Chemical world This week chlorine or organophosphate insecticides. The Monsanto scientist asserts that MON-0585 is practically inactive against nontarget species, practically nontoxic to fish (even the wriggler-eating Gambusia appears to be unharmed by field concentrations), and extremely safe for mammals. For example, the acute oral LD50 for rats is 1890 mg./kg., the minimum dermal lethal dose for rabbits is greater than 3160 mg./kg. MON-0585's mode of action is not understood. Dr. Sacher notes that pupae die "in a characteristic compact, stalky, unmelanized [undarkened] form/' which suggests that the chemical might inhibit the enzyme tyrosinase, known to play a key role in the hardening and darkening of the develping pupa. Tests show, however, that tyrosinase-inhibiting activity is not very high. MON-0585 might act by upsetting the insect's oxygen metabolism, but tyrosinase may also be involved, Dr. Sacher says. NARCOTICS:
animals showed a revulsion to morphine three and a half weeks after the compound was supposedly "washed out" of their systems. PMA says this suggests a wholly new approach to the narcotic addiction problem. Another promising approach uses McNeil Laboratories' nonaddicting tranquilizer, haloperidol, which has been evaluated in several hundred patients. Useful in the acute detoxification stage from both heroin and methadone, haloperidol might also be combined with a narcotic antagonist to provide protection against heroin challenge while removing craving for drugs. Four other drug firms currently have five agents under study. Some results: •Winthrop Laboratories' 1-cyclazocine, unlike racemic cyclazocine, produces no psychotomimetic effects in limited human studies. • Endo Laboratories' EN 1639, a relative of naloxone, is twice as potent and longer acting than naloxone. Studies on addict volunteers suggest that oral doses one tenth to
one thirtieth those of naloxone may be adequate for 24-hour protection against heroin challenge. • Bristol Laboratories' 1-BC 2605, a synthetic compound not requiring opium derivatives for its manufacture, is longer acting and more potent than both naloxone and cyclazocine. • Ciba-Geigy's new antagonist, GPA 2163, appears to be a "pure" antagonist in laboratory animals. PROCESSES:
Soviet hydrazine route A research group at the Institute of Chemical Physics of the U.S.S.R. Academy of Sciences has revealed the first results from a project to produce hydrazine under mild conditions. The group, headed by Prof. Aleksandr Shilov, believes that the new process is the closest thing yet to the biological fixation of nitrogen. The process reduces molecular nitrogen in aqueous and alcoholic media with titanium, vanadium, or chromium salts as reducing agents
Antidotes for addiction While the drug industry is still short of a major breakthrough in its search for safe and suitable agents to block and treat narcotic addiction, five agents under study offer advantages over the narcotic antagonists naloxone and cyclazocine and two new approaches appear promising, according to an industry task force. What's more, important research leads may be provided by declassification of the Department of Defense's long-secret work on antidotes to some of its chemical warfare agents. Compounds similar to opium alkaloids and their antagonists have been prepared by DOD, says Dr. John Adams, who represented the Pharmaceutical Manufacturers Association's task force at a news conference called by Rep. Paul G. Rogers (D.-Fla.), chairman of the Subcommittee on Public Health and En\dronment. Some of the DOD work has been declassified and received by the White House's special action office for drug abuse, and more is expected. Serendipity was involved in one of the two new and promising approaches. An unidentified drug firm experimenting with a new and also unidentified compound found that when testing the compound's analgesic properties on monkeys, the 10 C&EN NOV. 29, 1971
Mariner 9 photographs Martian south polar cap The dust storm that has obscured Mars from Mariner 9 cameras cleared sufficiently last week to permit this series of overlapping wide-angle pictures revealing the entire Martian south polar cap. The cap (at lower right in the photo) is about 200 miles in diameter and laced with fine, dark, frost-free markings reflecting a topographic pattern apparently unique to this area of
Mars. The dust storm appears to be subsiding first in the south polar cap region, NASA scientists say. Photos transmitted to earth as C&EN goes to press reveal surface features in the south polar region showing dimly through the haze for the first time since Mariner swung into its 90-day orbit. Equipment will measure water, oxygen, temperature, and pressure variations.
