Synteke Demandante Demonteverde was born in Iloilo Mission Hospital in 1923, eldest of 8 children to Macario and Victorina Demonteverde of Dumangas, Iloilo—a Presbyterian minister and a registered nurse.
At the outbreak of World War II, he joined the Division Signal Corps as a first sergeant. He was sent to Manila for training at the Adjutant's School. It was at the reception following the graduation ceremonies where he met Lilia Canero, his future wife. After their first meeting, he started writing letters to her which were promptly answered, not by Lilia, but by his future mother-in-law.
He graduated as the valedictorian of Central Philippine University and received his bachelor of science in pre-medicine from Silliman University in 1948. He obtained his M.D. from Manila Central University in 1953. The next year, he married Lilia and they relocated to Davao. From 1956 to 1960, he trained in surgery at the Emmanuel Lutheran Hospital in Portland, Oregon. He returned to the Philippines as Chief Resident at Manila Central University, eventually becoming medical director at Emmanuel Community Hospital in Tondo, Manila. In 1967, he and his family moved to the U.S. where he worked as a physician for the city of Pasadena. He credited his aunt, Dr. Primitiva Demandante, as a great influence in his decision to become a doctor. In 1971, he took over her medical practice in Wilmington, California, after she passed away.
He was very involved in professional and community organizations, namely the Los Angeles Medical Association, California Medical Association, California Academy of Family Practice, American Academy of Family Practice, and the Philippine Medical Society of Los Angeles, Rotary International Club President, American College of General Practice, Christian Medical Society of USA, American Geriatric Society, and Physician for the Rotary Free Medical Clinic for Wilmington. In 1997, he received the Dominguez Brand Award in recognition for his exemplary dedication and service to the community.
Synteke and Lilia have 5 children: Ruth, Nanette, Lilian, Alan and Macario and 4 grandchildren: William, Kathleen, Myles, and Jaryd.
In a tribute to his father, Synteke wrote: "My father, Macario, did not leave us any money or trust funds to make life a little easier for each one of us. He bestowed us things more valuable than manifest earthly riches. He cultivated in each one of us some spiritual values. Among these are: 1) love of God and fellow man; 2) a constant desire to improve one's self and one's lot; 3) to glorify God in keeping self clean, denying evil, and cleaving to that which is good; 4) to strive for excellence and goodness in thought and deed."