"Pheromones?"
In the office.
Tian Liangwei looked at Xu Yun in surprise. Xu Yun nodded firmly.
"That's right. I think pheromones are the key to developing fourth-generation Imidacloprid."
Tian Liangwei nudged his glasses up, his expression clouded with confusion and concern.
"Tell me more. Little Xu, don't tell me your idea is just to mix pheromones and Imidacloprid together. I could buy you twenty moth-pheromone sticky traps on Taobao for ten yuan."
Pheromones, also known as ectohormones,
were substances secreted by one individual into the environment and detected by other members of the same species through their olfactory organs. They could cause changes in the latter's behavior, emotions, mental state, or physiology.
For example, adult humans emitted pheromones. There was even a type of perfume called pheromones on the market.
Scientists still disagreed about the exact composition of human pheromones, but the substances most widely accepted were androstadienone in men and estratetraenol in women.
Pheromones were most abundant in the armpits and groin. You could smell those two areas and see if they smelled any different from the rest of the body.
Back in high school, Xu Yun had a friend who was always saying that a girl in their class smelled really nice. Curious, Xu Yun tried taking a sniff while they were lined up for morning exercises.
Good grief. A faint smell of body odor.
That was the difference in how pheromones were perceived: people who liked the smell loved it, while those who felt nothing in particular found it repulsive.
So, in a sense, "Your armpits smell so nice" was actually a line of romance.
In pest control, insect pheromones had a wide range of applications.
Their advantage was their high target specificity: they didn't harm natural enemies and left no pesticide residue. That specificity was also their drawback: they had no effect on other pests and worked only on adults, not larvae.
As a result, pheromones had significant limitations and were generally considered an auxiliary tool.
In other words, you used them to lure the insects in, then trapped them with a sticky board or box before dealing with them further.
A more advanced method was to mix the pheromones with a biological toxin, kneading them together like dough, then lure the target in to eat the poison.
In response to Tian Liangwei's concerns, Xu Yun first poured him a cup of tea, then said,
"Professor, I understand what you mean. Don't worry. I'm not trying to exploit some loophole in the concept."
He took out a pen and paper and began explaining as he wrote.
"I'm wondering if some kind of synthesis could combine pheromones and Imidacloprid into a new, potent poison.
"For example, could it both attract targets with pheromones and spread through multiple generations like Imidacloprid? In other words, could the pheromones spread along with the Imidacloprid?"
Tian Liangwei looked at the lines Xu Yun had written on the paper and began to understand.
"Create a new kind of poison? I think I see what you mean.
"With ordinary mixed pesticides, pheromones attract the target, which eats the poison and spreads it to others. But since the insects don't carry any pheromones, the effectiveness tends to drop off over successive rounds of transmission.
"Your idea, Little Xu, is to make the poison itself produce the same effect as pheromones. Once the target leaves the bait, it becomes a new lure that emits pheromones. It might even pass them on for several generations?"
Xu Yun nodded.
"Exactly. I think this is the direction for fourth- or even fifth-generation Imidacloprid."
Tian Liangwei pursed his lips and thought it over. His expression remained pessimistic.
"It might work in theory, but there are many technical problems to solve.
"First, there's the limited range of targets. An insect's pheromones only work on adult members of its own species. Take the moth traps I mentioned earlier: they catch moths, but they can't catch flies or mosquitoes.
"Second, synthesizing the compounds means breaking through the relevant information barriers. That's extremely difficult. Otherwise, the well-known companies and laboratories would have done it already."
As he spoke, Tian Liangwei couldn't help shaking his head.
As he'd said, nearly all pheromone-based pesticides were currently made by physically mixing their components.
That wasn't because the manufacturers were idiots. They simply couldn't synthesize pheromones and biological toxins into an entirely new substance.
As a leading authority at a domestic biomedical institute, Tian Liangwei knew just how difficult it was to synthesize pheromones and biological toxins. Companies like Bayer, Pfizer, Roche, and Novartis were all researching it.
A breakthrough in this technology wouldn't make much of a splash in the scientific community. It wouldn't win a Nobel Prize, or even come close to a Carisberg or Lasker Award. But the market it represented was far from small.
Of course,
most of the compounds those laboratories were trying to combine weren't Imidacloprid. They were third-generation Dinotefuran.
After all, in those high-end laboratories, Imidacloprid was to Dinotefuran as Aoi was to Mikami-sensei: a concept from a completely different era.
Tian Liangwei seemed to have been reminded of something unpleasant. Xu Yun, however, remained calm. He wrote another line on the paper.
"Professor, take a look at this."
Tian Liangwei glanced at the paper. After a moment, he asked hesitantly,
"Is this... a methylated alkane?"
Xu Yun nodded and drew a line through one of the CH3 groups, indicating that it should be removed.
Tian Liangwei gave a quiet gasp.
"A single-handed methyl group?"
Xu Yun continued writing:
CH3(CH2)2CH=CHCH=CH(CH2)8CH3,[Ru(p-cymene)_2Cl_2]_2,(HCHO)n,ZnBr_2,CH_3COON,DCE(CH2CLCH2CL), and a pyridine functional group.
"Professor, do you think this reaction could work?"
Tian Liangwei stared at the line Xu Yun had written. First he froze, then he took the pen and rapidly worked through the reaction on the paper and in his head.
"Remove one CH3C-H bond and cyclize. Use a transition-metal catalyst to directly cleave the substrate's C-H bond?
"The directing group forms an intermediate C-M... Hm? It really might form a selectively hydroxymethylated compound with pyridine?"
As everyone knew,
hydroxymethyl functional groups were common in pharmaceuticals and bioactive small molecules. They underwent nucleophilic addition with aldehydes, producing the corresponding alcohols, ethers, or esters.
If one CH3 group were removed from the upper right of the pheromone alkane, it could theoretically form a compound with pyridine under ruthenium catalysis.
Of course,
this was only a theoretical possibility. In practice, the outcome would be highly uncertain.
Seeing his teacher's expression grow increasingly serious, Xu Yun continued.
"As for your first point, you're right. Pheromones do have a drawback.
"Each pheromone only targets one species. Moths are moths, fruit flies are fruit flies. They can't be used interchangeably, and there's nothing we can do about that.
"So why not just focus on a specific target?"
"Focus on a specific target?"
Tian Liangwei raised his eyes to look at Xu Yun.
"What do you mean by that?"
"Just focus on one direction and ignore the rest."
Xu Yun spread his hands and smiled at his teacher.
"The field of biological pesticides is huge. We can't—and don't need to—cover all of it. So why not pick a particularly harmful pest and develop a specialized pesticide to kill it?"
"Sure, agriculture has plenty of pests. Kill wireworms, and there are moths; kill the moths, and there are bollworms. Unless we wipe them all out, agricultural products will never be free of pests and disease. But there are plenty of pests in our daily lives, too. Each one we eliminate solves a major problem, and the cost-effectiveness is much higher than in agriculture."
"Once this new compound can be produced, it might wipe out some pest until it becomes a protected animal. The next generation would only be able to see it in a zoo."
"For example..."
"Cockroaches!"
Before you continue