Caffeine

Caffeine is a bitter, white crystalline xanthine alkaloid that is a psychoactive stimulant drug. Caffeine was discovered by a German chemist, Friedlieb Ferdinand Runge, in 1820. He coined the term kaffein, a chemical compound in coffee (the German word for which is Kaffee), which in English became caffeine (and changed to Koffein in German).[3]
Caffeine is found in varying quantities in the beans, leaves, and fruit of some plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants.[4] It is most commonly consumed by humans in infusions extracted from the bean of the coffee plant and the leaves of the tea bush, as well as from various foods and drinks containing products derived from the kola nut. Other sources include yerba mate, guarana berries, and the Yaupon Holly.
In humans, caffeine is a central nervous system (CNS) stimulant, having the effect of temporarily warding off drowsiness and restoring alertness. Beverages containing caffeine, such as coffee, tea, soft drinks, and energy drinks, enjoy great popularity. Caffeine is the world’s most widely consumed psychoactive substance, but, unlike many other psychoactive substances, it is legal and unregulated in nearly all jurisdictions. In North America, 90% of adults consume caffeine daily.[5] The U.S. Food and Drug Administration (FDA) lists caffeine as a “multiple purpose generally recognized as safe food substance”.[6]
Caffeine has diuretic properties when administered in sufficient doses to subjects that do not have a tolerance for it.[7] Regular users, however, develop a strong tolerance to this effect,[7] and studies have generally failed to support the common notion that ordinary consumption of caffeinated beverages contributes significantly to dehydration.

crystalline
KK [ˋkrɪst!͵aɪn], DJ [ˋkristəlain]
1. 結晶的

xanthine
KK [ˋzænθɪn], DJ [ˋzænθin]
【化】黃嘌呤

黃嘌呤(英語:xanthine)是一組通常用作溫和的興奮劑和支氣管擴張劑,特別用於治療哮喘癥狀。黃嘌呤包括咖啡因,茶鹼,可可鹼(主要在巧克力中發現) ,和馬黛因。

alkaloid
KK [ˋælkə͵lɔɪd], DJ [ˋælkəlɔid]
【生化】生物鹼

生物鹼是存在於大自然動植物及蕈類中的胺類分子。
很多的生物鹼都對人或動物有藥理反應。生物鹼大都是胺基酸的衍生物,嚐起來有苦澀味。它們常以次生代謝物的形式出現於植物(例如:馬鈴薯、蕃茄)、動物(例如:貝殼類)及蕈類。大部份的生物鹼皆能由它們的植物提取液中以酸-鹼萃取獲得。
生物鹼的英文為「alkaloid」,這個字由「alkaline」一字衍生而成。原本「alkaloid」泛指一切含有氮的鹼基。 雖然大部份的生物鹼對於人體有毒,但也有些能入藥。主要有鎮痛或麻醉的作用,以嗎啡及可待因的作用尤其顯著。

alkaline
KK [ˋælkə͵laɪn], DJ [ˋælkəlain]
1. 鹼的; 含鹼的

psychoactive
KK [͵saɪkoˋæktɪv], DJ [͵saikəuˋæktiv]
精神刺激的

精神刺激藥物 (psychoactive drug):任何一種能顯著改變正常心理歷程的藥物,此藥物會影響個體之神經系統,及引起心智、意識的改變。通常精神刺激藥物包含三類,即興奮劑、抑鬱劑及迷幻劑。

stimulant
KK [ˋstɪmjələnt], DJ [ˋstimjulənt]
1. 興奮劑; 興奮飲料; 酒

pesticide
KK [ˋpɛstɪ͵saɪd], DJ [ˋpestisaid]
殺蟲劑

infusion /ɪnfj’uʒən/ 熬煮

Tea Bush 屬於茶科,俗稱烏龍茶、茶樹。

Kola \Ko”la\, Kola nut \Kola nut\ .可樂果(kola nut)
Same as {Cola}, {Cola nut}.

Yerba Maté [ˈɟɛrβa ˈmate] 馬黛茶

guarana  /ˌɡwɑrəˈnɑː/ 瓜拉那,巴西可可
瓜拉拿糊 一種乾糊,用產於巴西的無患子科植物瓜拉拿的種子經焙烘製成,含單寧、咖啡因;(用此種糊調味的)瓜拉拿飲料
瓜拿納(雙名法:Paullinia cupana)原產於巴西亞馬遜盆地,是無患子科泡林藤屬(保力藤屬)的木質葛藤藤植物。採用部分為樹子,含有4%咖啡因,能刺激中樞神經,並可使人生熱以及利尿,常作提神用。風味上具有苦味,類似仁丹或啤酒花,但食用後會感到甘甜味,很多時在不同飯料上找到。

Yaupon \Yau”pon\, n. (Bot.)
KK [ˋjɔpən], DJ [ˋjɔ:pən]
代茶冬青樹

holly
KK [ˋhɑlɪ], DJ [ˋhɔli]
【植】冬青; 冬青屬植物[U][C]

精神刺激物質 (Psychoactive Substance)

diuretic
KK [͵daɪjʊˋrɛtɪk], DJ [͵daijuəˋretik]
利尿劑
a. 利尿的

diuresis
KK [͵daɪjʊˋrisɪs], DJ [͵daijuəˋri:sis]
【醫】利尿

administer
KK [ədˋmɪnəstɚ]
給予, 提供, 施予, 給藥

subject 病人,患者,受治療者

urine
KK [ˋjʊrɪn], DJ [ˋjuərin]
尿[U]

caffeinated 含咖啡因的

dehydration
KK [͵dihaɪˋdreʃən], DJ [͵di:haiˋdreiʃən]
1. 脫水

hydration
KK [haɪˋdreʃən], DJ [haiˋdreiʃən]
水合作用

dehydrate
KK [diˋhaɪ͵dret], DJ [di:ˋhaidreit]
脫水; 使乾燥

dehydration
KK [͵dihaɪˋdreʃən], DJ [͵di:haiˋdreiʃən]
1. 脫水

http://dict.tw/index.pl

咖啡因是一種黃嘌呤生物鹼化合物,對人類來說是一種興奮劑。它存在於咖啡樹、茶樹、巴拉圭冬青(瑪黛茶)及瓜拿納的果實及葉片里,少量的咖啡因也存在於可可樹、可樂果及代茶冬青樹。存在於瓜拿納中的咖啡因有時也被稱為瓜拿納因(guaranine),而存在於瑪黛茶中的被稱為馬黛因(mateine),在茶中的則被稱為茶毒(theine)。總體上來說,作為一種自然殺蟲劑,在超過60種植物的果實、葉片和種子中能夠發現咖啡因,它能使以這些植物為食的昆蟲麻痹因而達到殺蟲的效果。
咖啡因是一種中樞神經興奮劑,能夠暫時的驅走睡意並恢復精力。有咖啡因成分的咖啡、茶、軟飲料及能量飲料十分暢銷,因此,咖啡因也是世界上最普遍被使用的精神藥品。在北美,90%成年人每天都攝入咖啡因。[2]
很多咖啡因的自然來源也含有多種其他的黃嘌呤生物鹼,包括茶鹼和可可鹼這兩種強心劑以及其他物質例如單寧酸。