Synephrine: Sympathetic alpha-adrenergic agonist with actions like PHENYLEPHRINE. It is used as a vasoconstrictor in circulatory failure, asthma, nasal congestion, and glaucoma.Evodia: A plant genus of the family RUTACEAE which is used in Chinese medicine (DRUGS, CHINESE HERBAL). Evodiamine and other quinazoline alkaloids (QUINAZOLINES) are obtained from the fruit of E. ruticarpa.2-Hydroxyphenethylamine: Simple amine found in the brain. It may be modulator of sympathetic functions. Its derivatives are adrenergic agonists and antagonists. It is also used in chemical industry.Octopamine: An alpha-adrenergic sympathomimetic amine, biosynthesized from tyramine in the CNS and platelets and also in invertebrate nervous systems. It is used to treat hypotension and as a cardiotonic. The natural D(-) form is more potent than the L(+) form in producing cardiovascular adrenergic responses. It is also a neurotransmitter in some invertebrates.Adrenergic Antagonists: Drugs that bind to but do not activate ADRENERGIC RECEPTORS. Adrenergic antagonists block the actions of the endogenous adrenergic transmitters EPINEPHRINE and NOREPINEPHRINE.Citrus: A plant genus of the family RUTACEAE. They bear the familiar citrus fruits including oranges, grapefruit, lemons, and limes. There are many hybrids which makes the nomenclature confusing.Drugs, Chinese Herbal: Chinese herbal or plant extracts which are used as drugs to treat diseases or promote general well-being. The concept does not include synthesized compounds manufactured in China.