests and valuable inspiring and indespensable guidance throughout the course of these studies and preparation of this thesis. I am very much grateful to Dr. M. Yusuff Ali, Ex-Vice Chancellor, Rajshahi University, Professor, Department of Chemistry, Rajshahi University, Rajshahi for his inspiration and encouragement during the study period. I am also grateful to Professor M.A . .lalil Miah, Chairman, Department of Chemistry, along with other professors of this department, Rajshahi University, Rajshahi for providing necessary facilities, inspiration and helpful advise. My sincere thanks are due to Dr. M. Rezaul Karim, Chainnan, Department of Bio-Chemistry, Rajshahi University, Rajshahi for providing necessary facilities 111 testing antibacterial activities of the synthesised products. My thanks are also extended to Dr. M. Golbar Hossain, Director, BCSIR Laboratories, Rajshahi for his cooperation and encouragement during the course of the study. I also take the opportunity to express my thanks to Mr. M. Ismail Hussain Khan, Senior Scientific Officer (Retd) BCSlR Laboratories, Rajshahi for his many fruitful discussions. I wish to express my thankfulness to the authority, BCSIR, Dhaka and Ministry of Sceince & Technology, Government of Bangladesh for the award of scholarship under Human Resource Development Programme (HRDP) and also for granting me study leave with fu1l pay for Ph.D. Programme. I am thankful to Mr. Akram Hossain, Department of Chemistry, Dhaka University, Dhaka for recording IR spectra of my research samples. I have no hesitation to express my gratefulness to my friends, M. Maksud Ali, M. Siddiqur Rahman, M. Abdul Hye and M. Rafiquzzaman for their occasional help during this work at the Laboratories. Thanks are also due to my colleagues, Mr. Ranajit Kumar Sarker, M. Mesbahul Alam, M. Azizur Ralunan, Mrs. Seatara Khatun, Mrs. G.R.M. Astaq Mohal Khan, M. Lutfor Ralunan, .M. Mostafizur Ralunan and M. Kobad Hossain for their cooperation throughout the progress of the work. I am thankful to Md. Shahazada, B.T.S. Commercial Institute for his sincere type setting. I express my heartiest gratitude to my parents who brought me up and opened my eyes of lrnowledge. Finally, I acknowledge with great pleasure the good wishes and cooperation of my other research co1leagues, friends and all other relations. This Thesis is Submitted to the Department of Chemistry, University of Rajshahi, Rajshahi, Bangladesh for The Degree of Doctor of Philosophy (PhD) 1999-01-01T00:00:00Z http://rulrepository.ru.ac.bd/handle/123456789/985 Synthesis of Chalcone Epoxides and Studies of their Antimicrobial Activities Rashid, Md. Mamun-Ar- Flavonoid compounds constitute one of the major classes of naturally occurring products. These types of compounds show antimicrobial (antibacterial and antifungal) activities and are used widely as drugs for the treatments of different types of diseases. Chalcone epoxides and their derivatives have attracted considerable attention due to their significant biocidal, pharmaceutical and antioxidant activities. Chalcone and its derivatives are used as inhibitors angiogenesis. Chalcone and its epoxides have been used as antiterror or anticancer agents and to treat a number of conditions or disease states in which angiogenesis is a factor, including angiogenic skin disease such as psoriasis, acne, rosacea, warts, eczema, hemangiomas, lymph angiogenesis, among numerous others, as well as chronic inflammatory disease such as arthritis. They also control and reduce hypertension. In the light of these results, we have chosen eight chalcones and their corresponding chalcone epoxides. We synthesized them and studied their biological activities. They were 21-hydroxy-2,4,5-trimethoxychalcone epoxide; 2'-benzyloxy- 2,4,5-trimethoxychalcone epoxide; 4'-methyl-2-chlorochalcone epoxide; 4'­methyl-4-chlorochalcone epoxide; 2'-hydroxy-4-nitrochalcone epoxide; 2'­benzyloxy-4-rnethoxychaclone epoxide; 21 -hydroxy-3 ,4-methylenedioxy chalcone epoxide; 2' -benzyloxy-3 ,4-methylene-dioxychalcone epoxide. The above chalcone epoxides were synthesized from their corresponding chalcones using NaOH'tf2O2 as an oxidizing agent. This Thesis is Submitted to the Department of Chemistry, University of Rajshahi, Rajshahi, Bangladesh for The Degree of Master of Philosophy (MPhil) 2010-01-01T00:00:00Z http://rulrepository.ru.ac.bd/handle/123456789/960 Studies on the Transition Metal Complexes of Acids and Imides with Amine Bases Rahman, Md. Mahabubar This thesis is presented on the interaction of metal ions with stoichiometric amounts of organic ligands containing O and N donors of which metal complexes have been widely used in biological and catalytical point of view. The thesis is divided into ten chapters. 1. First one is an introductory chapter. The chapter is designed to provide sufficient background and usefulness of the present study. 2. The second chapter describes the experimental techniques which include the physical measurement and analytical techniques. 3. Third chapter has been devoted to the preparation and characterization of mixed ligands complexes of Zr (VI) ions with oxalic acid and hetero cyclic amines. The general formula of the complexes are as follows; [Zr (IV) (oxa)2 L2]. Where oxa = oxalic acid L = Q, 2-Apy, 8-HQ, a-Pie, 2,2'-Bipy. The complexes were prepared in the solid form and characterized by elemental analysis, conductivity, magnetic measurements, infrared, and electronic spectroscopic studies. The infrared spectra of the complexes confirmed the co-ordination of metal ion with ligands. The presence of water molecule inside the co­ordination sphere was also confirmed by infrared spectra. Electronic spectra and magnetic measurement confirmed that the Zr (IV) complexes were of octahedral structure…………………….. This Thesis is Submitted to the Department of Chemistry, University of Rajshahi, Rajshahi, Bangladesh for The Degree of Master of Philosophy (MPhil) 2010-01-01T00:00:00Z http://rulrepository.ru.ac.bd/handle/123456789/947 Peroxo Complexes and Their Oxygen Transfer Reactions Khan, Mr. Abdur Rahim The chemistry of the peroxo complexes of various transition metals has received considerable attention in recent· years mainly because they are sources of active oxygen atoms and can be used as stoichiometric as well as catalytic oxidants for organic and inorganic substrates; eg,, they can be successfully used for the oxidation of olefins, ketones, phosphines, arsines etc. We have successfully employed peroxo complexes to generate glycerine from allyl alcohol which is. indeed an industrial aspect of the project. The present thesis describes isolation and characterisation of different peroxo complexes of Zr (IV), Th (IV), Mo (VI), W .{ VI) and U {VI) . ions containing different bi-dentate, tri-dentate and quardri-dentate ligands. A few oxygen transfer reactions of the complexes towards olefins, ketones, triphenyl phosphine and tripheny] arsine have been investigated.----- This Thesis is Submitted to the Department of Chemistry, University of Rajshahi, Rajshahi, Bangladesh for The Degree of Doctor of Philosophy (PhD) 1993-01-01T00:00:00Z