On March 11, 2017 (February 14, 2017 in the lunar calendar), Lloyd, the inventor of the most famous antibiotic in history, "tetracycline", passed away. Lloyd Conover was a chemist who developed an antibiotic that was later widely used. This groundbreaking invention was tetracycline, one of the most effective antibiotics. Its discovery revolutionized the way antibiotics were developed. On March 11, 2017, Lloyd passed away in St. Petersburg, Florida at the age of 93. His death was confirmed by Lloyd's son Clegg. Conover began his research at Pfizer in Brooklyn in 1950. The discovery of penicillin stopped infections on the battlefields of World War II, and pharmaceutical companies raced to develop new antibiotics. Most of the first antibiotics discovered were chemicals produced in natural conditions by microbes that grow in soil or feed on rotting fruit. For example, the antibiotic used to treat infections came from a rotting watermelon. No scientists at the time thought it might be possible to improve the properties of antibiotics. They believed that in the process of evolution, antibiotics were the ultimate weapon for microorganisms to survive. Dr. Konofel became interested in two naturally occurring antibiotics. Except for two atoms, the two antibiotics were chemically identical. To Konofel, the existence of these two atoms made no sense. Every antibiotic has a chlorine atom and an oxygen atom, two positions that are supposed to be hydrogen atoms. Would it be more effective to replace them both with hydrogen atoms? He replaced the chlorine atom of an antibiotic with a hydrogen atom through a conventional chemical operation, resulting in a more stable molecule. He had only one assistant, and in a 1992 interview with The ThePlainDealerofCleveland, he said: "If it failed, we didn't want the other audience there." The result of the replacement was tetracycline, a powerful antibiotic with few side effects compared to the drug used to extract it. "This proves that better drugs can be made by adjusting the substance," Conowell wrote. Virtually all antibiotics today are semi-synthetic, meaning that they can be modified to fight a wider variety of infections and reduce side effects. Antibiotics are considered almost a panacea, and tetracycline is effective against a wide range of deadly infections, including Salmonella, which causes food poisoning; bacteria that cause blood, skin and urinary infections; gonorrhea, pneumonia and streptococcal infections. The antibiotic is favored by farmers who raise pigs and chickens because it promotes growth and reduces mutual infections caused by intensive farming. Fruit farmers also spray tetracycline in their orchards to prevent diseases like fire blight. Although tetracycline has been a commercial success, it has led to numerous patent troubles. All three drug companies said their scientists had discovered tetracycline before Conovell, although they patented it later. Pfizer granted licenses to competitors as a way to settle disputes. The federal government has questioned that such licenses are anticompetitive on the basis of legal patent rights. "This gave me a second career: writing testimony and testifying in court," Conovell wrote in a 1984 article in the journal Research Management. He also wrote that at scientific conferences, he was chilled by colleagues who thought his patent application was a mistake. In 1982, more than three decades after Professor Conoville invented tetracycline, a federal appeals court in Philadelphia affirmed the patent, and their licensing agreement was legal. After the appeal, the extensive use of tetracycline made many bacteria resistant to antibiotics and reduced the effectiveness of tetracycline against many infections. Tetracycline is still widely used to treat acne and parasitic diseases such as Lyme disease, Los Angeles Mountain spotted fever, and Q fever. In order to control the development of bacterial resistance, many European countries and the United States currently resist the use of non-therapeutic tetracycline in agriculture. Lloyd Hilyard was born on June 13, 1923 in Orange County, New Jersey. His father, John, a lawyer, and his mother, MargueriteAnnaCameron, an artist, developed an interest in chemistry as a child when he saw his father mix cement to repair retaining walls. "The changes in matter really fascinate me," he said in an interview. To satisfy his curiosity, he began his science project with something he found near his home. Once, he used his mother's pots and pans to melt lead left behind by a plumber to make a miniature steam-powered cannon that could shoot lead pellets. He began studying at Emmerhurst University in Massachusetts in 1941, but was interrupted by World War II. During his three years in the Navy, he served with great ambition on a warship in the Pacific and rose to the rank of lieutenant. After the war, he returned to Emmerhurst University, where he earned his bachelor's degree in 1947. He earned his doctorate at Rochester in 1950, when Pfizer was better off than academic institutions, and came to Pfizer to support his family. His first wife, Virginia Kirk, died in 1988. His second, Mary Solomons, died in 2003. In 2005, Lloyd Conover swore in his wife, Katharine Meacham, at a wedding ceremony in which Meacham's granddaughter, WinifredMeachamLegerton, married David Clifford Love. Image copyright: Benjamin Porter/The New York Times In addition to his son Craig, his living relatives include his current wife, Katherine Meacham, his two sons, Kirk and Roger, his daughter, Heather Conover, and four stepdaughters, SueLove, Virginia Karpovich, Katharine Meacham and Laura Keane, two stepsons, Walter Solomons and Andrew Meacham, as well as 16 grandchildren and seven great-grandchildren. Pfizer added a team to study the structure of oxytetracycline and chlortetracycline. The project laid the groundwork for Professor Conofer's eventual invention. After the team completed its research, senior scientists began writing research papers, allowing Conofer to spend his time freely. "Everyone thought the project was over, but I wanted to continue working on these interesting molecules," Dr. Conofer said in an interview. Dr. Conofer completed the development of tetracycline within a few months. "The first experiment was successful, unlike most experiments I've ever done," he said. Within a year, Pfizer had human trials of tetracycline. Dr. Conofer spent his life at Pfizer as a researcher. He assisted in the development of pyrimidine and methylpyrimidine, both drugs used to treat parasitic infections. He rose from the top of the company to senior vice president of Agricultural Products Research & Development. He retired in 1984. Although Pfizer vigorously defended Conofer's patents, the company did not push the drug as hard as its competitors. "It's disappointing that Pfizer sold the invention of tetracycline and never promoted the antibiotic," Dr. Conofer said.