Hydrolyzes the pyrophosphate bond of UDP-2,3-diacylglucosamine to yield 2,3-diacylglucosamine 1-phosphate (lipid X) and UMP by catalyzing the attack of water at the alpha-P atom (PubMed:12000770). Involved in the biosynthesis of lipid A, a phosphorylated glycolipid that anchors the lipopolysaccharide to the outer membrane of the cell (PubMed:12000770, PubMed:12000771). Is essential for E.coli growth (PubMed:12000771). Does not cleave the unacylated UDP-GlcNAc, the mono-acylated UDP-3-O-(R)-3-hydroxymyristoyl-GlcNAc, and CDP-diacylglycerol (PubMed:12000770). H2O + UDP-2-N,3-O-bis[(3R)-3-hydroxytetradecanoyl]-alpha-D-glucosamine = 2-N,3-O-bis[(3R)-3-hydroxytetradecanoyl]-alpha-D-glucosaminyl 1-phosphate + 2 H(+) + UMP Binds 2 Mn(2+) ions per subunit in a binuclear metal center. Inhibited by a sulfonyl piperazine compound that shows antibacterial activity against E.coli; LpxH is the cellular target of this compound (PubMed:25733621). Inhibited by 0.01% (or more) Triton X-100 in vitro (PubMed:12000770). Assays with partially purified enzyme. Optimum pH is 8.0. Glycolipid biosynthesis; lipid IV(A) biosynthesis; lipid IV(A) from (3R)-3-hydroxytetradecanoyl-[acyl-carrier-protein] and UDP-N-acetyl-alpha-D-glucosamine: step 4/6. An insertion mutation defective in lpxH is not viable and accumulates UDP-2,3-diacylglucosamine. Belongs to the LpxH family.