( ( Although ( ( ( saliva ( ( is mostly ) water ) ) and ) ( ( its ( chief functions ) ) ( are ( ( ( lubrication and ) initiation ) ( of digestion ) ) ) ) ) ) ( , ( it ( ( contains ( ( hundreds ( of ( other compounds ) ) ) ( that ( form ( ( an ( elaborate ( protective mechanism ) ) ) ( for ( ( ( tooth enamel ) and ) ( the ( oral cavity ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN Although) (S (S (NP (NN saliva)) (VP (VBZ is) (ADVP (RB mostly)) (NP (NN water)))) (CC and) (S (NP (PRP$ its) (JJ chief) (NNS functions)) (VP (VBP are) (NP (NP (NN lubrication) (CC and) (NN initiation)) (PP (IN of) (NP (NN digestion)))))))) (, ,) (NP (PRP it)) (VP (VBZ contains) (NP (NP (NNS hundreds)) (PP (IN of) (NP (JJ other) (NNS compounds))) (SBAR (WHNP (WDT that)) (S (VP (VBP form) (NP (NP (DT an) (JJ elaborate) (JJ protective) (NN mechanism)) (PP (IN for) (NP (NP (NN tooth) (NN enamel)) (CC and) (NP (DT the) (JJ oral) (NN cavity)))))))))) (. .)))
Although saliva is mostly water and its chief functions are lubrication and initiation of digestion, it contains hundreds of other compounds that form an elaborate protective mechanism for tooth enamel and the oral cavity.
(ROOT (S (NP (NNP Saliva) (NNP secretion)) (VP (VBZ initiates) (NP (NN chemical) (NN digestion)) (PP (IN while) (S (ADVP (RB also)) (VP (VBG protecting) (NP (DT the) (JJ oral) (NN cavity)))))) (. .)))