QINGDAO, Sept. 1 (Xinhua) -- Guan Huashi, a 79-year-old Chinese scientist, is leading his research team to look for new drugs from the ocean.

Thanks to scientists including Guan, GV-971, a new Alzheimer's drug extracted from brown algae, completed its phase three clinical trial in July.

Alzheimer's is an irreversible, progressive brain disorder that slowly destroys memory, thinking skills, and the ability to carry out simple tasks.

The disease affects about 48 million people worldwide and the number is expected to increase with the aging population. There is no effective cure.

The drug is targeted at patients with mild-to-moderate Alzheimer's. Independent animal experiments also showed that it can regulate the immune system, reduce neuroinflammation and improve cognition.

"A phase three clinical trial is the last test before reaching the market," said Guan, a researcher with the Chinese Academy of Engineering.

Natural products produced by marine organisms sometimes have pharmacological activity that can be of therapeutic benefit in treating diseases such as cancer, according to Lyu Zhihua, a member of Guan's team and vice dean of the School of Medicine and Pharmacy at the Ocean University of China.

"Around 35,000 marine natural products have been discovered by humans. Half of them have biological activity. There are many more unknown natural products in the ocean," said Guan.

There are a dozen marine-derived drugs commercially available in the market and many more are in clinical trials. The industry has great potential.

Last year, Guan and his colleagues started establishing marine organism sample database and marine drug information database. A 5-billion-yuan (733 million U.S. dollars) fund has been set up to invest in developing new marine drugs.

Several challenges, including supply problems and target identification, need to be met for successful drug development of these often complex molecules.

"The development of marine drugs is always at a slow pace. For example, the research and development of GV-971 took 21 years," said Lyu.

It was like finding a needle in a haystack and then trying to figure out if the needle is useful for these diseases.

Approaches are available to overcome the hurdles. In addition to advances in sampling technologies and synthetic medicine, researchers with the Marine Biomedical Research Institute of Qingdao have sought help from supercomputing.

Based on supercomputing resources in the cities of Qingdao, Jinan, and Wuxi, researchers match and analyze the three-dimensional structures of 30,000 marine natural products with molecular targets of known drugs.

"Traditionally, scientists used one key to open a lock on which they conjecture the key could work. Now with supercomputing technology, one key could be tried on all different types of locks," said Yang Jinbo, chief scientist with the institute.

Yang said that the success rate of turning marine natural products into drug leads has been increased from 20 percent to more than 60 percent.

Scientists with Guan's team plan to take three to four new marine drugs into clinical trials in no more than five years, such as BG136 for the treatment of colon cancer.

Qingdao is famous for its marine science and technology. The city is home to 70 percent of China's marine experts, the deep-sea manned submersible Jiaolong and research vessel Kexue.

Guan describes what they are doing as setting up a blue pharmacy store. "Our aspirations cannot be achieved overnight. Generation after generation of Chinese scientists should work hard to seek potential cures for deadly diseases in the oceans."