WHEN 27-YEAR-OLD cartoonist Hugh Hefner left his job at Esquire Magazine to start Playboy with just US$7,000 of his own money, little did he know the impact he would have on sexual attitudes in America - and the rest of the world. On Wednesday, 50 years on, Playboy - now an empire that includes 70 television stations and magazines - will auction almost 400 paintings, photos, autographs and celebrity manuscripts at Christie's in New York. Despite its brand identity, Hefner describes Playboy as a 'lifestyle magazine', and over the years has seen it evolve from simple seduction, to seducing some of America's prime artists for contributions. Readers looking for more than titillation became familiar with names such as Norman Mailer, Lenny Bruce, Bob Dylan, Vladimir Nabokov and painters such as Salvador Dali, Antonio Vargas, and LeRoy Neiman. When John Steinbeck and Ernest Hemingway wrote for Playboy, the magazine went from notoriety to Nobel Prize-winners. And this is reflected in the auction catalogue, which reads like an index of American pop and serious art. There are original hand-corrected manuscripts by Jack Kerouac, Mailer, James Jones, William Saroyan and Ian Fleming, starting at US$20,000. A US$4,000 manuscript shows Bob Dylan making up his own Playboy interview spoof. For those who aren't interested only in the articles, there are dozens of Playboy covers for sale, as well as John Derek's original pictures of Bo Derek, and photos of Marilyn Monroe. (The very first cover of the magazine is without a date, because Hefner wasn't certain if there would be a second). Paintings and cartoons range from Nabokov's illustration of a Playboy bunny as a butterfly, to works by Neiman and Vargas. The latter is 'a class act', according to Playboy archivist Aaron Baker, a painter himself before taking over the Playboy archives. 'The women are gorgeous, yes. But he depicted the anatomy, the facial features with such detail that you know he is a respecter of beauty.' Neiman's painting Le Mans - one of the most impressive pieces to go under the hammer - starts at about US$20,000. Baker describes Neiman's art as 'combining traditional illustrations with abstract impressionism like Jackson Pollock. Plus he added Pop Art with bright colours. He depicts the excitement of the 20th century'. But were Playboy artists and writers prostituting themselves for the big money? Not at all, says Paul Oppenheimer, author of the definitive biography of Flemish baroque painter Peter Paul Rubens. 'The 17th-century equivalent of Playboy readers were European noblemen. They would commission Rubens to find the most voluptuous women and paint them. They would hang them on the walls of their bedrooms. It was for pure sexual titillation. Rubens painted these, and was paid well. Yes, plenty of artists lived in poverty, but Rubens wasn't one of them.' Hefner himself is represented by two stylised portraits, a few of his Little Black Books (starting at US$8,000), and the Hefner Mercedes Benz 560 Stretch Limousine, refurnished for US$40,000 and with a starting bidding price of about US$70,000. The successful bidder also gets an invitation to the Playboy new year's party in Los Angeles. Last December, Playboy approached Christie's, offering the goods to celebrate half a century. Narrowing the collection to 400 from the millions of pictures, letters and art, proved difficult. Christie's auctioneer Andrea Fiuczynski and assorted experts spent months looking through the archive for objects that were iconic and had sale potential. Successful previews were held in America and Britain. 'I'm prepared for the objects and the audience,' says Fiuczynski, of this week's auction. 'I can sense body language, eye contact. The Playboy bidders are a new group, but I'll be able to feel their energy.' The auction takes place on Wednesday. Anyone wanting to bid by phone must register 24 hours in advance of the sale. Further information is available at www.christies.com or tel (1-212) 6362437