Sotheby’s auction house said Wednesday that works by Vincent van Gogh and Paul Cézanne are expected to smash records for the artists in the Nov. 18 sale in New York. If so, it would be the latest sign that, in uncertain times, ultrawealthy art collectors are seeking security in masterpieces.

The paintings come from a collection amassed by the late Argentine art collector Nelly Arrieta de Blaquier and her sugar magnate husband, Carlos Pedro Blaquier, and are being sold by their children.

They include van Gogh’s landscape “Châtaigniers en fleurs,” (Chestnut Trees in Flower) estimated at $180 million, and Cézanne’s portrait “Arlequin,” which carries an estimate of $120 million. Neither has been seen in public for half a century.

Helena Newman, Sotheby’s head of Impressionist and modern art, said the collection was like a “mini- Musée D’Orsay,” the Paris museum that holds one of the world’s greatest collections of Impressionist and post-Impressionist artworks.

“In my 30-plus years at Sotheby’s, I’ve never had the privilege of handling a collection of quite this content and caliber,” she said.

Newman said van Gogh’s painting of flowering chestnut trees captures the “explosion of energy and vitality” the artist felt after his release from a psychiatric asylum in May 1890. He took his own life two months later.

The Cézanne portrait is one of four paintings of the artist’s son dressed as the Harlequin figure from clowning. The other three are in major museums.

Also in the collection are Parisian cityscapes by Claude Monet and Camille Pissarro, a horse-racing image by Edgar Degas and a boating scene by Pierre-Auguste Renoir, all valued in the tens of millions of dollars.

Art expert Philip Hook, a former Sotheby’s auctioneer, said the collection “really is the stuff of legend,” because the collectors did not loan out the works for exhibitions.

“No one knew really what was in it. So now, for this to be revealed, is tremendously exciting,” Hook said.

“They came out with a collection that, rather cleverly, is focused on getting one representative work by each of the major names (of Impressionist and post-Impressionist art), and that is incredibly difficult to do,” he added. “They succeeded with huge, huge style and success.”

Newman said sale is likely to attract global attention, with potential buyers ranging from American tech billionaires to well-endowed Middle Eastern institutions and rich collectors from North America, Europe, the Middle East and Asia.

“In times where there’s a lot of global macro geopolitical uncertainty, it’s almost like there’s a return to really established, tried and tested” works that are “unquestionably great,” Newman said.

“(This) museum-quality Impressionist collection … is pretty rare.”