白色结晶型粉末或颗粒
来源甜菜碱化合物天然存在于植物和动物中,如甜菜和海藻中。
生物活性甜菜碱是胆碱氧化代谢的最终产物,是一种普通的甲基供体,特别是在蛋氨酸生物合成的小途径中。它用于治疗同型半胱氨酸尿症,这是蛋氨酸生物合成主要途径的缺陷。
应用领域甜菜碱是一种天然的类维生素物质,无毒、吸湿性极强,味甘甜且有特殊气味。广泛存在于动植物体内,并具有重要的功能;其价值已被无数科学研究和实践所肯定。甜菜碱用途非常广泛,在医药方面可用于生产治疗和预防肝脏病的药物及抗生素原料。它可以用作食品添加剂,对老人保健、儿童生长发育都有良好的促进作用。在日用化工方面,由于其性质极其温和,是优异的渗透剂、保湿剂和甜味剂,因此可以添加到香波、浴液、护发素、护肤青和牙膏中。此外,向生长条件恶劣如干旱、高盐、高温、高湿等环境中的植物或作物施用外源性甜菜碱能够促进它们的生长,并提高产量。
工业用途甜菜碱在保护植物免受环境胁迫方面发挥着重要作用。此外,它和其他有机渗透剂在维持哺乳动物细胞渗透压中也起到关键作用。一水甜菜碱尽管纯度略低,但其杂质含量较少,因此广泛应用于医药、食品添加剂、饲料添加剂和化妆品等行业:
制备甜菜碱的方法主要有两种:一种是从甜菜糖蜜发酵液中提取,其工艺主要是离子排斥法,利用聚乙烯-二乙烯树脂色谱分离柱洗脱出的甜菜碱母液,经蒸发、浓缩、三段结晶和过滤后得到约98%纯度的无水或一水合甜菜碱。另一种方法是通过化学合成制备,采用氯乙酸和三甲胺为原料在碱性溶液中进行反应生成甜菜碱和氯化钠。
In order to study weak hydrogen bonds originating from inductively activated C(sp3)-H donor groups, low-temperature X-ray structures are reported for three onium salts of general formula BH+(MeSO2)2N-, where BH+ is Me3N+CH2CH2OH (1; orthorhombic, space group P212121, Z′ = 1), Me3N+CH2C(O)OH (2; orthorhombic, P212121, Z′ = 1), or Me2HN+CH2CH2NMe2 (3; monoclinic, P21/c, Z′ = 1). The asymmetric units consist of cationanion pairs assembled by an O-H···O=S hydrogen bond in 1, an O-H···N- bond in 2, and an N+-H ··· N- bond in 3. The packings display a plethora of short interionic C(sp3)-H···O/N contacts that are geometrically consistent with weak hydrogen bonding; those taken into consideration have normalized parameters d(H ··· O) ≤ 269 pm, d(H···N) ≤ 257 pm and θ(C-H···O/N) ≥ 127°. The roles of the weak hydrogen bonds are as follows: In structures 1 and 3, the anions are associated into corrugated layers, which intercalate catemers of cations (1) or stacks of discrete cations (3), whereas structure 2 involves cation catemers surrounded by four anion catemers and vice versa; moreover, all cations are linked to adjacent anions by several weak hydrogen bonds (and to one anion in particular by the strong H bond). Among the cation-anion interactions, the N+(CH2-H···)3O tripod pattern arising in 1 and 2 is of special interest.