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为什么玫瑰闻起来很甜 – 译学馆
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为什么玫瑰闻起来很甜

Why Do Roses Smell So Sweet? - GTKAM

认识分子

莎士比亚有言甚好:
Shakespeare said it best:
“玫瑰不叫玫瑰
“That which we call a rose by any other name
依然芳香如故”
would smell as sweet .”
结果证明 不完全是
Turns out… not quite.
玫瑰的品种成百上千 栽培品系成千上万
There are hundreds of rose species, thousands of cultivars,
它们大多都有气味
many of them smell,
其它的则毫无气味
and others don’t smell at all.
但是我们所熟悉的那些玫瑰香
But what about the rose smell we’re familiar with
那些来自化妆品 香水 食物 玫瑰油
from cosmetics, perfumes, foods,
和玫瑰水的气味又是什么呢?
rose oil and rose water?
这种气味可能来自一个单一玫瑰品种
It’s probably from a single rose species,
即大马士革玫瑰
the damask rose.
尽管这种最著名的玫瑰香味
And while the most famous rose smell
可能来自单一品种
might come from a single species,
真正的香味却并不是来自单一品源
its actual scent isn’t from a single source.
玫瑰香味来自于大量不同的化学成分
Rose scent comes from a lot of different chemicals.
其中一个听名就懂 叫做玫瑰醚
One has a somewhat obvious name: rose oxide.
玫瑰醚会产生一种嫩嫩的花的头香
Rose oxide produces a floral green top note,
还带有甜香 水果香
plus a sweet smell, a fruity smell,
薄荷香 以及柑橘香
a minty smell, and a citrus scent.
那么一种化学成分是怎样产生
How does one chemical contribute
多重香味的呢?很简单
all those smells? Simple.
玫瑰醚不是一种 而是四种化学成分的混合
Rose oxide isn’t one chemical, it’s four.
这四种玫瑰醚分子各有10个碳原子
All four rose oxides have 10 carbon atoms,
18个氢原子 以及1个氧原子
18 hydrogen atoms, and 1 oxygen atom,
原子都以相同的顺序连接在一起
all connected in the same order.
我们如何从一种结构里得到四种化学成分?
How do we get four chemicals from this one setup?
嗯 只要通过手性即可
Well, it’s all about chirality.
你可以把手性想象成我的左右手
Think of chirality as my left hand and my right hand.
每个手的手指数量都相同
They’ve got the same number of fingers
各有一个大拇指 想象一下
and one thumb, you get the idea.
我的双手就好像在互相照镜子
My hands are actually mirror image of each other.
但是 如果我试图重叠双手
But, if I try to superimpose
把左手放在右手之上
my left hand on top of my right hand,
对不大上啊
it doesn’t quite work.
我的左右手指们不能对齐
My fingers and thumbs don’t actually line up.
左手是 4321大拇指
Left hand: 4-3-2-1-Thumb,
右手是大拇指1234
right hand: Thumb-1-2-3-4.
它们看起来一模一样
They look identical,
但是 当我想再看看它们是否一样时
but, again, when I try to check to see if they’re,
我发现并非如此
I find out they are not!
对于这四种玫瑰醚也是同样的道理
The same principal applies to the four rose oxides.
四种玫瑰醚拥有同样的分子式
All four have the same molecular formula,
原子间的化学键连接也相同
the same chemical connections between the atoms,
但某些原子的空间排列
BUT some of the atoms are arranged
则有所不同
differently in space.
信不信由你 正是这种排序影响了
And believe it or not, that arrangement actually affects
每种玫瑰醚分子的气味
how each rose oxide smells.
科学家说玫瑰醚中的
Scientists say rose oxide that is known
2-S 4-R型是最臭的一种
as 2-S, 4-R is the stinkiest one,
却对经典的玫瑰香味贡献最大
contributing the most to that classic rose smell.
你大概只需要该型分子的
You only need about zero-point-five
十亿分之零点五浓度的量
parts per BILLION of 2-S, 4-R
就能靠鼻中的嗅探器闻到它
to be able to detect it with the nose sniffer.
至于另外三种呢
Our other three rose oxides?
你就得需要十亿分之五十到一百六十
You’ll need anywhere between 50 and 160 parts
的浓度才能拾起它们的气味
per billion to pick up their scent.
四种玫瑰醚产生四种不同的气味
All four rose oxides producedifferent types of smells.
为啥会有不同的气味和不同的气味感知强度呢?
Why the different scents and the different strengths?
啊 塑形!
Ah, shape!
每种玫瑰醚都会与鼻子中的
Each rose oxide actually interacts differently
嗅觉感受器发生不同的作用
with an olfactory receptor in our nose.
把它想象成一把能完美插入锁中的钥匙
Think of it as a key that fits perfectly in a lock,
而不是乱捅一番才能捅开的超烦人的那种
versus one that you have to annoyingly jiggle to make it work.
化学就是这样 充满了微妙的不同
Chemistry is full of these subtle differences.
原子排列中微小的不同
Arranging atoms even slightly differently
就可能意味着因此产生的另一种玫瑰
can mean a rose by any other configuration
闻起来没那么香甜了
DOESN’T smell as sweet.
感谢CAS对本节目的大力赞助
Thanks to CAS for sponsoring this video.
还有 如果你对分子充满兴趣
And hey, if you’re really into molecules,
可以多关注SciFinder Future Leaders in Chemistry项目
check out the SciFinder Future Leaders in Chemistry program.
像我一样来自世界各地的博士和博士后们
PhD students and postdocs like me from around the world
相聚在此 分享彼此的见解
are brought in to share their insights
并且和SciFinder一起走进幕后
and go behind the scenes with SciFinder.
这是一次全程免费的科学旅行
It’s an all-expense-paid trip,
在这里 你将亲眼目睹
where you’ll get to see firsthand
CAS是如何建立并维护
how CAS builds and maintains
世界上最权威的化学数据库的
the world’s most authoritative chemistry databases.
你也能够前往参加
You’ll also get to travel to
美国化学学会的全国会议与博览会
the American Chemical Society’s National Meeting and Exposition.
请访问cas.org/futureleaders以获得更多细节
For details, visit cas.org/futureleaders.
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予人玫瑰,手有余香。玫瑰香自何来?GTKAM带你从分子角度了解其中的奥秘!

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